Laboratory Detection and Initial Diagnosis of Monoclonal Gammopathies.

CONTEXT.­: The process for identifying patients with monoclonal gammopathies is complex. Initial detection of a monoclonal immunoglobulin protein (M protein) in the serum or urine often requires compilation of analytical data from several areas of the laboratory. The detection of M proteins depends on adequacy of the sample provided, available clinical information, and the laboratory tests used. OBJECTIVE.­: To develop an evidence-based guideline for the initial laboratory detection of M proteins. DESIGN.­: To develop evidence-based recommendations, the College of American Pathologists convened a panel of experts in the diagnosis and treatment of monoclonal gammopathies and the laboratory procedures used for the initial detection of M proteins. The panel conducted a systematic literature review to address key questions. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, recommendations were created based on the available evidence, strength of that evidence, and key judgements as defined in the Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision framework. RESULTS.­: Nine guideline statements were established to optimize sample selection and testing for the initial detection and quantitative measurement of M proteins used to diagnose monoclonal gammopathies. CONCLUSIONS.­: This guideline was constructed to harmonize and strengthen the initial detection of an M protein in patients displaying symptoms or laboratory features of a monoclonal gammopathy. It endorses more comprehensive initial testing when there is suspicion of amyloid light chain amyloidosis or neuropathies, such as POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome, associated with an M protein.

COVID-19 in pregnancy by race and ethnicity: Implications for development of a vaccination strategy.

OBJECTIVE: COVID-19 and associated morbidity and mortality has disproportionately affected minoritized populations. The epidemiology of spread of COVID-19 among pregnant women by race/ethnicity is not well described. Using data from a large healthcare system in California, we estimated prevalence and spread during pregnancy and recommend a vaccination approach based on minimizing adverse outcomes. METHODS: Patients delivering at Sutter Health are tested (molecular) for COVID-19. These results were combined with antibody test results, using samples drawn at delivery. For each racial/ethnic group, we estimated prevalence of COVID-19, using logistic regression to adjust for known sociodemographic and comorbid risk factors. Testing for immunoglobulin G and immunoglobulin M provided insight into timing of infections. RESULTS: Among 17,446 women delivering May-December, 460 (2.6%) tested positive (molecular). Hispanic women were at 2.6 times the odds of being actively infected as White women (odds ratio = 2.6, 95% confidence interval = 2.0-3.3). August and December were the highest risk periods for active infection (odds ratio = 3.5, 95% confidence interval = 2.1-5.7 and odds ratio = 6.1, 95% confidence interval = 3.8-9.9, compared with May, respectively). Among 4500 women delivering October-December, 425 (9.4%) had positive molecular or antibody tests, ranging from 4.0% (Asian) to 15.7% (Hispanic). Adjusting for covariables, compared with White patients, odds of infection was similar for Black and Asian patients, with Hispanic at 2.4 (1.8-3.3) times the odds. CONCLUSION: COVID-19 prevalence was higher among Hispanic women at delivery and in the last trimester than their White counterparts. Higher rates in Black patients are explained by other risk factors. Resources should be directed to increase vaccination rates among Hispanic women in early stages of pregnancy.

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology.

CONTEXT: - A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia. OBJECTIVE: - To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage. DESIGN: - The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus. RESULTS: - Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported. CONCLUSIONS: - The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.

BCL6 expression correlates with the t(1;19) translocation in B-lymphoblastic leukemia.

OBJECTIVES: Study to date suggests that BCL6 protein expression in B-cell neoplasia predominates in germinal center-derived tumors, but less is known regarding its expression in B-lymphoblastic leukemia. Therefore, we designed a comprehensive study of BCL6 expression in B-lymphoblastic leukemia. METHODS: BCL6, LMO, and HGAL protein expression in B-lymphoblastic leukemia was investigated using immunohistochemical staining of paraffin-embedded bone marrow specimens. Cryptic TCF3(E2A)-PBX1 rearrangements were investigated using interphase fluorescence in situ hybridization. RESULTS: Six (12%) of 52 B-lymphoblastic leukemias demonstrated BCL6 protein expression, with B-cell lymphoblastic leukemias containing a t(1;19) translocation demonstrating the strongest staining (three of three). Additional t(1;19) cases beyond the screening study showed similar results. Public microarray expression database mining showed that BCL6 messenger RNA expression levels in B-lymphoblastic leukemia correlated with the protein expression findings. Finally, other markers of B-cell development correlated with BCL6 expression in t(1;19) B-lymphoblastic leukemia cases, with LMO2 and HGAL proteins expressed in six (67%) of nine and eight (89%) of nine cases, respectively. CONCLUSIONS: BCL6 expression is present in a subset of B-lymphoblastic leukemias, especially in cases containing the 1;19 translocation. Investigation for TCF3(E2A)-PBX1 rearrangements may be useful in BCL6-positive B-lymphoblastic leukemia.

Rituximab therapy for pure red cell aplasia due to anti-epoetin antibodies in a woman treated with epoetin-alfa: a case report.

