WCN26-313 Cocaine and Tubulointerstitial Nephritis With Isolated ANA Positivity: Drug-Induced Autoimmunity or Lupus Mimicker?

Tubulointerstitial nephritis is a common cause of acute or chronic kidney injury, typically attributed to infectious, autoimmune, or toxic etiologies. Cocaine use, especially when adulterated with levamisole, has been linked to immunomodulatory agent known to trigger unusual autoimmune phenomena, even in the absence of classic lupus or ANCA-associated vasculitis criteria. Isolated antinuclear antibody positivity in this setting presents a diagnostic challenge. Its presence without other specific autoantibodies or immune complex-mediated glomerulopathy suggests a drug-induced autoimmune reaction or lupus mimicker.We present the case of a chronic drug user who developed TIN and isolated ANA positivity, and no other autoantibodies, raising the question: drug-induced autoimmunity or lupus mimicry?