[Anti-C. trachomatis IgG antibodies levels in serum to identify infertility caused by tubal damage].

Objective: To identify the serologic titers of anti-Chlamydia trachomatis IgG (Ab) antibodies that could be used to differentiate tubal damage infertility from other causes of subfertility in a group of Mexican women.

Material And Methods: This was a prospective, longitudinal and analytical study of 147 women selected in a non-random way. The women were classified into three sub-groups: 1) infertile women with tubal occlusion detected by laparoscopy (n = 58); 2) infertile women with alternative causes of subfertility (n = 50), and 3) fertile women for the control group (n = 39). An assay of indirect immunofluorescence was performed on all infertile women (n = 108). The results obtained were compared with the laparoscopic and hormonal analyses carried out on the 108 infertile women. The statistical analysis included a model in ROC Curve and Logistical Regression.

Results: The results showed that the titer 1:256 is able to differentiate fertile women from infertile women. Moreover, in the adjusted analysis, the titer 1:512 was able to identify infertile women with tubal occlusion (OR 2.6, CI 95% 1.24, 5.4), with a sensibility of 40% and a specificity of 90%. Positive and negative predictive values were 85% and 50%, respectively and the positive and negative likelihood ratios were 3.85 and 0.67, respectively. The pattern of the ROC curve confirmed a court value of 1:512, with an area under the curve of 62.2% (CI 95%: 53.4-72%).

Conclusion: A titer greater or equal to 1:512 of anti-C. trachomatis IgG antibodies is useful in the identification of tubal factor infertility.