Myoglobinuria and COX deficiency in a patient taking cerivastatin and gemfibrozil

The authors describe a patient who presented with myoglobinuria after starting cerivastatin-gemfibrozil therapy. Muscle histochemistry revealed ragged-red fibers and cytochrome c oxidase negative (COX) fibers, and biochemistry showed a defect of COX activity. Immunoblot analysis showed a 60% reduction of COX I and COX II polypeptides. Cerivastatin myotoxicity might be related to a depletion of essential metabolites needed to anchor COX subunit I to mitochondrial membrane.

Myocardial carnitine and carnitine palmitoyltransferase deficiencies in patients with severe heart failure

We studied myocardial tissue from 25 cardiac transplant recipients, who had end-stage congestive heart failure (CHF), and from 21 control donor hearts. Concentrations of total carnitine (TC), free carnitine (FC), short-chain acylcarnitines, long-chain acylcarnitines (LCAC) as well as carnitine palmitoyltransferase (CPT) activities were measured in myocardial tissue homogenates and referred to the concentration of non-collagen protein. Compared to controls, the concentrations of TC and FC as well as total CPT activities were significantly lower in patients. LCAC levels and the LCAC to FC ratio values were significantly greater in patients than in controls. While the malonyl-CoA sensitive fraction of CPT, which represents CPT I activity, was similar in patients and controls, the residual CPT activity after inhibition by malonyl-CoA, representing CPT II activity, was significantly reduced in patients compared to controls. Moreover, the activity of CPT in the presence of Triton X-100, which also represents the activity of CPT II, was significantly lower in patients than in controls. Malonyl-CoA concentrations required for half-maximal inhibition of CPT activity were significantly greater in patients than in controls. There was a linear relationship between ejection fraction (EF) values and concentrations of TC, FC, or total CPT activities. Values for LCAC and the LCAC to FC ratio were inversely related to EF values. We conclude that failing heart shows decreased total CPT and CPT II activities and carnitine deficiency that may be related to ventricle function.

Molecular analysis in Spanish patients with muscle carnitine palmitoyltransferase deficiency

The most common mutation in muscle carnitine palmitoyltransferase II (CPT II) deficiency is a missense mutation that replaces a leucine for a serine residue at amino acid position 113 of the CPT II protein (S113L). We performed molecular analysis in a group of 14 Spanish patients with CPT II deficiency from ten unrelated families. The S113L mutation was observed in 8 of the 14 patients studied. Seven patients were homozygous for the mutation, 1 patient was heterozygous, and 6 patients did not carry the mutation on either allele. Seven healthy relatives belonging to three different families carried the mutation on one allele. One patient carried the missense mutation that replaces a tyrosine for a serine at amino acid position 628 on one allele. Our data indicate that the S113L is also the most common mutation in Spanish patients with CPT II deficiency in muscle, and that further pathogenic mutations remain to be identified.