Prognostic value of an elevated CD8 lymphocyte count in HIV infection. Results of a prospective study of 152 asymptomatic HIV-positive individuals.

OBJECTIVE: To evaluate the prognostic value of an elevated CD8 lymphocyte count in the early stages of HIV infection. DESIGN: A prospective study ongoing since January 1986. METHODS: One hundred and fifty-two asymptomatic HIV-positive individuals with a CD4 lymphocyte count > 400 x 10(6)/l at enrollment were included. Disease progression was defined as a CD4 count < 200 x 10(6)/l. RESULTS: During the follow-up period, CD4 count decreased in 33 individuals; CD8 count increased to > 1500 x 10(6)/l in 38 individuals and doubled in 35. The risk of a decreasing CD4 count was estimated to be 1.7-fold higher, although not significantly so, after the elevation of the CD8 count to > 1500 x 10(6)/l than before or in the absence of such an increase. However, this predictive value disappeared when five baseline parameters found to predict the outcome (neopterin, beta 2-microglobulin, p24 antigen, anti-p18 antibody and immunoglobulin A) were adjusted. CONCLUSION: Elevated CD8 count appears to be a weak marker for disease progression.

Expression of CD11b (Leu15) antigen on CD3+, CD4+, CD8+, CD16+ peripheral lymphocytes. Estimation of CD3+8+11b+ and CD3+4-8-11b+ T-cell subsets using a single laser flow cytometer.

CD11b (Leu15) epitope is expressed on 20-30% of peripheral blood lymphocytes, including CD16+ large granular lymphocytes and CD8+ cells. This study confirms that 30% of CD8+ lymphocytes and virtually all CD16+ NK cells from healthy subjects express this determinant. In parallel, our data show that various proportions of CD3+4-8-, TCR-delta cytotoxic T lymphocytes and occasionally CD4+ lymphocytes subsets could also express this epitope. The CD8+11b+ phenotype is associated with suppression of T-cell proliferative response and has been extensively used to characterize suppressor T lymphocytes. Since about 25% of CD8 lymphocytes are non-T (CD3-) and express the CD16 NK antigen (CD8+16+3-), the expression of CD11b was also studied on CD8+3+ T-cell and CD8+16+ NK-cell subsets. To this end, we developed three methods using a flow cytometer equipped with a single laser and two fluorescence detectors. Results showed that T CD8+3+11b+ and NK CD8+16+11b+ lymphocytes account for 30% and 70% of CD8+11b+ cells respectively. Consequently, the CD8+3+11b+ phenotype would be more specific for suppressor T lymphocytes than the total CD8+11b+ phenotype which includes high proportions of CD16+ NK cells.

Triple labeling with two-color immunofluorescence using one light source: a useful approach for the analysis of cells positive for one label and negative for the other two.

Many laboratories do not have access to a flow cytometer allowing three-color immunofluorescence analysis through the use of multiple light sources. In view of the usefulness of such analyses in the dissection of cell parameters, we describe an approach permitting the study of three labels by using one light source and the two-color immunofluorescence assay. It is useful for the enumeration of cell subpopulations positive for one label and negative for two or more others as well as for qualitative analysis concerning the expression of these labels. This approach is simple and rapid; it does not require additional material and technical steps other than that used in the two-color immunofluorescence assay. Briefly, it consists of the use of a label coupled to a dye (PE or FITC or instance) and two different labels coupled to the other dye. An argon ion laser, operating at 488 nm and 60 mW, excites both fluorescein and phycoerythrin conjugated antibodies. We provided a general example, using three hypothetical labels (X, Y, and Z), and four practical applications: CD3+CD4CD8- and CD8+CD16-CD3- peripheral blood lymphocytes, CD2+CD16-CD3- and CD56+CD16-CD3- peripheral blood, and decidual infiltrating lymphocytes.

Granulocyte-associated immunoglobulins in asymptomatic HIV-infected subjects.

The purpose of this study was to determine the prevalence of granulocyte-associated immunoglobulins (GA-IgG) during the follow-up of asymptomatic human immunodeficiency virus (HIV)-infected subjects. An increase in GA-IgG was detected in 32 asymptomatic HIV seropositive subjects by a granulocyte immunofluorescence test (GIFT). At study onset, 7 (21.8%) had a positive GIFT. The prevalence of positive GIFT increased with time in the study subjects. No neutropenia was found. No significant difference was observed in subjects with positive or negative GIFT with respect to mean CD4 lymphocyte count and mean neutrophil count. The presence of GA-IgG was not associated to a positive direct antiglobulin test or of elevated platelet associated IgG.

[Early anomalies of CD4 and CD20 lymphocyte cycles in human immunodeficiency virus]. / Anomalies précoces des cycles lymphocytaires CD4 et CD20 au cours de l'infection par le virus de l'immunodéficience humaine.

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.

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.

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.

Platelet transfusion: automated selection of donors.

The selection of platelet donors, according to HLA antigens, has been computerized using a method based on the calculation of incompatibilities and risk of immunization between donors and recipients. Since the risk that an antigen present in a donor will immunize an incompatible recipient of known HLA phenotype, an incompatibility score is established and a donor file printed out, ranked according to the degree of incompatibility. The principle of this method is valuable for any other compatibility system and can be easily extended according to the computer potency. The method allows a rapid selection of the most appropriate plateletpheresis donors to avoid immunizing unsensitized patients or to achieve the best degree of compatibility in previously sensitized patients.