Significant Variability in the Identification and Reporting of Band Neutrophils by Participants Enrolled in the College of American Pathologists Proficiency Testing Program: Time for a Change.

CONTEXT.­: Increased band neutrophils in blood smear differential counts ("bandemia") are entrenched in medicine as a flag for sepsis. However, laboratory hematology experts have long advocated for discontinuation of reporting bands separately from segmented neutrophils because of poor sensitivity and specificity, poor interobserver agreement, and availability of alternative biomarkers for sepsis. OBJECTIVE.­: To describe band neutrophil reporting practices and reproducibility of band classification among laboratories participating in the College of American Pathologists (CAP) proficiency testing (PT) program. DESIGN.­: A survey questionnaire was distributed to hematology PT participants. A subsequent morphologic challenge included 12 preselected cell identifications of segmented neutrophils, bands, and metamyelocytes, and a 100-cell manual differential count of a digitally scanned blood smear. RESULTS.­: Among laboratories that reported manual differentials, most respondents reported bands (4554 of 5268; 86.4%). Only 3222 of 4412 respondents (73.0%) provided band reference ranges. Though participants classified "easy" band neutrophils well (78.0%-98.3%), categorization of cell identifications for "moderate" and "difficult" bands was poor (3.1%-39.0% of laboratories), with classification instead as segmented neutrophils. This pattern was seen regardless of laboratory demographic characteristics. Marked variability in band counts was observed on the 100-cell differential count for both CAP PT participants and CAP Hematology and Clinical Microscopy Committee (HCMC) members (coefficients of variation, 55.8% and 32.9%, respectively). Variability was significantly improved when segmented and band neutrophils were grouped together (coefficients of variation, 6.2% and 5.0%, respectively). CONCLUSIONS.­: Most CAP PT-participating laboratories report band counts, many without reference ranges. The survey confirms significant interlaboratory variability of band enumeration when bands are separately identified from segmented neutrophils. This study reaffirms the CAP Hematology and Clinical Microscopy Committee's strong recommendation to group segmented and band neutrophils together in manual differential counts.

Formalin Fixation Followed by Paraffin Embedding Allows Long-Term Storage of Proteins for Liquid Chromatography-Tandem Mass Spectrometry Analysis.

In an anatomical pathology laboratory, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is used to characterize amyloid deposits identified in formalin-fixed paraffin-embedded tissue (FFPET). However, the development of additional tests is partially limited by the lack of information the passage of time has on the proteins in FFPET. To investigate the reliability of LC-MS/MS in the analysis of old FFPET specimens, 1 bone marrow aspirate clot was analyzed by LC-MS/MS yearly from 2014 to 2018, in 3 consecutive months. Peptide-spectrum match, number of peptides identified, and percentage of the proteins covered were the parameters collected for the hemoglobin subunits alpha (HbA), beta (HbB), delta (HbD), and gamma (HbG). These proteins are constant components of the peripheral blood and are present in high and low abundance, allowing the monitorization of the performance of the test across varying protein concentrations. The hemoglobin subunits were stable over the years studied; 71% to 74% of HbA, 77% to 80% of HbB, 69% to 77% of HbD, and 57% to 63% of HbG were covered, with no statistical difference between 2014 and 2018. The number of peptides identified was also constant, 11 to 13 for HbA, 13 to 15 for HbB, 11 to 14 for HbD, and 7 to 9 for HbG. Peptide spectrum match was only slightly more variable: 209 to 327 for HbA, 569 to 1052 for HbB, 286 to 533 HbD, and 142 to 292 for HbG. In conclusion, high abundance hemoglobins, HbA and HbB, and relatively low abundance ones, HbD and HbG, are preserved in FFPET and confidently identified by LC-MS/MS for at least 5 years.

IgM monoclonal gammopathy of undetermined significance: clinicopathologic features with and without IgM-related disorders.

