[Detection of chlamydial antibodies by immunoblotting technique--in comparison of three commercially available test kits and micro-IF].

We reexamined the assay conditions of immunoblotting (W-B) technique to detect antibodies (IgG and IgA) to C. trachomatis serovar L2. Partially purified Chlamydia (35% urografin) was used as the antigen. The marker bands of W-B for positive and/or negative are major outer membrane protein (MOMP) band and either one or more bands staining in 40-62 KDa area. We then compared the sensitivity and specificity of three commercially available test kits and micro-IF by using W-B as a standard. The kits compared were sero-IPALISA-IgG-IgA, IP-Azyme-IgG-IgA and HITAZYME-IgG-IgA, and micro-IF. Serum samples were collected from the outpatient departments of gynecology, urology, and internal medicine and pediatrics. The results of agreement between W-B and test kits in IgG detection were as follows: in sero-IPALISA, total agreement was 85.7%, positive agreement 83.3%, negative agreement 90.9% and in IPAzyme: 85.7%, 83.3%, 90.9%, respectively and in HITAZYME: 82.9%, 75%, 100%, respectively. These results are almost the same as micro-IF: 85.7%, 79.2%, 100%, respectively. These kits may have relatively high sensitivity and specificity in IgG antibody detection. In IgA detection, the total agreement between W-B and sero-IPALISA was 82.9%, positive agreement 100%, negative agreement 66.7%, in IPAzyme: 77.1%, 58.8%, 94.4%, respectively and in HITAZYME: 65.7%, 64.7%, 66.7%, respectively and in micro-IF: 82.9%, 70.6%, 94.9%, respectively. Although these agreements are not so high in IgA detection, the W-B technique gives fairly consistent results as well as those kits. This indicates that W-B technique with MOMP and other protein bands (40-62 KDa) as marker for positive reaction is a useful method for detection of chlamydial antibodies.