| Abstract: | The cell surface phenotype of human peripheral blood mononuclear cells has been characterized before and after intravenous injection of cyclophosphamide or prednisolone. Low doses of cyclophosphamide (100-600 mg/m2) temporarily decrease levels of circulating B lymphocytes. Slightly higher doses of cyclophosphamide (200-600 mg/m2) produce transient depression of T8-, M1-, and Ia-positive cells. After doses of 200-400 mg cyclophosphamide/m2, T4-positive cells are spared, resulting in a transient elevation of the T4/T8 ratio. With higher doses of cyclophosphamide (greater than or equal to 600 mg/m2), all T cells are affected and the T4/T8 ratio declines to pretreatment levels. By contrast, intravenous injection of prednisolone at 40 mg/m2 reduces the T4/T8 ratio. Levels of both T4 and T8 cells decline, but T4 cells are affected more markedly than T8 cells. |
