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C Gastal

Publications and source records attributed to C Gastal.

7 recordsLinked to original sources
PubMed1994

[Evaluation of tests recommended by the CDC for the determination of CD4+ T lymphocytes in patients infected by the human immunodeficiency virus].

The "Centers for Disease Control" (CDC) recently published the guidelines for the performance of CD4+ T-cell determinations in persons with Human Immunodeficiency Virus (HIV) infection. Especially, a monoclonal antibody panel for lymphocyte immunophenotyping has been recommended i.e CD45/CD14, isotypic controls, CD3/CD4, CD3/CD8, CD3/CD19, CD3/CD56+ and/or CD16+. The authors compared, in 50 HIV+ patients, this method with the conventional method used in their laboratory i.e CD4/CD8 associated with isotypic controls. The mean values of CD4+ and CD8+ cells obtained using dual color immunophenotyping CD3/CD4 and CD3/CD8 did not differed significantly as compared with the values obtained using dual color immunophenotyping CD4/CD8. Especially, concerning CD4+ cells, differences did not exceed 4% considering each patient and 1% considering the mean values. However, in some patients, the differences between the levels of CD8+ cells obtained using the two methods were greater than 10%. These differences were due to an important percentage of CD3-CD8+ cells corresponding to NK cells. In another hand, there was no significant difference between the levels of CD4 and CD8+ cells obtained with or without correction using the gating reagent CD45/CD14. In conclusion, monoclonal antibody pannel recommended by CDC for lymphocyte immunophenotyping in HIV patients do not seem necessary in all cases. Analysis for CD4 and CD8 positive cells could be accomplish by three color simultaneous method (CD3/CD4/CD8), by first gating on CD3 positive T lymphocytes in order to eliminate both monocyte and NK cell contamination.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Lymphocyte surface antigens in the peripheral blood. Detection by flow cytometry. Applications to the immune system in clinical practice].

A flow cytometer enables observation of single cells providing morphological characterization of the cell and identification of cell markers. The cells pass a detection point where they are striked by a sharply focused beam. Light scattering by the cells gives informations about size and granularity. Detection of fluorescence emission permits identification of fluorescent tag such as antibodies. Flow cytometric analysis of immunologic phenotyping allows interpretation of weak fluorescence intensity and detection of two antigens on a single cell with dual fluorescence analysis. Evaluation of B and T cells and their subclasses from whole blood preparations, provides informations of immunological status. Immunophenotyping at the clinical level has been used in a variety of human diseases; immunophenotypic changes have been observed in congenital and acquired immunodeficiency syndromes and auto-immune disorders.

Antigens, Surface↗
PubMed1988

[Early anomalies of CD4 and CD20 lymphocyte cycles in human immunodeficiency virus].

Circadian variations in the number of circulating lymphocytes and their subpopulations have been observed in healthy subjects. These cyclic changes are characterized by a trough at 8:00 a.m. and a peak at midnight. Using multiple peripheral blood samplings, we were able to confirm that this cycle applied to CD4 T-cells (helpers) and to B-cells (CD20). No cycle of CD8 lymphocytes was observed. In a second stage, for greater comfort of the patient the number of samplings was reduced to two: one at 8:00 a.m. (trough) and one at midnight (peak). This method enabled us to calculate the amplitude of lymphocytes cycles in 18 controls and 74 human immunodeficiency virus (HIV) seropositive patients. In asymptomatic HIV carriers the amplitude of CD4 cycles was normal in 6/26 cases and that of B-cell cycles in 2/17 cases. In the group of asymptomatic HIV carriers the mean amplitude of the cycles was much less reduced than in the other two groups. These results incite us to believe that the loss of the CD4 T-cell cycles is an early sign of HIV infection antedating the decrease observed in the number of these cells.

Adult↗
PubMed1988

Disappearance of CD4-lymphocyte circadian cycles in HIV-infected patients: early event during asymptomatic infection.

Circadian variations have been observed in peripheral blood lymphocyte counts in normal subjects; they usually reflect variations in absolute CD4-cell count. For this population, nadir occurs around 0800 h (basal value) and the peak value occurs at midnight (1.6 times the 0800-h value). This cycle is thought to be of major importance in the efficacy of the immune response because it expresses the migration of lymphocytes into lymphoid organs.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Disappearance of CD4 lymphocyte circadian cycles after autologous bone marrow transplantation.

Circadian variations are observed in CD4 lymphocyte count in healthy people. Samples taken of the basal value occurring around 08.00 hr and peak value at midnight made it possible to define the range of cyclic variations. Movement of lymphocytes seems important in accounting for the observed circadian variations. CD4 circadian cycle amplitudes were investigated in 12 patients with autologous bone marrow transplantation. Cycle abnormalities were observed in 7 patients. Two of them had a normal CD4 lymphocyte count. It was therefore possible for functional abnormalities in CD4 lymphocytes to be detected in patients with a normal CD4 count. Because of these results, we are of the opinion that the evaluation of CD4 lymphocyte cycle might be a more sensitive test than the absolute CD4 count itself.

Bone Marrow Transplantation↗