Successful Treatment Using Interleukin-2 (IL-2) in a Patient with Idiopathic CD4+ Lymphopenia (ICL) and Mycobacterium avium (M.avium)

Abstract

RATIONALE: ICL is a rare immune defect characterized by: CD4+ T cells count <300 cells/mm3 on more than one occasion, lack of HIV infection or other immune deficiency, and presence of opportunistic infections. Isolated case reports suggest that IL-2 is efficacious in ICL. We report a case of a patient with M.avium due to ICL who was successfully treated with IL-2. METHODS: This patient is a 39 y/o WM who presented with 2 years of chronic cough and dyspnea. A sputum culture revealed M.avium. His CD4+ T cells were decreased at 182 cells/μl. Workup for other etiologies of CD4+ lymphopenia was negative including: HIV-1,2 , HTLV-1,2, chest CT and bone marrow biopsy. He was diagnosed with ICL and started on pegylated subcutaneous IL-2 at 500,000 units weekly. He was given incrementally higher doses until he reached a maintenance dosage 3 months later of 11 MU weekly. RESULTS: After 3 months of therapy, CD4+ T cells increased to 453 cells/μl. Nine months after initiation of IL-2, his CD4+ T cell counts have been >450 cells/μl. Sputum cultures became negative for M.avium, and he has tolerated the IL-2 with no side effects. CONCLUSIONS: IL-2 therapy appears to be a relatively safe and effective treatment for patients with ICL and should be considered for select patients to prevent the high morbidity associated with this syndrome.