Absence of chlamydial infection in Japanese patients with orbital adnexal MALT lymphoma

Abstract

18523 Background: The extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct B-cell lymphoma that develops in extranodal sites and usually has an indolent clinical course as a localized disease. Recent clinicopathological studies suggest a strong relation between MALT lymphoma and inflammatory diseases of the epithelium such as autoimmune diseases and infections (Sjogren’s syndrome, Hashimoto’s thyroiditis, Helicobacter pylori infection, and etc.), because chronic antigen stimulation has been causally linked to the development of B-cells lymphoproliferative diseases. MALT lymphoma grows in extranodal lymphoid tissue and exists in epithelium tissues, and it is often difficult to distinguish malignant lymphoid tissue from benign inflammation. This is one cause since recent positive or negative correlations between ocular adnexal MALT lymphomas and chlamydial infections have been reported from different researchers, indicate several possible explanations. Methods: Twenty-three cases of ocular adnexal MALT lymphoma in southern regions of Japan, whose monoclonality was confirmed by immunoglobulin heavy chain gene rearrangement and/or cell surface antigens, were analyzed for evidence of several causative factors using ELISA analysis to detect antibodies and Southern blot analysis followed by specific PCR gene amplification. Results: Our series of patients did not show any serological relations to Epstein-Barr virus, Hepatitis C virus, and Chlamydophila psittaci. Two cases had positive serum antibodies for autoimmunity, and another two cases had positive antibodies against Chlamydia trachomatis. None of our cases showed the presence of chlamydial 16S rRNA and 16S-23S spacer rRNA genes (C. psittac, C trachomatis, C. pneumoniae, and C. felis) after Southern blot analysis followed by PCR amplification. Conclusions: Inflammatory agents are still unknown in our series of orbital adnexal MALT lymphomas, and some types of chlamydial infections are not associated with orbital adnexal MALT lymphoma in southern regions of Japan. No significant financial relationships to disclose.