Cytokine Profiles in Pericardial Effusion in a Down Syndrome Infant with Transient Abnormal Myelopoiesis

Infants with Down Syndrome (DS) are at risk of developing a transient abnormal myelopoiesis(TAM). TAM is characterised by increased circulating blast cells but usually self-limiting. DS patients with TAM sometimes show fetal hydropsand effusionin body cavities, but the mechanism remains unclear. We report here a case of infant with DS who had pericardial effusion, TAM, and eosinophilia. In her pericardial effusion, white blood cell count was 6.0 × 103/µL, 41% of which were eosinophils. After administration of prednisolone, pericardial effusiongradually decreased, and TAM and eosinophiliaimproved. In order to elucidate the immunological mechanism, we measured the levels of 17 cytokinesin her pericardial effusionfluid and serum. In her pericardial fluid, there were high levels of 12 cytokines, and they were higher than those in her serum. In particular, IL-6 (44,573 pg/mL), IL-8 (4,865 pg/mL), and IL-13 (579.41 pg/mL) were at extremely high levels in her pericardial fluid. After administration of prednisolone, the levels of 8 of the 12 elevated cytokinesin her pericardial fluiddecreased and all of the elevated cytokinesdecreased in her serum. Corticosteroids can be effective to reduce cytokinelevels and the amount of effusionin patients with DS. It is presumed that effusionseen in DS with TAM could be related to an abnormal production of cytokinesat the effusionsite.