INTERLEUKIN-3, INTERLEUKIN-6, GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR AND ERYTHROPOIETIN CORD BLOOD-LEVELS OF PRETERM AND TERM NEONATES

The cascade of known haematopoietic growth factors controlling granulo monopoiesis and erythropoiesis includes interleukin-3 (IL-3), interleu kin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF ), and erythropoietin (EPO). Elevated endogenous IL-3 and IL-6 cord bl ood levels in infection-free premature and mature neonates may reflect their possible role for expansion of haematopoietic progenitor cells, granulocytes and monocytes. Within the erythroid lineage a synergisti c action of IL-3, IL-6 and EPO can be assumed. To identify the regulat ory role in fetal haematopoietic expansion cord blood plasma levels of these haematopoietic growth factors were assessed in 19 premature and 20 mature infants using commercial enzyme-linked immunosorbent assay and enzyme-amplified sensitivity immuno assay test kits. Peripheral bl ood IL-3, GM-CSF and EPO were studied in 5 and 10 premature infants re spectively. Compared with cord blood levels we found a decline in EPO levels but no decrease of IL-3 and GM-CSF during the lst month of life . We conclude that postnatal decrease in plasma burst-promoting activi ty levels in preterm infants is mainly explained by low postnatal EPO levels.