Absence of chlamydial infection in Japanese patients with ocular adnexal lymphoma of mucosa-associated lymphoid tissue

Ocular adnexal extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (ocular adnexal MALT lymphoma) are predominately low-grade, small B-cell types and may be caused by several putative inflammatory agents. Twenty-three ocular adnexal MALT lymphoma cases, the monoclonality of which was confirmed by examination of immunoglobulin heavy chain gene rearrangement and/or cell surface antigens, were analyzed for evidence of several causative factors. A serologic evaluation of our series of patients showed no evidence of infection by Epstein-Barr virus, hepatitis C virus, or Chlamydophila psittaci. Two patients tested positive for serum antibodies for autoimmunity, and another 2 patients tested positive for antibodies against Chlamydia trachomatis. Polymerase chain reaction analysis did not reveal the presence of the chlamydial 16S ribosomal RNA (rRNA) gene or the 16S-23S spacer rRNA gene. These results indicate that the inflammatory agents in our series of ocular adnexal MALT lymphomas are still unknown and that some types of chlamydial infections are not associated with orbital adnexal MALT lymphoma in southern regions of Japan.