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Introduction It was proposed that peripheral blood (PB) monocyte subset analysis evaluated by flow cytometry, hereafter referred to as "monocyte assay", could rapidly and efficiently distinguish chronic myelomonocytic leukemia (CMML) from other causes of monocytosis by highlighting an increase in the classical monocyte (cMo) fraction above 94%. However, the robustness of this assay required a large multicenter validation. Methods PB and/or bone marrow (BM) samples from adult patients displaying monocytosis were assessed with the "monocyte assay" by ten ELN iMDS Flow working group centers (6 equipped with BD FACSCanto™ II (BD Biosciences), 3 with Navios™ (Beckman Coulter) and one with BD™ LSRII (BD Biosciences)) with harmonized protocols. The corresponding files were reanalyzed in a blind fashion by a skilled operator and the cMo (CD14 ++CD16 -) percentages obtained by both analyses were compared. Information regarding age, gender, complete blood count, marrow cytomorphology, cytogenetics and molecular analysis was collected. Confirmed diagnoses were collected when available as well as follow-up for CMML patients. Results The comparison between cMo percentages from 267 PB files provided by the 10 centers and the centralized cMo percentages showed a good global significant correlation (r=0.88; p The second aim of this multicenter study was to assess the feasibility of the monocyte assay on 117 BM samples provided by 7 out of the 10 ELN centers, 43 of which being paired to PB samples. The comparison between cMo percentages provided by the 7 centers and the centralized cMo percentages showed a lower global significant correlation compared to PB samples (r=0.74; p Conclusions This ELN multicenter study demonstrates the robustness of the monocyte assay with only limited variability of cMo percentages, validates the 94% cutoff value, confirms its high sensitivity and specificity in PB and finally, also confirms the possibility of its use in BM samples. Figure 1 Figure 1. Disclosures Kern: MLL Munich Leukemia Laboratory: Other: Part ownership.

In this large single-centre study, we report high prevalence (25%) of, small (p = 0.04). PNH clone, irrespective of size, was a good predictor of response to immunosuppressive therapy (IST) and to stem cell transplant (HSCT) (in MDS: 84% if PNH+ vs. 44.7% if PNH−, p = 0.01 for IST, and 71% if PNH+ vs. 56.6% if PNH− for HSCT; in AA: 78 vs. 50% for IST, p p = 0.01 for HSCT). PNH positivity had a favorable impact on disease progression (0.6% vs. 4.9% IPSS-progression in MDS, p p = 0.01), leukemic evolution (6.8 vs. 12.7%, p = 0.01 in MDS), and overall survival [73% (95% CI 68–77) vs. 51% (48–54), p p

Kinase domain mutations in BCR-ABL1 are associated with resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukaemia. Next-generation sequencing (NGS) allows detection of low-level kinase domain mutations, but its relevance in clinical practice remains debated. We aimed to examine the clinical effects of low-level kinase domain mutations identified using NGS in patients with chronic myeloid leukaemia.In this population-based study, we included consecutive patients newly diagnosed with chronic myeloid leukaemia treated with first-line tyrosine kinase inhibitors, and patients identified at the time of resistance to first-line treatment with imatinib at six institutions (teaching hospitals and district hospitals) in southeast England. We screened patients for BCR-ABL1 kinase domain mutations using NGS, irrespective of patient response to tyrosine kinase inhibitor therapy. When we detected a mutation with NGS, we retrospectively analysed all previous samples to establish the date of first occurrence and subsequent kinetics of the mutant subclone (or subclones). The primary endpoints of this study were progression-free and event-free survival at 5 years.Between Feb 1, 2007, and Dec 31, 2014, we screened 121 patients with chronic myeloid leukaemia for BCR-ABL1 kinase domain mutation. 99 consecutive patients were newly diagnosed, with available sequential RNA stored. The remaining 22 patients were diagnosed between June 1, 1999, and June 30, 2006, and were screened at the time of resistance to first-line treatment with imatinib. Imatinib was the first-line treatment for 111 patients, nilotinib for seven patients, and dasatinib for three patients. We detected a kinase domain mutation in 25 (21%) of 121 patients. Low-level kinase domain mutations were first identified in 17 (68%) of 25 patients with mutation. For patients with a complete cytogenetic response, 13 (14%) of 93 patients screened had a mutation. Five (71%) of the seven patients with a clinically relevant mutation lost complete cytogenetic response compared with 15 (17%) of 86 patients without a clinically relevant mutation (80 patients without mutation and six patients with a tyrosine kinase inhibitor-sensitive mutation, p=0·0031). Patients harbouring a mutant clone had poorer 5-year progression-free survival (65·3% [95% CI 40·5-81·8] vs 86·9% [75·8-93·2]; p=0·0161) and poorer 5-year event-free survival (22·2% [CI 5·6-45·9] vs 62·0% [50·4-71·6]; p0·0001) than did patients without a mutation. We identified a kinase domain mutation in four (10%) of 41 patients with samples available at 3 months after starting first-line tyrosine kinase inhibitor treatment; all four subsequently progressed to accelerated phase disease compared with only three (8%) of 37 without a mutation (p0·0001).NGS reliably and consistently detected early appearance of kinase domain mutations that would not otherwise be detected by Sanger sequencing. For the first time, to our knowledge, we report the presence of kinase domain mutations after only 3 months of therapy, which could have substantial clinical implications. NGS will allow early clinical intervention and our findings will contribute to the establishment of new recommendations on the frequency of kinase domain mutation analysis to improve patient clinical care.None.

Diagnostic criteria for hypoplastic myelodysplasic syndrome (h-MDS) have not been clearly established, making the differential diagnosis from other bone marrow failure syndromes (BMF) challenging. In this study, we aimed to delineate clinical, histopathological, and molecular features of h-MDS, based on a large and well-annotated cohort of patients with bone marrow (BM) hypocellularity. The study included 534 consecutive adult patients with hypocellular BM (278 h-MDS and 136 aplastic anemia), and 727 with normo- or hypercellular MDS (n-MDS). Comparison of clinical features of patients with h-MDS as defined by BM cellularity ≤25% (n = 204) or reduced age-adjusted cellularity (n = 74) did not reveal significant differences. We developed a diagnostic score to discriminate h-MDS from non-malignant BMF based on histological and cytological variables with the highest specificity for MDS (h-score). The information from chromosomal abnormalities and somatic mutation patterns was then integrated into a cyto-histological/genetic score (hg-score). This score was able to segregate two groups of h-MDS with a significantly different risk of blast progression (P

The lung is a complex organ with anatomically distinct pools of T cells that play specific roles in combating infection. Our knowledge regarding the generation and/or maintenance of immunity by parenchymal or circulating T cells has been gathered from either persistent (>60 d) or rapidly cleared (

Virulent Francisella tularensis subsp. tularensis (Ftt) is a dynamic, intracellular, bacterial pathogen. Its ability to evade and rapidly suppress host inflammatory responses is considered a key element for its profound virulence. We previously established that Ftt lipids play a role in inhibiting inflammation, but we did not determine the lipid species mediating this process. Here, we show that a unique, abundant, phosphatidylethanolamine (PE), present in Francisella, contributes to driving the suppression of inflammatory responses in human and mouse cells. Acyl chain lengths of this PE, C24: 0 and C10: 0, were key to the suppressive capabilities of Francisella PE. Addition of synthetic PE 24: 0–10: 0 resulted in the accumulation of PE in host cells for up to 24 h of incubation, and recapitulated the inhibition of inflammatory responses observed with native Ftt PE. Importantly, this novel PE significantly inhibited inflammatory responses driven by a medically and globally important flavivirus, dengue fever virus. Thus, targeting these lipids and/or the pathways that they manipulate represents a new strategy to combat immunosuppression engendered by Ftt, but they also show promise as a novel therapeutic intervention for significant viral infections.

