Peripheral blood leucocyte subpopulations in patients splenectomized for trauma.

Monoclonal antibodies were used to type leucocyte subpopulations in peripheral blood mononuclear leucocytes (MNL) from patients who had had spleens removed following trauma. The proportion of OKT3+ (T) cell and OKT4+ ('T helper/inducer') cell was significantly decreased in splenectomized subjects. While a decrease was also observed for the OKT8+ ('T suppressor/cytotoxic') cells, this was not significant. The ratio of OKT4+/OKT8+ cells was significantly decreased in the splenectomized group. Interestingly, the absolute numbers of OKT3+, OKT4+ and OKT8+ cells were increased. The % of B lymphocytes (identified as Ig+ and FMC1+ cells) was significantly increased in patients. The proportion of MHC Class II+ cells (FMC4+) was also increased although not significantly. A marked increase in % of monocytes (FMC33+) was observed in patients. The changes in proportion of regulatory T cells and monocytes may in part explain the depressed mitogen responses of MNL from splenectomized subjects.