Acute interstitial nephritis: immunologic and clinical aspects

Acute interstitial nephritis after COVID-19 vaccination

A woman in her 70s presented to the hospital being generally unwell 8 days following the first dose of the AstraZeneca COVID-19 vaccination. She was in stage III acute kidney injury (AKI) with hyperkalaemia and metabolic acidosis. Urinalysis showed haematoproteinuria. Renal immunology screen was negative. She subsequently underwent two renal biopsies. The second biopsy showed features consistent with acute tubulointerstitial nephritis. She was commenced on oral steroids, which led to marked improvement of her renal function.There are reasons why AKI can occur post vaccination such as prerenal AKI from reduced oral intake postvaccination due to feeling unwell or developing vomiting or diarrhoea. Intravenous fluids were given to this patient but with no meaningful improvement in renal function. She developed a possible reaction to the AstraZeneca COVID-19 vaccine, which led to AKI as supported by the interstitial inflammation and presence of eosinophils on renal biopsy.

Eosinophilia and risk of incident end stage kidney disease

BACKGROUND

Eosinophils in kidney disease are poorly understood and are often incidental findings on kidney biopsy. Eosinophilia in blood and renal biopsy tissue is associated with a host of immune and non-immune kidney diseases. The significance of eosinophilia in renal diseases has not been well addressed. We evaluated the presence of peripheral eosinophilia (> 4% of blood leukocytes) with biopsy tissue eosinophilia and their association with end-stage-kidney-disease (ESKD).

METHODS

A nested case-control (2:1) of patients who underwent kidney biopsies at Johns Hopkins Hospital and Medical University of South Carolina from 2004 to 2018 were included in the study. From the 616 eligible patients, 178 patients were identified through the registry of kidney biopsies as 18 years or older without missing biopsy reports or hematology results. Controls (n = 154) had no ESKD at the time of case (n = 24) designation and were assembled using incident density sampling and matched on age and sex. The association of peripheral eosinophilia (> 4% of peripheral blood leukocytes) with the risk of progression to ESKD was evaluated using conditional logistic model after adjusting for clinical demographics.

RESULTS

Among 178 patients, 65 (37%) had peripheral eosinophilia and 113 (63%) had no eosinophilia. Compared to patients without eosinophilia, patients with peripheral eosinophilia were notably male and had a higher serum creatinine at the time of their biopsy. Peripheral eosinophilia was associated with higher risk of ESKD (OR 15.9 [1.9, 134.7]) adjusted for patient demographics including hypertension, proteinuria and eGFR at the time of kidney biopsy. Peripheral eosinophilia had a significant linear association with kidney tissue eosinophils, 22 (standard deviation [SD] 20) per high power field (hpf) in 4-10% peripheral eosinophilia, 19 (SD 18) per hpf in ≥10% eosinophilia and 3 (SD 7) per hpf in no eosinophilia (P <  0.001).

CONCLUSIONS

Peripheral eosinophilia is an independent predictor of tissue eosinophilia and subsequent progression to ESKD. Peripheral eosinophilia may be an early biomarker for underlying inflammation and disease, but further studies to investigate this clinical association are warranted.

Acid-suppressive drugs and risk of kidney disease: A systematic review and meta-analysis

BACKGROUND AND AIM

More concerns had been raised about the risk of kidney disease (KD) associated with acid-suppressive drugs. But whether they could directly increase such risk remained unclear. Meta-analysis was conducted to comprehensively investigate this relationship.

METHODS

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and three Chinese databases were searched until April 2017 for observational studies investigating the associations between acid-suppressive drugs and KD. Pooled log (odds ratios [ORs]) or log (hazard ratios [HRs]) with standard errors for KD risk were calculated using the generic inverse variance method and random-effect model.

