694 DRUG INDUCED KIDNEY INFARCTION: A CASE REPORT


 Isotretinoin (ISO) is a synthetic analog of vitamin A. Notwithstanding the well-known long-term efficacy in the treatment of severe resistant cystic acne, ISO induces several side effects too. Dyslipidemia, increased liver enzymes, as well as reduction of biotidinase have been already reported [1]. Homocysteine (HCY), a sulfur-containing amino acid, is recycled into methionine by a transmethylation reaction requiring folate and vitamin B12. Given that during ISO treatment elevated liver enzymes (SGOT, SGPT) are often observed, it has been hypothesized that iatrogenic liver dysfunction could affect cystathionine-b-synthase, an enzyme involved in HCY metabolism, [2]. Several studies have highlighted that elevated plasma HCY concentrations are associated with an increased risk of premature occlusive vascular disease.
 We hereby report a case of drug-induced kidney infarction after ISO therapy.
 A previously healthy 18-year-old male, on therapy with 40 mg/die isotretinoin for acne, was admitted to the Emergency Unit for abdominal pain, nausea and vomiting and dyspnea. A trans-thoracic echocardiogram showed dilated and hypocontractile left ventricle. During the hospitalization he had a total body CT that showed the presence of an ischemic lesion on left kidney without other pathological findings. He started therapy with 12 IU/kg UFH as soon as a surgical emergency was excluded. Subsequently, he underwent a coronary angiogram that resulted unremarkable. Cardiac MRI showed extensive delayed gadolinium late enhancement with intramural linear pattern.
 In the hypothesis of drug-induced vasculitis, an extensive serological testing was performed. Elevation of serum liver enzymes (SGOT, SGPT), CRP, LDH was found. Mutations on MTHFR gene and Leiden Factor were not detected, neither alteration in coagulation parameters. Finally the dosage of plasmatic HCY resulted over the range of normality and ISO was discontinued. The patient was discharged on optimized medical therapy for heart failure. He is currently managed as outpatient.
 HCY levels could be found elevated in patients with ischemic events during ISO treatment. Given the widespread use of this drug for acne, it could be reasonable to dose HCY in patients with suspected liver dysfunction. Physicians should be aware of this scenario and should act swiftly to avoid uneventful outcomes.
 [1] Schulpis KH et al. Elevated plasma homocysteine levels in patients on isotretinoin therapy for cystic acne. Int J Dermatol. 2001 Jan;40(1):33-6.
 [2] Polat M, et al. Plasma homocysteine level is elevated in patients on isotretinoin therapy for cystic acne: a prospective controlled study. J Dermatolog Treat. 2008;19(4):229-32.