Inhibition of phagocytosis of Trypanosome dionisii by pregnancy alpha-2 glycoprotein.

Trypanosome phagocytosis by normal polymorphonuclear leucocytes was studied in the presence of the pregnancy-associated alpha 2-glycoprotein (PAG). A serum fraction containing PAG at a concentration of 13.5 micrograms/ml significantly inhibited the uptake of Trypanosoma dionisii when contrasted with an identically obtained male serum fraction devoid of PAG (P less than .01). This finding of diminished trypanosome uptake in physiologic concentrations of PAG could account for the suggested increase in the frequency and severity of protozoal infections during gestation.