RESULTS

Ten studies involving 128 020 KD patients were included. Proton pump inhibitor (PPI) therapy was associated with higher risks of acute interstitial nephritis (OR, 2.78; 95% confidence interval [CI], 1.25-6.17), acute kidney injury (AKI) (HR, 1.85; 95% CI, 1.33-2.59), chronic kidney disease (CKD) (HR, 1.47; 95% CI, 1.03-2.09), and end-stage renal disease (ESRD) (HR, 1.61; 95% CI, 1.26-2.04) than non-PPI therapy. Additionally, PPI significantly increased the risks of AKI (HR, 1.32; 95% CI, 1.16-1.51), CKD (HR, 1.28; 95% CI, 1.24-1.33), and ESRD (HR, 1.96; 95% CI, 1.21-3.17) compared with histamine 2 receptor antagonist (H2 RA). Relationship between H2 RA therapy and AKI (OR, 0.98; 95% CI, 0.90-1.07) or CKD (OR, 1.00; 95% CI, 0.89-1.11) was not found.

CONCLUSIONS

Proton pump inhibitor therapy significantly increased the risks of acute interstitial nephritis, AKI, CKD, and ESRD. Similar risks were not identified for H2 RA therapy. More clinical trials are needed to confirm our findings.

Infection associated acute interstitial nephritis; a case report

Background

Acute interstitial nephritis (AIN) is a clinico-pathological syndrome associated with a variety of infections, drugs, and sometimes with unknown causes. It is a common cause of acute kidney injury (AKI) and subsequent renal impairment, which often times is under-diagnosed. Infection-associated AIN occurs as a consequence of many systemic bacterial, viral, and parasitic infec-tions; however, its incidence has decreased significantly after the advent of antimicrobials. Infection-associated AIN presents with both oliguric or non-oliguric renal insufficiency, without the classical clinical triad of AIN (fever, rash, and arthralgia). In this scenario the renal function is usually reversible after the infection is treated. In most cases, patients with acute renal failure present with extra-renal manifestations typically detected in underlying infections. Renal biopsy serves as the most definitive test for both the diagnosis and prognosis of AIN.

Case Presentation

In this paper, we will address one such case of biopsy-proven AIN. In this case, the patient presented with severe AKI induced by anaerobic streptococcus, leading to a periodontal abscess, which was successfully treated with corticosteroids and requiring renal replacement therapy (RRT).

Conclusions

AIN should be considered in the differential for unexplained AKI. Initial management should include conservative therapy by withdrawing any suspected causative agent. Renal biopsy is needed for confirmation in cases where kidney function fails to improve within 5–7 days on conservative therapy. Risk of immunosuppression is very important to consider when giving steroids in patients with infection induced AIN, and steroids may have to be delayed until the active infection is completely controlled.

Sildenafil Induced Acute Interstitial Nephritis

Acute interstitial nephritis (AIN) is characterized by inflammation of the renal interstitium and usually occurs in a temporal relationship with the medication. We present a case of an Asian male who had nephrotic range proteinuria and presented with acute kidney injury. The patient reported an acute change in physical appearance and symptomatology after the ingestion of a single dose of sildenafil. Renal biopsy was notable for minimal change disease (MCD) with acute and chronic interstitial nephritis. Renal replacement and glucocorticoid therapy were initiated. Renal recovery within six weeks permitted discontinuation of dialysis. AIN superimposed on MCD is a known association of NSAID induced nephropathy. The temporal association and the absence of any new drugs suggest that the AIN was most likely due to the sildenafil. NSAIDs are less likely to have caused the AIN given their remote use. The ease of steroid responsiveness would also suggest another cause as NSAID induced AIN is often steroid resistant. The MCD was most likely idiopathic given the lack of temporal association with a secondary cause. As the number of sildenafil prescriptions increases, more cases of AIN may be identified and physician awareness for this potential drug disease association is necessary.

