The diagnostic value of Chlamydia trachomatis antibody testing in the diagnosis of tubal pathology among infertile patients

Abstract

Objective: To evaluate the diagnostic value of Chlamydia trachomatis IgG antibody testing (CAT) in the diagnosis of tubal pathology among infertile patients. Materials and Methods: A prospective cross-sectional study at Kaunas University of Medicine Hospital within the period of 18 months was performed. Consecutive infertile women formed the study group according to defined criteria. Serum samples for CAT were collected from each patient before diagnostic laparoscopy and dye test for assessment of tubal pathology. CAT were tested using a micro-immunofluorescence assay (MIF). Sensitivity, specificity, likelihood ratios (LR) and post-test probabilities for predicting tubal pathology as determined by laparoscopy and dye test were calculated for different cut-off levels of CAT. Results: The study population comprised 149 infertile women. For 67 (45%) patients positive CAT result (>16) was found, 82 (55%) patients were negative for CAT (<16). Increasing the cutoff threshold improves specificity (from 75.6% to 97.8%) and LR+ (from 3.1 to 6.9) at the expense of sensitivity (from 76.3% to 15.3%) and LR− (from −0.3 to −0.9). Changes in post-test probabilities were observed as well. Conclusions: The diagnostic performance of CAT in the diagnosis of tubal pathology is fair. The diagnostic accuracy of CAT depends on the cut-off level. The optimum cut-off threshold of CAT should be considered according the aim of screening.