INTRODUCTION: Pure red cell aplasia due to anti-epoetin antibodies is a known complication of epoetin therapy for anemia due to chronic kidney disease. This disease has not previously been well described in the setting of therapy for chronic hepatitis C virus infection. While treatment for pure red cell aplasia due to anti-epoetin antibodies is usually with immunosuppressive therapy such as calcineurin inhibition, the safety of this treatment in chronic hepatitis C virus infection is unknown. To date, little has been published on the efficacy of rituximab on pure red cell aplasia due to anti-epoetin antibodies. CASE PRESENTATION: This report describes a 65-year-old Asian-American woman who developed pure red cell aplasia from high titer neutralizing anti-epoetin antibodies after epoetin-alfa therapy during ribavirin and peg-interferon treatment for chronic hepatitis C virus infection. We describe the outcome of her treatment with rituximab. The reticulocyte count increased, and anti-epoetin antibody titer decreased with a loss of neutralizing activity in vitro, leading to a reduction in blood transfusions, and eventual resolution of anemia, without reactivation of hepatitis C virus. CONCLUSION: The diagnosis of pure red cell aplasia from anti-epoetin antibodies should be considered in patients undergoing therapy for chronic hepatitis C virus infection who develop severe anemia after administration of erythropoietin or darbepoetin. Though it is currently an off-label indication, rituximab is a therapeutic option for patients with pure red cell aplasia due to anti-epoetin antibodies.

Chromatin condensation in terminally differentiating mouse erythroblasts does not involve special architectural proteins but depends on histone deacetylation.

Terminal erythroid differentiation in vertebrates is characterized by progressive heterochromatin formation and chromatin condensation and, in mammals, culminates in nuclear extrusion. To date, although mechanisms regulating avian erythroid chromatin condensation have been identified, little is known regarding this process during mammalian erythropoiesis. To elucidate the molecular basis for mammalian erythroblast chromatin condensation, we used Friend virus-infected murine spleen erythroblasts that undergo terminal differentiation in vitro. Chromatin isolated from early and late-stage erythroblasts had similar levels of linker and core histones, only a slight difference in nucleosome repeats, and no significant accumulation of known developmentally regulated architectural chromatin proteins. However, histone H3(K9) dimethylation markedly increased while histone H4(K12) acetylation dramatically decreased and became segregated from the histone methylation as chromatin condensed. One histone deacetylase, HDAC5, was significantly upregulated during the terminal stages of Friend virus-infected erythroblast differentiation. Treatment with histone deacetylase inhibitor, trichostatin A, blocked both chromatin condensation and nuclear extrusion. Based on our data, we propose a model for a unique mechanism in which extensive histone deacetylation at pericentromeric heterochromatin mediates heterochromatin condensation in vertebrate erythroblasts that would otherwise be mediated by developmentally-regulated architectural proteins in nucleated blood cells.

Medulloblastoma simulating acute myeloid leukemia: case report with a review of "myeloid antigen" expression in nonhematopoietic tissues and tumors.

Medulloblastoma is a primitive neuroectodermal tumor arising in the posterior fossa usually in the first decade of life. Systemic metastases are infrequent at diagnosis and usually occur after surgical resection or shunt placement. We report a rare case of medulloblastoma in an 18-year-old woman who presented with headache, leukopenia, and anemia. Neurologic examination was normal. Bone marrow evaluation revealed primitive cells morphologically resembling blasts. By flow cytometry, these cells lacked CD45 and expressed CD13/33, CD15, CD34, HLA-DR, and strong CD56. The presence of myeloid antigens and CD34 suggested acute myeloid leukemia; however, the bone marrow core biopsy architecture and tumor cells in cerebrospinal fluid were more compatible with a nonhematopoietic tumor. Further workup revealed a cerebellar mass, and a diagnosis of desmoplastic medulloblastoma was made. To our knowledge, this is the first reported case of a nonhematopoietic small round blue-cell tumor expressing multiple myeloid antigens and CD34 by flow cytometry.

Acquired Pelger-Huët anomaly in association with concomitant tacrolimus and mycophenolate mofetil in a liver transplant patient: a case report and review of the literature.

Pelger-Huët anomaly is a congenital or acquired abnormality of neutrophil nuclear segmentation. The acquired form may be a result of a clonal myeloid malignancy, such as myelodysplastic syndrome, or may be a secondary nonclonal change related to a variety of underlying causes, including infections and medications. We report a case of a 56-year-old man who developed acquired Pelger-Huët anomaly following liver transplantation while on the immunosuppressive agents tacrolimus and mycophenolate mofetil. These medications have been reported in association with this abnormality, but usually as a single agent or in combination with other drugs. In our case, the Pelger-Huët anomaly may be the result of the combination of these 2 drugs or mycophenolate alone with subsequent desensitization because resolution of the abnormality occurred after a reduction in mycophenolate mofetil dose, and the abnormality did not recur when mycophenolate mofetil was increased to a dose previously associated with Pelger-Huët anomaly during the time that tacrolimus was discontinued.