Acute Interstitial Nephritis: Etiology, Pathogenesis, Diagnosis, Treatment and Prognosis

Acute interstitial nephritis (AIN) is an important and common cause of acute kidney injury, particularly in hospitalized patients. The classic presentation of AIN includes fever, rash, arthralgias, eosinophilia, and acute kidney injury. While renal biopsy is considered the gold standard for diagnosis, the clinical presentation of fever and rash along with laboratory evidence of peripheral blood eosinophilia, eosinophiluria, and low-grade proteinuria strongly suggest the diagnosis. Histologically, interstitial inflammation with interstitial edema and tubulitis is the hallmark of interstitial nephritis. The most common causative factors are drugs, infections, and certain immune-mediated disorders. Discontinuation of the offending agent is considered the mainstay of therapy while the use of corticosteroids to hasten renal recovery may be beneficial. The role of interstitial nephritis in the pathogenesis of chronic kidney disease and end-stage renal disease is increasingly recognized, further emphasizing the importance of its early diagnosis and timely treatment.

Proton pump inhibitors and acute kidney injury: a nested case-control study

Background

Proton pump inhibitors (PPI) are a widely-used class of drugs for the treatment of gastro-esophageal reflux disease and other acid-related disorders of the gastrointestinal tract. As a class, PPIs have demonstrated a favorable safety profile. However, case reports have suggested that this class of drugs may be linked to acute kidney injury, which may in turn lead to chronic injury or failure. The objective of this study was to determine if an association between PPIs and kidney failure exists and to estimate an effect size for the relationship between PPI use and renal disease.

Methods

A nested case–control study was conducted in a privately insured population in a single Midwestern state including a total of 184,480 patients aged 18 years or older who were continuously enrolled with the insurer for at least 24 months between September 2002 and November 2005.

Of the patients eligible for the study, 854 cases were identified as having at least two claims for an acute renal disease diagnosis. Cases were randomly matched with up to four controls (n = 3,289) based on age, gender, county of residence, and date of entry into the cohort. Patient demographic data, PPI use, illnesses, and medications associated with renal disease and a proxy for health status using pre-existing patient comorbidities were collected from inpatient, professional, and prescription claims data. Conditional logistic regression models were used to evaluate the association between renal disease and PPI use.

Results

Renal disease was positively associated with PPI use (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.27, 2.32, p < 0.001) even after controlling for potential confounding conditions. After removing patients with potential confounding disease states from the study population, the number of cases (195 of the 854) and controls (607) was lower, but the relationship between renal disease and PPI use remained consistent (OR 2.25, CI 1.09-4.62, p < 0.001).

Conclusions

Patients with a renal disease diagnosis were twice as likely to have used a previous prescription for a PPI. Therefore, it is necessary for physicians to increase recognition of patient complaints or clinical manifestations of this potentially harmful event in order to prevent further injury.

Pediatric case of mesalazine-induced interstitial nephritis with literature review

We present the case of a 14-year-old boy with ulcerative colitis who was diagnosed with mesalazine-induced interstitial nephritis (M-IIN). Improvement in renal function occurred with discontinuation of mesalazine and corticosteroid therapy. We systematically searched the literature for pediatric cases of M-IIN. There were eight cases. Majority of the cases were boys (75%) with ulcerative colitis (75%). Average duration of mesalazine use prior to the diagnosis of interstitial nephritis was 24 ± 18 months. The median dose was 1.5 g/day. M-IIN appears to be an idiosyncratic reaction without any relation to dose or duration of mesalazine use. Although there are no guidelines to recommend routine surveillance of renal function, monitoring of serum creatinine in patients on mesalazine remains an inexpensive and non-invasive test that may lead to early detection and treatment of renal injury.

Eosinophiluria is common among patients after ileal conduit surgery

BACKGROUND

Urinary eosinophils are used to screen for acute interstitial nephritis (AIN). Technologists in the Mayo Clinic Renal Laboratory observed that patients with urinary diversion surgeries frequently had an unusually high number of urinary eosinophils.

METHODS

Urine samples from three cohorts of patients were studied (n=20 each): (1) urinalysis samples with a "stoma" source indicating a previous ileal conduit surgery; (2) urine samples clinically submitted for eosinophil quantification; (3) randomly selected urinalysis samples with a minimum of 1-3 white cells per high-powered field. Urinary eosinophils were quantified after Hansel staining as the mean of independent counts by four blinded technologists.

