The lupus anticoagulant titer is associated with elevated antiphosphatidylserine/prothrombin immunoglobulin-M isotype antibody levels.

Background: Clot based assays used for lupus anticoagulant (LAC) detection are typically interpreted in a qualitative fashion and may not reflect LAC potency. In this cross-sectional study, we describe a method for quantifying the LAC titer using serial (dependent) two-fold dilutions in normal pooled plasma.

Methods: Serial dilutions of 51 residual plasma samples from 50 patients were tested using the Russell's viper venom screening time (DRVVT) and activated partial thromboplastin screening time (APTT) methodologies.

Effect of residual platelets in frozen-thawed plasma on results of dilute Russell's viper venom time assay for lupus anticoagulant testing.

Objectives: To determine the impact of residual platelets on dilute Russell's viper venom time (DRVVT) assay in frozen-thawed plasma submitted for lupus anticoagulant (LAC) testing.

Methods: We measured platelet counts in frozen-thawed samples submitted for LAC testing and evaluated the association between platelet count and the DRVVT screening time and ratios. We also spiked platelets into a LAC-positive sample to observe the effect on the DRVVT.

Acute Intermittent Porphyria as a Rare Challenging Neuro-Metabolic Disease; a Case Report.

Porphyria is a challenging metabolic disease due to its heterogeneous presentation symptoms and its difficult diagnosis. Many affected individuals can complain of recurrent neuro-visceral attacks per year, some of which may be persistent and life-threatening, which is confusing if there is no established diagnosis. Although the motor manifestations, autonomic changes and seizure are highly suggestive, the diagnosis is often overlooked and needs confirmatory genetic testing.

Off-the-shelf cryopreserved platelets for the detection of HIT and VITT antibodies.

Heparin-induced thrombocytopenia (HIT) is suspected much more often than it is confirmed. Technically simple platelet factor 4 (PF4)-polyanion enzyme-linked immunosorbent assays (ELISAs) are sensitive but nonspecific. In contrast, accurate functional tests such as the serotonin release assay, heparin-induced platelet activation assay, and PF4-dependent P-selectin expression assay require fresh platelets and have complex assay end points, limiting their availability to specialized reference laboratories.

Revisiting the effects of spectral interfering substances in optical end-point coagulation assays.

Introduction: Hemolysis, icterus, and lipemia (HIL) are common pre-analytical variables in the clinical laboratory. Understanding their effects on coagulation laboratory results is essential.

Methods: HIL effects on the prothrombin time (PT), activated partial thromboplastin time (APTT), dilute Russell's viper venom time (DRVVT), thrombin time (TT), and protein C chromogenic activity (CFx) were evaluated on the ACL TOP 750 optical analyzer and STA-R Evolution mechanical analyzer (PT and APTT only) by spiking normal donor, patient, and commercial control samples with varying concentrations of hemolysate, bilirubin, or a lipid emulsion.

An In Silico Exploration of the Factors That Affect the Precision of the Bethesda Assay.

Objectives: Despite more than 40 years of experience performing the Bethesda assay (BA), poor intra- and interlaboratory precision remains the biggest laboratory challenge to date.

Methods: The BA procedure was modeled using stochastic simulation techniques to determine the precision of the BA up to dilutions of 1:4,096, to estimate the minimum significant relative change at various inhibitor titers, and to understand the laboratory procedural variables that could significantly affect the performance of the BA at high dilutions.

Results: Selecting the lowest dilution tube with a residual activity closest to 25% for calculating the reported Bethesda titer (BT), using a factor activity assay with a coefficient of variation less than or equal to 7.

Laboratory Evaluation of Antiphospholipid Syndrome.

Objectives: Anti-β2 glycoprotein I domain I (anti-domain I) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies are present in patients with antiphospholipid syndrome (APS); however, their use in evaluation remains unclear.

Methods: Diagnostic attributes of lupus anticoagulant (LAC), anti-domain I IgG, anti-cardiolipin, anti-β2 glycoprotein I (anti-β2GPI), and aPS/PT IgG and IgM antibodies were assessed in 216 patients evaluated for APS.

Results: LAC had the best odds ratio (OR, 14.

Evaluation of Mass Cytometry in the Clinical Laboratory.

Background: Mass cytometry can differentiate more channels than conventional flow cytometry. However, for clinical use, standardization and agreement with well-established methods is paramount. We compared mass cytometry to standard clinical flow cytometry.

Evaluation of a new commercial method for von Willebrand factor multimeric analysis.

Introduction: Evaluation of von Willebrand factor (VWF) multimeric distribution is useful for subclassification of von Willebrand disease (VWD). Multimer analysis has historically been a manual, labor-intensive laboratory-developed test. The first commercial method for multimeric analysis was recently developed that utilizes a single instrument for gel electrophoresis, staining, and densitometry.

Assessment of diagnostic methods for the detection of anticardiolipin and anti-βeta glycoprotein I antibodies in patients under routine evaluation for antiphospholipid syndrome.

Background: We assessed the performance characteristics and correlations of the traditional enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CIA) for detecting IgG and IgM antibodies to cardiolipin (aCL) and beta glycoprotein (anti-βGPI) antibodies in patients under routine evaluation for APS.

Methods: Patients (n = 216) referred to ARUP Laboratories for lupus anticoagulant (LAC) and/or aCL or anti-βGPI IgG/IgM antibodies evaluation were assessed by ELISA and CIA methods. Diagnostic accuracies, correlations between methods and specific clinical manifestations in APS were investigated.