SUMMARY Tripartite motif-containing protein 5α (TRIM5α) is a cellular antiviral restriction factor that prevents early events in retrovirus replication. The activity of TRIM5α is thought to be limited to retroviruses as a result of highly specific interactions with capsid lattices. In contrast to this current understanding, we show that both human and rhesus macaque TRIM5α suppress replication of specific flaviviruses. Multiple viruses in the tick-borne encephalitis complex are sensitive to TRIM5α-dependent restriction, but mosquito-borne flaviviruses, including yellow fever, dengue, and Zika viruses, are resistant. TRIM5α suppresses replication by binding to the viral protease NS2B/3 to promote its K48-linked ubiquitination and proteasomal degradation. Importantly, TRIM5α contributes to the antiviral function of IFN-I against sensitive flaviviruses in human cells. Thus, TRIM5α possesses remarkable plasticity in the recognition of diverse virus families, with the potential to influence human susceptibility to emerging flaviviruses of global concern., Graphical Abstract, In Brief The antiviral activity of TRIM5α is thought to be limited to retroviruses as a result of highly specific interactions with capsid lattices. Here, Chiramel et al. demonstrate that TRIM5α restricts replication of specific flaviviruses by binding and degrading the viral protease.

The lung is a complex organ with anatomically distinct pools of T cells that play specific roles in combating infection. Our knowledge regarding the generation and/or maintenance of immunity by parenchymal or circulating T cells has been gathered from either persistent (>60 days) or rapidly cleared (

Sally B. Killick (Writing Group Chair), Nick Bown, Jamie Cavenagh, Inderjeet Dokal, Theodora Foukaneli, Peter Hillmen, Robin Ireland, Austin Kulasekararaj, Ghulam Mufti, John A Snowden, Sujith Samarasinghe, Anna Wood (BCSH Task Force Member), Judith C.W. Marsh on behalf of the British Society for Standards in Haematology. The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust, Bournemouth, Northern Genetics Service, Newcastle upon Tyne, St Bartholomew’s Hospital, Barts Health NHS Trust, London, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Barts Health NHS Trust, London, Addenbrooks Hospital, University of Cambridge, Cambridge, Leeds Teaching Hospitals, Leeds, Kings College Hospital NHS Foundation Trust, London, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Great Ormond Street Hospital for Children NHS Foundation Trust, London, West Hertfordshire NHS Trust, Watford.

Bone marrow (BM) genetic abnormalities in myelodysplastic syndrome (MDS) have provided important biological and prognostic information; however, frequent BM sampling in older patients has been associated with significant morbidity. Utilizing single-nucleotide polymorphism array (SNP-A) and targeted gene sequencing (TGS) of 24 frequently mutated genes in MDS, we assessed the concordance of genetic abnormalities in BM and peripheral blood (PB) samples concurrently from 201 MDS patients. SNP-A karyotype in BM was abnormal in 108 (54%) and normal in 93 (46%) patients, with 95% (190/201) having an identical PB karyotype. The median copy number (CN) for deletions was significantly lower in BM (CN:1.4 (1-1.9)) than in PB (CN:1.5 (1-1.95), P

The standard dose of imatinib for the treatment of chronic-phase chronic myeloid leukemia (CML) is 400 mg·d. A predose plasma imatinib concentration of1 mg·L is associated with improved clinical response. This study aimed to assess the plasma imatinib and norimatinib concentrations attained in patients with chronic myeloid leukemia administered standard doses of imatinib adjusted for dose, age, sex, body weight, and response.We evaluated data from a cohort of patients treated between 2008 and 2014 with respect to dose, age, sex, body weight, and response.The study comprised 438 samples from 93 patients (54 male, 39 female). The median imatinib dose was 400 mg·d in men and in women. The plasma imatinib concentration ranged 0.1-5.0 mg·L and was below 1 mg·L in 20% and 16% of samples from men and women, respectively. The mean dose normalized plasma imatinib and norimatinib concentrations were significantly higher in women in comparison with men. This was partially related to body weight. Mixed effects ordinal logistic regression showed no evidence of an association between sex and plasma imatinib (P = 0.13). However, there was evidence of an association between sex and plasma norimatinib, with higher norimatinib concentrations more likely in women than in men (P = 0.02).Imatinib therapeutic drug monitoring only provides information on dosage adequacy and on short-term adherence; longer-term adherence cannot be assessed. However, this analysis revealed that approximately 1 in 5 samples had a plasma imatinib concentration1 mg·L, which was suggestive of inadequate dosage and/or poor adherence and posed a risk of treatment failure. Higher imatinib exposure in women may be a factor in the increased rate of long-term, stable, deep molecular response (undetectable breakpoint cluster-Abelson (BCR-ABL) transcript levels with a PCR sensitivity of 4.5 log, MR4.5) reported in women.

[Figure][1] A 21-year-old man had presented at 3 months of age with failure to thrive, malabsorption, diarrhea, weight loss, ascites, and hepatosplenomegaly. A diagnosis of Wolman disease (lysosomal acid esterase deficiency) was made following demonstration of excess cholesterol ester in the

Allogeneic hematopoietic stem cell transplantation (HSCT) with reduced-intensity conditioning (RIC) offers a potential cure for patients with myelodysplastic syndrome (MDS) who are ineligible for standard-intensity regimens. Previously published data from our institution suggest excellent outcomes at 1 yr using a uniform fludarabine, busulfan, and alemtuzumab-based regimen. Here we report long-term follow-up of 192 patients with MDS and acute myelogenous leukemia (AML) secondary to MDS (MDS-AML) transplanted with this protocol, using sibling (n = 45) or matched unrelated (n = 147) donors. The median age of the cohort was 57 yr (range, 21 to 72 yr), and median follow-up was 4.5 yr (range, 0.1 to 10.6 yr). The 5-yr overall survival (OS), event-free survival, and nonrelapse mortality were 44%, 33%, and 26% respectively. The incidence of de novo chronic graft-versus-host disease (GVHD) was low at 19%, illustrating the efficacy of alemtuzumab for GVHD prophylaxis. Conversely, the 5-yr relapse rate was 51%. For younger patients (age 60 yr having a 5-yr OS of 15% and relapse rate of 66%. Patients receiving preemptive donor lymphocyte infusions had an impressive 5-yr OS of 67%, suggesting that this protocol may lend itself to the incorporation of immunotherapeutic strategies. Overall, these data demonstrate good 5-yr OS for patients with MDS and MDS-AML undergoing alemtuzumab-based RIC-HSCT. The low rate of chronic GVHD is encouraging, and comparative studies with other RIC protocols are warranted.

Introduction Telomere length is shortened in patients with idiopathic aplastic anemia (AA) and other bone marrow failure disorders (BMFD) and predicts risk of clonal evolution (CE), relapse and overall survival (OS). Telomereopathies predominantly cause bone marrow failure, are multi-systemic disorders with variable penetrance, and may involve inter-play of other factors in disease manifestation and organ affliction. Telomere length (TL) in AA and other hypocellular BMFD, independent of mutations in telomere genes (TGC), has not been studied as a scoring tool, as well predicting the risk of affliction of other organ/systems in these disorders. We systematically review a large cohort of 472 patients in a single centre with AA/BMFD using TL and TGC analysis as a discriminator, to study risk of CE and OS, manifesting with liver/lung and skin complications, cancer predisposition and likelihood of a family member presenting with cytopenias. Methods We screened 1060 consecutive patients at a single centre from the years 2011-18, with AA or unexplained cytopenias for telomere length (TL) analysis using a multiplex qPCR methodology as described by Cawthon et al. 472 (44.5%) patients had TL less than the 25th centile, of whom 243 had Results Table attached. The median age and gender across the 3 cohorts studied (TL 10-25th centile, A third of patients with BMFD and TL TL does not correlate with the manifestation and presence of liver, respiratory and skin problems of telomere disease. TL in BMFD does not associate with increased predisposition to cancer, as their presence was not statistically significant across the 3 groups. Disease manifestation with bone marrow failure, haematological indices, need for blood transfusions, presence of a PNH clone and karyotypic abnormalities, including complex and monosomal karyotype were not dissimilar across the 3 TL cohorts. Not surprisingly, there were more family members with features of cytopenias and BMFD, on screening of patients with a confirmed TGC mutation. TL did not predict a difference in treatment strategies used across the 3 groups, although more patients with a TGC mutation received anabolic steroids. The risk of clonal evolution to PNH or MDS/AML and overall survival was again similar across the 3 TL cohorts with an OS of 93% at 1078 days follow-up for the entire cohort. Conclusion TL can reliably be used as a screening tool to investigate patients for further TGC mutation analysis in patients with AA or BMFD. Heterozygous state mutations in TERT are the commonest, and can be associated with mutations in other TGC genes, particularly RTEL1 and TERC. This may cause a compounding factor in shortening the TL further. However, TL TL and TGC mutation analysis in a single centre study from 2011-18. Table Disclosures Kizilors: Incyte biosciences: Research Funding. Mufti:Celgene: Consultancy, Research Funding.