RESULTS

Eosinophils composed an average 19% of the urinary white cells in the stoma group, even though none had a clinical suspicion of AIN. In contrast, only 3.5% and 4.6% of the urinary white cells were eosinophils among patients with clinically-ordered eosinophiluria testing and in a random sample of patients with pyuria, respectively (p<0.001 for each group vs. the stoma patients). Importantly, 90% (18 out of 20) of the stoma patients had >5% eosinophils, meeting the criterion for a positive test.

CONCLUSIONS

Patients with a previous ileal conduit surgery have markedly elevated urinary eosinophils, far in excess of typical patients with pyuria or those with clinically-ordered eosinophiluria testing. Therefore, urinary eosinophils are not a useful screen for AIN in patients after ileal conduit surgery.

The prevalence and meaning of eosinophilia in renal diseases on a nephrology consultation service

BACKGROUND

In recent years, we have come to understand that the eosinophil is more than the end point in clearance of parasitic infection or a maladaptive response to asthma and allergic reactions. Since eosinophilia has been reported to be common in renal diseases, we thought that an evaluation of the associations of eosinophilia on a renal consultation service would add some value to the understanding of their role in renal disease.

METHODS

This was a prospective cross-sectional study of 1339 consecutive patients referred to the nephrology service after hospitalization who were evaluated for the relationship of the amount of serum eosinophils to their diagnosis, gender, age and the presence of autoimmune disease, cancer, infection, liver disease, pleural effusions, allergies and use of prednisone, beta-blockers or beta agonists, in addition to the total white blood count, urine protein, serum concentration creatinine and phosphorus levels and estimated glomerular filtration rate.

RESULTS

The presence of vascular disease correlated the most strongly with increased eosinophil count (partial correlation coefficient, r = 0.18, P = 0.006), followed by pleural effusions (r = 0.17, P = 0.001), while total white cell count (r = -0.18, P = 0.008) and administration of beta-blockers (r = -0.13, P = 0.047) demonstrated significant inverse correlations and the presence of autoimmune disease, cancer, allergies, proteinuria and serum phosphorus concentration demonstrated no significant correlation.

CONCLUSION

There are multiple associations with increased eosinophil counts in patients seen on a nephrology consultant service; however, their presence appears less often in association with allergies or uremia and more often with vascular disease.

Acute Interstitial Nephritis Associated with Coadministration of Vancomycin and Ceftriaxone: Case Series and Review of the Literature

We report what we believe to be the first two cases of acute interstitial nephritis associated with vancomycin and ceftriaxone therapy in adults. A 40-year-old man with a medical history of traumatic brain injury and tonic-clonic seizure disorder was admitted to the hospital with a seizure episode and temperature of 103 degrees F. He was administered ceftriaxone, vancomycin, and acyclovir for suspected bacterial and/or viral meningitis. On day 4, the patient was noted to have diffuse erythematous plaques on the neck, chest, arms, abdomen, and back, as well as an elevated serum creatinine level of 3.1 mg/dl (baseline 0.9 mg/dl) and an elevated eosinophil count (6%). Dermatology and renal consultations were obtained, and a diagnosis of suspected acute interstitial nephritis was made. After a 3-day course of antibiotic treatment (day 4 of hospitalization), all antibiotics were discontinued and topical triamcinolone 0.1% ointment and hydrocortisone 2.5% cream were begun for the rash. The patient was discharged 5 days later with improvement in the rash, serum creatinine level (1.0 mg/dl), and eosinophil count (0.9%). A 59-year-old woman with a medical history of diabetes mellitus was admitted to the hospital with a serum creatinine level of 3.7 mg/dl, eosinophil count of 8.4%, and fractional excretion of sodium of 2.94%. The patient had been receiving treatment with vancomycin and ceftriaxone for osteomyelitis for 28 days before this hospital admission. Her baseline serum creatinine level (before antibiotic therapy) was 1.0 mg/dl. Renal consultation was obtained, and a diagnosis of probable acute interstitial nephritis was made. Ceftriaxone and vancomycin were discontinued, and her serum creatinine level gradually decreased to 3.3 mg/dl and then further to 1.5 mg/dl over the next 3 months. Use of the Naranjo adverse drug reaction probability scale revealed that the adverse reaction was possible in the first case and probable in the second case. Health care professionals need to be cognizant that drug-induced acute interstitial nephritis can be associated with concomitant administration of ceftriaxone and vancomycin therapy. Early detection of this rare adverse reaction is paramount in order to prevent acute renal insufficiency.

