Title: Idiopathic CD4 T Lymphocytopenia and the Association of Autoimmunity Involving the Nervous System
Abstract: Idiopathic CD4 T lymphocytopenia (ICL) is a rare immunodeficiency defined as absolute CD4 T-lymphocyte count <300/mm3, without evidence of infection with HIV or HTLV. ICL patients can have susceptibility to opportunistic infections and associated autoimmunity. Functional T-cell lymphocytopenia can result in a variety of organ-specific autoimmune diseases in animal models; autoreactive T cells undergo expansion as a mechanism of compensation for lymphopenia. Defects in T regulatory cells (CD4+CD25+) correlate with disease severity in myasthenia gravis and multiple sclerosis. We report two cases of patients with ICL who also had autoimmune disease involving the nervous system. A retrospective chart review was performed. Patient A is a 59 year old female with multiple sclerosis diagnosed at the same time that lymphocytopenia was reported. Her CD4+ T cell quantities range from 25-51 cells/mL and CD8+ 38-106 cells/mL. Review of medications did not reveal any associated with bone marrow suppression and bone marrow biopsy was also normal. Patient B is a 49 year old female with Sjögren's Syndrome, pulmonary Mycobacterium avium complex, and ICL that developed myasthenia gravis 1 year after ICL was diagnosed. Her CD4+ T cell quantities have ranged from 227-297 cells/mL, CD8 has ranged from 180-240 cells/mL. T regulatory cell repertoire is being examined in both patients. Although, lymphopenia is a common finding in autoimmune diseases it is not well described in those with neurologic autoimmunity, specifically multiple sclerosis and myasthenia gravis. Testing of lymphocyte subsets and proliferative studies is warranted in this population, as those results may affect management.