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•Largest and most diverse genetic study of plasma fibrinogen identifies 54 regions (18 novel), housing 69 distinct variants (20 novel).•Links to (1) liver enzyme, blood cell, and lipid genetic signals, (2) liver regulatory elements, and (3) thrombotic and inflammatory disease.

The current standard of care for moderate to severe ischemic stroke is thrombolytic therapy with tissue plasminogen activator (tPA). Treatment with tPA can significantly improve neurologic outcomes; however, thrombolytic therapy is associated with an increased risk of intracerebral hemorrhage (ICH). The risk of hemorrhage significantly limits the use of thrombolytic therapy, and identifying pathways induced by tPA that increase this risk could provide new therapeutic options to extend thrombolytic therapy to a wider patient population. Here, we investigate the role of protein kinase Cβ (PKCβ) phosphorylation of the tight junction protein occludin during ischemic stroke and its role in cerebrovascular permeability. We show that activation of this pathway by tPA is associated with an increased risk of ICH. Middle cerebral artery occlusion (MCAO) increased phosphorylation of occludin serine 490 (S490) in the ischemic penumbra in a tPA-dependent manner, as tPA−/− mice were significantly protected from MCAO-induced occludin phosphorylation. Intraventricular injection of tPA in the absence of ischemia was sufficient to induce occludin phosphorylation and vascular permeability in a PKCβ-dependent manner. Blocking occludin phosphorylation, either by targeted expression of a non-phosphorylatable form of occludin (S490A) or by pharmacologic inhibition of PKCβ, reduced MCAO-induced permeability and improved functional outcome. Furthermore, inhibiting PKCβ after MCAO prevented ICH associated with delayed thrombolysis. These results show that PKCβ phosphorylation of occludin is a downstream mediator of tPA-induced cerebrovascular permeability and suggest that PKCβ inhibitors could improve stroke outcome and prevent ICH associated with delayed thrombolysis, potentially extending the window for thrombolytic therapy in stroke.

•We present updated diagnostic criteria for FHL including revised clinical criteria and guidelines on genetic and cellular diagnostic assays.•HLH-2004 criteria (without NK-cell function) have significant validity (accuracy 99%) tested against infections and systemic inflammation.

The current standard of care for moderate to severe ischemic stroke is thrombolytic therapy with tissue plasminogen activator (tPA). Treatment with tPA can significantly improve neurological outcomes; however, thrombolytic therapy is associated with an increased risk of intracerebral hemorrhage (ICH). The risk of hemorrhage significantly limits the use of thrombolytic therapy and identifying pathways induced by tPA that increase this risk could provide new therapeutic options to extend thrombolytic therapy to a wider patient population. Here, we investigate the role of protein kinase (PK)Cβ phosphorylation of the tight junction protein occludin during ischemic stroke and its role in cerebrovascular permeability. We demonstrate that activation of this pathway by tPA is associated with an increased risk of ICH. Middle cerebral artery occlusion (MCAO) increased occludin serine 490 (S490) phosphorylation in the ischemic penumbra in a tPA-dependent manner, as tPA-/-mice were significantly protected from MCAO-induced occludin phosphorylation. Intra-ventricular injection of tPA in the absence of ischemia was sufficient to induce occludin phosphorylation and vascular permeability in a PKCβ-dependent manner. Blocking occludin phosphorylation either by targeted expression of a non-phosphorylatable form of occludin (S490A) or by pharmacologic inhibition of PKCβ, reduced MCAO-induced permeability and improved functional outcome. Further, inhibiting PKCβ after MCAO prevented ICH associated with delayed thrombolysis. These results reveal that PKCβ phosphorylation of occludin is a downstream mediator of tPA-induced cerebrovascular permeability and suggest that PKCβ inhibitors could improve stroke outcome and prevent ICH associated with delayed thrombolysis, potentially extending the window for thrombolytic therapy in stroke.

Myelodysplastic neoplasms (MDS) are characterized by ineffective hematopoiesis, peripheral cytopenia, and a risk of transforming into acute myeloid leukemia (AML). Interestingly, MDS is also associated with an increased prevalence of osteoporosis. Studies have suggested that dysregulated innate immune responses and a proinflammatory bone marrow (BM) microenvironment play significant roles in the pathogenesis of MDS. Targeting inflammatory pathways, especially in low-risk MDS patients, presents a potential strategy to modulate the progression of the disease. One such candidate is Tasquinimod (TASQ, ABR-215050, Active Biotech AB), a small-molecule oral inhibitor and second-generation quinoline-3-carboxamide compound. TASQ binds to the inflammatory protein S100A9 and inhibits its interaction with the proinflammatory toll-like receptor 4, thereby displaying both immunomodulatory and antitumor properties. Our in vitrodata provided evidence for a rescuing effect of TASQ on inflammatory signal-primed MDS stromal cells, leading to enhanced hematopoietic support.

Introduction: The documented treatment-induced excess mortality in Hodgkin lymphoma (HL) has led to significant changes in treatment regimens aimed at maintaining efficacy while reducing toxicity. These modifications include the replacement of alkylator-based regimens with anthracycline-based combinations and the adoption of highly conformal radiotherapy. Danish and Nordic radiation oncologists were pioneers in implementing these changes nationwide 10-15 years earlier than most other nations. These early adaptations make Danish HL data uniquely valuable for assessing long-term mortality in a cohort where modern treatment regimens have been implemented nationwide throughout the entire study period. The impact of these treatment modifications on mortality risk in HL survivors remains unclear, therefore, this study aims to assess cause-specific mortality among HL patients treated with contemporary strategies.

