Distal type of renal tubular acidosis after anti-epileptic therapy in a girl with infantile spasms

Abstract

An 11-month-old girl was referred to our hospital because of nausea and poor physical activity. She had a 5-month history of infantile spasms, which were successfully treated with valproic acid (VPA) and vitamin B6. Laboratory studies revealed hyperchloremic metabolic acidosis, mainly due to distal type renal tubular acidosis (RTA). Although a renal biopsy, performed 2 months after the onset of RTA, did not demonstrate tubulointerstitial lesions, her clinical course, in which administration of VPA led to an episode of RTA, with gradual subsidence on VPA removal, suggested that the probable causative agent of her distal type RTA was VPA. Although proximal type RTA associated with VPA administration has been reported, distal type is rarely seen. To our knowledge, a similar case has not been reported previously.