REDUCED LYMPHOCYTE SUBPOPULATIONS IN PATIENTS WITH ADVANCED OR DISSEMINATED MELANOMA

Background: Studies have revealed many features of lymphocyte behavior in patients with malignant melanoma, but there are conflicting result s. Objective. The aim of this study was to measure with easily reprodu cible assays the circulating lymphocytes and other immunologic aspects in 33 patients with advanced or disseminated malignant melanoma (MM). Methods. The following variables were measured: circulating monocytes ; total lymphocytes; B (CD19) and T-cell subpopulations; CD3, CD4, and CD8, natural killer cells (anti-Leu-7+ or CD57 and anti-Leu-11+ or CD 16) (cytofluorimetry); plasma levels of IgG, IgA, IgM, and IgE; comple ment fractions 3, 4, and 1Q; antibodies against foreign microorganisms (AaM) (adeno, herpes simplex, herpes zoster, measles, parotitis, cyto megalo, Epstein-Barr, and rubella viruses) and Toxoplasma; and cutaneo us delayed hypersensitivity (CDH) to recall antigens (tetanus, diphthe ria, Streptococcus, tuberculin, Proteus, Trichophyton, and Candida). W e also studied 96 healthy persons, matched for age and geographic loca tion, who were tested on the same days as the patients. Results. In MM the number of total lymphocytes and subsets CD19, CD3, CD4, and CD8 w as decreased from 25% to 40% (p < 0.001). The CD4/CD8 ratio increased (22%, p < 0.005) because of the relatively greater decrease of CD8. Th e CD57 and CD16 cells (expression of natural killer lymphocytes) were consistently reduced (30%; p < 0.002 to p < 0.003). C3 serum level was increased (30%;p < 0.001). Immunoglobulins, CDH, AaM, and all other t ests were the same in the two groups. Conclusion: The single most impo rtant result seems to be a reduction of CD57 and CD16 cells in patient s with advanced MM.