Effect of oral vs. parenteral cyclophosphamide on in vitro IgA and IgG production by murine Peyer's patches and cultured jejunal fragments.

The gut associated lymphoid tissue plays an important role in intestinal defenses, food allergy, oral tolerance, and certain intestinal diseases. This study describes the effect of either oral or parenteral cyclophosphamide on IgA and IgG production in the gut. Mice were treated with cyclophosphamide either IV or PO, and Peyer's patch cell cultures were established to evaluate mitogen induced production of IgA and IgG. To evaluate the effect of cyclophosphamide on the plasma cell rich lamina propria, segments of jejunum were cultured and overnight secretion of IgG and IgA were measured. We found, the secretion of IgA or IgG by jejunal fragments was not influenced by cyclophosphamide (IV or PO). Mitogen induced secretion of IgA and IgG by Peyer's patch cells was markedly decreased 24 hrs after drug administration, with significant recovery by day 7. Cell mixing experiments revealed that a single dose cyclophosphamide reduced the capacity of Peyer's patch B cells to secrete IgA or IgG when co cultured with normal T cells. This study demonstrates that a single dose cyclophosphamide can have profound effects on the gut immune system and that the drug has a similar effect when given either orally or parenterally.