Erythrophagocytosis by dysplastic neutrophils in chronic myelomonocytic leukemia and subsequent transformation to acute myeloid leukemia.

Erythrophagocytosis by neutrophils is a rare phenomenon in myeloid malignancies, and its clinicopathologic significance is not fully understood. We report a unique case of erythrophagocytosis by dysplastic neutrophils in chronic myelomonocytic leukemia (CMML) and subsequent transformation to acute myeloid leukemia (AML). Review of multiple marrow samples, both pretreatment and post-treatment, demonstrated a correlation between percentage of dysplastic neutrophils and degree of erythrophagocytosis. Erythrophagocytosis was observed only in dysplastic forms of neutrophils. Post-transplant marrows with engraftment of donor cells showed no neutrophilic dysplasia or erythrophagocytosis. Possible mechanisms of neutrophilic erythrophagocytosis in myeloid malignancies are discussed.

Clinically relevant differences in prothrombin time and INR values related to blood sample collection in plastic vs glass tubes.

We compared prothrombin times (PTs) and international normalized ratios (INRs) for blood samples drawn into plastic vs glass collection tubes. We collected 60 venous blood samples into 4.5-mL glass and 2 plastic tubes (2.7 and 3.5 mL). An additional 153 samples, including 63 from warfarin-anticoagulated patients, were collected only in glass and 2.7-mL plastic tubes. The PTs and INRs were determined following routine laboratory procedures. A subset of 35 frozen aliquot samples was analyzed with a different instrument-reagent combination. The PTs and INRs for samples in plastic tubes were significantly lower than for samples in glass tubes. The mean INR differences increased with INR magnitude from approximately -0.1 (INR, 1.5) to -0.7 (INR, 4.5). Of the plastic tube INRs, 50% were more than 10% lower than INRs from samples collected in glass tubes. Therapeutic monitoring based on plastic-tube INRs could result in higher doses of warfarin.

Invasive micropapillary carcinoma of the breast is associated with chromosome 8 abnormalities detected by comparative genomic hybridization.

Invasive micropapillary carcinoma (IMC) of the breast is a rare variant of invasive ductal carcinoma (IDC) characterized by unique histology and an extremely high incidence of lymph node metastases (approximately 95%). Comparative genomic hybridization (CGH) was used to characterize DNA extracted from 16 archival IMC cases to identify clonal genetic changes associated with this unique and highly metastatic cancer subtype. The average number of chromosomal alterations per IMC tumor was 7.4 +/-2.9 (3.4 gains and 3.9 losses), fewer than the number that we have observed in IDCs not otherwise specified (9.5 +/-6.6), IDCs with erbB-2 gene amplification (12.6 +/-5.9), and invasive lobular carcinomas (8.2 +/-5.5). The mean number of changes in IMC was significantly higher than we have observed in the rarely metastasizing tubular subtype of IDC (3.9 +/-2.3, P = 0.001), but less than the more aggressive subset of erbB-2-amplified IDC (P = 0.02). Remarkably, 100% of IMCs demonstrated loss involving the short arm of chromosome 8 (8p). Six cases showed loss of the entire 8p arm, whereas in 10 cases the loss was limited to the distal portion (8p21-pter) with localized gain of proximal 8p (8p11-p12). A reciprocal gain of 8q was detected in 14 cases (88%). Other common alterations included loss of 17p in 50% of tumors and loss of 16q in 50% of IMC cases. Gains of 17q (38%), 1q (31%), and 16p (25%) were also commonly detected. In comparison, IDCs (not otherwise specified), IDCs of the tubular subtype, and invasive lobular carcinomas showed only modest 8p loss (33%, 28%, and 13%, respectively). This region of chromosome 8 may contain 1 or more genes whose loss leads to this particular histology and/or the lymphotrophic phenotype associated with this histopathologic pattern.

Pediatric acute blastic natural killer cell leukemia.

The goal of this report is to describe a rare case of pediatric blastic natural killer (NK) cell leukemia and to compare pediatric blastic NK cell leukemia/lymphoma to other reported cases of pediatric NK cell leukemia. The patient, a 9-year-old girl, presented with acute leukemia with a phenotype similar to adult blastic NK cell leukemia/lymphoma. The blasts were agranular and expressed CD7, 45, 56, and HLA-DR, but not CD3, 11c, 13, 33, or TdT. She had a complete response to ALL-directed chemotherapy, but had multiple relapses involving the cerebrospinal fluid, nasal sinus, lymph node and skin. In addition to the reported case, a review of the literature identified 9 previously reported cases of NK cell leukemia in patients 18 years of age or less. Cases were subdivided into blastic, acute/aggressive, and myeloid precursor NK cell leukemia based upon CD13/33 expression and morphologic characteristics. Compared to pediatric acute/aggressive NK cell leukemia, children with blastic NK cell leukemia showed greater variation in age and race. Prognosis was poor for all groups. Pediatric blastic NK cell leukemia is a distinct clinicopathologic entity which differs from other types of pediatric NK cell leukemia.