Evaluation of the serum T cell population variations induced by PUVA therapy.

: In the present study we evaluated the effects of UVA irradiation on the serum T cell subpopulations (CD3, CD4, CD8, CD4/CD8, NK, T lymphocytes/mm3) by means of a Fluorescence Activate Cell Sorter (F.A.C.S. 420, Becton Dikinson). Twenty-eight psoriatic patients, never previously treated with PUVA, received UVA radiations (cabin Waldman 8001 K). Blood samples were taken before therapy and after 60 J/cm2 and 120 J/cm2 irradiations. Results were compared with those of our healthy control group of volunteers. A decrease of CD4 positive cells was observed in the psoriatic group before therapy. PUVA did not induce any statistically significant modification of the populations studied, except for a progressively increasing trend of CD4 positive cells. These data seem to stress that a medium-term PUVA therapy does not significantly modify the serum level of the T cell populations.