Secretory phospholipase A2 in newborn infants with sepsis

Abstract

Objective: To investigate secretory phospholipase A 2 (sPLA 2 ) activity in neonatal sepsis.Study Design: Plasma sPLA 2 activity, C-reactive protein (CRP) concentration, leukocyte count and immature/total neutrophil (I/T) ratio were assessed in a group of 156 infants admitted for neonatal intensive care, who were classified as documented sepsis (n ¼ 24), suspected infection (n ¼ 77) and controls (n ¼ 55). Interleukin-6 (IL-6) concentrations were assessed in a subgroup (n ¼ 29).Result: sPLA 2 activity, CRP concentration and I/T ratio were higher in sepsis than in suspected infection or control groups. sPLA 2 activity advanced with increasing CRP, I/T ratio and IL-6 was highest in infants with respiratory distress syndrome (RDS). Compared to CRP, sPLA 2 had equal sensitivity and lower specificity. Compared to I/T ratio, sensitivity and specificity of sPLA 2 were higher.Conclusion: Plasma sPLA 2 activity is increased in neonatal sepsis and highest in infants with RDS. Further studies should assess the potential of sPLA 2 inhibition in neonatal sepsis.

Pathophysiology of Neonatal Sepsis

“…172,173 These substances are produced predominantly by host endothelium and mast cells. Activated PMNs produce phospholipase A 2 (PLA 2 ), the level of which is increased in the serum of neonates with sepsis 174 and leads to generation of vasoactive substances, including prostaglandins and leukotriene. Thromboxane produced by activated platelets and endothelin 1 produced by activated endothelium 175 are potent vasoconstrictors that participate in the development of pulmonary hypertension.…”

“…Secretory PLA 2 can destroy gram-positive bacteria through hydrolysis of their membrane lipids. 174 PMN elastase is a serine protease released by activated PMNs with microbicidal function and is believed to play a role in the inflammatory damage seen with PMN recruitment, particularly in the lung. 116,136 Cathelicidin and the insufficiency, and PMN dysfunction.…”

Pathophysiology and Treatment of Septic Shock in Neonates

“…Vasoactive substances released from activated leukocytes, platelets, and endothelial cells are shown in Figure 2 and include platelet-activating factor (PAF), thromboxane (TBX), leukotrienes (LTE), nitric oxide (NO), histamine, bradykinin, and prostaglandins (PGE)201, 202. Activated PMNs produce phospholipase A2 (PLA 2 ), which is elevated in the serum of neonates with sepsis203 and leads to generation of vasoactive substances including PGE and LTE. Thromboxane produced by activated platelets and endothelin produced by activated endothelium 204 are potent vasoconstrictors that participate in the development of PPHN205–208.…”

Role of Innate Host Defenses in Susceptibility to Early-Onset Neonatal Sepsis

“…Lysozyme is present in tears, tracheal aspirates, skin, and in PMN primary and secondary granules and contributes to degradation of peptidoglycan of bacterial cell walls. Secretory phospholipase 2 (sPLA2) can destroy Gram-positive bacteria through hydrolysis of their membrane lipids207. PMN elastase is a serine protease released by activated PMNs with microbicidal function and is believed to play a role in the inflammatory damage seen with PMN recruitment, particularly in the lung89, 208.…”