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Background: κ and λ free light chains (FLCs) are monitored to aid in the diagnosis of plasma cell disorders. Our goal was to validate the Diazyme Human κ and λ assays on Beckman Coulter UniCel DxC 800 Synchron and compare to Freelite κ and λ assays on Roche Cobas Integra., Methods: Linearity verification, within- and between-run precision, method comparison, and reference range (RR) verification were conducted using CLSI guidelines. Statistical analysis was performed using EP Evaluator ® . Mean, SD, CV, and bias were determined., Results: Diazyme κ FLC assay was linear within 0.00-191.00 mg/L. Diazyme λ FLC assay was linear within 0.00-205.30 mg/L. Diazyme κ FLC QC1 had a mean of 16.70 mg/L, CV of 7.0%. QC2 had a mean of 33.37 mg/L, CV of 2.6%. Diazyme λ FLC QC1 had a mean of 21.73 mg/L, CV of 2.3%. QC2 had a mean of 42.05 mg/L, CV of 1.5%. Bias of DxC-Diazyme FLCs compared to Integra-Freelite FLCs was -2.55 mg/L (κ FLC), and 4.54 mg/L (λ FLC). Qualitative comparison of κ FLC assays indicated 100% agreement for both normal and abnormal values. For λ FLC assay, agreement was 95% for normal values and 75% for abnormal values. For κ/λ ratio there was 50% agreement for normal values, and 100% for abnormal values. For RR verification, 1 sample was outside the Diazyme κ RR. For λ, all samples were within the manufacturer's RR., Conclusions: Diazyme assays for FLCs have excellent precision and accuracy and are comparable to Freelite assays., (© 2019 American Association for Clinical Chemistry.)

The Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium was established to determine the host and virus factors associated with HIV transmission, infection and containment of virus replication, with the goal of advancing the development of an HIV protective vaccine. Studies to meet this goal required the use of cryopreserved Peripheral Blood Mononuclear Cell (PBMC) specimens, and therefore it was imperative that a quality assurance (QA) oversight program be developed to monitor PBMC samples obtained from study participants at multiple international sites. Nine site-affiliated laboratories in Africa and the USA collected and processed PBMCs, and cryopreserved PBMC were shipped to CHAVI repositories in Africa and the USA for long-term storage. A three-stage program was designed, based on Good Clinical Laboratory Practices (GCLP), to monitor PBMC integrity at each step of this process. The first stage evaluated the integrity of fresh PBMCs for initial viability, overall yield, and processing time at the site-affiliated laboratories (Stage 1); for the second stage, the repositories determined post-thaw viability and cell recovery of cryopreserved PBMC, received from the site-affiliated laboratories (Stage 2); the third stage assessed the long-term specimen storage at each repository (Stage 3). Overall, the CHAVI PBMC QA oversight program results highlight the relative importance of each of these stages to the ultimate goal of preserving specimen integrity from peripheral blood collection to long-term repository storage., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Accurate diagnosis of influenza is critical for clinical management, infection control, and public health actions to minimize the burden of disease. Commercially available rapid influenza diagnostic tests (RIDTs) that detect the influenza virus nucleoprotein (NP) antigen are widely used in clinical practice for diagnosing influenza because they are simple to use and provide results within 15 minutes; however, there has not been a recent comprehensive analytical evaluation of available RIDTs using a standard method with a panel of representative seasonal influenza viruses. This report describes an evaluation of 11 Food and Drug Administration (FDA)-cleared RIDTs using 23 recently circulating influenza viruses under identical conditions in a laboratory setting to assess analytical performance. Most RIDTs detected viral antigens in samples with the highest influenza virus concentrations, but detection varied by virus type and subtype at lower concentrations. Clinicians should be aware of the variability of RIDTs when interpreting negative results and should collect test samples using methods that can maximize the concentration of virus antigen in the sample, such as collecting adequate specimens using appropriate methods in the first 24-72 hours after illness onset. The study design described in this report can be used to evaluate the performance of RIDTs available in the United States now and in the future.

Early diagnosis and appropriate therapy are essential for the best prognosis and quality of life in patients with primary immunodeficiency diseases (PIDDs). Experts from several Latin American countries have been meeting on a regular basis as part of an ongoing effort to improve the diagnosis and treatment of PIDD in this region. Three programmes are in development that will expand education and training and improve access to testing facilities throughout Latin America. These programmes are: an educational outreach programme (The L-Project); an immunology fellowship programme; and the establishment of a laboratory network to expand access to testing facilities. This report provides the status of these programmes based on the most recent discussions and describes the next steps toward full implementation of these programmes., (Copyright © 2010 SEICAP. Published by Elsevier Espana. All rights reserved.)

