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Advanced systemic mastocytosis (AdvSM) encompasses heterogeneous mastocytosis subtypes and is associated with poor outcomes. Although midostaurin was the first tyrosine kinase inhibitor to be approved for AdvSM patients, long-lasting responses are limited. The mutation-Adjusted Risk Score (MARS), the International Prognostic Scoring System for mastocytosis (IPSM) and the Global Prognostic Score for Systemic Mastocytosis (GPSM) have been established to characterize the outcomes of patients with overall AdvSM. However, given the outcome's dependency on the AdvSM subtype, prognostic characterization within each subtype is critical. We aimed to study the predictive ability using Harrell's concordance index of prognostic scores according to the AdvSM subtype. We conducted a nationwide retrospective study using the French mastocytosis reference center's registry and included all midostaurin-treated patients with C finding. Overall, 170 patients were identified: 46 aggressive SM (ASM), 11 mast cell leukemia (MCL), and 113 SM with associated hematological neoplasm (SM-AHN). All risk scores improved their discriminative value for overall survival (OS) when combined with the AdvSM subtype. The best predictive value was for adjusted MARS (C-index = 0.689), followed by GPSM (C-index = 0.677) and IPSM (C-index = 0.618). In a multivariable analysis, MARS stratification and the AdvSM subtype were both prognostic for OS. Accordingly, five subgroups of patients with AdvSM and a different median OS were identified: 9.9 months for MCL, 24 months for intermediate/high-risk SM-AHN, 33 months for intermediate/high-risk ASM, 58 months for low-risk SM-AHN and was not reached for low-risk ASM (p < 0.001). The AdvSM subtype and the MARS are the most predictive of OS and should prompt specific management., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

While sickle cell anemia (SCA) and hereditary spherocytosis (HS) share common features of increased spleen erythrophagocytosis due to increased red blood cell (RBC) turnover, SCA is specifically characterized by susceptibility to infections. In this study, histological lesions in the spleens of pediatric patients with SCA were analyzed, in close correlation with past clinical history and comparatively to HS, healthy and transfused β-thalassemia patients (TDT). An evaluation of red pulp elementary lesions (red pulp fibrosis, iron deposition, number of Gandy-Gamna, and RBC trapping) combined into a severity score was established, as well as B-cell follicles analysis. Quantification on digitalized slides of iron deposition, RBC trapping, and red pulp fibrosis was additionally performed. Spleens from 22 children with SCA, eight with HS, eight with TDT, and three healthy controls (HC) were analyzed. Median age at splenectomy was not different between SCA and HS patients, 6.05 years (range: 4.5-16.0) versus 4.75 (range: 2.2-9.5). Marked heterogeneity was found in SCA spleens in contrast to other conditions. Contrary to previous reports, B-cell follicles were generally preserved in SCA. While RBC trapping was significantly increased in both SCA and HS (compared to TDT and HC), quantitative fibrosis and overall red pulp severity score were significantly increased in SCA spleens compared to other conditions. Moreover, there was an inverse correlation between quantitative fibrosis and number of B-cell follicles, linking these two compartments as well as spleen fibrosis to infectious susceptibility in SCA, potentially through impaired red pulp macrophage scavenging and B-cell subpopulations defects., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

Background and Aims: Systemic mastocytosis (SM) is characterized by the accumulation of atypical mast cells (MCs) in organs. Liver histology of SM has been marginally described and accurate histological classification is critical, given the consequences of aggressive SM diagnosis. We aimed to describe the histological features associated with liver SM using updated tools., Methods: Using the database of the French Reference Centre for Mastocytosis, we retrospectively identified patients with a liver biopsy (LB) and a diagnosis of SM. All LB procedures were performed according to the local physician in charge and centrally reviewed by an expert pathologist., Results: A total of 28 patients were included: 6 had indolent SM, 9 had aggressive SM, and 13 had SM with an associated hematologic neoplasm. Twenty-five (89%) patients presented hepatomegaly, and 19 (68%) had portal hypertension. The LB frequently showed slight sinusoid dilatation (82%). Fibrosis was observed in 3/6 indolent SM and in almost all advanced SM cases (21/22), but none of them showed cirrhosis. A high MC burden (>50 MCs/high-power field) was correlated with elevated blood alkaline phosphatase levels (p = .030). The presence of portal hypertension was associated with a higher mean fibrosis grade (1.6 vs. 0.8 in its absence; p = .026). In advanced SM, the presence of nodular regenerative hyperplasia (NRH) was associated with decreased overall survival (9.5 vs. 46.3 months, p = .002)., Conclusions: MC infiltration induced polymorphic hepatic lesions and the degree of fibrosis is associated with portal hypertension. NRH identifies a poor prognosis subgroup of patients with advanced SM. Assessing liver histology can aid in SM prognostic evaluation., (© 2024 The Authors. Liver International published by John Wiley & Sons Ltd.)

