Context: IntelliSep by Cytovale has received United States (U.S.) Food and Drug Administration (FDA) approval as a sepsis biomarker test. However, the clinical utility of this new test is not assessed in emergency departments. Objective: We investigated the clinical utility of this test using 44 patients visiting the emergency department at The University of Kansas Medical Center by comparing it with the monocyte distribution width (MDW) and other biomarkers including the von Willebrand factor (vWF) and ADAMTS13. Design and Methods: IntelliSep assesses the cellular host response via deformability cytometry of biophysical leukocyte properties and produces a score (IntelliSep Index; ISI: from 0.1 (lowest risk) to 10 (highest risk). We measured the ISI in 44 patients (19 high probability and 25 low probability of sepsis groups) using EDTA-anticoagulated blood. Left over plasma was used for measuring the plasma von Willebrand factor (vWF) and ADAMTS13 antigen by ELISA assays. The MDW was obtained during routine CBC analysis using a Beckman hematology analyzer. The lactate and high-sensitivity troponin I levels were measured using a Beckman analyzer. Procalcitonin was measured using a Cobas e801 analyzer. Results: The median ISI was twofold higher in the high-probability group than in the low-probability group (p < 0.01) while the median MDW was 34.5% higher in the high-probability group than in the low-probability group (p < 0.01). However, the correlation between the ISI and MDW was only modest (r = 0.66). In addition, significantly higher levels of plasma vWF antigen but lower levels of plasma ADAMTS13 antigen in the high-probability group were found, resulting in significantly higher vWF/ADAMTS13 ratios in the high-probability group than in the low-probability group. Conclusions: The new IntelliSep test along with vWF/ADAMTS13 ratios may be useful for the early diagnosis of sepsis in patients visiting the emergency department, which appears to be superior to the traditional marker, MDW.

This report describes a rare case of relapsed multiple myeloma in the gastrointestinal tract with aberrant CD3 expression. Upon admission for acute renal failure, the patient had abnormal computed tomography scan findings of the abdomen and pelvis. Subsequent colonoscopy found numerous polyps and masses. Histologic examination of a biopsy of one of the masses revealed a diffuse atypical cellular infiltrate with undifferentiated morphology in the submucosa that was positive for CD3, CD4, weak and variable CD79a, CD138, BCL2, CMYC, MUM1, vimentin, and monoclonal cytoplasmic lambda. A diagnosis of recurrent plasma cell myeloma was made. The positive expression of T-cell markers CD3 and CD4 may cause confusion with T-cell lymphoma in a scenario with undifferentiated morphology as in our case.

This study describes an unusual case of multiple myeloma that progressed to anaplastic multiple myeloma in the pleural fluid. The Wright-stained cytospin of the pleural fluid showed a predominant population of mononuclear plasma cells with pleomorphic nuclei, characterized by both small and large nuclei, which is typical of anaplastic multiple myeloma. However, there were also more binuclear plasma cells with pleomorphic nuclei. Morphometric analysis showed that the mean nuclear length was 1.9-fold and 2.3-fold higher in the large nuclei compared to the small nuclei for the mononuclear plasma cells and binuclear plasma cells, respectively (p<0.001). The patient received B cell maturation antigen chimeric antigen receptor T cell (CAR-T) therapy for relapsed disease, with a significant reduction of the serum monoclonal paraprotein level at day 51 post-therapy. Pathologists should be aware that pleomorphic binuclear plasma cells can be part of the morphologic spectrum in anaplastic multiple myeloma.

This study describes a rare case of Burkitt lymphoma with aberrant expression of cytoplasmic terminal deoxynucleotidyl transferase (TdT). Flow cytometry demonstrated a predominantly mature B cell immunophenotype as expected for Burkitt lymphoma, however, the immature marker TdT was also expressed. Immunohistochemistry showed that TdT was localized to the cytoplasm, with absent nuclear localization. The patient received standard intensive chemotherapy for Burkitt lymphoma and has remained in remission for nine years. Pathologists should be aware of this unusual phenomenon of aberrant cytoplasmic TdT expression to avoid confusing Burkitt lymphoma with B cell lymphoblastic leukemia/lymphoma.

INTRODUCTION:Factor XIII deficiency is a rare bleeding disorder which could be severe if inherited or less severe if acquired. We report a case of acquired Factor XIII inhibitor in a 75-year-old male with a suspicious left renal mass treated perioperatively with therapeutic plasma exchange (TPE).PATIENT AND METHOD:To perform kidney biopsy and ablation of the renal mass, six daily TPE treatments were performed before and after biopsy to minimize bleeding risk because the patient did not respond to drug therapy. Both thromboelastography (TEG) and laboratory-based coagulation tests were performed to assess coagulation status prior to and after TPE.RESULTS:The biopsy indicated oncocytoma which was removed by surgical procedure. Factor XIII activity remained below 15 % throughout TPE treatments, but Factor XIII inhibitor titer reduced from initial positive value of 1:40 to negative following the third TPE and remained negative through the sixth TPE. Unfortunately, the inhibitor titer was positive at 1:20 in the fifth month and 1:5 in the sixth month during follow-up.CONCLUSIONS:TPE is useful in removing XIII inhibitory factor, but the effects are only short term.

