How to use Chlamydia antibody testing in subfertility patients

Abstract

Screening for tubal factor subfertility by means of Chlamydia antibody testing (CAT) was introduced into the initial work-up of subfertile couples several years ago. The results reported, however, are heterogeneous, and no uniformity exists in cut-off levels of titres, or in definitions of tubal factor subfertility. We performed a prospective cohort study to evaluate the implications of varying the definitions of tubal pathology and of modifying the cut-off levels on the clinical impact of CAT in predicting tubal factor subfertility. In 227 consecutive patients who attended our fertility clinic, the Chlamydia IgG antibody titre was determined and related to tuboperitoneal abnormalities at laparoscopy as a reference standard. According to received operating characteristic (ROC) curve analysis, a titre of 16 is the optimum cut-off level. Increasing the cut-off level improves specificity and positive likelihood ratio (LR+), at the expense of sensitivity and negative LR (LR-). Changing the definition of tubal factor subfertility from unspecified tuboperitoneal abnormalities into extensive adhesions and/or bilateral distal tubal occlusion improves LR+, LR- and kappa significantly. We conclude that CAT is more accurate in predicting severe distal tubal pathology than unspecified tuboperitoneal abnormalities. Although from a statistical point of view a titre of 16 is the optimum cut-off level, from a clinical point of view 32 or 64 may be preferable, depending on the aim of screening and the inception cohort.

Association of Uterine and Salpingeal Fibrosis with Chlamydial Hsp60 and Hsp10 Antigen-Specific Antibodies inChlamydia-Infected Koalas

“…This phenomenon has been documented in a study of women affected by chlamydiosis, in which it was suggested that titers diminish with age, as most infections occur in young adulthood (22). The present study detected no effect of age on titers within the life span of koalas, nor did it suggest that the poor body condition and marked hypoproteinemia suffered by many koalas significantly impairs production of hsp-specific antibodies.…”

Comparison of four serological assays for the diagnosis of Chlamydia trachomatis in subfertile women

“…Of particular note, Chlamydia antibodies are associated with Chlamydia-induced tubal pathology only, and, as a consequence, the predictive value of CAT will be poor for disease not associated with Chlamydia infection. It has been shown that CAT is more accurate in predicting distal tubal pathology, instead of unspecified tuboperitoneal abnormalities or proximal tubal occlusion [11]. Moreover, in studying the implications of different cutoff titres for a positive test, it has been noted that increasing the cutoff titre will improve the specificity, at the expense of sensitivity [7,12,15].…”

“…The micro-immunofluorescence test (MIF) is generally regarded as a gold standard in the serological diagnosis of C. trachomatis infection [11,12]. However, MIF is not ideal for routine serodiagnostics because it is labour intensive, highly observer dependent, and interlaboratory variation is significant [13].…”

High follicle-stimulating hormone levels should not necessarily lead to the exclusion of subfertile patients from treatment

“…In case of risk factors for tubal pathology, such as, for example, ectopic pregnancy or abdominal surgery in the past, but no Chlamydia antibodies present, hysterosalpingography (HSG) was performed. Patients with no risk factors for tubal pathology and absent Chlamydia antibodies were assumed to have a very low chance of tubal damage (21,22), and further evaluation of tubal function was postponed or an HSG with oil-soluble contrast for therapeutic purposes was performed (23), as indicated by the guidelines of the Dutch Association of Obstetrics and Gynecology.…”