Severe cytopenia during adjuvant chemotherapy for early breast cancer in a patient with idiopathic CD4+ lymphocytopenia

Idiopathic CD4+ lymphocytopenia (ICL) is a rare immunodeficiency disorder characterized by decreased CD4+ T-cell counts in the absence of human immunodeficiency virus (HIV) infection. Similar to HIV infection, ICL is commonly associated with acquired immunodeficiency syndrome-defining cancers, such as Kaposi sarcoma, non-Hodgkin lymphoma and cervical cancer; however, the presentation of breast cancer in a patient with ICL is rare. The current study presented the clinical course of a patient with early breast cancer and ICL. Following surgery, the patient underwent adjuvant chemotherapy comprising doxorubicin plus cyclophosphamide, followed by paclitaxel. The patient's immunodeficiency status required the prophylactic administration of clarithromycin, trimethoprim-sulfamethoxazole and valganciclovir. Throughout the course of chemotherapy, the patient experienced severe complications of febrile neutropenia, anemia, neutropenia and thrombocytopenia, and was eventually forced to discontinue anticancer chemotherapy, as the relative dose intensity (RDI) could not be maintained. Similar hematological complications and reduced RDI, leading to worse outcomes, are also common in patients with HIV infection receiving chemotherapy, suggesting that CD4+ T cell-deficient patients are prone to developing cytopenia during chemotherapy. The present study demonstrates the importance of further data accumulation in patients with ICL with cancer and the development of a methodology for maintaining the RDI.