Chlamydia psittaci infection and clinicopathologic analysis of ocular adnexal lymphomas in Korea.

Ocular adnexal lymphoma (OAL) is a mostly extranodal marginal zone lymphoma (EMZL). Recent findings have suggested an association between Chlamydia psittaci (Cp) infection and OAL. We sought to confirm this issue and to analyze the clinicopathologic characteristics of OAL in Korea. Between 1993 and 2004, 33 OAL cases were identified at the Asan Medical Center, Seoul, Korea. DNA was extracted from paraffin-embedded tissues, and touchdown enzyme time release polymerase chain reaction was performed to identify three Chlamydia species (Cp, C. tracomatis, and C. pneumoniae). The same procedures were also performed in 21 samples from patients with non-neoplastic ocular adnexal disease (NNOAD). All OAL cases were EMZL. Cp DNA was detected in 26/33 (79%) OAL samples compared with 5/21 (23%) NNOAD samples (P < 0.001). With a median follow-up of 38.5 months (range: 1-105 months), the 5-year progression-free survival (PFS) and overall survival (OS) rates of OAL patients were 72% and 93%, respectively. Clinicopathologic characteristics, recurrence rate, PFS, and OS were not associated with Cp infection. Our study demonstrates an association between OAL and Cp infection in Korea, suggesting that Cp plays a role as a causative antigen in Korean OAL patients.