Transient secretory IgA deficiency in mice after cyclophosphamide treatment.

Cyclophosphamide (Cy), an alkylating agent widely used in chemotherapy of leukemia and cancer, causes a well-documented toxicity on hematopoietic and lymphoid cells. Neutropenia is thought to be the main factor involved in infectious complications following antimitotic chemotherapy. Little is known on the effects of these therapies on the mucosal associated lymphoid system which is one of the main barriers against environmental pathogenic agents. The present study examined the effects of a single administration of Cy (200 mg/kg) on murine T and B cell populations of Peyer's patches (PPs), IgA secretion in the proximal part of the small intestine, and plasma cells of the lamina propria. Cy induced in mice a transient decrease in the T and B cell populations of the PPs with a drastic fall of B cell counts and a profound decrease of intestinal IgA secretion due to a reduction of lamina propria plasma cells. This transient secretory IgA deficiency may contribute to the infectious complications following antimitotic chemotherapy.