Possible relationship between Chlamydia trachomatis and acquired immunodeficiency syndrome.

This study suggests the possibility that the intracellular parasite Chlamydia trachomatis (Ct) may facilitate the transmission of the human immunodeficiency virus (HIV) during vaginal or rectal intercourse. This is based on the following findings: a) elevated titers of anti-Ct IgG are present in symptomatic acquired immunodeficiency syndrome (AIDS) patients; b) elevated titers of anti-Ct IgA are found in asymptomatic AIDS patients; c) low anti-Ct IgA titers were observed during the progression of the disease; d) high titers of anti-Ct IgA were found in patients suffering from autoimmune diseases; e) high levels of C3 fraction of the complement are found in many of the Ct patients. The presence of anti-Ct IgA and high C3 may be crucial since IgA inactivates Ct and C3 which may increase the invasion of HIV into the cells. This activity of IgA and C3 in Ct patients may increase the susceptibility of male homosexuals and other risk groups in the population to AIDS.