Restoration of decreased suppressor cells by vitamin B12 therapy in a patient with pernicious anemia.

A unique case of pernicious anemia is described. Initially, the percentage of OKT8-positive blood cells was markedly decreased, resulting in an increase in the OKT4/OKT8 ratio. The level of OKT8-positive blood cells was, however, returned to normal after vitamin B12 therapy. The finding may propose a possible role of the imbalance of blood lymphocyte subpopulations on the pathogenesis of pernicious anemia and also a responsibility of vitamin B12 for such a selective reduction in the OKT8-positive blood cells.