Platelet dysfunction in the neonate with essential fatty acid deficiency.

Platelet aggregation in response to ADP was studied in five EFA-deficient sick premature newborn infants who were receiving fat-free parenteral nutrition. EFA deficiency was diagnosed by analysis of plasma lipid fatty acid values. The deficient infants had impaired platelet aggregation when compared to other low-birth-weight infants fed orally who served as control subjects (maximum 18.1% versus 43.4% at 2.5 muM ADP; 34.5% versus 52.2% at 5.0 muM ADP). In addition, the platelets from EFA-deficient infants demonstrated clearly evident disaggregation. On recovery from their deficient state, the low-birth-weight infants had platelet functions similar to those of apparently healthy premature infants. Clinical hemorrhage occurred in four of the EFA-deficient infants. Thus a deficiency of arachidonic acid, the precursor of thromboxane A2, is correlated with an impairment of the aggregation of platelets, a phenomenon mediated by thromboxane A2. This correlation provides the basis for a hypothesis that the observed EFA deficiency is causally related to the platelet dysfunction.