Adult T Cell Leukemia

Adult T-cell leukemia (ATL) is a highly aggressive mature T-cell neoplasm associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection, which affects around 10 million people in the world. Of them, approximately 1-5% eventually develop symptomatic ATL. HTLV-1 is the first human retrovirus and is endemic in the north and south parts of Japan, the Caribbean region, Africa, some parts in the Middle East, South, and Central America. HTLV-1 transmission occurs from mother to child through breastfeeding, sexual interaction, and blood transfusion. Initial presentation may vary, including generalized lymph node swelling, hepatosplenomegaly, skin involvement, and opportunistic infections.ATL is classified into four clinical subtypes: acute, lymphoma, chronic, and smoldering type. Aggressive ATL (acute, lymphoma, and chronic type with unfavorable prognostic factors) have a poor prognosis with an overall survival rate of less than a year. The favorable chronic and smoldering subtypes carry a relatively good prognosis, and watchful waiting is generally preferred until disease progression occurs. Patients who have rapidly progressive disease carry a poor prognosis due to the chemo-resistance of malignant cells and severe immunosuppression.