Polymorphonuclear leucocyte function during pregnancy.

Polymorphonuclear leucocyte (PMN) function was studied in pregnant women and related to the serum concentration of pregnancy zone protein (PZP) and to mixed lymphocyte culture (MLC) reactivity. Neutrophil chemotaxis was depressed in pregnant women. Pregnancy serum inhibited the MLC-reaction. The serum levels of PZP were inversely related to chemotactic responsiveness (P less than 0.05) and depression of MLC reactivity (P less than 0.01). The capacity to reduce nitroblue tetrazolium was depressed in PMNs from pregnant women, and pregnancy serum inhibited phagocytosis of Escherichia coli by control PMNs. Neutrophils from pregnant women showed increased chemiluminescence during phagocytosis of zymosan. The results may be explained by depression of ingestion by pregnancy serum and increased oxidative metabolism in PMNs from pregnant women.