Introduction: Acute interstitial nephritis, considered one of the major causes of reversible acute kidney injury, was frequently encountered as drug-treatment complication in the early stage of infection control. In some cases, drug-induced acute interstitial nephritis (DIAIN) resulted in delayed function recovery or chronic kidney disease. To study the underlying mechanism, the authors investigated the clinical and pathological features of DIAIN patients with delayed renal function recovery. The delayed recovery group consisted of patients with reduced renal function for more than 3 months after diagnosis.
Methods: In this retrospective study, 18 patients with DIAIN from January 2003 to December 2009 were identified as the delayed recovery group, whereas 54 patients with DIAIN who recovered completely within 3 months were treated as the control group. Clinical and pathological features were compared between the 2 groups.
Results: In the delayed recovery group, the average age at onset was 48.8 years, antibiotics and herbs were the 2 main causative drugs and the dominant extra-renal manifestation was gastrointestinal symptomatology. In comparison with patients in the control group, patients in the delayed recovery group had longer interval time from disease onset to hospitalization, and they presented with less oliguria. Moreover, these patients had higher levels of urine retinol binding protein, and more renal interstitial inflammatory cell infiltrations were observed in their renal histology.
Conclusion: Aging, long interval time from disease onset to hospitalization and renal interstitial inflammatory cell infiltration may predict delayed renal function recovery.