Hemophagocytic Lymphohistiocytosis Syndrome Secondary to Disseminated Histoplasmosis in a Presumably Immunocompetent Adolescent: A Novel Case

Factor V inhibitors are a rare cause of life-threatening bleeding. We present a case of an acquired factor V inhibitor likely caused by coronavirus disease 2019 infection. Bleeding was manifested by severe anemia requiring frequent red-cell transfusion, left psoas muscle hematoma, and left retroperitoneal cavity hematoma. Factor V activity was less than 1% and the factor V inhibitor titer was 31.6 Bethesda units. Severe acute respiratory syndrome coronavirus 2 RNA testing of the nasopharynx was positive 2 weeks before presentation and continued to be positive for 30 days. The patient failed treatment with intravenous immunoglobulin and dexamethasone. Three cycles of plasmapheresis with fresh frozen plasma replacement resulted in correction of the bleeding and laboratory coagulopathy. This is the first reported case of a factor V inhibitor in a coronavirus disease 2019 patient and suggests that plasmapheresis may be a successful treatment strategy.

: Lupus anticoagulant hypoprothrombinemia syndrome (LAHS) is a rare disorder characterized by development of lupus anticoagulant and antiprothrombin antibodies. The most common clinical manifestation is bleeding. Clinical management can be challenging due to the subtle balance between the bleeding and thrombotic tendencies. We report a novel case of LAHS in which the patient experienced the sequence of hemorrhage-thrombosis-hemorrhage before eventually dying of fatal pulmonary embolism and pulmonary hemorrhage. Specifically, she presented with multiple gastrointestinal bleeding episodes, followed by multifocal subdural hematomas, pulmonary embolism after normalization of prothrombin activity levels with immunosuppression, and finally with fatal pulmonary hemorrhage after enoxaparin treatment for pulmonary embolism. This case illustrates the importance of recognizing early minor bleeding episodes, and detecting specific antiprothrombin antibodies, in the diagnosis of LAHS. Furthermore, it highlights the complex challenge of normalizing prothrombin activity levels while at the same time preventing medical complications.

To evaluate the characteristic features of the dilute Russell's viper venom time (DRVVT) titer in the antiphospholipid syndrome (APS). The medical record of 3660 consecutive patients with DRVVT orders between 2006 and 2015 were examined for criteria satisfying the diagnosis of APS. DRVVT titer was studied as a function of titer distribution, titer stability, and clinicopathologic features. Twenty-six patients were diagnosed with APS based on a persistently positive DRVVT and a history of arterial or venous thrombosis. DRVVT titer was mostly of low magnitude (65–77% of patients), was of similar value between initial and repeat testing (mean DRVVT titer 1.40 vs. 1.38; P = 0.858; mean time interval 216 days), and was positively associated with anticardiolipin antibodies (IgG and IgM) and antibeta-2-glycoprotein I antibodies (IgG and IgM) (P < 0.020). Low titer and moderate/high titer DRVVT were associated with a triple positive antiphospholipid antibody profile in 0 and 62% of patients, respectively (P < 0.020). DRVVT titer in APS was predominantly low in magnitude, stable over time, and associated with specific antiphospholipid antibody profiles.

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder associated with hematoproliferative disorders, autoimmune conditions, neoplasia and cardiovascular disorders that often present a diagnostic challenge. Monoclonal gammopathy of undetermined significance (MGUS) is one of the most common causes of AVWS that typically presents later in life with mucocutaneous or postsurgical bleeding and multimers consistent with type I or II von Willebrand disease (VWD). Here, we present the case of a patient with a 32-year history of type III VWD that was ultimately found to be AVWS related to an IgG MGUS. In this case report, we highlight the diagnostic challenges of AVWS to ensure proper identification and potentially lifesaving treatment of this rare disorder.

