Purpose: Histopathology usually cannot be performed and cytology is unfortunately frequently insufficient to confirm a suspicion of primary intraocular lymphoma (PIOL). The purpose of this study was to evaluate the Immunoscope technique for the identification of ocular B-cell monoclonal infiltrates in patients with malignant or immune conditions.
Methods: Polymorphism analysis of the size of the third complementarity-determining region (CDR3) of heavy chain antibody transcripts was used to differentiate between a polyclonal infiltrate and a monoclonal infiltrate within a clinical vitreous sample of two groups of patients. PIOL was confirmed in all patients of the first group (n = 6). Five patients with autoimmune uveitis or immune-recovery uveitis associated with AIDS were included in the control group. The level of IL-10 in the vitreous was determined in all patients.
Results: In five cases of severe PIOL, CDR3 polymorphism analysis confirmed the presence of a dominant B-cell clone within the eye. In one case of confirmed PIOL presenting with mild vitritis, CDR3 polymorphism analysis was consistent with the existence of a polyclonal profile in the ocular sample studied. Conversely, it was shown that the detection of an intraocular monoclonal B-cell population does not necessarily imply ocular lymphoma. A clonal expansion was detected in a control patient who exhibited merely a nonmalignant response associated with immune-recovery uveitis.
Conclusions: This PCR-based technique can make an important contribution to the characterization of intraocular B cells, but it alone cannot confirm or exclude the existence of a malignant lymphocyte proliferation. In the evaluation of a patient with intraocular inflammation in whom PIOL is suspected, CDR3 polymorphism analysis is recommended to confirm clonality. In general, the information about lymphocyte diversity provided by this technology opens up new possibilities for the analysis of ocular infiltrates.