Many hemostatic factors are associated with age and age-related diseases; however, much remains unknown about the biological mechanisms linking aging and hemostatic factors. DNA methylation is a novel means by which to assess epigenetic aging, which is a measure of age and the aging processes as determined by altered epigenetic states. We used a meta-analysis approach to examine the association between measures of epigenetic aging and hemostatic factors, as well as a clotting time measure. For fibrinogen, we performed European and African ancestry–specific meta-analyses which were then combined via a random effects meta-analysis. For all other measures we could not estimate ancestry-specific effects and used a single fixed effects meta-analysis. We found that 1-year higher extrinsic epigenetic age as compared with chronological age was associated with higher fibrinogen (0.004 g/L/y; 95% confidence interval, 0.001-0.007; P = .01) and plasminogen activator inhibitor 1 (PAI-1; 0.13 U/mL/y; 95% confidence interval, 0.07-0.20; P = 6.6 × 10−5) concentrations, as well as lower activated partial thromboplastin time, a measure of clotting time. We replicated PAI-1 associations using an independent cohort. To further elucidate potential functional mechanisms, we associated epigenetic aging with expression levels of the PAI-1 protein encoding gene (SERPINE1) and the 3 fibrinogen subunit-encoding genes (FGA, FGG, and FGB) in both peripheral blood and aorta intima-media samples. We observed associations between accelerated epigenetic aging and transcription of FGG in both tissues. Collectively, our results indicate that accelerated epigenetic aging is associated with a procoagulation hemostatic profile, and that epigenetic aging may regulate hemostasis in part via gene transcription.

Hypomorphic RAG1 mutations allowing residual T- and B-cell development have been found in patients presenting with delayed-onset combined immune deficiency with granulomas and/or autoimmunity (CID-G/AI) and abnormalities of the peripheral T- and B-cell repertoire. To examine how hypomorphic Rag1 mutations affect the earliest stages of lymphocyte development, we used CRISPR/Cas9 to generate mouse models with mutations equivalent to those found in patients with CID-G/AI. Immunological characterization showed partial development of T and B lymphocytes, with persistence of naïve cells and preserved serum immunoglobulin but impaired antibody responses and presence of autoantibodies, thereby recapitulating the phenotype seen in patients with CID-G/AI. By using high-throughput sequencing, we identified marked skewing of Igh V and Trb V gene usage in early progenitors, with a bias for productive Igh and Trb rearrangements after selection occurred and increased apoptosis of B-cell progenitors. Rearrangement at the Igk locus was impaired, and polyreactive immunoglobulin M antibodies were detected. This study provides novel insights into how hypomorphic Rag1 mutations alter the primary repertoire of T and B cells, setting the stage for immune dysregulation frequently seen in patients.

Hypomorphic RAG1mutations allowing residual T- and B-cell development have been found in patients presenting with delayed-onset combined immune deficiency with granulomas and/or autoimmunity (CID-G/AI) and abnormalities of the peripheral T- and B-cell repertoire. To examine how hypomorphic Rag1mutations affect the earliest stages of lymphocyte development, we used CRISPR/Cas9 to generate mouse models with mutations equivalent to those found in patients with CID-G/AI. Immunological characterization showed partial development of T and B lymphocytes, with persistence of naïve cells and preserved serum immunoglobulin but impaired antibody responses and presence of autoantibodies, thereby recapitulating the phenotype seen in patients with CID-G/AI. By using high-throughput sequencing, we identified marked skewing of Igh Vand Trb Vgene usage in early progenitors, with a bias for productive Ighand Trbrearrangements after selection occurred and increased apoptosis of B-cell progenitors. Rearrangement at the Igklocus was impaired, and polyreactive immunoglobulin M antibodies were detected. This study provides novel insights into how hypomorphic Rag1mutations alter the primary repertoire of T and B cells, setting the stage for immune dysregulation frequently seen in patients.

We conducted a genome-wide association study (GWAS) to identify novel predisposition alleles associated with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and JAK2 V617F clonal hematopoiesis in the general population. We recruited a web-based cohort of 726 individuals with polycythemia vera, essential thrombocythemia, and myelofibrosis and 252 637 population controls unselected for hematologic phenotypes. Using a single-nucleotide polymorphism (SNP) array platform with custom probes for the JAK2 V617F mutation (V617F), we identified 497 individuals (0.2%) among the population controls who were V617F carriers. We performed a combined GWAS of the MPN cases plus V617F carriers in the control population (n = 1223) vs the remaining controls who were noncarriers for V617F (n = 252 140). For these MPN cases plus V617F carriers, we replicated the germ line JAK2 46/1 haplotype (rs59384377: odds ratio [OR] = 2.4, P = 6.6 × 10−89), previously associated with V617F-positive MPN. We also identified genome-wide significant associations in the TERT gene (rs7705526: OR = 1.8, P = 1.1 × 10−32), in SH2B3 (rs7310615: OR = 1.4, P = 3.1 × 10−14), and upstream of TET2 (rs1548483: OR = 2.0, P = 2.0 × 10−9). These associations were confirmed in a separate replication cohort of 446 V617F carriers vs 169 021 noncarriers. In a joint analysis of the combined GWAS and replication results, we identified additional genome-wide significant predisposition alleles associated with CHEK2, ATM, PINT, and GFI1B. All SNP ORs were similar for MPN patients and controls who were V617F carriers. These data indicate that the same germ line variants endow individuals with a predisposition not only to MPN, but also to JAK2 V617F clonal hematopoiesis, a more common phenomenon that may foreshadow the development of an overt neoplasm.

We conducted a genome-wide association study (GWAS) to identify novel predisposition alleles associated with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and JAK2V617F clonal hematopoiesis in the general population. We recruited a web-based cohort of 726 individuals with polycythemia vera, essential thrombocythemia, and myelofibrosis and 252 637 population controls unselected for hematologic phenotypes. Using a single-nucleotide polymorphism (SNP) array platform with custom probes for the JAK2V617F mutation (V617F), we identified 497 individuals (0.2%) among the population controls who were V617F carriers. We performed a combined GWAS of the MPN cases plus V617F carriers in the control population (n = 1223) vs the remaining controls who were noncarriers for V617F (n = 252 140). For these MPN cases plus V617F carriers, we replicated the germ line JAK246/1 haplotype (rs59384377: odds ratio [OR] = 2.4, P= 6.6 × 10−89), previously associated with V617F-positive MPN. We also identified genome-wide significant associations in the TERTgene (rs7705526: OR = 1.8, P= 1.1 × 10−32), in SH2B3(rs7310615: OR = 1.4, P= 3.1 × 10−14), and upstream of TET2(rs1548483: OR = 2.0, P= 2.0 × 10−9). These associations were confirmed in a separate replication cohort of 446 V617F carriers vs 169 021 noncarriers. In a joint analysis of the combined GWAS and replication results, we identified additional genome-wide significant predisposition alleles associated with CHEK2, ATM, PINT, and GFI1B. All SNP ORs were similar for MPN patients and controls who were V617F carriers. These data indicate that the same germ line variants endow individuals with a predisposition not only to MPN, but also to JAK2V617F clonal hematopoiesis, a more common phenomenon that may foreshadow the development of an overt neoplasm.

