Normal Serum Alanine Concentration Differentiates Transient Neonatal Lactic Acidemia from an Inborn Error of Energy Metabolism

Abstract

Background: Elevated blood lactate levels are common in the critically ill neonate; however, sometimes they are difficult to interpret. Persistent or recurrent lactic acidemia might point to an inborn error of metabolism, like disturbances of the oxidative phosphorylation. Chronic lactic acidemia results in increased serum alanine levels. Serum alanine levels in newborns with transient lactic acidemia have not yet been studied. Objective: We designed a pilot study to evaluate the use of serum alanine levels as an additional metabolic marker to differentiate the transient effect of circulatory failure from a possible mitochondrial dysfunction. Methods: We prospectively evaluated 10 newborns with transient lactic acidemia after mild dysoxia, and 10 newborns with recurrent lactic acidemia consecutively diagnosed with a disorder in oxidative phosphorylation. Results: No significant serum alanine level elevation was found in transient lactic acidemia. Increased serum alanine was a sensitive marker in mitochondrial dysfunction. Conclusions: We propose to measure the serum alanine level in hypotonic newborns with lactic acidemia to facilitate the decision making in further diagnostics and management.

Proteomic and Metabolomic Analyses of Mitochondrial Complex I-deficient Mouse Model Generated by Spontaneous B2 Short Interspersed Nuclear Element (SINE) Insertion into NADH Dehydrogenase (Ubiquinone) Fe-S Protein 4 (Ndufs4) Gene

“…This may cause an imbalance in the NAD ϩ /NADH ratio inside mitochondria and be the reason for the block in fatty acid ␤-oxidation. Studies in patients suffering from OXPHOS disorders have shown the presence of increased serum alanine levels and/or decreases in citrulline levels (67)(68)(69)(70). This was not found in the blood of Ndufs4 fky/fky mice, which only had levels of glycine, phenylalanine, and homocitrulline significantly elevated (Fig.…”

Análise comparativa entre a dosagem do lactato no líquor e sua detecção atráves da espectroscopia de prótons por ressonância magnética

“…O nível de creatina quinase pode ser normal ou moderadamente alto, exceto em pacientes com miopatias relacionadas à depleção do DNA mitocondrial, quando essa mensuração geralmente é superior a 1000 UI (DiMauro, Bonilla et al, 1999). Outra alteração sanguínea que pode ser observada em alguns pacientes é o aumento da alanina (Morava, Hogeveen et al, 2006).…”