Context.—D-dimer is widely used for exclusion, or as an aid in diagnosis, of venous thromboembolism (VTE); however, the D-dimer assay methods available from manufacturers and the laboratory application of those methods vary widely. Objective.—To describe the current laboratory practice regarding the assay and reporting of D-dimer. Design.—Laboratories’ D-dimer proficiency testing data were analyzed and laboratory practices regarding the performance and reporting of D-dimer were surveyed. Results.—Initial grading of D-dimer proficiency testing demonstrated high variability within and among methods. This variability continued to be present for several years after attempts to intervene. The number of laboratories using D-dimer to exclude VTE grew from 1500 in 2004 to more than 3500 in 2012. Survey and proficiency testing data demonstrated that 33% of laboratories changed the type or magnitude of units from that recommended by the manufacturer, a practice associated with as much as a 20fold increase in the failure of proficiency testing. Many laboratories used a threshold for the exclusion of VTE that is higher than that recommended by the manufacturer. Many laboratories continue to use qualitative assays with insufficient sensitivity for exclusion of VTE. Conclusions.—There is considerable variability both within and among quantitative methods used to assay Ddimer by laboratories. Laboratory practice continues to vary widely regarding the type and magnitude of units reported and the setting of the threshold for the exclusion of VTE. Although improved, the variability continues despite initial efforts to intervene. (Arch Pathol Lab Med. 2013;137:1030–1038; doi: 10.5858/arpa.2012-0296-CP)

Context.—D-dimer is widely used for exclusion, or as an aid in diagnosis, of venous thromboembolism (VTE); however, the D-dimer assay methods available from manufacturers and the laboratory application of those methods vary widely. Objectives.—To describe the current laboratory practice regarding the assay and reporting of D-dimer. Design.—Laboratories' D-dimer proficiency testing data were analyzed and laboratory practices regarding the performance and reporting of D-dimer were surveyed. Results.—Initial grading of D-dimer proficiency testing demonstrated high variability within and among methods. This variability continued to be present for several years after attempts to intervene. The number of laboratories using D-dimer to exclude VTE grew from 1500 in 2004 to more than 3500 in 2012. Survey and proficiency testing data demonstrated that 33% of laboratories changed the type or magnitude of units from that recommended by the manufacturer, a practice associated with as much as a 20-fold increase in the failure of proficiency testing. Many laboratories used a threshold for the exclusion of VTE that is higher than that recommended by the manufacturer. Many laboratories continue to use qualitative assays with insufficient sensitivity for exclusion of VTE. Conclusions.—There is considerable variability both within and among quantitative methods used to assay D-dimer by laboratories. Laboratory practice continues to vary widely regarding the type and magnitude of units reported and the setting of the threshold for the exclusion of VTE. Although improved, the variability continues despite initial efforts to intervene.

Context.-Proper diagnosis and therapy of fibrinogen deficiency requires high-quality fibrinogen assays.Objective.-To assess the interlaboratory bias, precision, and grading of fibrinogen assays used by laboratories participating in the United States College of American Pathologists proficiency testing program in coagulation.Design.-Two identical vials of normal plasma were sent to more than 3500 laboratories. Participants measured fibrinogen levels using local methods.Results.-Fifty different fibrinogen methods were evaluated. All-method bias was 8.3% (range of method-specific biases, 0.0%-27.0%) and all-method coefficient of variation was 7.7%(range of method-specific coefficients of variation, 0.7%-25.8%). After controlling for reagent/instrument type, mean fibrinogen levels were 11.6% higher for prothrombin time-based reagents compared to Clauss (P<.001), and coefficient of variation was 46% lower for mechanical endpoint instruments compared to photo-optical. Most testing events (97.4%) could be reliably graded as pass or fail using a target range of +/- 20% from the method mean (total pass rate, 98.8%). Total fail rate was 3.0-fold lower for mechanical instruments compared to photo-optical (0.5% versus 1.5%, P=.001). Nonetheless many photo-optical methods had very high precision and very low fail rates.Conclusions.-Fibrinogen assays showed highly variable methodology and performance characteristics. Bias, precision, and grading were affected by the type of reagent or instrument used. (Arch Pathol Lab Med. 2012; 136: 789-795; doi: 10.5858/arpa.2011-0322-OA)

CONTEXT Hereditary and acquired deficiencies of antithrombin (AT), protein C (PC), and protein S (PS) are risk factors for venous thromboembolism. Proper diagnosis requires high-quality assays for these proteins. OBJECTIVE To determine the accuracy and interlaboratory precision of AT, PC, and PS assays used by laboratories participating in the United States College of American Pathologists proficiency testing program in thrombophilia and to grade the performance of laboratories. DESIGN Standardized normal plasma with assigned analyte values was sent in 2 separate challenges to participating laboratories. Participants measured AT, PC, and PS levels using local methods. RESULTS When compared with the assigned values for the international standard, the order of assay accuracy from highest to lowest was AT activity, PC antigen, AT antigen, total PS antigen, PC activity, PS activity, and free PS antigen (range of assay bias, 2.6%-8.8%). The order of assay precision from highest to lowest was PC activity, AT activity, AT antigen, total PS antigen, PS activity, free PS antigen, and PC antigen (range of assay coefficient of variation, 6.1%-20.0%). Most testing events (87.8%) could be graded as pass or fail using a target range of ±3 standard deviations from the method-specific mean. The pass rate was 98.2% for all AT, PC, and PS testing events combined. CONCLUSIONS Accuracy and precision were higher for AT assays and lower for PC and PS assays. It was feasible to grade individual laboratory performance.