Drug-induced granulomatous interstitial nephritis in a pediatric patient

Acute interstitial nephritis (AIN) is a known cause of acute renal failure in children. In most instances, drug therapy is the offending agent. Although granuloma formation has been observed in drug-induced interstitial nephritis, it is not a commonly associated manifestation. This is a case of a 15-year-old white female with Tetralogy of Fallot and pulmonary atresia who developed acute renal failure secondary to drug-induced interstitial nephritis and renal granulomas. In addition to interstitial edema with eosinophils and lymphocytes, her renal biopsy showed interstitial granulomas, immune complexes within tubular basement membranes, and the unusual feature of multinucleated giant cells engulfing tubules. Her acute renal failure resolved after the withdrawal of antibiotics and the initiation of intravenous steroid therapy.

Eosinophilia: secondary, clonal and idiopathic

Blood eosinophilia signifies either a cytokine-mediated reactive phenomenon (secondary) or an integral phenotype of an underlying haematological neoplasm (primary). Secondary eosinophilia is usually associated with parasitosis in Third World countries and allergic conditions in the West. Primary eosinophilia is operationally classified as being clonal or idiopathic, depending on the respective presence or absence of a molecular, cytogenetic or histological evidence for a myeloid malignancy. The current communication features a comprehensive clinical summary of both secondary and primary eosinophilic disorders with emphasis on recent developments in molecular pathogenesis and treatment.

Adult onset tubulointerstitial nephritis and uveitis syndrome

A Turkish woman aged 44 years who presented with a 1 month history of abdominal pain, fatigue and weight loss of 10 kg was diagnosed as having acute tubulointerstitial nephritis. Opthalmological evaluation revealed unilateral uveitis and contralateral chorioretinal scarring. X-ray films of the pelvis revealed unilateral sacroileitis. An elevated erythrocyte sedimentation rate, C-reactive protein, tubular proteinuria and renal glucosuria returned to normal 2 weeks after treatment was started. It is important to be aware of tubulointerstitial nephritis and uveitis syndrome in order to achieve a quick diagnosis in patients with renal impairment and tubular dysfunction with minor symptoms so that appropriate management can be started early.

Acute granulomatous interstitial nephritis secondary to bisphosphonate alendronate sodium

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world and is characterized by a progressive accumulation of functionally incompetent monoclonal lymphocytes. Renal involvement has been described in CLL but is uncommon. Granulomatous interstitial nephritis is a rare but characteristic hallmark of certain diseases such as sarcoidosis and tuberculosis. These epithelial reactions have also been reported with medications, infections, inflammation, Wegener's granulomatosis, and jejunoileal bypass. We present a 74-year-old woman with a stage 0 chronic lymphocytic leukemia who developed acute renal failure following the initiation of alendronate. The renal biopsy revealed an acute granulomatous interstitial nephritis. Infectious and inflammatory etiologies were ruled out. Hemodialysis was required despite discontinuation of all medications. Partial recovery of renal function occurred after 6 weeks of prednisone therapy and cyclophosphamide. This report describes a unique case of acute granulomatous interstitial nephritis and leukemic cell kidney infiltration by CLL.