Clinical management guidelines on malignant disorders are generally based on data from clinical trials with selected patient cohorts. In Sweden, more than 95% of all patients diagnosed with chronic myeloid leukemia (CML) are reported to the national CML registry, providing unique possibilities to compile population-based information. This report is based on registry data from 2002 to 2010, when a total of 779 patients (425 men, 354 women; median age, 60 years) were diagnosed with CML (93% chronic, 5% accelerated, and 2% blastic phase) corresponding to an annual incidence of 0.9/100 000. In 2002, approximately half of the patients received a tyrosine kinase inhibitor as initial therapy, a proportion that increased to 94% for younger (<70 years) and 79% for older (>80 years) patients during 2007-2009. With a median follow-up of 61 months, the relative survival at 5 years was close to 1.0 for patients younger than 60 years and 0.9 for those aged 60 to 80 years, but only 0.6 for those older than 80 years. At 12 months, 3% had progressed to accelerated or blastic phase. Sokal, but not European Treatment and Outcome Study, high-risk scores were significantly linked to inferior overall and relative survival. Patients living in university vs nonuniversity catchment areas more often received tyrosine kinase inhibitors up front but showed comparable survival.

We conducted a genome-wide association study to identify novel associations between genetic variants and circulating plasminogen activator inhibitor-1 (PAI-1) concentration, and examined functional implications of variants and genes that were discovered. A discovery meta-analysis was performed in 19 599 subjects, followed by replication analysis of genome-wide significant (P< 5 × 10−8) single nucleotide polymorphisms (SNPs) in 10 796 independent samples. We further examined associations with type 2 diabetes and coronary artery disease, assessed the functional significance of the SNPs for gene expression in human tissues, and conducted RNA-silencing experiments for one novel association. We confirmed the association of the 4G/5G proxy SNP rs2227631 in the promoter region of SERPINE1(7q22.1) and discovered genome-wide significant associations at 3 additional loci: chromosome 7q22.1 close to SERPINE1(rs6976053, discovery P= 3.4 × 10−10); chromosome 11p15.2 within ARNTL(rs6486122, discovery P= 3.0 × 10−8); and chromosome 3p25.2 within PPARG(rs11128603, discovery P= 2.9 × 10−8). Replication was achieved for the 7q22.1 and 11p15.2 loci. There was nominal association with type 2 diabetes and coronary artery disease at ARNTL(P< .05). Functional studies identified MUC3as a candidate gene for the second association signal on 7q22.1. In summary, SNPs in SERPINE1and ARNTLand an SNP associated with the expression of MUC3were robustly associated with circulating levels of PAI-1.

Sema4D, also known as CD100, is a constitutively expressed immune semaphorin on T cells and NK cells. CD100 has important immune regulatory functions that improve antigen-specific priming by antigen-presenting cells, and can also act as a costimulatory molecule on T cells. We investigated the consequence of HIV-1 infection on CD100 expression by T cells, and whether CD100 expression signifies functionally competent effector cells. CD100 expression on T cells from healthy individuals was compared with HIV-1–infected subjects including elite controllers, noncontrollers, and patients receiving antiretroviral therapy. The frequency and fluorescence intensity of CD100 on CD8+ and CD4+ T cells were decreased during HIV-1 infection. Furthermore, the absolute number of CD100-expressing CD8+ T cells was positively associated with the magnitude of HIV-1–specific T-cell responses. CD8+ T cells lacking CD100 expression were functionally impaired and present in increased numbers in HIV-1–infected individuals. The number of CD100−CD8+ T cells positively correlated with T-cell immunosenescence, immune activation, and viral load. Loss of CD100 expression appears to result from direct antigen stimulation, as in vitro cytokine exposure and viral replication did not significantly impact CD100 expression. These data suggest that loss of CD100 expression probably plays an important role in dysfunctional immunity in HIV-1 infection.

Sema4D, also known as CD100, is a constitutively expressed immune semaphorin on T cells and NK cells. CD100 has important immune regulatory functions that improve antigen-specific priming by antigen-presenting cells, and can also act as a costimulatory molecule on T cells. We investigated the consequence of HIV-1 infection on CD100 expression by T cells, and whether CD100 expression signifies functionally competent effector cells. CD100 expression on T cells from healthy individuals was compared with HIV-1–infected subjects including elite controllers, noncontrollers, and patients receiving antiretroviral therapy. The frequency and fluorescence intensity of CD100 on CD8+and CD4+T cells were decreased during HIV-1 infection. Furthermore, the absolute number of CD100-expressing CD8+T cells was positively associated with the magnitude of HIV-1–specific T-cell responses. CD8+T cells lacking CD100 expression were functionally impaired and present in increased numbers in HIV-1–infected individuals. The number of CD100−CD8+T cells positively correlated with T-cell immunosenescence, immune activation, and viral load. Loss of CD100 expression appears to result from direct antigen stimulation, as in vitro cytokine exposure and viral replication did not significantly impact CD100 expression. These data suggest that loss of CD100 expression probably plays an important role in dysfunctional immunity in HIV-1 infection.