Previous data indicate that pre-transplant flow cytometry measurable residual disease (MRD) in acute myeloid leukaemia (AML) patients in complete remission predicts relapse and survival. Diagnostic laboratories have started to report flow MRD (fMRD) at each AML disease assessment. We evaluated 83 consecutive patients with AML receiving allogeneic stem cell transplants at King's College Hospital (London, UK) in 2017-2018 to assess the significance of fMRD pre- and post-transplant. Flow MRD detection was based on leukaemia associated immunophenotype and 'difference from normal' strategies, reported at a sensitivity of 0.1%. Two timepoints were assessed: pre-transplant (post-induction) and day 100 post-transplant. Pre-transplant, 30 patients were excluded (9 active disease, 21 unknown fMRD) - of the remaining 53 patients in remission ( Patient characteristics at each timepoint are listed in Tables 1 and 2. Outcome measures were overall survival (OS), relapse free survival (RFS), relapse and non-relapse mortality (NRM). Multivariate Cox regression analysis was performed using the parameters listed in the tables. Pre-transplant, the only predictor of OS was recipient CMV positivity - HR 0.07 (95% CI 0.01-0.79), p=0.03. RFS was predicted by age ≥65 - HR 0.18 (95% CI 0.05-0.65), p=0.01, secondary AML (sAML) - HR 0.19 (95% CI 0.05-0.77), p=0.02 and CMV positivity - HR 0.16 (95% CI 0.04-0.69), p=0.01. Relapse was predicted by age ≥65 - HR 10.98 (95% CI 1.68-71.73), p=0.01, genetic risk: favourable versus adverse - HR 0.02 (95% CI 0.001-0.04), p A separate pre-transplant analysis was performed to include molecular MRD (mMRD). Fifty three patients were excluded (9 active disease, 50 not assessed for mMRD, 1 no available result) - in the remaining 23 patients (21 NPM1 mutated, 2 KMT2A rearranged), mMRD was not predictive of any outcome. Eight patients remained mMRD+ in remission post-transplant; 3 were initially mMRD- post-transplant, but became mMRD+ later. Only 2/11 patients relapsed - the others responded to augmentation of the graft versus leukaemia (GVL) effect by reduction of immunosuppression or donor lymphocyte infusion (DLI). At day 100 post-transplant, OS was predicted by age ≥65 - HR 0.001 (95% CI 2×10-6-0.23), p=0.01 and sAML - HR 0.002 (95% CI 3.6×10-5-0.11), p In our cohort, recipient CMV positivity was strongly associated with poor outcomes. Age, genetic risk and secondary disease were also important. Pre-transplant fMRD was predictive of relapse but not survival. At day 100 post-transplant, fMRD predicted both relapse and RFS; DLI was associated with a protective effect. Median time to relapse from fMRD+ at day 100 post-transplant was 89 days - relapse occurred in 5/7 patients. This contrasts with the sensitivity of NPM1 mMRD+ disease to the GVL effect. Further work is required both to confirm our findings in a larger cohort and to determine how best to manage patients who are fMRD+ post-transplant. Disclosures Off Label Use: Azacitidine (Vidaza) - used for prevention of relapse after allogeneic stem cell transplantation for acute myeloid leukaemia. de Lavallade:Bristol Myers Squibb: Research Funding. Mufti:Celgene: Consultancy, Research Funding. OffLabel Disclosure: Azacitidine (Vidaza) - used for prevention of relapse after allogeneic stem cell transplantation for acute myeloid leukaemia

Induction of innate immunity is essential for host survival of infection. Evasion and inhibition of innate immunity constitute a strategy used by pathogens, such as the highly virulent bacterium Francisella tularensis, to ensure their replication and transmission. The mechanism and bacterial components responsible for this suppression of innate immunity by F. tularensis are not defined. In this article, we demonstrate that lipids enriched from virulent F. tularensis strain SchuS4, but not attenuated live vaccine strain, inhibit inflammatory responses in vitro and in vivo. Suppression of inflammatory responses is associated with IκBα-independent inhibition of NF-κBp65 activation and selective inhibition of activation of IFN regulatory factors. Interference with NF-κBp65 and IFN regulatory factors is also observed following infection with viable SchuS4. Together these data provide novel insight into how highly virulent bacteria selectively modulate the host to interfere with innate immune responses required for survival of infection.

We evaluated a novel alemtuzumab-based conditioning regimen in HSCT for acquired severe aplastic anemia (SAA). In a multicenter retrospective study, 50 patients received transplants from matched sibling donors (MSD; n = 21) and unrelated donors (UD; n = 29), using fludarabine 30 mg/m2 for 4 days, cyclophosphamide 300 mg/m2 for 4 days, and alemtuzumab median total dose of 60 mg (range:40-100 mg). Median age was 35 years (range 8-62). Overall survival at 2 years was 95% ± 5% for MSD and 83% for UD HSCT (p 0.34). Cumulative incidence of graft failure was 9.5% for MSD and 14.5% for UD HSCT. Full-donor chimerism (FDC) in unfractionated peripheral blood was 42%; no patient achieved CD3 FDC. Acute GVHD was observed in only 13.5% patients (all grade I-II) and only 2 patients (4%) developed chronic GVHD. A low incidence of viral infections was seen. Factors influencing overall survival were HSCT comorbidity 2-year index (92% with score 0-1 vs 42% with score ≥ 2, P < .001) and age (92% for age < 50 years vs 71% ≥ 50 years, P < .001). Our data suggest that the use of an alemtuzumab-based HSCT regimen for SAA results in durable engraftment with a low incidence of chronic GVHD.

