Scattered inspissated hyaline/ proteinaceous coarse granular cast and sloughed epithelial cells are seen in the tubular lumina.Focal chronic interstitial inflammation admixed with few eosinophils and patchy interstitial edema present.Arteries show mild medial thickening.Arterioles reveal focal hyalinosis lesion and vacuolization in smooth muscle cells.The immunofluorescent examination showed negative expression of immunoglobulins IgG, IgA, IgM, complement fragments C3, C1q and k, l light chains in glomeruli, tubules and vessels.With this biopsy report, his chemotherapy was stopped and was initiated on prednisone 1mg/kg/day and along with mycophenolate mofetil (MMF) 500mg twice daily.After 15 days of therapy, his creatinine started to decline and after 2 months of treatment with a tapering steroid dose, his creatinine was 1.1 mg/dl (April 2025).After 3 months of therapy, MMF and prednisone were stopped.Results: Cancer patients are already at increased risk of developing renal insufficiency.For treatment of non-small cell lung cancer, the most common nephrotoxic anti-cancer drugs are platinum-agents and checkpoint-inhibitors.Incidence of Carboplatin induced acute kidney injury involving focal tubular necrosis and acute interstitial nephritis is very lower.On the other hand, PEM, inhibiting key enzymes within the folate metabolic pathway and impending the synthesis of purine and thymidine nucleotides.Kidney injury caused by PEM exhibits acute tubular injury, nephrogenic diabetes insipidus, and renal tubular acidosis. Conclusion:Based on a literature review, I believe Carboplatin is a more likely cause of a recovering acute kidney injury (AKI) compared to PEM, which is more commonly associated with non-recovering kidney dysfunction.Several key differences in their mechanisms of nephrotoxicity support this distinction.Both drugs were withheld because it was impossible to differentiate which one was causing a kidney injury-is consistent with standard clinical practice.This precautionary approach prioritizes patient safety by removing all potential causes of a serious side effect.I have no potential conflict of interest to disclose.I did not use generative AI and AI-assisted technologies in the writing process.
Parthasarathy et al. (Wed,) studied this question.