Single nucleotide polymorphisms (SNPs) in FCγ-receptor genes FCGR3A (rs396991) and FCGR2A (rs1801274) influence the affinity of the Fc portion of anti-CD20 immunoglobulin G1 monoclonal antibody. Their roles in diffuse large B-cell lymphoma (DLBCL) treated with rituximab in combination with anthracycline-based chemotherapy remain controversial. To address this question, we genotyped FCGR2A and FCGR3A SNPs in two prospective DLBCL cohorts from Lymphoma Study Association trials (N = 554) and Iowa/Mayo Specialized Program Of Research Excellence (N = 580). Correlations with treatment response and hematological toxicity were assessed in Lymphoma Study Association. Correlation with event-free survival (EFS) and overall survival (OS) was performed in both cohorts, followed by a meta-analysis to increase power. Our study shows the absence of correlation between these SNPs and treatment response. Grades 3 and 4 febrile neutropenia during treatment was more frequently observed in FCGR3A VV (39%) than VF (29%) and FF (32%) carriers (p = 0.04). Our analysis for EFS and OS shows that FCGR3A was not associated with outcome. In a meta-analysis using an ordinal model, FCGR2A (per R allele) was associated with a better EFS (hazard ratio = 0.87; 95%CI, 0.76-0.99; p = 0.04) and OS (hazard ratio = 0.86; 95%CI, 0.73-1.00; p = 0.05) which was not altered after adjustment for the International Prognostic Index. Overall, our data demonstrate that patients with DLBCL with the low-affinity FCγRIIA RR had an unexpectedly better outcome than FCγRIIA H carriers. Whether rituximab efficacy is improved in FCγRIIA RR patients due a clearance reduction or other functions of FCγRIIA in DLBCL should be investigated (clinicaltrials.gov identifiers: NCT00135499, NTC00135499 NCT00140595, NCT00144807, NCT00144755, NCT01087424, and NCT00301821). Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein. Am. J. Hematol. 91:923-930, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

FcgammaRIIB, a low affinity receptor for the Fc portion of immunoglobulin G (IgG), is thought to drive negative selection of B cells in germinal centers (GC) by inducing apoptosis upon interaction with immune complexes. Its expression was investigated by immunohistochemistry in 22 reactive lymphoid tissues and 112 B-cell lymphomas. Pre-GC mantle cells, marginal zone cells and their neoplastic counterparts expressed FcgammaRIIB. The B chronic lymphocytic leukaemia (B-CLL)/small lymphocytic lymphomas were also positive. Not detected in GC, FcgammaRIIB was expressed in 52% of follicular lymphomas and in 20% of diffuse large B cell lymphomas (DLBCL). In DLBCL, FcgammaRIIB expression was linked to transformation (P < 0.001). Re-analysis of a gene profile data set from the Lymphochip microarrays showed that FcgammaRIIB expression in the activated B-like DLBCL subgroup was higher than in the GC-like one (P < 0.04), and was associated with an adverse prognostic both in univariate (P < 0.003) and in multivariate analysis including the International Prognostic Indicator (IPI) (P < 0.01). Thus these results challenge the potential role of FcgammaRIIB during B-cell selection in GC, and suggest a prognostic value of FcgammaRIIB expression in DLBCL.

Rearrangement of the bcl-2 gene at the MBR (major breakpoint region) locus with the immunoglobulin heavy-chain joining region has been reported in a high proportion of follicular lymphomas. This rearrangement has also been reported in very few normal B cells of the blood, tonsils, follicular lymphoid hyperplasia (FLH) of the lymph nodes. HIV infection is often associated at the onset of the disease with FLH, but the presence of rearranged bcl-2 B cells in these lymph nodes has not been described. In using a standard PCR assay with Southern blot or a semi-nested PCR on 48 cases of FLH, we demonstrated that there were a few bcl-2 rearranged B cells in HIV FLH, at almost the same level as that in non-HIV-related FLH. The usual absence of bcl-2 rearrangement in the HIV-associated B-cell lymphomas suggests that the bcl-2 oncogene in the rearranged B cells of FLH is not cooperating with other oncogenes during HIV lymphomagenesis.