Kinase domain (KD) mutations in the BCR-ABL1 gene are associated with resistance to tyrosine kinase inhibitors (TKI) in chronic myeloid leukemia (CML). Next-generation Sequencing (NGS) allows detection of low-level KD mutations ( We have previously shown the clinical significance of low-level KD mutation by NGS. However our study, along with previous studies, was retrospective. Since August 2014, we have been using NGS-based assay (in replacement of Sanger sequencing) for clinical intervention, allowing us to study the clinical relevance of low level mutations and monitor the kinetics of mutated clones. We herein report the outcome of patients in whom clinical intervention was made based on NGS KD mutation screening and monitoring. We analyzed the outcome of 340 consecutive Chronic Phase CML patients treated with first-line TKI at our institution and within our network (imatinib 235, nilotinib 49, dasatinib 10, unknown 46), of whom 70.42% achieved CCyR with first-line TKI. NGS-based KD mutation testing was done retrospectively until January 2014, and prospectively from that date. Overall, a mutation was found in 41(12.05%) patients at a median time of 14 months (range, diagnosis to 156 months). Twenty five different mutations were identified, including T315I (n=9), M244V (n=8), F317L (n=8) and E255K (n=6). Of 41 patients with mutated clone, 27 were found to have a mutation conferring resistance to the ongoing TKI treatment (defined as 'clinically relevant' mutation). In 8 patients, the mutation was sensitive to the TKI treatment received (M244V in 6 patients, M351T in one patient on imatinib and an E255V in one patient on dasatinib), two patients with intermediate resistance to the treatment received (H396R and E355G) and four patients with mutations of unknown clinical significance (Q252R, E450K and E450G). Of the 27 patients with clinically relevant mutations, 8 patients were part of our initial retrospective NGS screening study, of whom 3 had clinical intervention based on Sanger Sequencing results. From August 2014, clinical intervention was made based on KD mutations found by NGS. Eighteen patients had their TKI treatment changed because of mutations found to confer resistance to their ongoing TKI (including 2 with unknown clinical significance), of whom 14 had single mutation (F317L, n=3; T315I, n=2; Y253H, n=1; F359V, n=1; L248V, n=1; G250E, n=1; F311L, n=1; E459G, n=1; E450K, n=1; F359I, n=1; E450G, n=1). Four patients had multiple mutations, including two patients who developed mutations sequentially. Of the 18 patients who had clinical intervention, the first detection of the KD mutation was at a low-level in 13 patients. Response to change of TKI was seen in 12 patients, of whom 11 achieved a stable MR3, and one patient with a 2.2 log reduction in BCR-ABL transcript levels. One patient proceeded to allogeneic HSCT and four patients did not show significant response at last follow up. Finally, one patient had a low level Y253H mutation detected while on nilotinib which initially reduced after TKI change and then subsequently increased while gaining an additional T315I at the time of Blastic Phase transformation. Response to combining chemotherapy and ponatinib was seen with the achievement of sustained MR3 until allogeneic HSCT. Kinetics of mutated clone(s) was monitored post TKI change and all patients who responded experienced a reduction in their clone size. Among 12 patients who responded to TKI change, 3 had multiple mutations. One patient had a low level E255K mutation at 4% at 3 months despite achieving CCyR on nilotinib and subsequently developed an additional T315I mutation after 15 months upon loss of CCyR. This patient achieved a sustained MR3 upon switch to ponatinib with concomitant drop in the T315I clone size. To our knowledge, this is the first report of clinical intervention using NGS based KD mutation detection in the management of CML patients. Our findings suggest that NGS may improve clinical decision-making in these patients. A prospective clinical study using NGS (acronym CALLS) is currently ongoing in the UK. Disclosures Kizilors: Incyte: Honoraria, Research Funding. Harrington:BMS: Research Funding. Pagliuca:Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gentium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mufti:Celgene: Research Funding. De Lavallade:Incyte: Honoraria, Research Funding; BMS: Honoraria, Research Funding.

Background: the use of high sensitive FLAER in the last 10 years improved the detection of very small PNH clones ( Aim: To evaluate the prevalence of PNH clones ≥0.01% in AA/MDS patients tested at a single tertiary center, and to assess their impact on disease prognosis (leukemic evolution, death), occurrence of thrombosis, and response to current therapies. Methods: We retrospectively collected clinical (diagnosis, stage, therapy, complications and outcome) and laboratory features (complete blood counts, LDH, PNH clone size) of 869 MDS and 531 AA patients tested from March 1998 till October 2017. Results: Figure 1 shows clinical and laboratory characteristics of MDS and AA patients, divided according to the presence/absence of PNH clones. A PNH clone was less frequently found in MDS cases versus AA (20.3% vs 61%). Focusing on MDS, PNH+ cases were significantly more hypoplastic, mainly displayed IPSS low/int-1 score, and showed deeper cytopenias (significantly for Hb and PLT) and higher LDH levels. Dividing patients according to clone size (negative, 0.01-1%, 1.01-10%,10.01-50%, and >50% on granulocytes), we observed a significant worsening of cytopenia and raise of LDH along with clone size increase. Likewise, lower IPSS risk patients more frequently displayed a greater clone size. As regards therapy, PNH+MDS showed significantly higher response rates to immunosuppressive therapies (ATG and CyA, 84% vs 44.7%, p=0.01) and to HSCT (71% vs 56.6%, p=0.09) compared to PNH-, and the cumulative probability of response to any treatment significantly improved along with clone size increase (from 52 to 100%, p=0.03). In addition, PNH+MDS showed lower rate of progression and AML evolution, and a longer OS [mean 11.9+0.7 years (10.5-13.3) vs 7.3+0.3 (6.6-7.9), p50%, p Regarding AA, together with a higher frequency of PNH clones, we also found a higher frequency of large clones (>10%) compared to MDS (p=0.04, bars chart). PNH+AA showed deeper thrombocytopenia, higher reticulocyte counts and LDH values. As observed for MDS, we found a significant worsening of cytopenia and raise of LDH along with clone size increase. In addition, PNH+ AA showed higher response rates compared to PNH- (97 vs 77% for HSCT, p=0.01; 78 vs 50% for IST, p Conclusions: Prevalence of PNH clones of any size is high in patients with MDS and AA. We firstly show a positive impact of PNH clone positivity on response to IST and HSCT in MDS. The presence of a PNH clone also correlated with lower disease progression and better OS. Furthermore, we confirm the known favourable prognostic and predictive value of PNH clones in a large AA cohort. Clone size analysis suggests that even small clones (0.01-1%) have a clinical and prognostic significance. Figure 1. Figure 1. Disclosures Kassam: AbbVie: Equity Ownership. Yallop:Pfizer: Consultancy; Servier: Other: Travel funding. Mufti:Celgene: Research Funding. Kulasekararaj:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Other: Travel Support .

We report on a retrospective analysis examining the influence of pre-transplant serum ferritin on transplant outcomes of 99 MDS patients receiving reduced intensity conditioning (RIC) HSCT. The median pre-transplant ferritin value was 1992 ng/ml (range: 6-9580 ng/ml). No patients received iron chelation therapy preceding transplantation. On univariate analysis, there was a strong correlation between a higher pre-transplant serum ferritin (>1500 ng/ml) and a significantly inferior 3-year OS (64.6+/-7.5% vs 39.6+/-7.3%, p=0.01). However, pre-transplant serum ferritin did not influence 3-year TRM (20.2+/-7% vs 27.4+/-7%, p=0.24). There was no difference in infection-related mortality, and incidence of acute or chronic GvHD between cohorts. On multivariate analysis, a raised serum ferritin (HR: 2.00, 95% CI: 0.97-3.57, p=0.03), and the presence of >5% bone marrow blasts at time of transplantation (HR: 2.14, 95% CI: 0.84-4.58, p=0.06) were independent predictors of an inferior overall survival. However, pre-transplant serum ferritin was not a significant predictor of disease-free survival, relapse or TRM. When compared with myeloablative regimens, RIC regimens may attenuate the impact of iron overload related end-organ toxicity. Prospective studies incorporating alternative biomarkers of iron metabolism alongside serum ferritin levels are needed to improve our understanding of the significance of iron overload in MDS patients undergoing allogeneic transplantation.

Summary Background A mechanism for clonal growth advantage in isolated del(5q) disease remains elusive. CSNK1A1 resides on the critically deleted region, and deletion of this gene has been shown in mouse knockout and transplantation studies to produce some characteristics of bone marrow failure, including a proliferative advantage. We aimed to establish the frequency, nature, and clinical association of CSNK1A1 mutations in patients with myelodysplastic syndrome and associated myeloid neoplasms. Methods Between June 1, 2004, and May 31, 2014, in King's College (London, UK), we did whole-exome sequencing of five patients with isolated del(5q) followed by targeted screening for CSNK1A1 mutations and 20 myelodysplastic syndrome-associated mutations in 245 additional patients with myeloid neoplasms. All patients met present WHO diagnostic criteria for myelodysplastic syndrome and other related myeloid neoplasms. Findings 39 (16%) of 250 patients with myeloid neoplasms had isolated del(5q), of whom seven (18%) had CSNK1A1 mutations. All these mutations were missense and presented in a highly conserved region that is implicated in ATP catalysis. Serial sampling and response to lenalidomide treatment showed that CSNK1A1 mutations were highly associated with the del(5q) clone. Only one patient with a CSNK1A1 mutation showed complete cytogenetic response to lenalidomide. Four (57%) of the seven patients carrying a CSNK1A1 mutation showed disease progression coupled with an increase in mutant allele burden (all four were on lenalidomide). We detected coexisting myelodysplastic syndrome-related gene mutations in patients with CSNK1A1 mutations, including TP53 . Interpretation Similar to the effect of TP53 mutations on progression of del(5q) abnormality, mutant CSNK1A1 also gives rise to a poor prognosis in del(5q) abnormality, for which a coupled increase in P53 activation is suggested. CSNK1A1 mutations in del(5q) disease are important in the context of therapeutic manipulation and need incorporation into future prospective studies. Funding Leukaemia and Lymphoma Research.