A subset of patients with immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) develop IgM-related disorders (IgM-RD) including peripheral neuropathy, cryoglobulinemia and/or cold agglutinin disease (CAD). We examined the clinical and bone marrow pathologic findings in 191 IgM MGUS patients (2016 World Health Oragnization criteria). Clonal plasma cells were identified in 41 of 171 (24%) cases by immunohistochemistry (IHC) and clonal B cells in 43 of 157 (27%). IgM-RD was identified in 82 (43%) cases, including peripheral neuropathy (n=67, 35%), cryoglobulinemia (n=21, 11%), and CAD (n=10, 5%). Cases of CAD showed distinctive features including lack of MYD88 mutations (P=0.048), supporting the concept of primary CAD as a distinct clinicopathologic disorder. Following exclusion of CAD, comparison of the remaining cases with (n=72) or without (n=109) IgM-RD showed IgM-RD to be more frequent in men than women (P=0.02) and to be more highly associated with MYD88 L265P (P=0.011). Cases with and without IgM-RD otherwise showed similar features including serum IgM concentrations, presence of lymphoid aggregates, clonal B cells by flow cytometry or clonal plasma cells by IHC. No differences were observed in overall survival between cases with and without IgM-RD. No cases in this series met criteria for plasma cell type IgM MGUS as defined in the 2022 International Consensus Classification of lymphoid neoplasms. These results show IgM-RD to be common in patients with IgM MGUS. While CAD shows distinctive features, the remaining cases of IgM-RD largely show pathologic findings similar to IgM MGUS without IgM-RD.

Risk Assessment of Hospitalized Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)-Infected Patients Using Laboratory Data and Immune Cell Morphologic Assessment.

CONTEXT.­: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious agent, with the propensity to cause severe illness. While vaccine uptake has been increasing in recent months, many regions remain at risk of significant coronavirus disease 19 (COVID-19)-related health care burden. Health systems will continue to benefit from the availability of a variety of clinical and laboratory models when other triaging models are equivocal. OBJECTIVE.­: To validate previously reported clinical laboratory abnormalities seen in COVID-19 patients and identify what laboratory parameters might be outcome predictive. DESIGN.­: We undertook an observational study of hospital-admitted COVID-19 patients (n = 113), looking at a broad selection of clinical, laboratory, peripheral blood smear, and outcome data during discrete discovery and validation periods from March 2020 to November 2020. RESULTS.­: We confirmed the findings of previous studies noting derangement of a variety of laboratory parameters in COVID-19 patients, including peripheral blood morphologic changes. We also devised a simple-to-use decision tree by which patients could be risk stratified on the basis of red blood cell count, creatinine, urea, and atypical plasmacytoid lymphocyte ("covidocyte") count. This outcome classifier performed comparably to the World Health Organization clinical classifier and the neutrophil-lymphocyte ratio. CONCLUSIONS.­: Our data add to the increasing number of studies cataloguing laboratory changes in COVID-19 and support the clinical utility of incorporating blood morphologic assessment in the workup of hospitalized COVID-19 patients.

Pathology Residents as Testing Personnel in the Hematology Laboratory.

CONTEXT.­: Clinical laboratories and the training of pathology residents are tightly regulated environments. Compliance with regulatory requirements must be addressed when developing entrustable professional activities (EPAs) for pathology residents. OBJECTIVE.­: To describe the development of EPAs for peripheral blood and body fluid review in compliance with Clinical Laboratory Improvement Amendments and College of American Pathologists personnel and testing requirements. To examine the impact of EPA implementation on the workflow in a busy hematology laboratory. DESIGN.­: A training program was designed to prepare pathology residents to function as independent testing personnel in compliance with Clinical Laboratory Improvement Amendments. After a series of lectures, hands-on microscopy sessions, self-assessment quizzes, and achievement of a passing score on a training assessment exam, residents were deemed competent to release certain results independently. The volume and the turnaround time of hematology tests were compared before and after residents were integrated into the laboratory workflow. Faculty and residents were surveyed to assess satisfaction with the training. RESULTS.­: Empowering residents to independently release noncritical results from peripheral blood and body fluid reviews had no adverse impact on test turnaround time. The resident contribution to workflow resulted in a corresponding decrease in the number of cases that required attending pathologist review. Faculty and residents viewed the EPAs as beneficial to service and education. CONCLUSIONS.­: The implementation of the EPAs had a beneficial effect on the laboratory, the trainees, and faculty. Our experience may be helpful to other training programs as EPAs become more widely implemented in residency training.