Telithromycin-induced acute interstitial nephritis: a first case report

Telithromycin, a ketolide antibiotic used for the treatment of community-acquired respiratory infections, is widely prescribed in primary care practice. Treatment-related adverse events are mainly of gastrointestinal origin and generally mild in intensity. The authors report the first case of telithromycin-induced severe acute interstitial nephritis. Practitioners should be aware of the possibility that telithromycin therapy could result in this form of drug-induced acute renal failure.

Ciprofloxacin-induced acute interstitial nephritis and autoimmune hemolytic anemia

Ciprofloxacin has been associated with several side effects including interstitial nephritis and hemolytic anemia. The combination of both side effects is extremely rare. In this report, we describe a case of ciprofloxacin-induced interstitial nephritis and autoimmune hemolytic anemia. Hemolytic anemia improved after stopping the drug and initiation of steroid therapy. Unfortunately, acute interstitial nephritis was irreversible and the patient developed end-stage renal disease.

The tubulointerstitial nephritis and uveitis syndrome

The world's medical literature on tubulointerstitial nephritis and uveitis (TINU) syndrome was reviewed, and data on 133 patients with TINU syndrome were identified. The median age of onset was 15 years (range 9-74 years) with a 3:1 female-to-male predominance. Common laboratory abnormalities included elevated Westergren erythrocyte sedimentation rates and elevated urinary beta-2-microglobulin levels. Ocular symptoms preceded systemic symptoms in 21% of cases, and followed systemic symptoms by up to 14 months in 65% of cases. Uveitis involved only the anterior segment in 80% of cases. Uveitis was bilateral at presentation in 77% of cases. Patients were treated with systemic corticosteroids in 80% of cases and with immunosuppressive drugs in 9% of cases. Uveitis recurred or followed a chronic course in 56% of patients and persisted for several years in some cases. Ocular complications (including posterior synechiae, cataracts, and elevated intraocular pressure) were reported in 21% of cases. The visual prognosis appears to be good. Persistent renal dysfunction was reported in 11% of cases, including five patients who required renal dialysis. TINU syndrome is a distinct clinical entity that may be under-recognized and may account for some cases of unexplained chronic or recurrent uveitis. It is important for ophthalmologists, nephrologists, and primary care providers to be familiar with this disorder to ensure early diagnosis and appropriate treatment.

Acute granulomatous interstitial nephritis and colitis in anticonvulsant hypersensitivity syndrome associated with lamotrigine treatment

We present the case of a 17-year-old woman with a history of bipolar disorder, who developed a clinical syndrome manifested by fever, lymphadenopathy, skin rash, diarrhea, and acute renal failure requiring dialysis after the use of lamotrigine. Renal biopsy showed acute interstitial nephritis (AIN) with focal granulomas. Similarly, colonic biopsy specimens showed colitis and ileitis with non-necrotizing epithelioid granulomas. The patient had a complete recovery after withdrawal of the medication and steroid treatment. Although lamotrigine has been previously implicated in the development of anticonvulsant hypersensitivity syndrome, there have been no previous reports of acute granulomatous interstitial nephritis or colitis associated with the use of this drug.

Sonographic evaluation of renal failure

Sonography is a critical component of the evaluation of both acute and chronic renal failure; however, most nephrologists have a limited knowledge of this procedure. The acoustic properties, limited spectrum of pathological changes, and ease of visualization of the kidneys, coupled with the safety, simplicity, and low cost of sonography, make it the modality of choice for renal imaging. This review discusses the basics of sonography as they apply to the kidney and describes the findings encountered in the more common causes of renal failure. Although many sonographic findings are nonspecific, their diagnostic use is greatly enhanced by a familiarity with the clinical presentation and a thorough understanding of renal pathophysiological characteristics. Therefore, nephrologists should be knowledgeable about renal sonography and participate in its interpretation.