Biologic and clinical observations suggest that combining imatinib with IFN-α may improve treatment outcome in chronic myeloid leukemia (CML). We randomized newly diagnosed chronic-phase CML patients with a low or intermediate Sokal risk score and in imatinib-induced complete hematologic remission either to receive a combination of pegylated IFN-α2b (Peg–IFN-α2b) 50 μg weekly and imatinib 400 mg daily (n = 56) or to receive imatinib 400 mg daily monotherapy (n = 56). The primary endpoint was the major molecular response (MMR) rate at 12 months after randomization. In both arms, 4 patients (7%) discontinued imatinib treatment (1 because of blastic transformation in imatinib arm). In addition, in the combination arm, 34 patients (61%) discontinued Peg–IFN-α2b, most because of toxicity. The MMR rate at 12 months was significantly higher in the imatinib plus Peg–IFN-α2b arm (82%) compared with the imatinib monotherapy arm (54%; intention-to-treat, P= .002). The MMR rate increased with the duration of Peg–IFN-α2b treatment (< 12-week MMR rate 67%, > 12-week MMR rate 91%). Thus, the addition of even relatively short periods of Peg–IFN-α2b to imatinib markedly increased the MMR rate at 12 months of therapy. Lower doses of Peg–IFN-α2b may enhance tolerability while retaining efficacy and could be considered in future protocols with curative intent.

Warfarin-dosing algorithms incorporating CYP2C9 and VKORC1 −1639G>A improve dose prediction compared with algorithms based solely on clinical and demographic factors. However, these algorithms better capture dose variability among whites than Asians or blacks. Herein, we evaluate whether other VKORC1 polymorphisms and haplotypes explain additional variation in warfarin dose beyond that explained by VKORC1 −1639G>A among Asians (n = 1103), blacks (n = 670), and whites (n = 3113). Participants were recruited from 11 countries as part of the International Warfarin Pharmacogenetics Consortium effort. Evaluation of the effects of individual VKORC1 single nucleotide polymorphisms (SNPs) and haplotypes on warfarin dose used both univariate and multi variable linear regression. VKORC1 −1639G>A and 1173C>T individually explained the greatest variance in dose in all 3 racial groups. Incorporation of additional VKORC1 SNPs or haplotypes did not further improve dose prediction. VKORC1 explained greater variability in dose among whites than blacks and Asians. Differences in the percentage of variance in dose explained by VKORC1 across race were largely accounted for by the frequency of the −1639A (or 1173T) allele. Thus, clinicians should recognize that, although at a population level, the contribution of VKORC1 toward dose requirements is higher in whites than in nonwhites; genotype predicts similar dose requirements across racial groups.

Warfarin-dosing algorithms incorporating CYP2C9and VKORC1−1639G>A improve dose prediction compared with algorithms based solely on clinical and demographic factors. However, these algorithms better capture dose variability among whites than Asians or blacks. Herein, we evaluate whether other VKORC1polymorphisms and haplotypes explain additional variation in warfarin dose beyond that explained by VKORC1−1639G>A among Asians (n = 1103), blacks (n = 670), and whites (n = 3113). Participants were recruited from 11 countries as part of the International Warfarin Pharmacogenetics Consortium effort. Evaluation of the effects of individual VKORC1single nucleotide polymorphisms (SNPs) and haplotypes on warfarin dose used both univariate and multi variable linear regression. VKORC1−1639G>A and 1173C>T individually explained the greatest variance in dose in all 3 racial groups. Incorporation of additional VKORC1SNPs or haplotypes did not further improve dose prediction. VKORC1explained greater variability in dose among whites than blacks and Asians. Differences in the percentage of variance in dose explained by VKORC1across race were largely accounted for by the frequency of the −1639A (or 1173T) allele. Thus, clinicians should recognize that, although at a population level, the contribution of VKORC1toward dose requirements is higher in whites than in nonwhites; genotype predicts similar dose requirements across racial groups.

Mantle cell lymphoma (MCL) has a heterogeneous clinical course. The recently proposed Mantle Cell Lymphoma International Prognostic Index (MIPI) predicted the survival of MCL better than the International Prognostic Index in MCL patients treated with conventional chemotherapy, but its validity in MCL treated with more intensive immunochemotherapy has been questioned. Applied here to 158 patients of the Nordic MCL2 trial of first-line intensive immunochemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation, the MIPI and the simplified MIPI (s-MIPI) predicted survival significantly better (P < .001) than the International Prognostic Index (P > .004). Both the MIPI and the s-MIPI mainly identified 2 risk groups, low and intermediate versus high risk, with the more easily applied s-MIPI being just as powerful as the MIPI. The MIPIB (biological), incorporating Ki-67 expression, identified almost half of the patients as high risk. We suggest that also a simplified MIPIB is feasible. This trial was registered at www.isrctn.org as #ISRCTN 87866680.

Genetic variants of cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase (VKORC1) are known to influence warfarin dose, but the effect of other genes has not been fully elucidated. We genotyped 183 polymorphisms in 29 candidate genes in 1496 Swedish patients starting warfarin treatment, and tested for association with response. CYP2C9*2 and *3 explained 12% (P = 6.63 × 10−34) of the variation in warfarin dose, while a single VKORC1 SNP explained 30% (P = 9.82 × 10−100). No SNP outside the CYP2C gene cluster and VKORC1 regions was significantly associated with dose after correction for multiple testing. During initiation of therapy, homozygosity for CYP2C9 and VKORC1 variant alleles increased the risk of over-anticoagulation, hazard ratios 21.84 (95% CI 9.46; 50.42) and 4.56 (95% CI 2.85; 7.30), respectively. One of 8 patients with CYP2C9*3/*3 (12.5%) experienced severe bleeding during the first month compared with 0.27% of other patients (P = .066). A multiple regression model using the predictors CYP2C9, VKORC1, age, sex, and druginteractions explained 59% of the variance in warfarin dose, and 53% in an independent sample of 181 Swedish individuals. In conclusion, CYP2C9 and VKORC1 significantly influenced warfarin dose and predicted individuals predisposed to unstable anticoagulation. Our results strongly support that initiation of warfarin guided by pharmacogenetics would improve clinical outcome.

