Síndrome mieloproliferativa transitória associada à trissomia do 21 e fibrose hepática

Abstract

Neonates with Down's Syndrome (DS) occasionally show an excess of blast cells in their peripheral blood and bone marrow. The leukocyte counts are high and just the evolution can discriminate the diagnosis of Transient Myeloproliferative Disorder (TMD) from acute myelogenous leukemia (AML). In contrast to AML, complete spontaneous recovery takes place within 4 - 8 weeks. Liver dysfunction and fibrosis have a major prognostic impact. The aim of this work is to relate the case of a child with TMD, DS and hepatic fibrosis. A male infant with characteristic findings of DS, hepatosplenomegaly and cardiac murmur was examined. The white blood cell count was 95,000/mm³, 19% blast cells, platelets 170,000/mm³, total bilirubin 35.86 mg/dL, AST 184 UI and ALT 122 UI. The echocardiogram showed total atrial-ventricular septal defect, pulmonary hypertension and patent ductus arteriosus. The serology proved to be negative and a hepatic biopsy showed colestasis, sinusoidal and portal fibrosis and immature myeloid elements. The leukocyte count diminished, the platelet count remained low and the liver function worsened. The patient received anti-neoplastic treatment with daunorubicin and cytarabine on the 50th day of life. He later developed pneumonia and renal failure and died on the 61st day. The natural history of TMD raises intriguing questions regarding its origin, clinical course and the subsequent development of leukemia. Liver fibrosis may have a major prognostic impact. It has been reported that 6 out of 8 cases of TMD with hepatic dysfunction died, and liver fibrosis associated with extramedullary hematopoiesis was found in 4 cases. The hypothesis is that liver fibrosis could be caused by cytokines produced by the megakaryocytes in the liver.