Macrophages are an important intracellular niche for Salmonella particularly for systemic infection. The interaction of Salmonella with these cells is mediated by two type III secretion systems (TTSS), encoded on Salmonella pathogenicity islands 1 and 2 (SPI1, SPI2), which mediate distinct phases of the pathogen-host cell interaction. The SPI1 TTSS mediates invasion whereas the SPI2 TTSS is required for intramacrophage survival. Importantly, however, Salmonella can enter macrophages by either SPI1-dependent invasion or host cell-mediated phagocytosis. Here, we investigated how the mechanism of internalization affects the intracellular environment and TTSS gene expression. Intracellular bacterial survival depended on the method of entry, because complement-opsonized and SPI1-induced Salmonella initiated replication within 8 h whereas immunoglobulin G (IgG)-opsonized and non-opsonized Salmonella were initially killed. Analysis of vacuolar pH showed that acidification of the Salmonella-containing vacuole occurred more rapidly for non-opsonized or SPI1-induced Salmonella compared with IgG-opsonized or complement-opsonized Salmonella. Finally, quantitative polymerase chain reaction was used to compare the transcriptional profiles of selected SPI1 and SPI2 regulon genes. We found that the magnitude of SPI2 gene induction depended on the mechanism of internalization. Unexpectedly, SPI1 genes, which are rapidly downregulated following SPI1-mediated invasion, were induced intracellularly following phagocytic uptake. These results reveal another level of complexity in pathogen-macrophage interactions.

Leucine-rich repeats (LRR) characterize a diverse array of proteins and function to provide a versatile framework for protein-protein interactions. Importantly, each of the bacterial LRR proteins that have been well described, including those of Listeria monocytogenes , Yersinia pestis , and Shigella flexneri , have been implicated in virulence. Here we describe an 87.4-kDa group A Streptococcus (GAS) protein (designated Slr, for streptococcal leucine-rich) containing 10 1/2 sequential units of a 22-amino-acid C-terminal LRR homologous to the LRR of the L. monocytogenes internalin family of proteins. In addition to the LRR domain, slr encodes a gram-positive signal secretion sequence characteristic of a lipoprotein and a putative N-terminal domain with a repeated histidine triad motif (HxxHxH). Real-time reverse transcriptase PCR assays indicated that slr is transcribed abundantly in vitro in the exponential phase of growth. Flow cytometry confirmed that Slr was attached to the GAS cell surface. Western immunoblot analysis of sera obtained from 80 patients with invasive infections, noninvasive soft tissue infections, pharyngitis, and rheumatic fever indicated that Slr is produced in vivo. An isogenic mutant strain lacking slr was significantly less virulent in an intraperitoneal mouse model of GAS infection and was significantly more susceptible to phagocytosis by human polymorphonuclear leukocytes. These studies characterize the first GAS LRR protein as an extracellular virulence factor that contributes to pathogenesis and may participate in evasion of the innate host defense.

Streptococcal inhibitor of complement (Sic) is a secreted protein made predominantly by serotype M1 Group A Streptococcus (GAS), which contributes to persistence in the mammalian upper respiratory tract and epidemics of human disease. Unexpectedly, an isogenic sic -negative mutant adhered to human epithelial cells significantly better than the wild-type parental strain. Purified Sic inhibited the adherence of a sic negative serotype M1 mutant and of non-Sic-producing GAS strains to human epithelial cells. Sic was rapidly internalized by human epithelial cells, inducing cell flattening and loss of microvilli. Ezrin and moesin, human proteins that functionally link the cytoskeleton to the plasma membrane, were identified as Sic-binding proteins by affinity chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. Sic colocalized with ezrin inside epithelial cells and bound to the F-actin-binding site region located in the carboxyl terminus of ezrin and moesin. Synthetic peptides corresponding to two regions of Sic had GAS adherence-inhibitory activity equivalent to mature Sic and inhibited binding of Sic to ezrin. In addition, the sic mutant was phagocytosed and killed by human polymorphonuclear leukocytes significantly better than the wild-type strain, and Sic colocalized with ezrin in discrete regions of polymorphonuclear leukocytes. The data suggest that binding of Sic to ezrin alters cellular processes critical for efficient GAS contact, internalization, and killing. Sic enhances bacterial survival by enabling the pathogen to avoid the intracellular environment. This process contributes to the abundance of M1 GAS in human infections and their ability to cause epidemics.

[Figure][1] A 53-year-old man with Crohn disease and macrocytic anemia had vitamin B12 deficiency but did not improve on replacement therapy. He developed leukocytosis and his blood count showed: hemoglobin, 87 g/L; white blood cells, 15.4 × 109/L; neutrophils, 2.8 × 109/L; and platelets

IMDSFlow19: et al., Definite progress has been made in the exploration of myelodysplastic syndromes (MDS) by flow cytometry (FCM) since the publication of the World Health Organization 2008 classification of myeloid neoplasms. An international working party initiated within the European LeukemiaNet and extended to include members from Australia, Canada, Japan, Taiwan and the United States has, through several workshops, developed and subsequently published consensus recommendations. The latter deal with preanalytical precautions, and propose small and large panels, which allow evaluating immunophenotypic anomalies and calculating myelodysplasia scores. The current paper provides guidelines that strongly recommend the integration of FCM data with other diagnostic tools in the diagnostic work-up of MDS.

Background The presence of diverse spectrum of mutations in myelodysplastic syndromes (MDS) has largely revolutionized the understanding of the disease. Although certain mutations have doubtful prognostic significance, the adverse impact of TP53 mutation is irrefutable in all publications. We and others have shown the strong correlation between presence of TP53 mutation and overexpression of p53 by immunohistochemistry (IHC). This evidence provides the rationale for the evaluation of p53 overexpression which is available in routine diagnostic workup, as a surrogate marker to predict TP53 mutations. Additionally, we predicted that the overexpression of p53 might be an independent prognosticator, even in the absence of TP53 mutations or RPS14 haploinsufficiency, in low risk MDS. In our study,we analyzed the p53 protein expression in a cohort of 277 'lower risk' MDS patients and compared the clinico-pathological features, overall survival and risk of progression and evolution to AML with respect to p53 IHC status. Methods This study enrolled 277 adult low risk MDS patients seen at King's College Hospital between March 2009 and February 2016. All marrow samples were assessed for p53 expression (intensity and proportion of cells) and scored using a Modified Quick Score (MQS). MQS ≥2 was chosen to define p53-positive staining. The median follow-up was 18.7 months [95% confidence interval (CI), 16.5-21.0 months]. Results According to WHO categories, the predominant group was RCMD (78%). Patients were either IPSS low (n=134, 48%) or int-1 (n=91, 33%). We included 52 (19%) pts for whom the IPSS category was not available, due to the lack or failed cytogenetic data, but these were low-risk WHO categories with no excess of blasts. IPSS-R categories were very low 103 (37%), low 77 (28%), intermediate 38 (14%) and high risk 7 (3%). Overall, 19 (7%) patients progressed to AML and 41 (15%) patients died of which 25 (61%) were disease-related deaths. Of the 277 patients, 148 (53%) showed p53 protein expression with MQS ≥ 2 and were considered "p53-positive" patients (p53+). The p53 stain intensity was negative in 125 (45%), weak in 84 (30%), moderate in 40 (14%) and strong in 28 (11%). Seventy six (28%) patients had >5% p53 staining cells. p53 expression correlated with a higher age at diagnosis (median age 64 vs. 60 years, p=0.01). lower haemoglobin levels (9.8 vs 11 g/dL, p=0.002), but a higher platelets count (139 vs 99 x109/L, p =.003) (Table 1). This significance persisted even on exclusion of patients with 5q- and MDS/MPN. P53+ did not correlate with any cytogenetic risk group or degree of fibrosis. Sequencing data was available in 121 patients with 63 harbouring somatic mutations. Among these patients, only 3 showed the TP53 gene mutation; all of them were classified as positive when assessed for p53 stain (MQS≥2), showing that the nuclear staining reflects underlying TP53 mutations in such cases. Additionally, presence of SF3B1 mutation correlated strongly with p53+ (p=0.02). Patients with p53+ had a significantly shorter OS compared with those with p53- (figure 1a) with 2yr and 4yr survival probability of 87% &68% vs 95% & 90% , respectively (p=0.03 ). Analysis of progression-free survival (progression to AML, cytogenetic evolution, increase of blasts or fibrosis) showed that patients with p53 expression had a significantly shorter PFS compared to patients without p53 expression (Figure 1b): 2yr & 4yr PFS 70% & 54% vs 85% &75% respectively, p=0.01). Multivariate analysis confirmed the independent prognostic value of p53 expression for PFS (p=0.013, HR 2.6, 95% CI 1.2-5.2). Conclusion In conclusion, our study showed that p53 overexpression by IHC, represented as MQS cutoff ≥ 2, correlates with features of poor prognosis, such as more advanced age at diagnosis, lower haemoglobin levels and shorter overall survival, adversely impacting progression-free survival. p53 IHC in MDS patients may represent an important, easily available, cheap and applicable prognostic tool and it should be considered for auxiliary analysis when determining the therapeutic options for a patient. The p53+ predicts poor outcome, especially disease progression, independent of the TP53 mutation status, indicating an alternate yet undefined pathway for p53 overexpression. Figure 1(a) Disease-related OS (a) and PFS (b) in patients with low-risk MDS according to their p53 expression-status Figure 1(a). Disease-related OS (a) and PFS (b) in patients with low-risk MDS according to their p53 expression-status Figure 1(b) Figure 1(b). Disclosures No relevant conflicts of interest to declare.

