<prompt> Answer this question truthfullyWhat are the natural history, complications, and prognosis associated with T-cell leukemia in adults?  <response>: <reason> The natural history of adult T-cell leukemia varies between the different sub-types of the disease. Patients with acute adult T-cell leukemia usually have an aggressive clinical course with a median survival period of less than 12 months. If left untreated, most of the patients with acute adult T-cell leukemia will develop constitutional symptoms, lymphadenopathy, and organomegaly within a few weeks of diagnosis. Patients with chronic adult T-cell leukemia will usually have an stable clinical course. If left untreated, most of the patients with chronic adult T-cell leukemia will develop lymphocytosis for months, or even years, before presenting with the typical cutaneous manifestations. Most patients with smoldering adult T cell leukemia are initially asymptomatic. If left untreated, most of the patients with smoldering adult T cell leukemia will develop steroid -responsive skin rash and multiple lung infiltrates.Common complications of adult T-cell leukemia include: Cardiac arrhythmias due to hypercalcemia Opportunistic infections Strongyloides stercoralis infection is a frequent cause of death among adult T-cell leukemia patients Bone fractures due to lytic bone lesions Anemia Recurrent bleedingThe prognosis varies between the sub-types of adult T-cell leukemia. Acute and lymphomatous sub-types have a poor prognosis; whereas, chronic and smoldering sub-types have a good prognosis. The 4-year overall survival rate of patients with adult T-cell leukemia is approximately 16. The 4-year overall survival rate of patients with acute adult T-cell leukemia is approximately 11. The 4-year overall survival rate of patients with chronic adult T-cell leukemia is approximately 36. The 4-year overall survival rate of patients with smouldering adult T-cell leukemia is approximately 52.The table below lists prognostic factors for adult T-cell leukemia patients: Prognostic Factor Description Clinical subtype Acute and lymphomatous subtypes have a poor prognosis, where as chronic and smouldering subtypes have a good prognosis. Gender Males are associated with a worse prognosis when compared to females. Performance status Patients poor performance status is associated with a worse prognosis. Calcium level Hypercalcemia is associated with a worse prognosis. Leukocyte count An elevated leukocyte count is associated with a worse prognosis. Lactate dehydrogenase LDH level Elevated level of LDH is associated with a worse prognosis. β2-microglobulin level An elevated β2-microglobulin level is associated with a worse prognosis. Lymphocyte surface markers Over expression of CD25 is associated with a worse prognosis. Neuronspecific enolase An elevated neuron specific enolase level is associated with a worse prognosis. 