Transient abnormal myelopoiesis (TAM) における肝線維化マーカーの検討

: Transient abnormal myelopoiesis (TAM) is usually a self-limiting myeloproliferative disorder observed in approximately 10% of newborn infants with Down syndrome. However, progressive liver fibrosis may occur in patients with TAM and is often lethal. We investigated the utility of the serum levels of hyaluronic acid (HA) and N-terminal peptide of III procollagen (P-III-P) as markers of liver fibrosis and indication for chemotherapy. We reviewed 4 cases of TAM retrospectively. HA levels were more than one hundred times as high as the upper limit of the normal range in 2 patients, one of whom died from gastrointestinal bleeding. His HA and P-III-P had increased up to 18,800 U/ml and 26.2 ng/ml, respectively, just before he died. Another patient's serum HA and P-III-P increased to 6,100 U/ml and 12.8 ng/ml, respectively, however his liver fibrosis resolved with low-dose cytosine arabinoside treatment after exchange transfusion during his clinical course. We suggest that serum HA is useful as a marker of liver fibrosis and a prognostic indicator for chemotherapy in patients with TAM. Early treatment including both exchange transfusion and chemotherapy should be considered for patients presenting with extremely high or an elevating tendency of their HA serum levels.