Synthetic cannabinoid-associated acute interstitial nephritis: An emerging cause of pediatric acute kidney injury?

Synthetic cannabinoid (SCB) usage among children is a rapidly emerging public health concern in the United States. Acute kidney injury (AKI) is an uncommon manifestation of SCB usage, with acute tubular necrosis (ATN) as the predominant histology. Here we describe a 16-year-old adolescent who sustained severe non-oliguric AKI in association with SCB usage. Emesis, right flank pain, and hypertension were the presenting clinical features. There was no uveitis, skin rash, joint pains, or eosinophilia. Urinalysis showed absence of proteinuria or hematuria. Urine toxicology was negative. Renal sonogram showed bilateral echogenic kidneys. Renal biopsy demonstrated severe acute interstitial nephritis (AIN), mild tubulitis, and absence of ATN. AIN responded with pulse steroid followed by oral steroid. Renal replacement therapy was not required. Although the exact pathophysiology of SCB-associated AIN is not known, immune response elicited by the renal tubulointerstitial cells against the antigens present in the SCB is the most likely mechanism. A high index of suspicion for SCB-induced AKI is necessary in adolescents who present with AKI of unclear etiology.