IgM Plasma Cell Myeloma.

OBJECTIVES: Immunoglobulin M plasma cell myeloma (IgMPCM) is a rare entity that is difficult to distinguish from other IgM-related neoplasms. The study aims to characterize the clinicopathologic features of IgMPCM, including MYD88 L265P and CXCR4 mutations. METHODS: From our institutional archives, bone marrow biopsy specimens from January 1, 2008, to December 1, 2018, with monotypic plasma cells (PCs) expressing IgM that met current International Myeloma Working Group/World Health Organization criteria for PCM were included. Sanger sequencing was used to test for MYD88 L265P and WHIM-like CXCR4 mutations. RESULTS: Nine cases of IgMPCM were identified. Serum IgM paraproteins were detected in eight cases. CD138-positive PC burden averaged 41.9% (5%-80%). In four cases, PCs had lymphoplasmacytic morphology with cyclin D1 expression by immunohistochemistry. Three of four tested cases were positive for t(11;14) by fluorescence in situ hybridization, one with monosomy 13. The remaining case was positive for del13q14. All were negative for MYD88 L265P and WHIM-like CXCR4 mutations. Eight patients received immunochemotherapy, with four receiving autologous hematopoietic stem cell transplant. Median follow-up was 61 months (range, 11-120). All patients were alive except one. CONCLUSIONS: Distinguishing IgMPCM from other IgM-related disorders requires correlation with clinical, laboratory, and radiologic findings. Exclusion of MYD88 L265P and WHIM-like CXCR4 mutations may be useful to diagnose IgMPCM.

Cardiac Amyloidosis Screening at Trigger Finger Release Surgery.

Cardiac amyloidosis is often preceded by orthopedic manifestations such as carpal tunnel syndrome, and 10% of patients who underwent idiopathic carpal tunnel release surgery will have biopsy-confirmed amyloid deposits in the tenosynovial sheath. Trigger finger is also commonly reported in patients with amyloidosis and involves the same tendon sheath as carpal tunnel syndrome, but the prevalence of amyloid deposition is unclear. This prospective cross-sectional study enrolled 100 patients aged ≥50 years at the time of surgery for idiopathic trigger finger. Patients underwent release surgery, and a sample of the tenosynovium of the affected finger was excised, stained with Congo red, and subtyped with mass spectrometry if amyloid was demonstrated. Further cardiac evaluation was performed in patients with amyloid deposition. Of the 100 patients (mean age 65.5 ± 8.1 years) enrolled, only 2 demonstrated amyloid deposits on Congo red staining. One patient with previous proteinuric kidney disease had fibrinogen A α-chain amyloidosis, and the other patient had untyped amyloidosis. Neither patient had cardiac involvement. A total of 13 of the 100 patients underwent concomitant carpal tunnel release surgery, and 2 of these patients had amyloid deposits in the carpal tunnel with "false-negative" samples from the trigger finger tenosynovium. In conclusion, biopsy during trigger finger release surgery demonstrated a 2% yield for amyloidosis, which is significantly lower than the previously published yield of 10% during carpal tunnel release surgery. This observation has important implications for the development of diagnostic algorithms to screen patients for amyloidosis during orthopedic operations.

Update on the Diagnosis and Treatment of POEMS (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal Gammopathy, and Skin Changes) Syndrome: A Review.

