Conclusions
We demonstrated significant differences in the metabolomes of the PNH patients compared to healthy controls. Eculizumab infusion seemed to improve deficiencies in the acyl CoA metabolism and may have a role in the mitochondrial oxidative process of long and medium-chain fatty acids, reducing oxidative stress, and inflammation.
Methods
Plasma metabolic profiles, comprising 186 specific annotated metabolites, were quantified using targeted quantitative electrospray ionization tandem mass spectrometry in 23 PNH patients and 166 population-based controls. In addition, samples from 12 PNH patients on regular eculizumab maintenance therapy collected before and 24 hours after eculizumab infusion were also analyzed.
Results
In the PNH group, levels of the long-chain acylcarnitines metabolites were significantly higher as compared to the controls, while levels of histidine, taurine, glutamate, glutamine, aspartate and phosphatidylcholines were significantly lower in the PNH group. These differences suggest altered acylcarnitine balance, reduction in the amino acids participating in the glycogenesis pathway and impaired glutaminolysis. In 12 PNH patients who were receiving regular eculizumab therapy, the concentrations of acylcarnitine C6:1, the C14:1/C6 ratio (reflecting the impaired action of the medium-chain acyl-Co A dehydrogenase), and the C4/C6 ratio (reflecting the impaired action of short-chain acyl-Co A dehydrogenase) were significantly reduced immediately before eculizumab infusion, revealing impairments in the Acyl CoA metabolism, and reached levels similar to those in the healthy controls 24 hours after infusion. Conclusions: We demonstrated significant differences in the metabolomes of the PNH patients compared to healthy controls. Eculizumab infusion seemed to improve deficiencies in the acyl CoA metabolism and may have a role in the mitochondrial oxidative process of long and medium-chain fatty acids, reducing oxidative stress, and inflammation.