Circulating antibodies to a conserved epitope of the Chlamydia trachomatis 60 kDa heat shock protein (hsp60) in infertile couples and its relationship to antibodies to C.trachomatis surface antigens and the Escherichia coli and human HSP60

To evaluate the relationship between immunity to specific regions of theChlamydia trachomatis 60 kDa heat shock protein (hsp60), autoimmunity tohuman HSP60 and infertility, sera from 50 women and 45 men seen for aninfertility evaluation were tested. Humoral immunity to human HSP60 wasdetected in 18% of women and 8.9% of men while antibodies to theEscherichia coli hsp60 were detected in 12% of women and 4.4% of men. Thesedifferences were not statistically significant. In contrast, antibodies toa synthetic peptide epitope of the chlamydial hsp60, encompassing aminoacids 260-271 (chsp 260-271), were present in sera from 16 (32%) of thewomen but in only six (13.3%) of the men (P=0.03). Antibodies to chsp260-271 were present in 11 out of 17 (64.7%) individuals with high titre(>1:160) immunoglobulin (Ig)G antibody to C.trachomatis surface antigensas opposed to only two out of 15 (13.3%) with low titre antibody and twoout of of 17 (11.8%) with undetectable chlamydial antibody (P < 0.004).Antibodies to chsp 260- 271 were also associated with humoral immunity tohuman HSP60. 50% of sera with, as opposed to only 18.6% of sera without,anti-human HSP60 IgG were positive for antibodies to chsp 260-271 (P=0.03).In contrast, there was no relationship found between immunity to the E.colihsp60 and antibodies to human HSP60. Antibodies to chsp 260-271 were moreprevalent in women with at least two spontaneous abortions (eight out of13, 61.5%) than in women with other infertility diagnoses (six out of 35,17.1%) (P=0.004). Thus, immunity to chsp 260-271 is more prevalent in womenthan in men, associated with autoimmunity to human HSP60 and may be animmunological marker for spontaneous abortion.