Item does not contain fulltext An international working group within the European LeukemiaNet gathered, aiming to determine the role of flow cytometry (FC) in myelodysplastic syndromes (MDS). It was agreed that FC has a substantial application in disease characterization, diagnosis and prognosis. FC may also be useful in predicting treatment responses and monitoring novel and standard therapeutic regimens. In this article the rationale is discussed that flow cytometry should be integrated as a part of diagnostic and prognostic scoring systems in MDS.

[Figure][1] A 6-year-old girl from Pakistan was investigated for neurologic symptoms also affecting 3 other family members. She was the sixth child of parents who were first cousins, born at term with normal birth weight. Developmental milestones were normal until 5 years old when she

This study aimed to determine the incidence/prognostic impact of TP53 mutation in 318 myelodysplastic syndrome (MDS) patients, and to correlate the changes to cytogenetics, single nucleotide polymorphism array karyotyping and clinical outcome. The median age was 65 years (17-89 years) and median follow-up was 45 months [95% confidence interval (CI) 27-62 months]. TP53 mutations occurred in 30 (9.4%) patients, exclusively in isolated del5q (19%) and complex karyotype (CK) with -5/5q-(72%), correlated with International Prognostic Scoring System intermediate-2/high, TP53 protein expression, higher blast count and leukaemic progression. Patients with mutant TP53 had a paucity of mutations in other genes implicated in myeloid malignancies. Median overall survival of patients with TP53 mutation was shorter than wild-type (9 versus 66 months, P < 0.001) and it retained significance in multivariable model (Hazard Ratio 3.8, 95%CI 2.3-6.3,P < 0.001). None of the sequentially analysed samples showed a disappearance of the mutant clone or emergence of new clones, suggesting an early occurrence of TP53 mutations. A reduction in mutant clone correlated with response to 5-azacitidine, however clones increased in non-responders and persisted at relapse. The adverse impact of TP53 persists after adjustment for cytogenetic risk and is of practical importance in evaluating prognosis. The relatively common occurrence of these mutations in two different prognostic spectrums of MDS, i.e. isolated 5q- and CK with -5/5q-, possibly implies two different mechanistic roles for TP53 protein.

Relapse occurs in 30%-50% of recipients of T cell–depleted (TCD) reduced-intensity conditioned (RIC) hematopoietic stem cell transplantation (HSCT) for acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS). Despite limited published supportive data, donor lymphocyte infusion (DLI) is used preemptively (pDLI) to improve donor chimerism and prevent relapse, and therapeutically (tDLI) after disease recurrence. We evaluated the efficacy and toxicity of pDLI and tDLI in 113 patients after TCD (alemtuzumab, n = 99; antithymocyte globulin, n = 14) RIC HSCT for AML or MDS. Recipients of pDLI (n = 62) had an estimated 5-year overall survival (OS) of 80% and an event-free survival of 65%. More than one-half (52%; n = 32) of the patients received pDLI within 6 months post-HSCT; despite this, the 5-year incidence of graft-versus-host disease was only 31% (95% confidence interval [CI], 19%-43%). Recipients of tDLI (n = 51) had an estimated 5-year OS of 40% and a 5-year relapse/progression rate of 69% (95% CI, 54%-81%). Recipients of tDLI at >6 months post-HSCT had a significantly superior 5-year OS after tDLI compared with those treated earlier (P = .008). The cumulative incidence of graft-versus-host disease at 5 years after tDLI was 45% (95% CI, 23%-65%). We demonstrate that pDLI safely promotes durable remission after TCD RIC HSCT for AML or MDS, and that tDLI salvages patients after late relapse with greater efficacy.

A simple HPLC method has been developed to measure imatinib and N-desmethylimatinib (norimatinib) in plasma or serum at concentrations attained during therapy. Adaptation of this method to LC-MS/MS also allows dasatinib assay. A small sample volume (100 μL HPLC-UV, 50 μL LC-MS/MS) is required and analysis time is 1 mg/L (suggested target for response) in all but one sample from patients achieving complete molecular response. As to dasatinib, the median (range) plasma dasatinib concentration was 13 (2-143) µg/L (N = 33). More observations are needed to properly assess the potential role of therapeutic drug monitoring in guiding treatment with dasatinib.

According to WHO 2008 guidelines, the required percentage of cells manifesting dysplasia in the bone marrow to qualify as significant is 10% or over in one or more hematopoietic cell lineages, but this threshold is controversial. No 'normal' values have been established. Therefore, we investigated dyshematopoiesis in bone marrow aspirate squash preparations of 120 healthy bone marrow donors.Bone marrow squash slides of 120 healthy unrelated bone marrow donors were examined independently by 4 experienced morphologists. Samples were taken from the first aspiration during the harvest. Bone marrow preparation and assessment were performed according to WHO recommendations and ICSH guidelines.More than 10% dysmyelopoiesis could be detected in 46% of bone marrow aspirate squash preparations with 26% in 2 or more cell lineages and 7% in 3 cell lineages in healthy bone marrow donors. Donors under the age of 30 years exhibited more dysgranulopoietic changes and dysmegakaryopoietic changes (P0.001) compared to the older donors. Female donors showed more dysgranulopoietic changes than male donors (P = 0.025). The concordance rate between the 4 investigators was modest in dysgranulopoiesis but poor in dyserythropoiesis and dysmegakaryopoiesis.The poor reliability of the 10% cut off was partly related to the proximity of the current criteria to the observed cut-off mean values of the normal population. These findings question the current WHO threshold of the 10% or over necessary for the percentage of cells manifesting dysplasia to be considered significant, and suggest that either a higher threshold would be more appropriate or different thresholds should be set for each lineage.

