Evaluation of a flow cytometry method for CD4 T cell enumeration based on volumetric primary CD4 gating using thermoresistant reagents.
Summary of "Evaluation of a flow cytometry method for CD4 T cell enumeration based on volumetric primary CD4 gating using thermoresistant reagents."
Laboratory follow-up of HIV patients in resource-limited settings requires appropriate instruments for CD4 T cell enumeration. In this study, we evaluated the application of a simplified, mobile and robust flow cytometry system, the Apogee Auto 40 analyzer (Auto40) using thermoresistant reagents, for CD4 T cell enumeration. We measured the absolute CD4 counts in fresh whole blood samples from 170 Senegalese subjects, including 129 HIV-positive (HIV+) patients and 41 HIV-negative (HIV-) controls. Based on volumetric primary CD4 gating, cells were stained with commercially available reagents (Easy MoAb CD4;Bio-D, Valenzano, Italy) and analyzed on the Auto40. The results were compared with those from the FACSCount system (Becton Dickinson, San Jose, USA). Repeatability analysis was performed on duplicate testing of 49 samples on both FACSCount and Auto40. The intra-run precision was measured by 10 replicates using 3 clinical blood samples with low, intermediate and high CD4 concentrations. The results from the two instruments were in good agreement. The percent similarity between the results of both instruments was 99%±relative standard deviation of 12.7%. The concordance correlation coefficient was 0.99. The absolute bias and limits of agreement (LOA) between the two instruments, calculated by Bland-Altman analysis, were clinically acceptable (bias: +4 cells/μl;
-111 to +120 cells/μl). The clinical agreement between the two instruments at a cutoff of 200 CD4 cells/μl was 94%. The repeatability of measurements on the Auto40 was also similar to that observed with FACSCount system (bias +0.1 cells/μl, coefficient of variation 2.5% vs bias -1.1cells/μl, coefficient of variation 2.9% respectively). In conclusion, our results indicate that the Auto 40 system, using thermoresistant reagents, is suitable for CD4 T cell enumeration and will be a helpful tool to improve HIV laboratory monitoring in resource-limited settings.
Immunology Unit, Laboratory of Bacteriology-Virology, CHU Le Dantec University Teaching Hospital, BP 7325 Dakar, Senegal; Immunology Service, Department of Pharmaceutical and Biological Sciences, Faculty of Medicine, Pharmacy et Odontostomatology, Cheikh
This article was published in the following journal.
Name: Journal of immunological methods
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21835181
- DOI: http://dx.doi.org/10.1016/j.jim.2011.07.012
Accurate estimation of haematopoietic stem cell (HSC) counts by flow cytometry may be difficult in laboratories in which sophisticated equipment and staff with specific expertise are not available. Af...
The development of new therapeutic monoclonal antibodies (mAbs) for cancer therapy will rise in the following years. The evaluation of biological activity of mAbs is required during drug development a...
Background: Cell counts in bodyfluids such as ascitic fluid can be difficult to perform and report rapidly. The current gold standard for cell counting in body fluids is a suitable automated cell coun...
Autophagy is a dynamic process of bulk degradation of cellular proteins and organelles in lysosomes. Current methods of autophagy measurement include microscopy-based counting of autophagic vacuoles (...
Gingivitis is a common inflammatory condition. We explored the value of flow cytometry of saliva in patients with periodontal inflammation.
RATIONALE: Lenalidomide and dexamethasone may stop the growth of multiple myeloma by blocking blood flow to the tumor. PURPOSE: This phase II trial is studying how well lenalidomide works...
Electron beam computed tomography (EBCT) has been regarded as the state-of-the-art investigation for detecting and quantitating coronary artery calcification. However, EBCT is expensive,...
The aim of this study is to show that flow cytometry can be an accurate tool to help physicians regarding the diagnosis, the SIT decision and the SIT arrest of hymenoptera venom allergy....
RATIONALE: Gathering information about patients with cutaneous T-cell lymphoma over time may help doctors learn more about the disease. PURPOSE: This natural history study is collecting d...
This study is designed to determine the response of adult stems cells, also referred to as mesenchymal stem cells (MSCs), to tissue injury resulting from thermal burns. The study will cons...
Medical and Biotech [MESH] Definitions
Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. Each colony (i.e., microbial colony-forming unit) represents the progeny of a single cell in the original inoculum. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.
A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining.
A scanning microscope-based, cytofluorimetry technique for making fluorescence measurements and topographic analysis on individual cells. Lasers are used to excite fluorochromes in labeled cellular specimens. Fluorescence is detected in multiple discrete wavelengths and the locational data is processed to quantitatively assess APOPTOSIS; PLOIDIES; cell proliferation; GENE EXPRESSION; PROTEIN TRANSPORT; and other cellular processes.