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There is mounting evidence that the immune system can spontaneously clear malignant lesions before they manifest as overt cancer, albeit this activity has been difficult to demonstrate in humans. The calreticulin (CALR) exon 9 mutations are driver mutations in patients with chronic myeloproliferative neoplasms (MPN), which are chronic blood cancers. The CALR mutations generate a neo-antigen that is recognized by patient T cells, and T cells isolated from a patient with a CALR-mutation can recognize and kill autologous CALR-mutant cells. Surprisingly, healthy individuals display frequent and strong T cell responses to the CALR neo-antigens too. Furthermore, healthy individuals display immune responses to all parts of the mutant CALR epitope, and the CALR neo-epitope specific responses are memory T cell responses. These data suggest that although healthy individuals might acquire a CALR mutation, the mutant cells can be eliminated by the immune system. Additionally, a small fraction of healthy individuals harbor a CALR exon 9 mutation. Four healthy individuals carrying CALR mutations underwent a full medical examination including a bone marrow biopsy after a median follow up of 6.2 years. None of these patients displayed any signs of CALR-mutant MPN. Additionally, all healthy individuals displayed strong CALR neo-epitope specific T cell responses suggesting that these healthy individuals retained their CALR-mutant cells in the editing stage for several years. Thus, we suggest that CALR-mutant MPN could be a disease model of cancer immuno-editing, as we have demonstrated that CALR-mutant MPN displays all three stages described in the theory of cancer immuno-editing. [ABSTRACT FROM AUTHOR]

Discovery of somatic mutations in the calreticulin gene (CALR) has identified a subgroup of Philadelphia-negative chronic myeloproliferative neoplasms (MPN) with separate haematological characteristics and prognosis. CALR mutations serve as novel markers both of diagnostic value and as targets for monitoring molecular responses during therapy. Interferon-α (IFN) selectively targets the malignant clone in a subset of MPN patients and can induce both haematological and molecular remissions in CALR mutated essential thrombocythemia (ET) patients. We investigated the response to IFN in a cohort of 21 CALR mutated MPN patients including ET, prefibrotic primary myelofibrosis (pre-PMF), and primary myelofibrosis (PMF) with a median follow-up of 31 months. For evaluation of a molecular response, we developed highly sensitive quantitative PCR (qPCR) assays for monitoring the mutant allele burden of the two most prevalent CALR mutations (type 1 and type 2). Thirteen patients (62%) experienced a decrease in the mutant allele burden with a median decline of 29% from baseline. However, only four patients, including patients with ET, pre-PMF, and PMF diagnosis, achieved molecular responder (MR) status with >50% reduction in mutant allele burden according to European LeukemiaNet (ELN) guidelines. MR patients displayed significant differences in the dynamics of the CALR mutant load with regard to time to response and dynamics in mutant allele burden after discontinuation of IFN treatment. Furthermore, we highlight the prognostic value of the CALR mutant allele burden by showing a close association with leucocyte- and platelet counts, hemoglobin concentration, in addition to plasma lactate dehydrogenase (LDH) irrespective of molecular response and treatment status. [ABSTRACT FROM AUTHOR]

The myeloproliferative neoplasms are associated with chronic kidney disease but whether clonal haematopoiesis of indeterminate potential (CHIP) is associated with impaired kidney function is unknown. In the Danish General Suburban Population Study (N = 19 958) from 2010 to 2013, 645 individuals were positive for JAK2V617F (N = 613) or CALR (N = 32) mutations. Mutation‐positive individuals without haematological malignancy were defined as having CHIP (N = 629). We used multiple and inverse probability weighted (IPW)‐adjusted linear regression analysis to estimate adjusted mean (95% confidence interval) differences in estimated glomerular filtration rate (eGFR; ml/min/1.73 m2) by mutation status, variant allele frequency (VAF%), blood cell counts, and neutrophil‐to‐lymphocyte ratio (NLR). We performed 11‐year longitudinal follow‐up of eGFR in all individuals. Compared to CHIP‐negative individuals, the mean differences in eGFR were −5.6 (−10.3, −0.8, p =.02) for CALR, −11.9 (−21.4, −2.4, p = 0.01) for CALR type 2, and −10.1 (−18.1, −2.2, p =.01) for CALR with VAF ≥ 1%. The IPW‐adjusted linear regression analyses showed similar results. NLR was negatively associated with eGFR. Individuals with CALR type 2 had a worse 11‐year longitudinal follow‐up on eGFR compared to CHIP‐negative individuals (p =.004). In conclusion, individuals with CALR mutations, especially CALR type 2, had impaired kidney function compared to CHIP‐negative individuals as measured by a lower eGFR at baseline and during 11‐year follow‐up. [ABSTRACT FROM AUTHOR]