Mantle cell lymphoma (MCL) is considered incurable. Intensive immunochemotherapy with stem cell support has not been tested in large, prospective series. In the 2nd Nordic MCL trial, we treated 160 consecutive, untreated patients younger than 66 years in a phase 2 protocol with dose-intensified induction immunochemotherapy with rituximab (R) + cyclophosphamide, vincristine, doxorubicin, prednisone (maxi-CHOP), alternating with R + high-dose cytarabine. Responders received high-dose chemotherapy with BEAM or BEAC (carmustine, etoposide, cytarabine, and melphalan/cyclophosphamide) with R-in vivo purged autologous stem cell support. Overall and complete response was achieved in 96% and 54%, respectively. The 6-year overall, event-free, and progression-free survival were 70%, 56%, and 66%, respectively, with no relapses occurring after 5 years. Multivariate analysis showed Ki-67 to be the sole independent predictor of event-free survival. The nonrelapse mortality was 5%. The majority of stem cell products and patients assessed with polymerase chain reaction (PCR) after transplantation were negative. Compared with our historical control, the Nordic MCL-1 trial, the event-free, overall, and progression-free survival, the duration of molecular remission, and the proportion of PCR-negative stem cell products were significantly increased (P < .001). Intensive immunochemotherapy with in vivo purged stem cell support can lead to long-term progression-free survival of MCL and perhaps cure. Registered at www.isrctn.org as #ISRCTN 87866680.

The leukocyte response in inflammation is characterized by an initial recruitment of polymorphonuclear leukocytes (PMN) preceding a second wave of monocytes to the site of injury or infection. In the mouse, 2 populations of monocytes have been identified, Gr1−CCR2−CX3CR1hi resident monocytes and Gr1+CCR2+CX3CR1lo inflammatory monocytes. Here, intravital microscopy of the musculus cremaster and a subcutaneous air pouch model were used to investigate a possible link between PMN extravasation and the subsequent emigration of inflammatory monocytes in response to local stimulation with PAF. In mice that were made neutropenic by injection of a PMN-depleting antibody, the extravasation of inflammatory monocytes, but not resident monocytes, was markedly reduced compared with mice with intact white blood cell count but was restored by local treatment with secretion of activated PMN. Components of the PMN secretion were found to directly activate inflammatory monocytes and further examination revealed PMN-derived LL-37 and heparin-binding protein (HBP/CAP37/azurocidin) as primary mediators of the recruitment of inflammatory monocytes via activation of formyl-peptide receptors. These data show that LL-37 and HBP specifically stimulate mobilization of inflammatory monocytes. This cellular cross-talk functionally results in enhanced cytokine levels and increased bacterial clearance, thus boosting the early immune response.

Vogl: Active Biotech: Consultancy, Research Funding; Janssen: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Oncopeptides: Consultancy; MorphoSys: Consultancy. Nefedova:Active Biotech: Consultancy, Research Funding. Bondesson:Active Biotech: Current Employment. Eriksson:Active Biotech: Current Employment. Tuvesson:Active Biotech: Current Employment.Tasquinimod for multiple myeloma

No relevant conflicts of interest to declare.

Heparin-induced thrombocytopenia (HIT) is caused by platelet-activating IgG antibodies that recognize platelet factor 4 (PF4) bound to heparin. Immunogenicity of heparins differs in that unfractionated heparin (UFH) induces more anti–PF4/heparin antibodies than low-molecular-weight heparin (LMWH) and UFH also causes more HIT. Fondaparinux, a synthetic anticoagulant modeled after the antithrombin-binding pentasaccharide, is believed to be nonimmunogenic. We tested 2726 patients for anti–PF4/heparin antibodies after they were randomized to receive antithrombotic prophylaxis with fondaparinux or LMWH (enoxaparin) following hip or knee surgery. We also evaluated in vitro cross-reactivity of the IgG antibodies generated against PF4 in the presence of UFH, LMWH, danaparoid, or fondaparinux. We found that anti–PF4/heparin antibodies were generated at similar frequencies in patients treated with fondaparinux or enoxaparin. Although antibodies reacted equally well in vitro against PF4/UFH and PF4/LMWH, and sometimes weakly against PF4/danaparoid, none reacted against PF4/fondaparinux, including even those sera obtained from patients who formed antibodies during fondaparinux treatment. At high concentrations, however, fondaparinux inhibited binding of HIT antibodies to PF4/polysaccharide, indicating that PF4/fondaparinux interactions occur. No patient developed HIT. We conclude that despite similar immunogenicity of fondaparinux and LMWH, PF4/fondaparinux, but not PF4/LMWH, is recognized poorly by the antibodies generated, suggesting that the risk of HIT with fondaparinux likely is very low.

Platelet-derived growth factor-D (PDGF-D) is a recently characterized member of the PDGF family with unknown in vivo functions. We investigated the effects of PDGF-D in transgenic mice by expressing it in basal epidermal cells and then analyzed skin histology, interstitial fluid pressure, and wound healing. When compared with control mice, PDGF-D transgenic mice displayed increased numbers of macrophages and elevated interstitial fluid pressure in the dermis. Wound healing in the transgenic mice was characterized by increased cell density and enhanced recruitment of macrophages. Macrophage recruitment was also the characteristic response when PDGF-D was expressed in skeletal muscle or ear by an adeno-associated virus vector. Combined expression of PDGF-D with vascular endothelial growth factor-E (VEGF-E) led to increased pericyte/smooth muscle cell coating of the VEGF-E–induced vessels and inhibition of the vascular leakiness that accompanies VEGF-E–induced angiogenesis. These results show that full-length PDGF-D is activated in tissues and is capable of increasing interstitial fluid pressure and macrophage recruitment and the maturation of blood vessels in angiogenic processes.

The immunoglobulin variable heavy chain (IgVH) gene mutation status is an important prognostic factor in chronic lymphocytic leukemia (CLL), since cases with mutated VH genes show significantly longer survival than unmutated cases. Recently, we reported a preferential use of the VH3-21 gene in mutated CLL and showed that mutated VH3-21 cases had an inferior overall survival compared with other mutated CLL. In order to further characterize this subset, we performed VH gene analysis in 265 CLL cases and identified 31 VH3-21 cases (11.7%); 21 cases had mutated and 10 cases unmutated VH genes. Regardless of VH gene mutation status, a poor overall survival was found in the VH3-21 cases with a median survival of 83 months. These survival data confirm that VH3-21 cases do not fit into the general prognostic grouping of mutated and unmutated CLL. A large fraction of VH3-21 cases also demonstrated unique features with shorter lengths of the third complementarity determining region (CDR3) and CDR3s with highly homologous amino acid sequences. Furthermore, the VH3-21 cases showed a striking dominance of λ light chain expression, and analysis of the Igλ gene rearrangements revealed highly restricted use of the Vλ2-14/Jλ3 genes in the majority of cases. Taken together, our new findings strengthen the suggestion that VH3-21–using cases comprise a new CLL entity, irrespective of VH gene mutation status, and implicate that a common antigen epitope, perhaps of pathogenic significance, is recognized by the highly homologous VH3-21/Vλ2-14 Ig molecules expressed in individual tumors.

