Differences in Clinical Characteristics of Transient Myeloproliferative Disease and Leukemia in Down Syndrome: A Single University Hospital Study.

Abstract

BACKGROUND: Children with Down syndrome (DS) have a 10- to 20-fold increased risk of developing leukemia. However, in some patients, leukemia does not become apparent despite significant number of blast cells in the peripheral blood. This condition is called Transient myeloproliferative disorder (TMD), and is a disease entity unique to DS newborns and defined as the morphologic detection of blasts in DS less than three months of age. The present study investigated whether there was a difference between leukemia and TMD, and determined prognostic and risk factors. METHODS: We collected blood samples from 317 patients of 433 DS confirmed patients. We found 18 patients who had blast cells in their peripheral blood. RESULTS: Twelve patients were positive for blasts during the neonate period, and only one patient progressed to leukemia. The other 11 patients were later diagnosed with TMD. Six more patients were later diagnosed with leukemia, therefore, 7 patients were diagnosed with leukemia in total. All patients diagnosed with leukemia had anemia at the time of diagnosis, which was not found in TMD patients. All leukemia patients developed their disease after three months of life. Acute Myeloid Leukemia (AML) patients had additional chromosome mutation to trisomy 21 when they were diagnosed. CONCLUSION: In patients with Down Syndrome, anemia at diagnosis and age of onset could be helpful in distinguishing TMD from acute leukemia. Cancerous mutations in the chromosomes of peripheral and marrow blast cells of Down syndrome patients may foreshadow acute leukemia.