Acute interstitial nephritis (AIN) is a drug induced renal failure.
Patients classically have fever, rash and eosinophilia.
During my fellowship there was little data to support the use of steroids and I came down opposed to steroids. Last year Gonzales Et al. published a retrosprective analysis of 61 patients with biopsy proven AIN. 9 were not given steroids and the remiander were given a hodge-podge of different steroid protocols.
In addition to providing data on the question of steroids the article is a goldmine of data regarding AIN.
The culprit was usually an antibiotic:
- Antibiotic in 34 cases
- Cephalosporin in 15 cases
- Quinolone in 12 cases
- Penicillin in 7 cases
- NSAID in 23 cases
- Allopurinol in 1 case
- Ranitidine in 1 case
- Omeprazole in 1 case
- Pimozide in 1 case
Only 8 patients (13%) had the classic triad of fever, rash and eosinophilia. Table 1:
The key result was a signifigant difference in the need for long-term dialysis and a reduction in the final creatinine with steroids.
The data is not the most compelling (It’s retrospective, the control group was tiny compared to the intervention group) but it is by far best we have on the subject and it changed the way I treat AIN.
Great article, thanks. I continue to be surprised by the number of times I get biopsies for unexplained RF and find a rip-roaring AIN on the biopsy. Urine eosinophils I have always thought was too sensitive but not specific enough… but I have also seen negative urine eos with biopsy consistent with AIN. The classic triad I nearly never see (especially fever.. I am thankful for the rash and +Urine eos combo) I have used steroids more recently for AIN (I judge based on the degree of acute inflammation seen in the biopsy). My small sample has been mixed at best…but I appreciate this review.
Simon