Serum Free Carnitine Levels in Children with Kawasaki Disease.

BACKGROUND Carnitine plays an essential role in transfer of long-chain fatty acids to mitochondria for β-oxidation. No studies have characterized carnitine in children with Kawasaki disease (KD). The objective of this study is to clarify the characteristics of serum free carnitine (FC) in hospitalized pediatric patients with KD. METHODS We retrospectively analyzed 45 patients with KD in whom serum FC levels were measured. We investigated the clinical and laboratory parameters before the intravenous immunoglobulin including serum FC levels according to the response to intravenous immunoglobulin. We also analyzed the relation between serum FC, and laboratory data and clinical variables. RESULTS Intravenous immunoglobulin was effective in 33 children (responders) and was ineffective in 12 (non-responders). The serum FC levels were higher in non-responders than in responders: 35.3 μmol/L (range, 26.8-118.4 μmol/L) vs 31.4 μmol/L (range, 20.9-81.2 μmol/L), p<0.05. The FC levels before intravenous immunoglobulin in four-fifths of responders were below the normal range. The levels of aspartate aminotransferase, alanine aminotransferase, total bilirubin, and FC were higher in non-responders than in responders. FC levels were correlated with aspartate aminotransferase (R2 =0.364, P=0.0015) and alanine aminotransferase (R2 =0.423, P<0.001) levels. CONCLUSIONS FC levels were elevated in some of patients with KD, especially in those who were refractory to intravenous immunoglobulin. Additionally, FC levels in children with KD correlated with aspartate aminotransferase and alanine aminotransferase levels.