ARTICLE Prevalence and diagnostic significance of specific IgA and anti-heat shock protein 60 Chlamydia trachomatis antibodies in subfertile women A. Arsovic & A. Nikolov & P. Sazdanovic & S. Popovic & D. Baskic Received: 13 September 2013 /Accepted: 21 October 2013 # Springer-Verlag Berlin Heidelberg 2014 Abstract 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 deter- mined a high degree (64.5 %) of seropositivity against chla- mydial 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 per- sistent 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. Introduction Chlamydia trachomatis infection is the most common sexu- ally transmitted bacterial infection in the world [1, 2]. Genital strains of C . trachomatis (serovars D–K) target columnar epithelial cells in the endocervix of women and the urethra of men to initiate their unique, biphasic infectious process, usually characterized by intermittent infectious elementary body (EB) and noninfectious reticulate body (RB) stages [3]. Most C . trachomatis infections are asymptomatic and, there- fore, remain undiagnosed and, consequently, untreated [4]. While many individuals eventually clear infection, this can take several months to several years [5, 6]. If left untreated, C . trachomatis infection can progress to chronic inflammatory disease, and bacteria can ascend from the endocervix into the endometrium and fallopian tubes. At these sites, C . trachomatis infection is associated with pelvic inflammatory disease (PID) and potentially results in endometritis and varying degrees of tubal pathology [3]. The linkage between C . trachomatis IgG antibodies in serum and tubal pathology has been documented at the end of the last century [7]. Serum IgG antibodies are known to remain detectable for many years after C . trachomatis infec- tion [8]. Therefore, serum chlamydia IgG antibody testing is considered as a useful assay in infertile women to reflect a A. Arsovic Institute of Medical Microbiology and Immunology, Medical Faculty, University of Pristina, Kosovska Mitrovica, Serbia A. Nikolov : P. Sazdanovic (*) Department of Gynecology and Obstetrics, Clinical Center Kragujevac, Kragujevac, Serbia e-mail: spredragster@gmail.com S. Popovic : D. Baskic Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia D. Baskic e-mail: dejan.baskic@gmail.com D. Baskic Public Health Institute Kragujevac, Kragujevac, Serbia Eur J Clin Microbiol Infect Dis DOI 10.1007/s10096-013-2008-4