Proinflammatory cytokinemia associated with transient myeloproliferative disorder in down syndrome.

A transient myeloproliferative disorder (TMD) occurs in 10% of the infants with Down syndrome. While most cases resolve within a few months, in 20% of them TMDs are life-threatening or fatal. We encountered 4 patients with TMD, including 1 patient who died of liver failure and disseminated intravascular coagulation. Suspecting involvement of proinflammatory cytokines, we serially assayed them in patients' sera. Cytokines were significantly more abundant in patients than in controls. Interleukins 1 and 2, tumor necrosis factor alpha, interferon gamma, and granulocyte-macrophage colony-stimulating factor were greatly increased, especially in the infant who died. Sustained cytokinemia is likely to participate in TMD pathophysiology, and very high serum concentrations might predict a poor outcome.