Protein S testing in patients with protein S deficiency, factor V Leiden, and rivaroxaban by North American Specialized Coagulation Laboratories.

In 2010-2012, the North American Specialized Coagulation Laboratory Association (NASCOLA) distributed 12 proficiency testing challenges to evaluate laboratory testing for protein S (PS). Results were analysed to assess the performance of PS activity, PS free antigen, and PS total antigen testing. Statistical analysis was performed on the numeric results and qualitative classification submitted for each method.

Thymic output: Assessment of CD4 recent thymic emigrants and T-Cell receptor excision circles in infants.

Background: CD4 recent thymic emigrants (CD4 RTEs) constitute a subset of T cells recently generated in the thymus and exported into peripheral blood. CD4 RTEs have increased copy numbers of T-cell receptor excision circles (TREC). They are characterized by the expression of CD31 on naïve CD4 T-cells.

Improved harmonization of eosin-5-maleimide binding test across different instruments and age groups.

Background: The eosin-5'maleimide (EMA) binding test has been studied extensively for the detection of hereditary spherocytosis (HS). Its performance characteristics have been compared to NaCl-based or glycerol lysis-based red cell osmotic fragility tests and cryohemolysis. HS samples are also better identified when both mean channel fluorescence (MCF) of EMA relative to controls and the coefficient of variation (CV) are analyzed.

Laboratory evaluation of anti-phospholipid syndrome: a preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at-risk patient cohort.

Immunoglobulin (Ig)G/IgM autoantibodies to phosphatidylserine/prothrombin (aPS/PT) were evaluated individually and in combination with criteria anti-phospholipid (aPL) tests in a prospectively ascertained cohort of patients at risk for anti-phospholipid syndrome (APS). One hundred and sixty (160) consecutive requests for lupus anti-coagulant (LAC) from the University of Utah Health Sciences Center were identified during 8 weeks. Of these, 104 unique patients had additional requests for cardiolipin (aCL) and/or beta2 glycoprotein I (aβ2 GPI) IgG and/or IgM; samples were retained and analysed for aPS/PT, aCL and/or aβ2 GPI IgG and IgM antibodies.

Evaluating eosin-5-maleimide binding as a diagnostic test for hereditary spherocytosis in newborn infants.

Objective: Neonates with undiagnosed hereditary spherocytosis (HS) are at risk for developing hazardous hyperbilirubinemia and anemia. Making an early diagnosis of HS in a neonate can prompt anticipatory guidance to prevent these adverse outcomes. A recent comparison study showed that a relatively new diagnostic test for HS, eosin-5-maleimide (EMA)-flow cytometry, performs better than other available tests in confirming HS.

Neoplastic plasma cell aberrant antigen expression patterns and their association with genetic abnormalities.

Little is known about aberrant antigen expression patterns and their association with cytogenetic aberrations in multiple myeloma (MM). We examined the correlation between flow cytometry and florescence in situ hybridization (FISH) in 167 marrow specimens with MM. Gene expression profiling of CD56, CD117, CD52 and CD20 mRNA in plasma cells (PCs) from patients treated on Total Therapy 2 and Total Therapy 3 trials were also evaluated.

Deparaffinization with mineral oil: a simple procedure for extraction of high-quality DNA from archival formalin-fixed paraffin-embedded samples.

Extracting DNA from formalin-fixed paraffin-embedded (FFPE) archival samples remains difficult. Successful polymerase chain reactions (PCR) with DNA extracted from FFPE samples is still very low. We extracted DNA from 12 recent and old archival FFPE bone marrow trephine biopsies by use of a simple protocol on the basis of deparaffinization with molecular biology-grade mineral oil followed by DNA extraction with the Qiagen FFPE kit.

Germline mutations in NFKB2 implicate the noncanonical NF-κB pathway in the pathogenesis of common variable immunodeficiency.

Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by antibody deficiency, poor humoral response to antigens, and recurrent infections. To investigate the molecular cause of CVID, we carried out exome sequence analysis of a family diagnosed with CVID and identified a heterozygous frameshift mutation, c.2564delA (p.

Elevated factor IX activity is associated with an increased odds ratio for both arterial and venous thrombotic events.

Objectives: Elevations of factor IX (FIX) are thought to contribute to thrombotic risk, but this has not been well characterized. We retrospectively sought to determine whether elevated FIX levels are a risk factor for thrombosis in 81 adult subjects younger than 65 years (mean, 47 years) who were referred for evaluation of a hypercoagulable state.

Methods: Patients were classified by arterial transient ischemic attack/stroke (TIA/stroke, n = 62) or venous thromboembolism (VTE, n = 19) events.

Laboratory testing for platelet antibodies.

Laboratory testing for immune-mediated thrombocytopenias involves identification and classification of antibodies present in patient sera or attached to patient platelets. This article summarizes the available types of platelet antibody testing and applications in disorders such as neonatal alloimmune thrombocytopenia, post-transfusion purpura, multiple platelet transfusion refractoriness, immune thrombocytopenia, and drug-induced thrombocytopenia.

Immune function surveillance: association with rejection, infection and cardiac allograft vasculopathy.

Background: Rejection, cardiac allograft vasculopathy (CAV), and infection are significant causes of mortality in heart transplantation recipients. Assessing the immune status of a particular patient remains challenging. Although endomyocardial biopsy (EMB) and angiography are effective for the identification of rejection and CAV, respectively, these are expensive, invasive, and may have numerous complications.