The effect of gestational age on platelet surface expression of CD62P in preterm newborns

Abstract

Hemostasis in preterm newborns is characterized by low reserve functional capacity with special reference to the presence of such risk factors as asphyxia or infection. Platelets play vitally important role in hemostasis. Expression of CD62P is a marker of stimulated or activated blood platelets. The study involved a group of 16 preterm newborns, five girls and 11 boys. DAKO QIFIKIT was applied to calculate the number of these antigens. The mean CD 62P expression was found to be 23,792 per platelet. Correlation was found between antigen density and gestational age r = 0.954, p = 0.01. Evident deficit of P-selectin on the surface of platelets in preterm newborns may be at least in part responsible for platelet dysfunction, with special reference to interaction between circulating leukocytes and combating infection.

Thrombocytopenia in the First 24 Hours After Birth and Incidence of Patent Ductus Arteriosus

“…We also did not find an association between platelet number in the first 24 hours after birth and PDA on DOL 4 to 5 in VLBW/ELBW preterm infants, regardless of whether the infants had subsequently received pharmacologic COX inhibition, secondary ligation, or no therapy (Fig 2). Moreover, when we used the exact same inclusion criteria as Echtler et al 13 (24)(25)(26)(27)(28)(29)(30) weeks' gestation), we still did not find any association between platelet number and PDA (n = 947; data not shown).…”

“…Interestingly, all the latter variables may affect platelet function. 23,24 Given the findings on platelettriggered ductal sealing in mice, 13 we speculate that platelet dysfunction (due to immaturity [25][26][27] or critical illness 23,24,28 ) rather than platelet number contributes to the pathogenesis of PDA. 22 Although the platelet numbers reported in our study were determined in the first 24 hours after birth, and before any indomethacin or ibuprofen administration, we cannot rule out that a platelet nadir occurred on DOL 2 to 5, which may have influenced the efficiency of COX inhibition or the need for secondary surgical ligation in infants with hemodynamically significant PDA, especially when other risk factors such as sepsis/inflammation were present.…”

Assessment of neonatal platelet adhesion, activation, and aggregation

“…Studies using FACS analysis have reported that neonatal platelets from peripheral blood in the first days of life are hyporesponsive to ADP, TRAP‐6, the GPVI ligand CRP, and the TxA 2 receptor agonist U46619 , have reduced P‐selectin expression following agonist stimulation and have a reduced number of α‐granules relative to adult platelets. At 24 h of life, we found that neonatal platelets expressed significantly less P‐selectin in response to both GPCR and ITAM signaling pathway agonists than adult platelets.…”

Platelet expression of CD62P in hypotrophic newborns

“…This probably results from impaired thrombopoiesis in hypotrophic newborns [11] as in the case of pre-term newborns [17]. This may be due to the limited maturity of the organs responsible for this process, which takes place in the liver and spleen [18].…”