Acute tubulointerstitial nephritis, treatment with steroid and impact on renal outcomes.

Background: The use and timing of steroids in the management of acute tubulointerstitial nephritis (ATIN) remains debatable.

Aims: To determine the incidence and aetiology of ATIN in our unit, and to examine trends in the use of steroids and their impact on renal outcomes.

Methods: Patients with a histological diagnosis of ATIN over a 9-year period were identified and divided into steroid-treated (StG) and steroid-naïve groups (SnG). Mean change in estimated glomerular filtration rate (eGFR) was determined.

Results: Forty-nine patients had ATIN as their main diagnosis, 67% of cases were drug-induced, and proton pump inhibitors (PPI) were the second commonest implicated drug category. Majority (75%) of patients received steroids, and eGFR improved to a significantly greater degree in these steroid-treated patients (3.4-fold improvement vs 2.0-fold in SnG; P < 0.05, unpaired t-test). Despite comparable eGFR at presentation (StG: 11.7; SnG: 15.4), steroid-treated patients were less likely to receive dialysis, although not significantly so (OR 0.27; 95% CI 0.06-1.15, P = 0.066, chi-squared test). However, there was no significant relation between the degree of eGFR improvement and delay in starting steroids (Pearson r = -0.25, P > 0.45), and no difference in eGFR at the time of last follow-up (StG: 33 ± 3; SnG: 32 ± 7; P > 0.9, unpaired t-test).

Conclusion: StG patients had a greater degree of improvement in renal function, but with no correlation between degree of improvement in eGFR and delay in starting steroids, and similar eGFR values at final follow-up. PPI were the second commonest drug category among drug-induced cases.