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 hydrops and effusion in 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 effusion gradually decreased, and TAM and eosinophilia improved. In order to elucidate the immunological mechanism, we measured the levels of 17 cytokines in her pericardial effusion fluid 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 cytokines in her pericardial fluid decreased and all of the elevated cytokines decreased in her serum. Corticosteroids can be effective to reduce cytokine levels and the amount of effusion in patients with DS. It is presumed that effusion seen in DS with TAM could be related to an abnormal production of cytokines at the effusion site.