Mantle cell lymphoma (MCL) is believed to originate from a naive B cell. However, we recently demonstrated that a subset of MCL displayed mutated VHgenes. We also reported restricted use of certain VHgenes. To assess the prognostic impact of these new findings, we performed VHgene analysis of 110 patients, revealing that 18 (16%) patients had mutated and 92 (84%) patients had unmutated VHgenes. Because the mutation rate was low in the mutated group (2.2%-6.7%), further investigation of the germline VHgene in T cells from 5 patients with mutated VHgenes was carried out; results showed that the unrearranged VHgene was identical to the published sequence. These data confirm that the base pair substitutions within the rearranged VHgenes represent hypermutations, and indicate germinal center exposure. However, VHgene mutation status did not correlate with prognosis because there was no difference in clinical outcome between the unmutated and mutated groups. The most frequently used VHgenes were VH3-21 (21 patients) and VH4-34 (19 patients). A novel finding was that VH3-21+MCL almost exclusively expressed λ light chains and displayed highly restricted use of the Vλ3-19 gene. VH3-21+patients had longer median survival than the remaining patients (53 vs 34 months; P= .03), but they tended to be younger at diagnosis. The combined use of VH3-21/Vλ3-19 suggests a possible role for antigen(s) in the pathogenesis of these tumors and indicates that VH3-21+patients constitute a new MCL entity.

Mantle cell lymphoma (MCL) is believed to originate from a naive B cell. However, we recently demonstrated that a subset of MCL displayed mutated VH genes. We also reported restricted use of certain VH genes. To assess the prognostic impact of these new findings, we performed VH gene analysis of 110 patients, revealing that 18 (16%) patients had mutated and 92 (84%) patients had unmutated VH genes. Because the mutation rate was low in the mutated group (2.2%-6.7%), further investigation of the germline VH gene in T cells from 5 patients with mutated VH genes was carried out; results showed that the unrearranged VH gene was identical to the published sequence. These data confirm that the base pair substitutions within the rearranged VH genes represent hypermutations, and indicate germinal center exposure. However, VH gene mutation status did not correlate with prognosis because there was no difference in clinical outcome between the unmutated and mutated groups. The most frequently used VH genes were VH3-21 (21 patients) and VH4-34 (19 patients). A novel finding was that VH3-21+ MCL almost exclusively expressed λ light chains and displayed highly restricted use of the Vλ3-19 gene. VH3-21+patients had longer median survival than the remaining patients (53 vs 34 months; P = .03), but they tended to be younger at diagnosis. The combined use of VH3-21/Vλ3-19 suggests a possible role for antigen(s) in the pathogenesis of these tumors and indicates that VH3-21+ patients constitute a new MCL entity.

After myeloablative treatment and allogeneic stem cell transplantation (SCT), patients are kept in isolation rooms in the hospital to prevent neutropenic infections. During a 3-year period, patients were given the option of treatment at home after SCT. Daily visits by an experienced nurse and daily phone calls from a physician from the unit were included in the protocol. We compared 36 patients who wished to be treated at home with 18 patients who chose hospital care (control group 1). A matched control group of 36 patients treated in the hospital served as control group 2. All home care patients had hematologic malignancies and 19 were in first remission or first chronic phase. Of the donors, 25 were unrelated. The patients spent a median of 16 days at home (range, 0-26 days). Before discharge to the outpatient clinic after SCT, patients spent a median of 4 days (range, 0-39 days) in the hospital. In the multivariate analysis, the home care patients were discharged earlier (relative risk [RR] 0.33, P= .03), had fewer days on total parenteral nutrition (RR 0.24, P< .01), less acute graft-versus-host disease (GVHD) grades II-IV (RR 0.25,P= .01), lower transplantation-related mortality rates (RR 0.22, P= .04), and lower costs (RR 0.37, P< .05), compared with the controls treated in the hospital. The 2-year survival rates were 70% in the home care group versus 51% and 57% (not significant) in the 2 control groups, respectively (P< .03). To conclude, home care after SCT is a novel and safe approach. This study found it to be advantageous, compared with hospital care.

The role of ursodeoxycholic acid (UDCA) in the prevention of hepatic complications after allogeneic stem cell transplantation was studied in a prospective randomized open-label multicenter trial. A total of 242 patients were allocated to receive (n = 123) or not to receive (n = 119) UDCA in the dose of 12 mg/kg/d orally from the day preceding the conditioning until day 90 after transplantation. In the UDCA-treated group a significantly smaller proportion of patients developed a serum bilirubin level exceeding 50 μM (18 of 123 versus 31 of 119, P = .04), and similarly a smaller proportion of patients exceeded the alanine aminotransferase level of 100 U/L. There was no difference in the incidence of veno-occlusive disease of the liver. Compared to the control group, in the UDCA-treated group there was a nonsignificant trend toward a lower overall incidence of acute graft-versus-host disease (GVHD) and a significantly lower incidence of grade III to IV acute GVHD (5 of 123 versus 17 of 119,P = .01), stage II to IV liver and intestinal GVHD, and stage III to IV skin GVHD. There was no difference in the incidence of chronic GVHD or in the relapse rate. Among the patients given UDCA, the survival at 1 year was significantly better, 71% versus 55% (P = .02), and the nonrelapse mortality rate was lower, 19% versus 34% (P = .01), than in the control group. There were significantly more deaths in GVHD in the control group. In conclusion, UDCA administration reduced hepatic problems and severe acute GVHD and improved survival. These results suggest a role for UDCA in the prevention of transplant-related complications in allogeneic transplantation.

