A previously healthy 65‐year‐old man presented to Dartmouth‐Hitchcock Medical Center with 3 months of decreased energy, dyspnea, and fever. The patient was afebrile and normotensive but required 100% O2 by face mask. His exam was notable for globally decreased breath sounds and diffuse rhonchi. A CXR revealed a left‐sided pneumothorax, and follow‐up CT of the chest showed multiple blebs in both lungs, with diffuse ground‐glass opacities and increased interstitial markings. Sputum analysis confirmed the presence of Pneumocystis jirovecii. Subsequent lab analysis showed absolute number of CD4+ of 94(<200 = low), 16% CD4 (nl = 40%‐65%) 27% CD8+, and 43% CD3+. HIV ELISA, Western blot, HIV2 assay, and HIV viral load assay were negative. The patient was treated for P. jirovecii pneumonia (PJP) with antibiotics, and the pneumothorax resolved with chest‐tube placement. The patient was discharged on prophylaxis for PJP.
ICL is a rare disease defined by the Centers for Disease Control as a CD4+ absolute count of <300 cells/jiL or <20% of the total number of T cells a minimum of 2 times at least 6 weeks apart, with no laboratory evidence of infection with HIV‐1 or HIV‐2 and the absence of any defined immunodeficiency or therapy associated with depressed levels of CD4 T cells. There is no detectable bias in sex or age, and there is no evidence of sexual transmission. The pathogenesis of this disorder is currently unknown; however, recent studies indicate that a decrease in T‐cell precursors at the level of the bone marrow may be responsible and may be triggered by a change in the cytokine environment in the bone marrow. Immunologic phenotyping has shown a substantial decrease in naive CD4+ T cells compared with memory CD4+ T cells, further supporting a production deficit as opposed to increased destruction. Current treatment focuses on treating opportunistic infections as well as prescribing prophylaxis against infection using the same guidelines as those for HIV‐infected patients. Recent research suggests possible therapies to include IL‐2 administration to increase CD4+ counts; however, early trials have found potentially associated lymphoma after 1 year of treatment.
ICL is a rare condition. It is important to look for other sources of decreased CD4+ cells before considering this diagnosis. These include HIV, other infection, malignancy, autoimmune disease, and drugs (especially immunosuppressants). In this case, the patient's continued lymphocytopenia more than 6 weeks later confirmed the diagnosis.
K. Desrosiers, none; J. Perras, none.
To cite this abstract:Desrosiers K, Perras J. Idiopathic CD4+ T‐Cell Lymphocytopenia. Abstract published at Hospital Medicine 2008, April 3-5, San Diego, Calif. Abstract 138. Journal of Hospital Medicine. 2008; 3 (suppl 1). https://www.shmabstracts.com/abstract/idiopathic-cd4-tcell-lymphocytopenia/. Accessed April 3, 2020.