IMPORTANCE: POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare plasma cell disorder characterized by demyelinating peripheral neuropathy and clonal plasma cell proliferation. Clinical manifestations are believed to be associated with a surge of inflammatory and angiogenic mediators, including interleukins and vascular endothelial growth factor (VEGF), elicited by clonal and polyclonal plasma cells. The clinical manifestations of POEMS syndrome can be debilitating; therefore, early diagnosis is essential. This review discusses several aspects of POEMS syndrome and includes the most recently published findings, with a special emphasis on diagnosis and treatment strategies. OBSERVATIONS: POEMS syndrome may be underdiagnosed because of its rarity, and it can be mistaken for chronic inflammatory demyelinating polyneuropathy; this misdiagnosis may lead to delayed therapy and progressive worsening of symptoms, especially neuropathy. Therefore, in addition to measurement of the VEGF level, patients with a monoclonal protein detected in blood and/or urine and neuropathy should be evaluated for POEMS syndrome with use of imaging to assess whether sclerotic bone lesions, effusions, and organomegaly are present. Clinical trials are scant, and treatment is largely based on small case series in which plasma cell-directed therapies, borrowed from the myeloma armamentarium, were used. High-dose melphalan and autologous hematopoietic cell transplantation may be offered to eligible patients. Lenalidomide and dexamethasone can be prescribed for patients who are ineligible for transplants. The main goals of therapy are to attain complete hematologic and VEGF responses and to reduce symptoms, although it may take up to 3 years for neurologic deficits to be ameliorated. CONCLUSIONS AND RELEVANCE: POEMS syndrome should be considered in the differential diagnosis for patients who have peripheral neuropathy and paraproteinemia among other multisystem manifestations. The syndrome can be debilitating if not recognized early in its course; thus, appropriate diagnosis and treatment are important for optimal clinical outcomes.

Eosinophilia/Hypereosinophilia in the Setting of Reactive and Idiopathic Causes, Well-Defined Myeloid or Lymphoid Leukemias, or Germline Disorders.

OBJECTIVES: To report the findings of the 2019 Society for Hematopathology/European Association for Haematopathology Workshop within the categories of reactive eosinophilia, hypereosinophilic syndrome (HES), germline disorders with eosinophilia (GDE), and myeloid and lymphoid neoplasms associated with eosinophilia (excluding entities covered by other studies in this series). METHODS: The workshop panel reviewed 109 cases, assigned consensus diagnosis, and created diagnosis-specific sessions. RESULTS: The most frequent diagnosis was reactive eosinophilia (35), followed by acute leukemia (24). Myeloproliferative neoplasms (MPNs) received 17 submissions, including chronic eosinophilic leukemia, not otherwise specified (CEL, NOS). Myelodysplastic syndrome (MDS), MDS/MPN, and therapy-related myeloid neoplasms received 11, while GDE and HES received 12 and 11 submissions, respectively. CONCLUSIONS: Hypereosinophilia and HES are defined by specific clinical and laboratory criteria. Eosinophilia is commonly reactive. An acute leukemic onset with eosinophilia may suggest core-binding factor acute myeloid leukemia, blast phase of chronic myeloid leukemia, BCR-ABL1-positive leukemia, or t(5;14) B-lymphoblastic leukemia. Eosinophilia is rare in MDS but common in MDS/MPN. CEL, NOS is a clinically aggressive MPN with eosinophilia as the dominant feature. Bone marrow morphology and cytogenetic and/or molecular clonality may distinguish CEL from HES. Molecular testing helps to better subclassify myeloid neoplasms with eosinophilia and to identify patients for targeted treatments.

Characterisation and prognostic impact of immunoparesis in relapsed multiple myeloma.

Characterisation and prognostic impact of immunoparesis in relapsed multiple myeloma (MM) is lacking in the current literature. We evaluated 258 patients with relapsed MM, diagnosed from 2008 to 2015, to investigate the prognostic impact of deep immunoparesis on post-relapse survival. On qualitative immunoparesis assessment, no, partial and full immunoparesis was present in 9%, 30% and 61% of patients, respectively. Quantitative immunoparesis was assessed by computing the average relative difference (ARD) between polyclonal immunoglobulin(s) and corresponding lower normal limit(s), with greater negative values indicating deeper immunoparesis. The median ARD was -39%, with an optimal cut-off of -50% for overall survival (OS) by recursive partitioning analysis. Deep immunoparesis (ARD ≤-50%) was associated with a higher tumour burden at first relapse compared to none/shallow [ARD >-50%] immunoparesis. The OS (P = 0·007) and progression-free survival (PFS; P < 0·001) differed significantly between the deep and none/shallow immunoparesis groups. Kaplan-Meier estimates for 3-year OS were 36% and 46%, and for 2-year PFS were 17% and 27%, respectively. On multivariable analysis (MVA) for PFS, both qualitative and quantitative immunoparesis retained negative prognostic impact independently. However, only quantitative immunoparesis was independently prognostic for OS on MVA. Depth of immunoparesis in relapsed MM is an important prognostic factor for post-relapse survival in the era of novel agents and continuous therapy.

