Biotin‐responsive immunoregulatory dysfunction in multiple carboxylase deficiency

Abstract
Multiple carboxylase deficiency could be associated with defects of the immunoregulatory system. A boy with documented multiple carboxylase deficiency was found to display a fatty acid and biotin‐responsive impairment of his lymphocyte suppressive activityin vitro. Furthermore, prostaglandin E2 (PGE2), a major product of unsaturated fatty acid elongation required forin vitro activation of the immunoregulatory system, was found to be very low in the patient's monocytes. Finally, PGE2 monocytic production responded well to biotin therapy. PGE2 deficiency could result from the combination of an essential fatty acid deficiency with an impaired elongation of unsaturated fatty acids possibly due to a defect of the biotin‐dependent acetyl‐CoA carboxylase reaction.