The US Food and Drug Administration (FDA) requires reproducibility studies for premarket approval of in vitro diagnostic (IVD) tests. Results of reproducibility studies provide an estimate of the variability of the IVD test among study sites, reagent lots, site operators, within a single test run, and over multiple test days. In planning the study, discuss the product registration strategy, including the intended use of the product and desired label claims, and define the study team. Design the sample panel according to the limit of detection or quantitation of the test, dynamic range of the test, FDA guidelines, sample matrix, and genotype. Consider legal and ethical issues for obtaining the panel parent specimen, such as minimizing the privacy risk and keeping promises to donors. During the study, review data promptly to determine invalid runs, discover trends in the data that may require additional operator training, ensure correct completion of case report forms, and resolve queries quickly. At the end of the study, gather the study team to review and improve processes. Use the outcome to set expectations of other functional areas and to provide product feedback.

The symptoms of fibromyalgia and lupus can be similar, but the treatments are very different. Although the antinuclear antibody (ANA) test has often been used to make the distinction, this approach has its pitfalls. This paper offers strategies for more accurate diagnosis.

The Rubella Subcommittee of the National Committee for Clinical Laboratory Standards has proposed lowering the breakpoint to define rubella immunity from 15 to 10 IU/mL. This recommendation stems from epidemiologic studies on vaccinated persons with low levels of antibody and anecdotal reports. Additional support comes from Centers for Disease Control and Prevention studies and reports. The effectiveness of rubella vaccination is well documented and the 10 IU/mL antibody level is protective in the vast majority of persons. Sporadic reports of viremia and/or reinfection among previously immunized persons with low antibody levels have been reported but proven cases of reinfection have also occurred in persons with titers greater than or equal to the 15 IU/mL cut-off. Despite the occasional occurrence of rubella reinfection in persons with low titers, the theoretical risks are small especially as compared with significantly greater risk in persons who have not been vaccinated. Immunity in a given patient is a clinical decision and the results of antibody tests for rubella, like other laboratory tests, must be evaluated in the context of the clinical setting.

During 1985 and 1986, the Centers for Disease Control conducted eight surveys to evaluate laboratory performance in testing for antibody to human immunodeficiency virus (HIV). (Other names for this virus include "human T-lymphotropic virus type III" and "lymphadenopathy associated virus.") The first survey was conducted with ten samples and 50 laboratories; the remaining surveys used six samples, but enrollment increased to as many as 475 laboratories. The purpose of these surveys was to measure test performance by the laboratories under the actual conditions of use. The surveys contained duplicate samples to permit measurement of within- and between-survey reproducibility. One survey included positive and negative reference materials as evaluation samples. Results of the Western blot (WB) test were not always positive on samples that were positive by enzyme immunoassay (EIA), and sometimes they were positive on samples that had negative results by EIA. The percentage of positive results reported by laboratories using Electronucleonics tests was lower than that reported by users of Abbott and of Litton tests. positive results on the negative reference material were reported by 13.7% of the Abbott EIA test users. The tests do not seem to be calibrated against an equivalent standard. Within-survey reproducibility was usually above 95% for EIA and WB methods and for the major manufacturers of EIA tests. Between-survey reproducibility was usually above 90%. Reproducibility was below 75% for some combinations of samples, method, and manufacturer. The test performance observed in these surveys may be lower than is actually achieved on patient samples because the samples were selected to measure technical competence and contain a higher frequency of samples with low reactivity than would be encountered with clinical samples. Stratification and weighting of the results in these surveys to estimate performance parameters for a blood bank population indicate that the tests are performing well in this application. If single EIA tests at the performance levels achieved in these surveys were used (no repeat and no confirmation), about 1 sample with positive results in every 50,000 samples tested would be missed and about 2.5% would be false positive results. Because tests are duplicated and confirmed in blood banks, better performance would be expected. Testing for antibody to HIV virus continues to undergo rapid change because of the introduction of new tests, changes in technical aspects of existing tests, and application of testing to changing populations. Such dynamic factors necessitate an ongoing, comprehensive monitoring of test performance.