IgA plasma cell neoplasms are characterized by poorer long-term survival and increased genomic complexity compared to IgG neoplasms.

The characteristics of the IgA plasma cell neoplasms are not clearly reported in the literature. The main goal of this study is to examine IgA plasma cell neoplasms (PCN) and to compare them to IgG lesions. After at least 5 years from the identification of an M protein, 98 cases were selected, the presentation and clinical evolution of 45 IgA neoplasms were compared to 43 cases of IgG gammopathies. The classification at presentation as monoclonal gammopathy of undermined significance (MGUS)-22 of 45 IgA and 20 of 43 IgG (49 vs 46%), plasma cell myeloma (PCM)-22 of 45 IgA and 22 of 43 IgG (49 vs 51%) and smoldering PCM (SPCM)-1 each (2% for both) was essentially identical. No solitary plasmacytomas were identified. At presentation, IgA patients were younger (66.5 ± 11.3 vs. 69.2 ± 10.7 years), less likely to have bone lesions (12/45 vs 18/43, p < 0.14) or immunoparesis (51% vs. 63%), differences statistically insignificant. Cases with normal fluorescence in-situ hybridization (FISH) results, 27% for IgA vs 61% for IgG (p < 0.037) were statistically different. The IgA patients had worse survival (80 vs 108 months median IgA vs IgG, p < 0.013), difference not detectable in the first 5 years, but substantial after 10. In conclusion, poorer long-term survival and increased genomic complexity by FISH are characteristics of IgA PCNs.

Mutations in Splicing Factor Genes in Myeloid Malignancies: Significance and Impact on Clinical Features.

Components of the pre-messenger RNA splicing machinery are frequently mutated in myeloid malignancies. Mutations in LUC7L2, PRPF8, SF3B1, SRSF2, U2AF1, and ZRSR2 genes occur at various frequencies ranging between 40% and 85% in different subtypes of myelodysplastic syndrome (MDS) and 5% and 10% of acute myeloid leukemia (AML) and myeloproliferative neoplasms (MPNs). In some instances, splicing factor (SF) mutations have provided diagnostic utility and information on clinical outcomes as exemplified by SF3B1 mutations associated with increased ring sideroblasts (RS) in MDS-RS or MDS/MPN-RS with thrombocytosis. SF3B1 mutations are associated with better survival outcomes, while SRSF2 mutations are associated with a shorter survival time and increased AML progression, and U2AF1 mutations with a lower remission rate and shorter survival time. Beside the presence of mutations, transcriptomics technologies have shown that one third of genes in AML patients are differentially expressed, leading to altered transcript stability, interruption of protein function, and improper translation compared to those of healthy individuals. The detection of SF mutations demonstrates the importance of splicing abnormalities in the hematopoiesis of MDS and AML patients given the fact that abnormal splicing regulates the function of several transcriptional factors (PU.1, RUNX1, etc.) crucial in hematopoietic function. This review provides a summary of the significance of the most frequently mutated SF genes in myeloid malignancies and an update on novel targeted therapies in experimental and clinical trial stages.

Monoclonal gammopathy of undetermined significance: A primary care guide.

Monoclonal gammopathy of undetermined significance (MGUS) is commonly diagnosed in outpatients being worked up for an array of clinical concerns. It carries a risk of progression to myeloma and other lymphoproliferative disorders that, albeit low (1% per year), warrants regular follow-up. Patients with MGUS can be risk-stratified on the basis of the amount and type of their monoclonal protein as well as whether they have an abnormal light-chain ratio. Here, we provide a guide to the diagnosis, workup, and management of MGUS.

Impact of Interventions to Change CBC and Differential Ordering Patterns in the Emergency Department.

