SEROLOGICAL RESPONSE TO CHLAMYDIA-PNEUMONIAE IN PATIENTS WITH SARCOIDOSIS

The antigen-specific serological response to Chlamydia pneumoniae was studied in 24 patients with sarcoidosis and compared to that seen in a cute C. pneumoniae respiratory infection. By the micro-immunofluoresce nce test, five sarcoidosis patients had acute antibody, 15 had chronic antibody and four had no antibody against C. pneumoniae. By enzyme im munoassay. 20 sarcoidosis patients had antibody against ReLPS that cro ss-reacts with chlamydial LPS. Immunoblot analysis of sera using purif ied C. pneumoniae elementary bodies showed that recognition of the 40 kDa C. pneumoniae major outer membrane proteins was rare (20%). Reacti vities with proteins with M(W) of 42 K (70%), 60 K (65%), 98 K (55%) a nd 52 K (50%) were often noted. To study reactivity of chlamydial HSP 60 in sarcoidosis sera, sarkosyl-soluble (contains the 60 kDa HSP) and sarkosyl-insoluble (contains the 60 kDa structural protein) fractions of C. pneumoniae elementary bodies were prepared. The 60 kDa structur al protein was recognized with equal frequency by sera from patients w ith sarcoidosis and acute respiratory infection, while the HSP 60 was more frequently recognized by sera acute respiratory infection than sa rcoidosis. Recombinant fusion proteins expressed from pGEX-2T containi ng overlapping DNA fragments of the C. pneumoniae 60 kDa HSP gene were purified. Different recognition patterns were identified for sera fro m sarcoidosis patients and from patients with acute C. pneumoniae resp iratory infection.