The variable natural history of mucosa-associated lymphoid tissue (MALT) lymphoma poses a challenge in predicting clinical outcome. Since Wnt signaling, as indicated by nuclear localization of beta-catenin, is believed to be key in stem cell activation and stem cell self-renewal, we explored the possibility that it might have a predictive value in marginal zone lymphoma. We chose to analyze pbeta-catenin-S552 because its nuclear localization by immunohistochemistry appears to coincide with Wnt signaling-initiated tumorigenesis in intestinal and hematopoietic tissues. Wnt signaling and activation was studied in 22 tissue samples of extranodal marginal zone lymphoma, atypical lymphoid hyperplasia, reactive lymphoid hyperplasia, and normal lymphoid tissue to determine whether Wnt signaling could help distinguish MALT lymphoma from benign lesions. Compared to normal or reactive lymphoid tissue, we found increased nuclear expression of localized pbeta-catenin-S552 in atypical lymphoid hyperplasia and extranodal marginal zone lymphoma. We show that the anti-pbeta-catenin-S552 antibody may be useful in diagnosing and monitoring the progression of or response to therapy of MALT lymphoma.

T cells coexpressing CD3 and CD10 are a characteristic feature of angioimmunoblastic T-cell lymphoma (AITL) [1]. However, they are not unique to AITL, as these cells are also present in B cell lymphoma and reactive lymphoid hyperplasia [2]. To determine the significance of CD3+ CD10+ T cells, we used flow cytometry with cell sorting and molecular biology techniques for T cell gene rearrangement to study T cells from patients with AITL, B cell lymphoma, and reactive lymph node hyperplasia. We found that CD3+ CD10+ T cells in B cell lymphoma and reactive lymphoid hyperplasia were polyclonal. In early stage of AITL, they were oligoclonal, and became monoclonal as AITL progressed. These findings illustrate the differences between early and late lymphoma and could be important for the diagnosis of AITL.

Context.—The international normalized ratio (INR) is widely used to monitor oral anticoagulation and to evaluate patients with coagulation disorders. Objective.—To examine the variability of the performance and reporting of the INR and to evaluate laboratory calculation of the INR. Design.—Between 1993 and 2003, laboratories participating in proficiency testing were surveyed. Participants provided the international sensitivity index and the mean normal prothrombin time used to calculate the INR. The INR was calculated from the data provided and compared with the INR reported to determine if the calculation was correct. Results.—Survey data regarding the INR collected between 1993 and 2003 demonstrate an improvement in reporting, using appropriate anticoagulant, using lower international sensitivity index reagents, and matching international sensitivity index and prothrombin time method. The all-method coefficient of variation of the INR improved from 18% to 5.8%. Among 3813 laboratories studied in 2002 and 2003, 4.1% miscalculated INR. Of 29 laboratories that reported investigation of the INR miscalculation, 11 (38%) reported correcting an INR that was being reported in patient results and that this error was corrected as a result of the study. Since beginning grading of the INR calculation, miscalculation of the INR has fallen to less than 1%. Conclusions.—Recommendations for change in laboratory practice made by consensus conferences are implemented during the course of many years. Difficulty calculating the INR was documented, and both the calculation and the variability in the reporting of the INR showed improvement. Proficiency testing, when closely evaluated and acted on, can have a direct impact on the quality of patient care.

External quality assurance (EQA) is an important component of the total quality assurance program of a clinical hemostasis laboratory. The College of American Pathologists (CAP) helps meet this requirement by providing a proficiency testing program that evaluates a broad range of hemostasis methods and analytes. This article reviews the published experience of the CAP proficiency testing program in hemostasis. The purpose is to formulate general conclusions about the benefits of EQA. Between 1963 and 2006, the performance characteristics of a variety of tests have been evaluated, including the prothrombin time, activated partial thromboplastin time, coagulation factor activity assays (e.g., fibrinogen, factor [F] VIII, FIX, FXI), von Willebrand factor assays, unfractionated heparin monitoring, lupus anticoagulant testing, and platelet function. Based on the results of these evaluations, the major benefits of EQA are to (1) enhance patient care and safety through improved laboratory testing; (2) characterize test accuracy and precision across multiple methods; (3) correlate specific method variables with accuracy and precision; (4) identify interfering substances and quantify their effects across multiple methods; (5) identify clinical laboratories that are at risk for poor performance so that their performance can improve; and (6) satisfy accreditation and regulatory requirements.