Asymmetric dimethylarginine and L-arginine levels in neonatal sepsis and septic shock.

OBJECTIVE: Nitric oxide (NO) formed by the enzyme NO synthase (NOS) from L-arginine, is an important mediator for pathogen elimination. Being a potent vasodilator NO is implicated in hypotension and decreased organ perfusion in sepsis. Asymmetric dimethylarginine (ADMA) is an endogenous NOS inhibitor. We investigated ADMA and L-arginine levels in neonatal sepsis and their relation to disease severity.
METHODS: A prospective controlled study was conducted including 31 neonates with sepsis and 20 controls. Serum ADMA and L-arginine levels were measured within 24 h of sepsis diagnosis. Clinical and laboratory data including clinical risk index for babies (CRIB) score, presence of septic shock, organ dysfunction and death were recorded.
RESULTS: L-arginine and ADMA levels were higher in neonates with sepsis compared to controls (p = 0.029 and p = 0.001, respectively). Neonates with septic shock had higher ADMA levels compared to septic neonates without shock (p = 0.026) and controls (p < 0.001). L-arginine levels were higher in neonates with septic shock compared to septic neonates without shock (p = 0.012) and controls (p < 0.001). Survivors and non-survivors had similar L-arginine and ADMA levels. ADMA levels were correlated with CRIB score (rho = 0.320, p = 0.025).
CONCLUSION: L-arginine and ADMA levels are elevated in neonatal sepsis and even higher levels are observed in septic shock.