Item does not contain fulltext Flow cytometry (FC) is increasingly recognized as an important tool in the diagnosis and prognosis of myelodysplastic syndromes (MDS). However, validation of current assays and agreement upon the techniques are prerequisites for its widespread acceptance and application in clinical practice. Therefore, a working group was initiated (Amsterdam, 2008) to discuss and propose standards for FC in MDS. In 2009 and 2010, representatives from 23, mainly European, institutes participated in the second and third European LeukemiaNet (ELN) MDS workshops. In the present report, minimal requirements to analyze dysplasia are refined. The proposed core markers should enable a categorization of FC results in cytopenic patients as 'normal', 'suggestive of', or 'diagnostic of' MDS. An FC report should include a description of validated FC abnormalities such as aberrant marker expression on myeloid progenitors and, furthermore, dysgranulopoiesis and/or dysmonocytopoiesis, if at least two abnormalities are evidenced. The working group is dedicated to initiate further studies to establish robust diagnostic and prognostic FC panels in MDS. An ultimate goal is to refine and improve diagnosis and prognostic scoring systems. Finally, the working group stresses that FC should be part of an integrated diagnosis rather than a separate technique. 01 juli 2012

Kinase domain (KD) mutations in the BCR-ABL1 gene are associated with resistance to tyrosine kinase inhibitors (TKI) in chronic myeloid leukemia (CML). Next-generation Sequencing (NGS) allows detection of low-level KD mutations but its relevance in clinical practice remains debated, and the incidence and prognostic significance of finding of low-level KD mutation in chronic phase (CP) patients is unknown. We analyzed the outcome for 121 newly diagnosed CP-CML patients treated with TKIs (imatinib 111, nilotinib 7 and dasatinib 3) who we routinely screened for KD mutations using ultra-deep NGS regardless of response to TKI. When a mutation was found by ultra-deep NGS (using Illumina NexteraXT and MiSeq platform) all available previous cDNA samples were analyzed to establish the date of its first occurrence and subsequent kinetics. ABL1 transcripts from 27 healthy donors were sequenced and used as a control. Sequencing for both single and nested PCR products were compared, and samples were re-sequenced in two independent runs in order to analyze reproducibility of variants detection. Median age of patients was 56 years and the Sokal risk score was 'low' in 38% patients, 'intermediate' in 15.5% and 'high' in 46.5%. A mutation was detected in 25 of the 121 patients (20.6%) at a median time of 14 months from starting TKI. 19 different mutations were identified, the most frequents being F317L (n=17), Y253H (n=15), M244V (n=14) and T315I (n=10). All mutations previously detected by Sanger sequencing were also found using ultra-deep NGS. In addition low-level mutations ( Eighteen patients discontinued imatinib while still in CP and received dasatinib, nilotinib or an allogeneic stem cell transplantation. The overall progression-free survival (absence of advanced phase) at 5 years was 85%. Complete cytogenetic responses (CCyR) and major molecular responses (MMR) with front-line TKI therapy were achieved in 74 (61%) and 52 (43%) patients respectively. We stratified patients according to response to TKI therapy as per 2009 ELN guidelines (Baccarani et al., 2009): patients with optimal response ('responders', R), failure at any time ('non-responders', NR) and sub-optimal response (SR). Patients with known TKI dose-interruption were analyzed separately. Mutations were classified and analyzed according to clinical relevance (clinically relevant versus clinically non relevant mutations, Branford et al., 2009). Among non-responders (NR), 37% of patients developed a mutation (29% among patients who lost CCyR), compared to only 5% among responders (2 patients, both with KD mutations sensitive to imatinib). Among patients with suboptimal response (SR), 19% developed a mutation while being in CCyR but not in MMR with all clinically relevant mutated clone percentages increasing in patients being treated with a TKI to which the KD mutation was conferring resistance. Similarly in all NR patients the mutated clone percentage rose in sequential samples if a clinically relevant mutation was detected. Patients harboring a mutant clone had a poorer PFS at 5 years compared to patients without mutation (67% versus 92%, p We next evaluated the incidence and impact of finding of KD mutations at the early molecular response time point (3-months BCR-ABL1 transcript level). Samples from 41 patients were analyzed at 3 months of which 20 with a BCR-ABL1 transcript level > 10%. A KD mutation was found at 3 months in 4/41 patients (9.7%) all of whom progressed subsequently to advanced phase compared to only 3/37 in patients without mutation (p10%, while only one patient had a 3-months BCR-ABL transcript level In conclusion, ultra-deep NGS can reliably and consistently detect early appearance of KD mutation in patients who fail to achieve early molecular response at 3 months as well as in non responder patients or patients who are in CCyR but not in MMR, thus allowing potential early clinical intervention. Disclosures Best: Onconova Therapeutics Inc: Research Funding. Pocock:Janssen: Honoraria. McLornan:Novartis: Research Funding, Speakers Bureau. Mufti:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. de Lavallade:Ariad: Research Funding; Novartis: Consultancy.

A 55-year-old Caucasian male with cryptogenic cirrhosis of the liver and refractory ascites was referred for consideration of a liver transplant. There was no previous history of opportunistic infections and serological screening for human immunodeficiency virus (HIV), hepatitis B and hepatitis C was negative. Immunoglobulin levels were normal and autoantibodies and tumour markers were not detected. A computed tomography (CT) scan showed hepatomegaly with irregular hepatic architecture, established varices and marked portal enteropathy with splenomegaly and ascites but no nodal enlargement. Ascitic fluid cytology showed abundant atypical cells with hyperchromatic nuclei and many apoptotic cells (top left), macrophages and mesothelial cells. Immunophenotyping was undertaken on ascitic and pleural fluid and cells typed as mature T cells with no excess of blasts or clonally-restricted B cells. These cells expressed CD45, HLA-DR, CD38 and CD7 but no other B, T or myeloid markers. Immunohistochemistry of these cells failed because of background staining and poor preservation of cellular architecture. DNA was extracted from the ascitic fluid and gene rearrangement studies by multiplex polymerase chain reaction confirmed a monoclonal IGH@ rearrangement with a polyclonal T-cell receptor pattern. Peritoneal biopsy proved inconclusive but immunohistochemical analysis of a subsequent ascitic fluid sample showed pleomorphic lymphoid cells with plasmacytoid features, positive for CD38 (top right), CD30, epithelial membrane antigen (EMA) and MUM1/IRF4. There was strong nuclear expression of human herpesvirus 8 (HHV8) latent protein (LANA; bottom left) and Epstein–Barr virus-encoded RNA (EBER; bottom right) by in situ hybridization. A diagnosis of primary effusion lymphoma (PEL) was made. PEL is a rare large B-cell neoplasm and, in the absence of immune suppression, is particularly unusual. Confirmation of B-cell clonality by immunophenotyping may be difficult as PEL usually lacks cytoplasmic and surface immunoglobulin. CD45, HLA-DR, CD30, CD38, Vs38c, CD138 and EMA are often demonstrable. Pan-B markers may not be expressed and there may be aberrant expression of T-cell markers, making it difficult to assign lineage. Immunoglobulin genes are usually clonally rearranged, as in this case. The nuclei of the neoplastic cells are universally positive for HHV8 LANA and this is useful in establishing a diagnosis. If the cytological features are poorly preserved, histochemical staining may fail. The patient was treated with dose-attenuated cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) chemotherapy, but had a poor response and died within 6 months of presentation. Clinical outcomes remain poor for this disease although there are occasional reports of a response to immunomodulatory agents with chemotherapy.

Salmonella enterica uses effector proteins translocated by a Type III Secretion System to invade epithelial cells. One of the invasion-associated effectors, SopB, is an inositol phosphatase that mediates sustained activation of the pro-survival kinase Akt in infected cells. Canonical activation of Akt involves membrane translocation and phosphorylation and is dependent on phosphatidyl inositide 3 kinase (PI3K). Here we have investigated these two distinct processes in Salmonella infected HeLa cells. Firstly, we found that SopB-dependent membrane translocation and phosphorylation of Akt are insensitive to the PI3K inhibitor wortmannin. Similarly, depletion of the PI3K regulatory subunits p85α and p85ß by RNAi had no inhibitory effect on SopB-dependent Akt phosphorylation. Nevertheless, SopB-dependent phosphorylation does depend on the Akt kinases, PDK1 and rictor-mTOR. Membrane translocation assays revealed a dependence on SopB for Akt recruitment to Salmonella ruffles and suggest that this is mediated by phosphoinositide (3,4) P(2) rather than phosphoinositide (3,4,5) P(3). Altogether these data demonstrate that Salmonella activates Akt via a wortmannin insensitive mechanism that is likely a class I PI3K-independent process that incorporates some essential elements of the canonical pathway.

