Chen, Dong

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a low-grade B-cell neoplasm and ∼2% to 9% patients develop an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (Richter transformation, DLBCL-RT). Programmed death-1 (PD-1) pathway plays a crucial role in tumor host immunity evasion and its blockade has emerged as an effective anti-cancer immunotherapy. PD-L1 and PD-1 expression has shown predictive value in anti-PD cancer immunotherapy; however, it has not been well documented in CLL/SLL and DLBCL-RT. We evaluated PD-1 and PD-L1 expression by immunohistochemistry in 39 CLL/SLL, 15 DLBCL-RT, and 26 other DLBCL. In CLL/SLL, neoplastic B-cell PD-1 expression was weak and restricted to prolymphocytes/paraimmunoblasts within proliferation centers (PCs) and accentuated PCs of all sizes. Neoplastic B-cell PD-1 expression was highly prevalent and demonstrated increased intensity in DLBCL-RT, but in contrast was only rarely seen in other DLBCL (12/15 vs. 1/26; P<0.0001). An excellent correlation (90% concordance) was observed between neoplastic B-cell PD-1 immunohistochemistry positivity and molecularly defined CLL/SLL clonal relatedness in DLBCL-RT. PD-L1 expression was observed on the neoplastic B cells in rare DLBCL-RT and other DLBCL cases (1/15 vs. 1/26; P>0.05) as well as background histiocytes and dendritic cells. Overall survival of DLBCL-RT was significantly inferior to that of the other DLBCL (median, 16.9 vs. 106.1 mo; P=0.002). Our findings suggest a biological continuum from prolymphocytes/paraimmunoblasts in CLL/SLL PCs to the neoplastic B-cells in DLBCL-RT. The characteristic PD-1 expression in DLBCL-RT makes it a potential surrogate marker for determining clonal relatedness to CLL/SLL, which may have important prognostic and therapeutic implications.

AbstractIn hemophilia B (HB), factor IX gene (F9) genotyping is used for molecular confirmation of affected individuals, for carrier testing, to facilitate the identification of those at risk for anaphylaxis/inhibitors (associated with large deletions), and to assist in assigning disease severity. Owing to test costs, optimal test utilization involves pre/post-test counseling and appropriate patient and test selection (e.g., mutation screening [F9MS] vs. known mutation [F9KM] testing). This article aims to review the trends and outcomes of F9-genotyping orders and describe the spectrum of variants identified in a sample of individuals in our reference laboratory. We performed a retrospective review of consecutive orders submitted to the Special Coagulation DNA Diagnostic Laboratory, Mayo Clinic, between 2012 and 2015. A total of 133 orders (38%) were identified for men: 118 (88%) were F9MS and 15 (12%) were F9KM. Thirteen orders (10%) were cancelled. A total of 209 orders were identified for women: 178 (85%) were F9MS and 31 (15%) were F9KM. Thirty-seven orders (18%) were cancelled and 30% of the tests performed yielded negative results. A total of 164 samples (47%) were received without clinical information. Seventeen previously unreported variants were identified. F9 genotyping provides useful information for HB management; however, 18% of our orders were cancelled and almost half were received without relevant clinical information, thus reaffirming the need for ongoing scrutiny of submitted orders. Optimal patient and test selection is important as is the accurate interpretation of variants identified. Most of the pathogenic variants identified were point mutations, with very few large deletions, consistent with the literature.

Rivaroxaban and dabigatran are among the newest anticoagulants, and measuring their concentration in patients is a new challenge for clinical laboratories. We analyzed data from the ECAT proficiency program to determine how well the assays are performing in clinical laboratories internationally. Most laboratories received a passing grade (Z score <3) for the results of their dabigatran and rivaroxaban testing. Failing Z scores were not associated with any particular method. With dabigatran, some homemade calibrators gave higher results than the commercially available calibrators. There were no significant differences among the instruments or the 5 reagents in use, but results showed inter‐laboratory variability that could have clinical significance. The 3 reagents with the lowest number of users had poor inter‐laboratory precision. Ten different anti‐Xa reagents were in use for rivaroxaban testing. One reagent gave lower results than other reagents at 100 ng/mL but not at 300 ng/mL. There were no significant differences among the different rivaroxaban calibrators or instruments. In conclusion, inter‐laboratory precision could be improved for both dabigatran and rivaroxaban assays. Homemade dabigatran calibrators differed from commercially available calibrators, and there was a statistically significant difference between some of the rivaroxaban reagents. About 10% of results received failing Z scores or passed but fell in a range that require the laboratory to investigate for bias or other inaccuracy in their method. Am. J. Hematol. 91:E464–E467, 2016. © 2016 Wiley Periodicals, Inc.

In routine practice, the World Health Organization classification of systemic mastocytosis (SM) is also the de facto prognostic system; a core value is distinguishing indolent (ISM) from advanced SM (includes aggressive SM [ASM], SM with associated hematological neoplasm [SM‐AHN] and mast cell leukemia [MCL]). We sequenced 27 genes in 150 SM patients to identify mutations that could be integrated into a clinical‐molecular prognostic model for survival. Forty four patients (29%) had ISM, 25 (17%) ASM, 80 (53%) SM‐AHN and 1 (0.7%) MCL; overall KITD816V prevalence was 75%. In 87 patients, 148 non‐KIT mutations were detected; the most frequently mutated genes were TET2 (29%), ASXL1 (17%), and CBL (11%), with significantly higher mutation frequency in SM‐AHN > ASM > ISM (P < 0.0001). In advanced SM, ASXL1 and RUNX1 mutations were associated with inferior survival. In multivariate analysis, age > 60 years (HR = 2.4), hemoglobin < 10 g/dL or transfusion‐dependence (HR = 1.7), platelet count < 150 × 109/L (HR = 3.2), serum albumin < 3.5 g/dL (HR = 2.6), and ASXL1 mutation (HR = 2.3) were associated with inferior survival. A mutation‐augmented prognostic scoring system (MAPSS) based on these parameters stratified advanced SM patients into high‐, intermediate‐, and low‐risk groups with median survival of 5, 21 and 86 months, respectively (P < 0.0001). These data should optimize risk‐stratification and treatment selection for advanced SM patients. Am. J. Hematol. 91:888–893, 2016. © 2016 Wiley Periodicals, Inc.