What are the guideline sources, guidelines and references for Acute interstitial nephritis ?
Guideline sources The following summarized guidelines for the evaluation and management of acute interstitial nephritis (AIN) are prepared by our editorial team based on guidelines from the American Association of Family Physicians (AAFP 2003). 1 1 2 2 2 Definition AIN is an acute disease characterized by the presence of inflammatory infiltrates and edema within the interstitium that is associated with a decline in renal function. 2 Epidemiology AIN is mostly caused by drugs (> 75%) such as NSAIDs, allopurinol, acyclovir, furosemide, famotidine, omeprazole, phenytoin; infections (5-10%) such as viruses (HIV, CMV, EBV), Mycobacterium tuberculosis, Mycoplasma, Rickettsia, Toxoplasma, Leptospira, Schistosoma; idiopathic (5-10%) such as tubulointerstitial nephritis and uveitis syndrome; and associated with systemic diseases (10-15%) such as sarcoidosis, Sjogren's syndrome and SLE. 2 Disease course The delayed hypersensitivity immune reactions to foreign antigens result in AIN, which leads to the clinical features of AKI, acute renal failure requiring dialysis, arthralgias, fever, skin rash, and gross hematuria. 2 Prognosis and risk of recurrence https://web.pathway.md/diseases/rec52jA9P3m9WGEa5 1/3 6/23/23, 1:45 AM Acute interstitial nephritis Pathway Prognosis and risk of recurrence AIN is not associated with an increase in mortality. 1 Guidelines 1. Diagnostic investigations Laboratory investigations: basic laboratory investigations (urinalysis and microscopy, serum chemistry profile, CBC, LFTs) may provide evidence suggestive of AIN and help guide conservative management or empiric treatment with steroids. Unfortunately, none of these tests have sufficient predictive value to be diagnostically reliable. Renal ultrasound: renal ultrasound may demonstrate kidneys that are normal to enlarged in size, with increased cortical echogenicity, but there are no ultrasonographic findings that will reliably confirm or exclude AIN versus other causes of acute renal failure. 2. Diagnostic procedures Kidney biopsy: Consider implementing a trial of supportive management in patients in whom the diagnosis seems likely, for whom a probable precipitating drug can be easily withdrawn, or who improve readily after withdrawal of a potentially offending drug. Consider obtaining a renal biopsy in patients who do not improve following withdrawal of the likely precipitating medications, who have no contraindications to renal biopsy, and who are being considered for steroid therapy. 3. Medical management Withdrawal of offending agents: discontinue any potential precipitating medications in patients with AIN. Supportive care measures: Provide standard supportive care interventions in patients with AIN, such as: fluid and electrolyte management avoiding volume depletion or overload symptomatic relief for fever and rash avoiding use of nephrotoxic drugs avoiding use of drugs that impair renal blood flow adjusting drug dosages for existing level of renal function. Immunosuppressive therapy: insufficient evidence to make a recommendation regarding the use of corticosteroids in treatment of AIN. If steroid therapy is started, a reasonable dosage is prednisone, 1 mg per kg per day PO (or equivalent intravenous dose) for two to three weeks, https://web.pathway.md/diseases/rec52jA9P3m9WGEa5 2/3 6/23/23, 1:45 AM Acute interstitial nephritis Pathway followed by a gradually tapering dose over three to four weeks. In patients who do not respond to corticosteroids within two to three weeks, treatment with cyclophosphamide can be considered. Likelihood Ratios Pertinent positives The following findings increase the probability of acute interstitial nephritis in adults. -1 Finding LR+ Value Increased urine eosinophils 3.72 Pertinent negatives The following findings decrease the probability of acute interstitial nephritis in adults. -1 Finding LR- Value urine eosinophils not increased 0.41 References 1. Charles M Kodner, Archana Kudrimoti. Diagnosis and management of acute interstitial nephritis. Am Fam Physician. 2003 Jun 15;67 12 2527 34. Open 2. Manuel Praga, Ester Gonzalez. Acute interstitial nephritis. 2010 Jun;77 11 956 61.2010 Jun;77 11 956 61. Open https://web.pathway.md/diseases/rec52jA9P3m9WGEa5 3/3