Philadelphia-negative myeloproliferative neoplasms (MPNs) are a diverse group of diseases whose common feature is the presence of V617F mutation of the JAK2 gene. In the era of novel therapeutic strategies in MPNs, such as JAK-inhibitor therapy, there is a growing need for establishing high sensitive quantitative methods, which can be useful not only at diagnosis but also for monitoring therapeutic outcomes, such as minimal residual disease (MRD). In this study, we compared the qPCR and ddPCR methods and their clinical utility for diagnosis, prognostication, and treatment monitoring of MPNs with JAK2 V617F mutation in 63 MPN patients of which 6 were subjected to ruxolitinib treatment. We show a high conformance between the two methods (correlation coefficient r = 0.998 (p < 0.0001)). Our experiments revealed high analytical sensitivity for both tests, suggesting that they are capable of detecting the JAK2 V617F mutation at diagnosis of MPN with a limit of detection (LoD) of 0.12% for qPCR and 0.01% for ddPCR. The alterations of JAK2 V617F allele burden in patients treated with ruxolitinib were measured by both methods with equal accuracy. The results suggest an advantage of ddPCR in monitoring MRD because of allele burdens below the LoD of qPCR. Overall, the clinical utility of qPCR and ddPCR is very high, and both methods could be recommended for the routine detection of the V617F mutation at diagnosis, though ddPCR will probably supersede qPCR in the future due to cost-effectiveness. [ABSTRACT FROM AUTHOR]

Purpose Development of secondary central nervous system involvement (SCNS) in patients with diffuse large B-cell lymphoma is associated with poor outcomes. The CNS International Prognostic Index (CNS-IPI) has been proposed for identifying patients at greatest risk, but the optimal model is unknown. Methods We retrospectively analysed patients with diffuse large B-cell lymphoma diagnosed between 2001 and 2013, staged with PET/CT and treated with R-CHOP(-like) regimens. Baseline clinicopathologic characteristics, treatments, and outcome data were collected from clinical databases and medical files. We evaluated the association between candidate prognostic factors and modelled different risk models for predicting SCNS. Results Of 1532 patients, 62 (4%) subsequently developed SCNS. By multivariate analysis, disease stage III/IV, elevated serum LDH, kidney/adrenal and uterine/testicular involvement were independently associated with SCNS. There was a strong correlation between absolute number of extranodal sites and risk of SCNS; the 144 patients (9%) with >2 extranodal sites had a 3-year cumulative incidence of SCNS of 15.2% (95% confidence interval [CI] 9.2–21.2%) compared with 2.6% (95% CI 1.7–3.5) among those with ≤2 sites ( P < 0.001). The 3-year cumulative risks of SCNS for CNS-IPI defined risk groups were 11.2%, 3.1% and 0.4% for high-, intermediate- and low-risk patients, respectively. All risk models analysed had high negative predictive values, but only modest positive predictive values. Conclusions Patients with >2 extranodal sites or high-risk disease according to the CNS-IPI should be considered for baseline CNS staging. Clinical risk prediction models suffer from limited positive predictive ability, highlighting the need for more sensitive biomarkers to identify patients at highest risk of this devastating complication. [ABSTRACT FROM AUTHOR]

Involvement of the internal female reproductive organs by diffuse large B-cell lymphoma ( DLBCL) is uncommon, and there are sparse data describing the outcomes of such cases. In total, 678 female patients with DLBCL staged with positron emission tomography/computed tomography and treated with rituximab-containing chemotherapy were identified from databases in Denmark, Great Britain, Australia, and Canada. Overall, 27/678 (4%) had internal reproductive organ involvement: uterus ( n = 14), ovaries ( n = 10) or both ( n = 3). In multivariate analysis, women with uterine DLBCL experienced inferior progression-free survival and overall survival compared to those without reproductive organ involvement, whereas ovarian DLBCL was not predictive of outcome. Secondary central nervous system ( CNS) involvement ( SCNS) occurred in 7/17 (41%) women with uterine DLBCL (two patients with concomitant ovarian DLBCL) and 0/10 women with ovarian DLBCL without concomitant uterine involvement. In multivariate analysis adjusted for other risk factors for SCNS, uterine involvement by DLBCL remained strongly associated with SCNS (Hazard ratio 14·13, 95% confidence interval 5·09-39·25, P < 0·001). Because involvement of the uterus by DLBCL appears to be associated with a high risk of SCNS, those patients should be considered for CNS staging and prophylaxis. However, more studies are needed to determine whether the increased risk of secondary CNS involvement also applies to women with localized reproductive organ DLBCL. [ABSTRACT FROM AUTHOR]