Acute interstitial nephritis (AIN) is a potentially reversible cause of AKI, yet diagnosis and follow-up remain challenging in routine practice.1–3 Kidney biopsy is the reference standard but is invasive and not always feasible.4 Urinary chemokines such as CXCL9 and CXCL10 have emerged as promising biomarkers of AIN,5–7 but their role in daily practice, particularly for longitudinal disease monitoring, remains incompletely defined.