Cell adhesion molecules are critically involved in the multistep process of leukocyte recruitment in inflammation. The specific receptors used by polymorphonuclear leukocytes (PMN) for locomotion in extravascular tissue have as yet not been identified. By means of immunofluorescence flow cytometry and laser scanning confocal microscopy, this study demonstrated that surface expression of the α2β1(VLA-2) integrin, though absent on blood PMN, is induced in extravasated PMN collected from human skin blister chambers, and rat PMN accumulated in the peritoneal cavity after chemotactic stimulation. Intravital time-lapse videomicroscopy was used to investigate chemoattractant-induced PMN locomotion in the rat mesentery in vivo. Local administration of function-blocking monoclonal antibody or peptide recognizing the α2β1integrin reduced PMN migration velocity in the extravascular tissue by 73% ± 3% and 70% ± 10%, respectively ( means ± SD). The distance f-met-leu-phe peptide (fMLP)-stimulated human PMN migrated in a collagen gel in vitro was markedly reduced by treatment with anti-α2mAbs or peptide, whereas no effect was observed with antibodies or peptides recognizing the α4β1or α5β1integrins. Further evidence for a critical role of expression of α2β1integrin in PMN locomotion in extravascular tissue was obtained in the mouse air pouch model of acute inflammation where chemoattractant-induced PMN recruitment was substantially inhibited by local anti-α2mAb treatment. Thus, expression of α2β1integrin on extravasated PMN has been identified and a novel role of this receptor in regulating the extravascular phase of leukocyte trafficking in inflammation has been formulated.

Cell adhesion molecules are critically involved in the multistep process of leukocyte recruitment in inflammation. The specific receptors used by polymorphonuclear leukocytes (PMN) for locomotion in extravascular tissue have as yet not been identified. By means of immunofluorescence flow cytometry and laser scanning confocal microscopy, this study demonstrated that surface expression of the 2β1 (VLA-2) integrin, though absent on blood PMN, is induced in extravasated PMN collected from human skin blister chambers, and rat PMN accumulated in the peritoneal cavity after chemotactic stimulation. Intravital time-lapse videomicroscopy was used to investigate chemoattractant-induced PMN locomotion in the rat mesentery in vivo. Local administration of function-blocking monoclonal antibody or peptide recognizing the 2β1 integrin reduced PMN migration velocity in the extravascular tissue by 73% ± 3% and 70% ± 10%, respectively ( means ± SD). The distance f-met-leu-phe peptide (fMLP)-stimulated human PMN migrated in a collagen gel in vitro was markedly reduced by treatment with anti-2 mAbs or peptide, whereas no effect was observed with antibodies or peptides recognizing the 4β1 or 5β1integrins. Further evidence for a critical role of expression of 2β1 integrin in PMN locomotion in extravascular tissue was obtained in the mouse air pouch model of acute inflammation where chemoattractant-induced PMN recruitment was substantially inhibited by local anti-2 mAb treatment. Thus, expression of 2β1 integrin on extravasated PMN has been identified and a novel role of this receptor in regulating the extravascular phase of leukocyte trafficking in inflammation has been formulated.

Introduction

Introduction

G-protein coupled receptors (GPCRs) are the most abundant superfamily of cell surface receptors. Approximately 35% of approved drugs target GPCRs and class A GPCRs account for ~85% of this superfamily. Class A GPCRs are characterized in part by two highly conserved disulfides in their extracellular domains that are thought to stabilize protein structure. Whether these disulfides can be enzymatically modified to influence G-protein signaling is not known. We and others have previously shown that disulfide bond modification by thiol isomerases such as protein disulfide isomerase (PDI) represent a previously unrecognized level of control of thrombus formation. We therefore evaluated the ability of recombinant PDI (rPDI) to modulate signaling through modification of the canonical disulfides within platelet GPCRs. Exposure of platelets to rPDI had no effect on stimulation through PAR1, PAR4, or the α 2A-adrenergic receptor. In contrast, rPDI exposure dramatically decreased platelet activation induced by the TP receptor agonists U46619 or arachidonic acid, implicating rPDI-mediated modulation of TP receptor signaling. Consistent with this finding, rPDI blocked U46619-mediated activation of α IIbβ 3, α-granule release, and dense granule release. Conversely, inhibition of endogenous PDI using either inhibitory antibodies or PDI-targeted small molecules enhanced TP receptor-mediated platelet aggregation and granule release, indicating that endogenous platelet PDI influences TP receptor signaling. Inhibition of TP receptor-mediated signaling required PDI active site cysteines since rPDI mutants lacking these cysteines lost inhibitory activity. Evaluation of the inhibitory activity of different PDI fragments showed that the PDI substrate binding domain is also critical for inhibitory activity. The ability to inhibit signaling through the TP receptor was specific for rPDI since incubation with other recombinant thiol isomerases including ERp57, ERp5, and ERp72 had no effect. To determine the specific modifications to TP receptor canonical disulfides induced by PDI, HEK cells were transfected with TP receptor and exposed to rPDI. TP receptor was subsequently immunopreciptated and disulfide-linked peptide analysis was performed using mass spectrometry. Compared to untreated controls, TP receptor exposed to rPDI demonstrated cleavage of Cys11-Cys102 and Cys105-Cys183 bonds and the generation of a new Cys102-Cys183 bond. To determine how modification of the disulfide bonding pattern affected signaling through the TP receptor, we evaluated signaling through specific Gα subunits in platelets. The platelet TP receptor signals through Gα q(which couples to phospholipase and increases calcium flux) and Gα 13(which couples to RhoA and myosin light chain kinase). PDI-mediated cleavage of the platelet TP receptor resulted in biased signaling, with substantial inhibition of G α13-mediated RhoA-GTP activation and myosin light chain phosphorylation and little effect on Gα q-mediated calcium flux. These results show how PDI can modify platelet signaling and represent the first demonstration that a thiol isomerase can modulate the function of a GPCR via rearrangement of canonical disulfide bonds.

