Changes in lymphocyte subpopulations in peripheral blood of splenectomized patients.

Twenty-five patients who had undergone splenectomy were investigated. Splenectomy was performed in 16 patients because of traumatic rupture of the spleen, in 6 due to idiopathic thrombocytopenic purpura (ITP) and in 3 because of other causes. The absolute numbers of T-cell subclasses--helper/inducer (CD4+) and suppressor/cytotoxic (CD8+)--and of B-cells were determined in peripheral blood. The CD4+/CD8+ was decreased in 7 patients and inverted in 10. The change in the ratio was not due to a decreased number of CD4+ cells but to an increase of CD8+ cells. Sex, age, and the time at which splenectomy was performed bore no relation to the CD4+/CD8+ ratio. In 13 of the 25 patients a significant increase in the number of polyclonal B-cells was found. None of the patients had severe infections. These observations suggest that splenectomy is responsible for the change in the CD4+/CD8+ ratio. Susceptibility to infections seems to correlate with the absolute decrease of CD4+ cells rather than with the change of the ratio.