Dark Web Steroids Cause Kidney Failure? A Case of Proteinuria and CKD in a Young Bodybuilder

Introduction: Drug-induced acute interstitial nephritis is a well studied, common cause of AIN, estimated to be around 70-75% of all cases. Generally associated with NSAIDS, antibiotics and more recently proton pump inhibitors and immune checkpoint inhibitors, there is importance in differentiating these causes as the renal failure is generally reversible. Diagnosis however can be difficult when multiple causes are involved, such as in this case of a patient on NSAIDs, testosterone supplements with non-nephrotic range proteinuria and these patients may benefit from earlier genetic screening, renal biopsy. Case Description: Patient L.R. is a 27yo African-American male who presents with chest pain, dyspnea, leg swelling and hand pain. Had previously been admitted with same symptoms at different hospital 1 week and found to be significantly hypertensive, diagnosed with HTN emergency and started on amlodipine, hydralazine at discharge, but symptoms did not resolve, and he returned for re-evaluation. Noted during that stay he had hypoalbuminemia with nephrotic-range proteinuria. He is a bodybuilder, admitted to using testosterone injections which he buys through online site. Also following protein-only diet for past 1-2 months. History also significant for daily NSAID use for leg pain after tibial surgery 1 year ago. On evaluation, had serum creatinine of 2.1 with eGFR ~45-50 which remained stable throughout stay. Proteinuria elevated to 2.3g. CBC with anemia. UA with suggestive AIN given eosinophilia (800/uL) and eosinophilia of 6% on CBC. Initial evaluation suggests that his serum creatinine had component of false elevation due to high-protein diet, supplement/testosterone use, however Cystatin C performed which estimated eGFR of 46 highlighting underlying CKD. He was later seen in clinic 3 months later with stable CKD, repeat UPCR with proteinuria ~2.3g/day. Renal U/S with evidence of medical renal disease. He is awaiting renal biopsy and genetic testing. Discussion: This case highlights some of the causes of CKD that can be seen with younger patients, in this case with significant NSAID use and steroid use history which are known causes of AIN. This case also shows some of the confounding factors such as high-protein intake which can cause elevated serum Cr. Patient’s such as this may benefit from early genetic testing, renal biopsies which may improve long-term outcome.