Prevalence and diagnostic significance of specific IgA and anti-heat shock protein 60 Chlamydia trachomatis antibodies in subfertile women.

The objective of the present study was to evaluate the clinical usefulness of the simultaneous measurement of three serological markers of chlamydial infection in women with tubal factor infertility (TFI) and spontaneous miscarriage. Serum was collected from 87 patients (33 with TFI and 54 with spontaneous miscarriage) and analyzed for the presence of IgG and IgA antibodies against Chlamydia trachomatis MOMP antigen (Dia.Pro) and IgG antibodies to chlamydial heat shock protein 60 (cHSP60) antigen (Medac). We determined a high degree (64.5 %) of seropositivity against chlamydial antigens in our study population. The prevalence of persistent chlamydial infection has tended to be higher in the group of patients with TFI (41.4 %) than in patients with spontaneous miscarriage (21.3 %). The serum level of IgA, as a marker of active infection, was statistically higher in the TFI group with persistent infection than in the corresponding spontaneous miscarriage group (p = 0.008), while the serum level of IgG showed no statistically significant differences compared with the spontaneous miscarriage group with persistent infection (p = 0.227). Also, using the receiver operating characteristic (ROC) curve, we found that the serum level of IgA has the ability to discriminate patients with persistent chlamydial infection between the TFI and miscarriage groups, with a sensitivity and specificity of 74.3 % and 71.4 %, respectively. To the best of our knowledge, the present study is the first study which, besides the already confirmed linkage between serologic evidence of persistent chlamydial infection and TFI, also confirmed associations between spontaneous miscarriage and serologic evidence of persistent chlamydial infection.