Tubulointerstitial nephritis associated with minimal self reexposure to rifampin

We report the case of a 27-year-old Asian man who self-medicated with two capsules of rifampin 1 year after completing a continuous course of chemotherapy for tuberculosis that included that drug. He developed flank pain and edema and presented with uremia requiring dialysis; despite this, he had a serum potassium of only 3.5 mEq/L. Renal biopsy showed interstitial infiltrate with inflammation of the tubules. Renal function began to improve after a 3-week course of prednisone. This case is remarkable for the severity of the renal failure despite such a minimal self-exposure.

Drug-induced acute interstitial nephritis

Acute interstitial nephritis (AIN) is a form of inflammatory renal disease affecting predominantly the tubules and the interstitium. Drugs, particularly beta-lactam antibiotics and non-steroidal anti-inflammatory drugs, are currently the most common causes. The pathogenesis of drug-induced AIN is complex but there is good clinical evidence for an immune-mediated reaction. Clinical findings may be variable depending on the drug involved and the individual response. Most patients recover from the acute renal failure; however, in older patients or in patients with pre-existing renal insufficiency the recovery of renal function may be incomplete.

Vancomycin-induced acute interstitial nephritis

OBJECTIVE

To report a case of acute interstitial nephritis (AIN) related to administration of vancomycin for the treatment of Staphylococcus aureus sternal wound infection, osteomyelitis, and infective endocarditis.

CASE SUMMARY

Reports in the literature regarding vancomycin-induced AIN are scarce. We describe the fifth known case of AIN, in a 64-year-old white man who developed fever, maculopapular rash, acute renal failure, eosinophilia, and eosinophiluria after approximately 1 month of vancomycin treatment. The results of the renal biopsy were consistent with an allergic drug reaction. Four months after his initial episode of AIN, the patient was rechallenged with vancomycin for the treatment of S. aureus septic arthritis. One day after initiation of vancomycin, serum eosinophils started to rise, his urine tested positive for eosinophils, but his serum creatinine remained stable.

CONCLUSIONS

Our case report and others from the literature suggest vancomycin causes allergic AIN. Clinicians should be aware of this adverse effect in an era of increasing use of vancomycin for treatment of resistant gram-positive organisms.

Tubulointerstitial nephritis induced by the leukotriene receptor antagonist pranlukast

A 7-year-old boy with asthma was receiving the leukotriene receptor antagonist pranlukast (Ultair; SmithKline Beecham; Pittsburgh) as part of an open-label clinical trial. The patient's asthma improved, and he remained asymptomatic; but routine study evaluations 9 to 12 months into therapy showed microhematuria, proteinuria, glucosuria, anemia, and renal insufficiency. Renal biopsy demonstrated changes classic for acute allergic tubulointerstitial nephritis (ATIN), with mixed interstitial inflammatory infiltrate including eosinophils. Within 6 months of pranlukast withdrawal, anemia resolved and urinary sediment and renal function normalized. The case demonstrates that hypersensitivity reaction to pranlukast and resultant ATIN is possible, and that periodic urine testing in patients receiving pranlukast should be considered.

Drug-induced acute tubulointerstitial nephritis: the clinical spectrum

Clinical and laboratory findings vary with the drug involved. A definitive diagnosis requires renal biopsy; a gallium scan may be helpful when biopsy is not feasible. Outcome depends on drug withdrawal, but corticosteroids may be beneficial.

Ranitidine-induced acute interstitial nephritis with epithelial cell foot process fusion

Although acute interstitial nephritis has been well described with the histamine H2-receptor antagonist cimetidine, we found only one previous case report of ranitidine-induced interstitial nephritis in the literature. We describe an additional patient who developed acute interstitial nephritis after taking ranitidine. Electron microscopy showed focal fusion of the epithelial cell foot processes that was not described in the previous report of ranitidine-induced interstitial nephritis.

