Platelet-Neutrophil Interactions Are Lower in Cord Blood of Premature Newborns.

OBJECTIVE: To quantify platelet-neutrophil interaction by flow cytometry, in newborn cord blood, as a function of gestational age. RATIONALE: Little is known about platelet function markers in the newborn, and developmental variations in these markers are not well described. METHODS: Cord blood samples were obtained from 64 newborns between 23 and 40 weeks' gestation. The neonates were grouped into three categories: preterm (< 34 weeks' gestation, n = 21), late preterm (34 to < 37 weeks' gestation, n = 22), and term (≥37 weeks' gestation, n = 21). We monitored the expression of P-selectin and the formation of platelet-neutrophil aggregates (PNAs) by flow cytometry while using adenosine 5'-diphosphate (ADP) or thrombin receptor-activating peptide (TRAP) as agonists. RESULTS: PNAs were significantly lower in preterm compared to term neonates after TRAP or ADP stimulations (11.5 ± 5.2% vs. 19.9 ± 9.1%, p < 0.001, or 24.0 ± 10.1% vs. 39.1 ± 18.2%, p = 0.008, respectively). The expression of P-selectin also tended to be lower in preterm neonates, with significant positive correlations between P-selectin expression and PNA formation. CONCLUSIONS: The potential formation of PNAs correlates with gestational age. This suggests that the development of functional competencies of platelets and neutrophils continues throughout gestation, progressively enabling interactions between them.

Recurrence of microangiopathic hemolytic anemia after apparent recovery from the HELLP syndrome. A case report.

BACKGROUND: The syndrome of hemolytic anemia, elevated liver enzymes and low platelets (HELLP) can accompany preeclampsia and eclampsia. Delivery of the infant usually results in improvement in the mother's condition, with the recovery time dependent on the severity of the disease. We report a case of eclampsia with the HELLP syndrome in which microangiopathic hemolytic anemia (MAHA) and thrombocytopenia recurred after apparent recovery. CASE: A 28-year-old woman, gravida 4, para 0, therapeutic abortion 3, presented with signs and symptoms of severe preeclampsia and became eclamptic. The patient's condition improved as expected following cesarean delivery. However, the hemolytic anemia recurred and was successfully treated with a course of fresh frozen plasma (FFP). CONCLUSION: Hemolytic anemia in women with eclampsia and the HELLP syndrome occurs secondary to microvascular endothelial damage. In this case resolution of the HELLP syndrome and eclampsia occurred, as expected, in two to three days; however, MAHA and low platelets recurred on day 4. Treatment of MAHA with FFP was successful.