Idiopathic CD4 Lymphocytopenia: Immunologic Characteristics, Clinical Manifestations, and Disease Course
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Jenni Y. Yoon, MD, Panida Sriaroon, MD, Jennifer W. Leiding, MD, Mark Ballow, MD FAAAAI

Rationale: Idiopathic CD4 lymphocytopenia (ICL) is a heterogeneous disorder that confronts our specialty. Issues concerning diagnosis, treatment and long-term prognosis are common.

Methods: Retrospective chart reviews were performed on four patients with a diagnosis of ICL to evaluate clinical features, laboratory variations, and disease course.

Results:  All patients were diagnosed with ICL based on at least 2 measurements of absolute CD4 count <300 cells/uL (normal range 490-1740 cells/uL). Median absolute CD4 count was 173 cells/uL (61-268 cells/uL). Median age at diagnosis was 66.5 years (44-72 years).  One of four had an opportunistic infection at presentation: disseminated histoplasmosis. Autoimmunity with inflammatory arthritis and uveitis occurred in another. Anti-thyroid peroxidase antibodies were present in one patient without evidence of thyroiditis.  The only malignancy was basal cell carcinoma of the skin in one patient. In addition to low CD4 T cells, CD19+ B cells and CD16+ NK cells were decreased in two and T cell proliferative responses were decreased in two. Specific antibody titers were decreased in one prompting therapy with gammaglobulin replacement.

Conclusions: ICL is a heterogeneous disease with variable presentation. Profoundly low absolute lymphocyte count or CD4 T cells did not correlate with severity of disease.  Decreased NK cell quantities have reportedly been associated with more severe disease, but did not in our cohort. Autoimmune disease with presence of autoantibodies is closely associated with ICL and malignancy is a possible complication.