Coenzyme Q₁₀ and Pyridoxal Phosphate Deficiency Is a Common Feature in Mucopolysaccharidosis Type III

Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by deficiencies of lysosomal enzymes catalyzing degradation of glycosaminoglycans (GAGs). Previously, we reported a secondary plasma coenzyme Q₁₀ (CoQ) deficiency in MPS patients. For this study, nine MPS patients were recruited in the Hospital Sant Joan de Déu (HSJD, Barcelona) and two patients in the Neurometabolic Unit, National Hospital (NMU, London), to explore the nutritional status of MPS type III patients by analyzing several vitamins and micronutrients in blood and in cerebrospinal fluid. Plasma CoQ and plasma and cerebrospinal fluid pyridoxal phosphate (PLP) content were analyzed by high-pressure liquid chromatography (HPLC) with electrochemical and fluorescence detection, respectively. We found that most MPS-III patients disclosed low plasma pyridoxal phosphate (PLP) values (seven out of nine) and also low plasma CoQ concentrations (eight out of nine). We observed significantly lower median values of PLP, tocopherol, and CoQ (Mann-Whitney U test, p = 0.006, p = 0.004, and p = 0.001, respectively) in MPS patients when compared with age-matched controls. Chi-square test showed a significant association between the fact of having low plasma PLP and CoQ values in the whole cohort of patients. Cerebrospinal fluid PLP values were clearly deficient in the two patients studied. In conclusion, we report a combined CoQ and PLP deficiency in MPS-III patients. These observations could be related to the complexity of the physiopathology of the disease. If our results are confirmed in larger series of patients, CoQ and PLP therapy could be trialed as coadjuvant therapy with the current MPS treatments.