Chlamydia pneumoniae and screening for tubal factor subfertility

Chlamydia antibody testing (CAT) by micro-immunofluorescence (MIF) tests ha s been introduced into the fertility work-up as a screening test for tubal factor subfertility. In this study the role of C. pneumoniae antibodies, as a cause for false positive CAT results due to cross-reactivity with C, tra chomatis antibodies in the MIF test, has been evaluated. In 240 subfertile women serological data were compared to laparoscopy findings, The prevalenc e of C, pneumoniae antibodies using enzyme-linked immunosorbent assay (ELIS A) was 75% and did not differ between patients with and without tubal patho logy, C, pneumoniae antibodies were found in 87% of women with a positive M IF test (greater than or equal to 32), and in 66% with a negative MIF test (P < 0.0005). Using ELISA instead of MIF for the detection of C. trachomati s antibodies, C, pneumoniae antibodies were found in 87% of C. trachomatis positive women, and in 69% of C, trachomatis negative women (P < 0.0005). P atients without tubal factor subfertility but a positive MIF test showed C, pneumoniae antibodies more frequently than patients without tubal factor s ubfertility and a negative MTF test. Therefore it was suggested that C, pne umoniae antibodies may be the cause of false positive CAT results. Remarkab ly, tubal pathology was more common in patients who had antibodies to both C. trachomatis and C, pneumoniae.