Evaluation of four different serological assays in gynaecological Chlamydial diagnostics

Genital chlamydial infections persist for years in both women and men. Because of low numbers of organisms found in the urogenital tract direct detection of Chlamydia trachomatis may be difficult. In these cases serology serves as a useful diagnostic supplement in clinically suspected infection or tubal factor sterility. A total of 178 sterility patients (63 with pelviscopically proven occluded, 115 with open fallopian tubes), 103 women with positive cervical swabs, 100 obstetric patients (6% with positive cervical swabs), and 100 blood donors were serologically tested. The following tests were used: 1. microimmunofluorescence test (MIF, Graystone), 2. a commercial test using lipopolysaccharide (LPS) extracted elementary bodies as antigen, 3. a commercial ''whole inclusion'' test, 4. a commercial recombinant chlamydial LPS test. The positive predictive values of these tests were 71%, 65%, 66%, 52% for tubal occlusion and 40%, 40%, 21%, 13% for a positive cervical swab (obstetric patients), respectively. Principally, only the Chlamydia trachomatis species-specific tests (MIF test and LPS extracted elementary body test) were suited for gynaecological chlamydial diagnostics. Due to its cross-reactivity with Chlamydia pneumoniae the ''whole inclusion'' test should be restricted to high prevalence groups such as sterility patients. The genus-specific LPS test proved to be of no help for the gynaecologist. No serological test allowed any differentiation between past and present infection with Chlamydia trachomatis.