Chlamydia psittaci in Ocular Adnexal MALT Lymphoma: a Possible Causative Agent in the Pathogenesis of This Disease

Purpose of Review To elucidate the role and to summarize the current literature of Chlamydia psittaci (Cp ) as a causative factor in ocular adnexal extranodal marginal B cell lymphomas (OAEMZLs). Recent Findings The association of Cp and OAEMZLs varies according to geographic location. Antibiotic therapy is an effective therapeutic approach in Cp+ OAEMZLs. Cp+ OAEMZLs are significantly associated with chronic conjunctivitis and prolonged household animal contact. Furthermore, somatic hypermutation, intraclonal microheterogeneity, genetic aberrations, and gene promotor methylation can be found in Cp+ OAEMZLs. Summary It has been shown that antibiotic therapy is an effective therapeutic approach in Cp -positive OAEMZLs, therefore raising the question if Cp is an important etiologic agent of this disease. Since there is evidence pointing in this direction, we summarize the recent findings and support the pathophysiological model of Cp as a causative agent in OAEMZLs.