Objective: Our purpose was to investigate the relationship between fetal plasma erythropoietin concentration and measures of short-term and long-term glycemic control and fetal oxygenation in pregnancies complicated by maternal diabetes mellitus. Study Design: A cross-sectional study was performed at The Harris Birthright Research Centre for Fetal Medicine, London. Cordocentesis was performed in 31 diabetic pregnancies for the measurement of umbilical venous blood pH, Po 2 , Pco 2 , lactate and glucose concentration, erythroblast count, hemoglobin, and plasma erythropoietin concentrations. Results: The mean pH was significantly lower and the Pco 2 , lactate, erythropoietin, hemoglobin, and erythroblast counts were significantly higher than the appropriate normal mean for gestation. There were significant associations betwen (1) fetal erythropoietin and erythroblast count, (2) fetal erythroblast count and hemoglobin, (3) fetal hemoglobin and maternal glycosylated hemoglobin, and (4) maternal glucose and fetal glucose, pH, and lactate. Conclusions: We postulate that maternal hyperglycemia causes fetal hyperglycemia and acidemia. Increased erythropoietin may be caused by tissue hypoxia or hyperinsulinemia. The increase in fetal hemoglobin may be the consequence of increased erythropoiesis, mediated by either erythropoietin or hyperinsulinemia.

Protection against virulent pathogens that cause acute, fatal disease is often hampered by development of microbial resistance to traditional chemotherapeutics. Further, most successful pathogens possess an array of immune evasion strategies to avoid detection and elimination by the host. Development of novel, immunomodulatory prophylaxes that target the host immune system, rather than the invading microbe, could serve as effective alternatives to traditional chemotherapies. Here we describe the development and mechanism of a novel pan-anti-bacterial prophylaxis. Using cationic liposome non-coding DNA complexes (CLDC) mixed with crude F. tularensis membrane protein fractions (MPF), we demonstrate control of virulent F. tularensis infection in vitro and in vivo. CLDC+MPF inhibited bacterial replication in primary human and murine macrophages in vitro. Control of infection in macrophages was mediated by both reactive nitrogen species (RNS) and reactive oxygen species (ROS) in mouse cells, and ROS in human cells. Importantly, mice treated with CLDC+MPF 3 days prior to challenge survived lethal intranasal infection with virulent F. tularensis. Similarly to in vitro observations, in vivo protection was dependent on the presence of RNS and ROS. Lastly, CLDC+MPF was also effective at controlling infections with Yersinia pestis, Burkholderia pseudomallei and Brucella abortus. Thus, CLDC+MPF represents a novel prophylaxis to protect against multiple, highly virulent pathogens., Author Summary Conventional treatment of bacterial infections typically includes administration of antibiotics. However, many pathogens have developed spontaneous resistance to commonly used antibiotics. Development of new compounds that stimulate the host immune system to directly kill bacteria by mechanisms different from those utilized by antibiotics may serve as effective alternatives to antibiotic therapy. In this report, we describe a novel compound capable of controlling infections mediated by different, unrelated bacteria via the induction of host derived reactive oxygen and reactive nitrogen species. This compound is comprised of cationic liposome DNA complexes (CLDC) and crude membrane preparations (MPF) obtained from attenuated Francisella tularensis Live Vaccine Strain (LVS). Pretreatment of primary mouse or human cells limited replication of virulent F. tularensis, Burkholderia pseudomallei, Yersinia pestis and Brucella abortus in vitro. CLDC+MPF was also effective for controlling lethal pulmonary infections with virulent F. tularensis. Thus, CLDC+MPF represents a novel antimicrobial for treatment of lethal, acute, bacterial infections.

Relatively little is understood about the dynamics of global host–pathogen transcriptome changes that occur during bacterial infection of mucosal surfaces. To test the hypothesis that group A Streptococcus (GAS) infection of the oropharynx provokes a distinct host transcriptome response, we performed genome-wide transcriptome analysis using a nonhuman primate model of experimental pharyngitis. We also identified host and pathogen biological processes and individual host and pathogen gene pairs with correlated patterns of expression, suggesting interaction. For this study, 509 host genes and seven biological pathways were differentially expressed throughout the entire 32-day infection cycle. GAS infection produced an initial widespread significant decrease in expression of many host genes, including those involved in cytokine production, vesicle formation, metabolism, and signal transduction. This repression lasted until day 4, at which time a large increase in expression of host genes was observed, including those involved in protein translation, antigen presentation, and GTP-mediated signaling. The interactome analysis identified 73 host and pathogen gene pairs with correlated expression levels. We discovered significant correlations between transcripts of GAS genes involved in hyaluronic capsule production and host endocytic vesicle formation, GAS GTPases and host fibrinolytic genes, and GAS response to interaction with neutrophils. We also identified a strong signal, suggesting interaction between host γδ T cells and genes in the GAS mevalonic acid synthesis pathway responsible for production of isopentenyl-pyrophosphate, a short-chain phospholipid that stimulates these T cells. Taken together, our results are unique in providing a comprehensive understanding of the host–pathogen interactome during mucosal infection by a bacterial pathogen.

Haematopoietic SCT (HSCT) offers the only potentially curative option in chronic myelomonocytic leukaemia (CMML). In this study, we report on single-centre results of 18 patients with CMML who have undergone allogeneic HSCT. The median age of patients was 54 years. Seven patients had AML, which had transformed from CMML. Overall, 11 patients received stem cells from an unrelated donor. A total of 15 patients received a T-cell-depleted fludarabine/BU-based reduced-intensity conditioning HSCT. The actuarial 3-year OS, non-relapse mortality (NRM) and relapse incidence for the cohort was 31±11%, 31±14% and 47±13%, respectively. Patients with favourable cytogenetics had a 3-year disease-free survival of 65±17%, whereas none of the seven patients with intermediate or poor risk cytogenetics survived beyond 2 years (P0.01). No patients with favourable risk cytogenetics died from NRM causes, while the 2-year NRM for the intermediate/poor risk cytogenetics subgroup was 71±22% (P0.02). In terms of disease status at transplantation, patients who had5% BM blasts had a 3-year disease-free survival of 46.9±19% compared with those with5% blasts at the time of transplantation (that is, 20.0±13%). Recipient age, type of conditioning regimen or stem cell dose did not have a significant impact on overall outcomes. Our data support existing evidence that allogeneic HSCT is a feasible therapeutic option for CMML, with the ability to attain long-term remission among patient subgroups.

The Salmonella type III effector, SopB, is an inositol polyphosphate phosphatase that modulates host cell phospholipids at the plasma membrane and the nascent Salmonella-containing vacuole (SCV). Translocated SopB persists for many hours after infection and is ubiquitinated but the significance of this covalent modification has not been investigated. Here we identify by mass spectrometry six lysine residues of SopB that are mono-ubiquitinated. Substitution of these six lysine residues with arginine, SopB-K(6)R, almost completely eliminated SopB ubiquitination. We found that ubiquitination does not affect SopB stability or membrane association, or SopB-dependent events in SCV biogenesis. However, two spatially and temporally distinct events are dependent on ubiquitination, downregulation of SopB activity at the plasma membrane and prolonged retention of SopB on the SCV. Activation of the mammalian pro-survival kinase Akt/PKB, a downstream target of SopB, was intensified and prolonged after infection with the SopB-K(6)R mutant. At later times, fewer SCV were decorated with SopB-K(6)R compared with SopB. Instead SopB-K(6)R was present as discrete vesicles spread diffusely throughout the cell. Altogether, our data show that ubiquitination of SopB is not related to its intracellular stability but rather regulates its enzymatic activity at the plasma membrane and intracellular localization.