using recombinant chlamydia trachomatis omp2 as antigen in diagnostic elisa test.

background and objectives: the obligate intracellular bacterium chlamydia trachomatis causes sexually transmissible diseases in human. timely and sensitive detection of this pathogen is very important. there are many cross-reactions in bacteriological and serological methods in detection of this type of pathogens. the aim of this study was to achieve a more specific antigen for serological tests. materials and methods: blood samples were taken from 192 women with suspected chlamydial infection and sera were isolated. elisa plate wells were coated with recombinant c. trachomatis omp2 as antigen. cut-off system was determined with 40 negative sera. the final results of this research were compared with euroimmun commercial kit. results: the elisa system c ut-off was calculated at 0.27 using negative sera samples. ods of positive samples were higher than 0.27 and negative samples were lower than it. we obtained 30 samples (15.62%) as positive and 162 cases (84.37%) as negative. sensitivity and specificity of the recombinant antigen were 90% and 86%, respectively. this antigen showed no cross-reactivity with sera of patients infected with hydatid cyst, hcv, epstein barr virus, hbv, helicobacter pylori , toxo- plasma gondii , cytomegalovirus , mycoplasma , measles and varicella zoster virus. conclusion: the sensitivity and specificity of romp2 in elisa for detection of c. trachomatis were 90% and 86%, respec- tively. though the sensitivity was higher than results of euroimmun commercial kit, its specificity was calculated lower than reference kit.