Citations

Context.— The College of American Pathologists (CAP) developed proficiency testing for platelet function assays by using blood collected by the participant added to challenge tubes containing either saline (normal) or tirofiban (abnormal). Objective.— To analyze platelet function proficiency testing for Platelet Function Analyzer PFA-100, platelet aggregation, PlateletWorks, and PlateletMapping. Design.— Proficiency testing data from 2012–2016 were analyzed. Results.— For PFA-100, a total of 1200 laboratories participated; the coefficient variation (CV) of cartridge closure times was 22% (saline); 44,952 of 45,616 survey responses (99%) provided an interpretation, and 42,934 of 44,952 (96%) were correct. For optical platelet aggregation, 190 laboratories participated; the CV was 17% (saline), 7444 of 7813 survey responses (95%) provided an interpretation, and 7015 of 7444 (94%) were correct. For PlateletWorks, 60 laboratories participated; the CV was 3% to 11% (saline); 2412 of 2454 survey responses (98%) provided an interpretation, and 1207 of 1276 (95%) were correct for adenosine diphosphate (ADP) and 936 of 1136 (82%) for collagen. For PlateletMapping, 200 laboratories participated. For ADP, 1128 of 2697 survey responses (42%) provided an interpretation, but only 927 of 1128 (82%) were correct. For arachidonic acid, 1139 of 2604 survey responses (44%) provided an interpretation and 964 of 1139 (85%) were correct. Conclusions.— CAP is the first to provide proficiency testing for platelet aggregation, PlateletWorks, and PlateletMapping. Platelet aggregation, PFA-100, and PlateletWorks using ADP as an agonist performed well with more than 90% of laboratories providing an interpretation and a similar number providing correct results. PlateletWorks using collagen and PlateletMapping showed worse interpretive accuracy than the other methods.

Heřmanský–Pudlák syndrome (HPS), a rare autosomal recessive disorder, manifests with oculocutaneous albinism and a bleeding diathesis. However, severity of disease can be variable and is typically related to the genetic subtype of HPS; HPS type 6 (HPS‐6) is an uncommon subtype generally associated with mild disease. A Caucasian adult female presented with a history of severe bleeding; ophthalmologic examination indicated occult oculocutaneous albinism. The patient was diagnosed with a platelet storage pool disorder, and platelet whole mount electron microscopy demonstrated absent delta granules. Genome‐wide SNP analysis showed regions of homozygosity that included the HPS1 and HPS6 genes. Full length HPS1 transcript was amplified by PCR of genomic DNA. Targeted next‐generation sequencing identified a novel homozygous missense variant in HPS6 (c.383 T > C; p.V128A); this was associated with significantly reduced HPS6 mRNA and protein expression in the patient's fibroblasts compared to control cells. These findings highlight the variable severity of disease manifestations in patients with HPS, and illustrate that HPS can be diagnosed in patients with excessive bleeding and occult oculocutaneous albinism. Genetic analysis and platelet electron microscopy are useful diagnostic tests in evaluating patients with suspected HPS.Clinical Trial registration:Registrar: ClinicalTrials.govWebsite: www.clinicaltrials.govRegistration Numbers: NCT00001456 and NCT00084305.

AbstractBackgroundAlthough the prognosis of core‐binding factor (CBF) acute myeloid leukemia (AML) is better than other subtypes of AML, 30% of patients still relapse and may require allogeneic hematopoietic cell transplantation (alloHCT). However, there is no validated widely accepted scoring system to predict patient subsets with higher risk of relapse.MethodsEleven centers in the US and Europe evaluated 247 patients with t(8;21)(q22;q22).ResultsComplete remission (CR) rate was high (92.7%), yet relapse occurred in 27.1% of patients. A total of 24.7% of patients received alloHCT. The median disease‐free (DFS) and overall (OS) survival were 20.8 and 31.2 months, respectively. Age, KIT D816V mutated (11.3%) or nontested (36.4%) compared with KIT D816V wild type (52.5%), high white blood cell counts (WBC), and pseudodiploidy compared with hyper‐ or hypodiploidy were included in a scoring system (named I‐CBFit). DFS rate at 2 years was 76% for patients with a low‐risk I‐CBFit score compared with 36% for those with a high‐risk I‐CBFit score (P < 0.0001). Low‐ vs high‐risk OS at 2 years was 89% vs 51% (P < 0.0001).ConclusionsI‐CBFit composed of readily available risk factors can be useful to tailor the therapy of patients, especially for whom alloHCT is not need in CR1 (ie, patients with a low‐risk I‐CBFit score).

We report a case of a patient with severe postoperative bleeding complication, secondary to dietary and herbal supplements induced platelet dysfunction. This case demonstrates the importance of preoperative assessment which includes questioning the patient with regards to their dietary and herbal supplements and of stressing the importance of discontinuing them prior to surgery.

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.