Two cases of aquaporin-4 positive neuromyelitis optica associated with T-cell lymphoma

Background: Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory condition associated with antibodies against aquaporin-4 (AQP4). To date, 4 cases of B-cell lymphomas have been reported in patients with NMOSD. Here we describe two individuals with AQP4+ NMOSD and T-cell lymphomas (TCL). Conclusion: Possible mechanisms that may explain co-existence of NMOSD with TCL include a paraneoplastic syndrome leading to AQP4 antibody production, or a generalized dysfunction of the adaptive immune system. Both patients were diagnosed with NMOSD and initiated on anti-CD20 agents prior to lymphoma diagnosis, though the short duration of exposure argues against a direct role. Further research is needed to examine the rate of lymphoproliferative disorders in NMOSD.