Identification of Chlamydia trachomatis in a patient with ocular lymphoma

Accumulating evidence suggests that infectious agents may play a role in ocular adnexa lymphomas (OALs) of MALT-type. In particular, Chlamydia psittaci, the causative agent of psittacosis, has been detected by PCR in most patients from Italy or isolated eastern Asiatic countries with OALs in absence of other Chlamydia species. These patients have also been shown to have a complete or partial response to doxycycline, recognized to be a cheap and safe treatment in these patients. In contrast, OAL patients from other geographic areas and with different genetic background were found to be negative for C. psittaci DNA or had a quite variable response to antibiotic treatment, assuming that this pathogen might not play a ubiquitous role in OALs and that bacterial infection is not associated with OAL. Here, we show the molecular detection and characterization of C. trachomatis but not of other Chlamydiae in PBMCs and lymphoma lesions from an Italian patient with OAL. C. trachomatis 16S rRNA, ompA, and different HsP-60 encoding genes were demonstrated using high-sensitive nested PCR and reverse transcriptase PCR (RT-PCR) in specimens cocultured in optimized Hep-2 cell lines [14–16]. The patient successfully responded to 1-month doxycycline therapy with regression of the ocular lesion and the disappearance of bacterial DNA but not of mRNA from PBMCs. This experience expands the knowledge that other doxycylline-sensitive organisms are involved in the pathogenesis of OALs. Moreover, the continual detection of HsP-60 mRNA transcripts after clinical recovery indicates a persistent antigenic condition that can favor the onset of OAL. Molecular methods combined with cell cultures would be useful for monitoring the chlamydia persistence related genes and to assess the effectiveness of therapy in these patients.