Tubulointerstitial nephritis

Tubulointerstitial nephritis (TIN) describes a range of pathological processes that are at least partly responsible for the progression of renal disease of nearly all aetiologies. TIN is frequently the most important pathological manifestation of progressive glomerulonephritis, obstructive uropathy, reflux nephropathy and cystic diseases, although it may also present as a primary disease process associated with infection, drug use or other immunologically mediated disease. Recent clinical and laboratory research has increased our knowledge of tubulointerstitial structure, physiological function and tubulointerstitial response to injury. This review presents a classification of TIN in which acute and chronic tubulointerstitial diseases are recognized as forming a continuum. Primary TIN and TIN associated with glomerulonephritis, obstructive nephropathy and chronic progressive renal disease are discussed from both clinical and pathogenic aspects. It is argued that chronic TIN is a disease process in which inflammation is accompanied by a destructive tubulopathy and fibrogenesis. In acute TIN there is a cessation and reversal of this process. It is suggested that most forms of TIN have an immunological basis because of the presence of immune cell infiltrates, the occurrence of TIN in several immune diseases and immunological animal models of TIN. However, to date TIN has not been convincingly modified in patients by immune manipulation. Experimental evidence suggesting an important pathogenic role for proteinuria and antigenuria, and the renal tubule cell acting as an antigen-presenting cell is discussed.

Drug-induced renal disease

OBJECTIVE

To review drug-induced renal disease with emphasis on current issues and practical problems with commonly used agents.

DATA SOURCES

English language literature search using MEDLINE, Index Medicus, textbook articles and relevant reviews.

STUDY SELECTION

Drugs in common use were reviewed in detail. Uncommonly used drugs or those with only a few reports of nephrotoxicity were excluded from this review.

DATA SYNTHESIS

The clinical patterns of nephrotoxicity include an episode of acute deterioration of renal function, chronic renal failure and proteinuria which may be severe enough to cause the nephrotic syndrome. Diagnosis is made by clinical suspicion, distinctive clinical patterns and usually improvement in renal function on drug withdrawal.

CONCLUSION

A high index of suspicion is necessary to detect drug-induced renal disease particularly with increasing availability of over-the-counter drugs. Drugs should always be suspected of causing renal disease where no alternative cause is obvious. When any doubt exists the agent in question should be withdrawn.

Acute interstitial nephritis associated with cefotetan therapy

We report a case of acute interstitial nephritis associated with cefotetan therapy. Cefotetan should be considered a potential cause of acute renal failure in patients who develop rash, eosinophilia, and fever in association with an acute deterioration of renal function.

Drug-induced nephropathies

Drug-induced renal disease is a common problem. Drugs cause several renal syndromes, such as prerenal azotemia, fluid and electrolyte abnormalities, acute tubular necrosis, acute interstitial nephritis, and chronic interstitial nephritis. Acute renal failure due to acute tubular necrosis is the most common syndrome and is most frequently caused by aminoglycoside antibiotics, radiographic contrast agents, and amphotericin B. Avoidance of these drugs in volume-depleted or hypotensive patients with preexisting renal disease or in those receiving multiple nephrotoxic drugs is the most effective way to reduce nephrotoxicity. Acute interstitial nephritis is an immune process that is most commonly caused by penicillins, diuretics, allopurinol, nonsteroidal anti-inflammatory drugs, cimetidine, and sulfonamides. Prompt recognition of the disease and cessation of the responsible drug are usually the only necessary therapy. Chronic interstitial nephritis is most often seen after prolonged use of several different types of analgesic agents, including aspirin, acetaminophen, and nonsteroidal anti-inflammatory drugs. These patients develop recurrent papillary necrosis and eventually chronic renal failure. They are also at risk of developing transitional cell carcinomas of the urinary collecting system. Some patients who are receiving cyclosporine also develop chronic renal failure due to interstitial fibrosis.

Acute tubulointerstitial nephritis

Acute tubulointerstitial nephritis (ATIN) is a common disorder characterized by a spectrum of clinical manifestations ranging from asymptomatic urinary abnormalities to acute oliguric renal failure. Tubular dysfunction out of proportion to the degree of renal failure is an important clue to the diagnosis. This review describes its pathogenesis, pathophysiology, diagnosis, differential diagnosis and therapy, emphasizing the drug-induced form of ATIN.