Recent studies have provided evidence for associations between common polymorphic markers in the coagulation factor VII (FVII) gene and plasma FVII levels. Here we describe two common, nonrelated, functional polymorphisms in the promoter region of the FVII gene, a G to T substitution at position −401 and a novel G to A substitution at position −402. Both polymorphisms strongly influence the binding properties of nuclear protein(s). The rare −401T allele is associated with a reduced basal rate of transcription of the FVII gene in human hepatoblastoma cells and with reduced plasma concentrations of total FVII (VIIag) and fully activated FVII molecules (VIIa). In contrast, the rare −402A allele confers increased transcriptional activity and is associated with increased plasma FVII levels. Together, the two polymorphisms explained 18% and 28% of the variation in VIIag and VIIa, respectively, in a group of 183 healthy, middle-aged men. It is concluded that these polymorphisms are important for the regulation of the plasma levels of FVII and that they are likely to be useful genetic markers to resolve the issue of whether a causal relationship exists between FVII levels and risk of coronary heart disease.

Phenotypes of transcobalamin II (TC2) were determined in 95 maternal- cord serum pairs in order to identify the origin of TC2 in human cord blood. Unsaturated (apo) TC2 in serum was labeled with radioactive (57Co) cobalamin (CbI) and separated into isoproteins by polyacrylamide gel electrophoresis and autoradiography. Discordancy between the maternal and the cord serum type was observed in 45% of the pairs. The results demonstrated that, at the end of pregnancy, the fetus is capable of TC2 synthesis and that there is no detectable transplacental passage of maternal apo-TC2. Presence of maternal saturated (holo) TC2 in cord serum could be excluded in 9 informative discordant pairs by exchanging endogenously bound CbI with 57Co-CbI. Our finding that TC2 in human cord serum is of fetal rather than maternal origin suggests an essential role for fetal TC2 in CbI utilization and appears to contradict the hypothesis that transplacental passage of maternal TC2 may explain the normal fetal development in cases of congenital TC2 deficiency. The total immunoreactive TC2 content in 23 maternal serum samples collected at the end of pregnancy (812 +/- 175 pM CbI equivalent) was significantly higher than in the corresponding cord sera (605 +/- 148 pM; p less than 0.001) and did not significantly differ from the value in a control group of healthy male and female adults (841 +/- 192 pM). At the end of pregnancy, the apo-TC2 content in 12 maternal serum samples (760 +/- 347 pM) was significantly higher than in the corresponding cord sera (501 +/- 254 pM; p less than 0.05) and did not significantly differ from the value in the control group (747 +/- 137 pM).

Recombinant hirudin has been found to be immunogenic in patients treated with lepirudin following heparin-induced thrombocytopenia (HIT). We assessed the incidence of immunoglobulin G (IgG) antihirudin antibodies by enzyme-linked immunosorbent assay in 112 patients enrolled in a dose-finding study with desirudin. Patients received desirudin subcutaneously following orthopedic hip surgery at 10 mg twice a day (n = 17), 15 mg twice a day (n = 75), and 20 mg twice a day (n = 20). Of 112 patients, 11 (9.8%) developed antihirudin antibodies independently of the dose. The rate of immunization did not differ from that observed in HIT patients treated with lepirudin (P= .113). Plasma concentrations of desirudin did not differ between antihirudin antibody–positive and –negative patients. Antihirudin antibodies had no impact on incidences of deep vein thrombosis and/or pulmonary embolism, allergic reactions, and hemorrhage. However, the total number of immunized patients observed was low and so infrequent (but severe) effects of antihirudin antibodies cannot be excluded.

No relevant conflicts of interest to declare.

The text of this abstract was removed on August 17, 2018 at the request of the authors [S Mueller, AK Meinecke, S Buchwald, D Eriksson, T Wilke]. Based on a post-study agreement with the license holder of the 8-MMAS questionnaire, which was used in the study, the authors decided that this abstract should be removed.

Introduction:

Protein disulfide isomerase (PDI) is an intracellular oxidoreductase that cleaves and forms disulfide bonds in substrate proteins to facilitate their proper folding. However, platelets and endothelium release PDI upon vascular injury. This extracellular PDI serves a critical function in platelet activation and thrombus formation. A PDI antagonist is currently in phase II/III clinical trials for thrombosis prevention. Yet the mechanisms of how PDI enables platelets to respond to the local redox environment remain poorly understood. In particular, the substrates on which PDI acts to modify platelet function have yet to be elucidated.

The text of this abstract was removed on August 17, 2018 at the request of the authors [S Mueller, AK Meinecke, S Buchwald, D Eriksson, T Wilke]. Based on a post-study agreement with the license holder of the 8-MMAS questionnaire, which was used in the study, the authors decided that this abstract should be removed.

Stentoft: Ariad: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Bristol-Myers-Squibb: Research Funding. Richter:Pfizer: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ariad: Honoraria, Research Funding. Höglund:Akinion Pharmaceuticals: Consultancy; Janssen-Cilag: Honoraria. Mustjoki:Ariad: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding.

No relevant conflicts of interest to declare.

Hjorth-Hansen: Ariad: Honoraria; Novartis: Honoraria; Pfizer: Honoraria, Research Funding; Bristol-Myers Squibb: Research Funding. Off Label Use: Dasatinib and Pegylated IFN combination in CML. Richter:Ariad: Honoraria; Bristol-Myers Squibb: Honoraria; Novartis: Honoraria. Porkka:Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Pfizer: Honoraria. Mustjoki:Bristol-Myers Squibb: Honoraria, Research Funding.

Schellong: Boehringer Ingelheim: Consultancy. Eriksson:Boehringer Ingelheim: Consultancy. Goldhaber:Boehringer Ingelheim: Consultancy, Research Funding. Feuring:Boehringer Ingelheim: Employment. Hantel:Boehringer Ingelheim Pharma GmbH and Co. KG: Employment. Kreuzer:Boehringer Ingelheim Pharma GmbH and Co. KG: Employment. Schulman:Boehringer Ingelheim: Honoraria, Research Funding; Bayer: Honoraria; Baxter: Honoraria; Octapharma: Research Funding. Kakkar:Boehringer Ingelheim: Consultancy, Honoraria, Research Funding.