Objectives: A CBC with leukocyte differential (CBC-DIFF) is a frequently ordered emergency department (ED) test. The DIFF component often does not add to clinical decision making. Our objective was to evaluate the impact of a performance improvement project on CBC ordering. Methods: ED orders for CBC-DIFF were identified through the laboratory information system. Two interventions were evaluated: an educational intervention regarding CBC-DIFF uses and a reprioritization of ED CBC-DIFF and CBC in the electronic medical record (EMR) orders. Pearson χ2 tests were used to assess for differences in the proportions. Results: There was no difference in the proportion of CBC tests performed after the education intervention (175/6,192, 2.8% [95% CI, 2.39%-3.21%] vs 219/6,270, 3.5% [95% CI, 3.05%-3.95%]). There was a significant increase in CBC samples ordered following the EMR intervention (604/6,044, 9.1% [95% CI, 8.37%-9.83%]; P < .01). Conclusions: Reprioritizing EMR laboratory orders can reduce overutilization of CBC-DIFF testing.

T cell Large Granular Lymphocytic Leukemia with Pulmonary Hypertension.

T cell large granular lymphocytic leukemia is a hematological disorder which is characterized by the proliferation of CD 3+ cytotoxic T cells. We present a case about a patient who was diagnosed with T cell large granular lymphocytic leukemia and then developed pulmonary hypertension. He was treated for his leukemia with methotrexate and simultaneously treated for his pulmonary hypertension with selexipag and ambrisentan. As his leukemia improved, we also noticed an improvement in his pulmonary hypertension from a NYHA class IV to class I. Hence, we believe there is an etiopathological link between the T cell large granular leukemia and associated pulmonary hypertension.

High Quality Maize Centromere 10 Sequence Reveals Evidence of Frequent Recombination Events.

The ancestral centromeres of maize contain long stretches of the tandemly arranged CentC repeat. The abundance of tandem DNA repeats and centromeric retrotransposons (CR) has presented a significant challenge to completely assembling centromeres using traditional sequencing methods. Here, we report a nearly complete assembly of the 1.85 Mb maize centromere 10 from inbred B73 using PacBio technology and BACs from the reference genome project. The error rates estimated from overlapping BAC sequences are 7 × 10(-6) and 5 × 10(-5) for mismatches and indels, respectively. The number of gaps in the region covered by the reassembly was reduced from 140 in the reference genome to three. Three expressed genes are located between 92 and 477 kb from the inferred ancestral CentC cluster, which lies within the region of highest centromeric repeat density. The improved assembly increased the count of full-length CR from 5 to 55 and revealed a 22.7 kb segmental duplication that occurred approximately 121,000 years ago. Our analysis provides evidence of frequent recombination events in the form of partial retrotransposons, deletions within retrotransposons, chimeric retrotransposons, segmental duplications including higher order CentC repeats, a deleted CentC monomer, centromere-proximal inversions, and insertion of mitochondrial sequences. Double-strand DNA break (DSB) repair is the most plausible mechanism for these events and may be the major driver of centromere repeat evolution and diversity. In many cases examined here, DSB repair appears to be mediated by microhomology, suggesting that tandem repeats may have evolved to efficiently repair frequent DSBs in centromeres.

Transient abnormal myelopoiesis of a newborn not associated with chromosome 21 abnormalities or GATA1 mutations.

Transient abnormal myelopoiesis (TAM) is a disorder of Down syndrome newborns characterized by megakaryocytic blasts indistinguishable from acute myeloid leukemia (AML), which undergoes spontaneous remission. Acquired GATA1 mutations are present in blasts of both TAM and the subsequent AML which sometimes develops. We present a unique case of a newborn with leukemic megakaryoblasts indistinguishable from those of TAM who had neither extra material from chromosome 21 in the germline or blasts, nor evidence of GATA1 mutations. These findings suggest there are other genetic abnormalities that can lead to TAM besides GATA1 mutation in the setting of trisomy 21. Pediatr Blood Cancer 2015;62:353-355. © 2014 Wiley Periodicals, Inc.