Peripheral Blood Lymphocytes Subpopulations and Apoptotic Markers in Patients with Lymphoid Malignancies and in Controls: An Epidemiologic Case-Control Study.

Few references ranges of normal peripheral blood lymphocytes subpopulations are available in the literature and fewer data were available regarding activation, proliferation and apoptosis antigen expression on such populations. We studied these parameters in patients included in an epidemiologic case-control study on risk factors of lymphoid malignancies conducted within European countries.

Cell surface staining of peripheral blood lymphocyte antigens were analysed by multicolour flow cytometry in 300 cases and 300 controls. We determined CD3+, CD3+/CD4+, CD3+/CD8+, CD3−/CD56+CD16+, CD19+, CD19+/CD5+, CD19+/CD5− and CD57+ populations. Expression of CD25, CD16, CD40, CD154, CD95 and CD178 were studied on these populations. CD expressions were compared by multiple regressions between controls and diseases, after stratification on circulating phase. In controls we observed a significant decrease of B cells and an increase of NK cells with age. No difference was found according to sex, smoking status and Body Mass Index. In Follicular Lymphoma, Diffuse Large B Cell Lymphoma and Marginal Zone Lymphoma (MZL) without circulating phase cases, we observed a decrease of the B cell subset and an increase of the NK cell subset instead of only a trend was found in Multiple Myeloma, Mycosis Fongoides, Hodgkin Disease and Lymphoplasmacytic Lymphoma. CD95 expression was increased in HD, DLBCL, MZL without circulating phase and Hairy Cell Leukemia but decreased in B-cell Chronic Lymphocytic Leukemia and MZL with circulating phase. CD40 was decreased on B cells in HD, FL, MZL, B-ALL and CLL.

This study was one of the most important, in term of number of patients included, particularly concerning data on activation, proliferation and apoptosis markers in normal subjects but also in several lymphoid malignancies.