Rifampicin-Induced Nephrotoxicity in a Tuberculosis Patient: Treatment Dilemma?

Acute kidney injury related to rifampin is usually a clinical diagnosis. We report a case of a man being treated for pulmonary tuberculosis with acute tubulointerstitial nephritis related to rifampicin.

Acute tubulointerstitial nephritis associated with antineutrophil cytoplasmic antibody following cimetidine treatment: a case report

Background Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis usually induces rapidly progressive glomerulonephritis, including pauci-immune necrotizing crescentic glomerulonephritis. Acute tubulointerstitial nephritis (ATIN), which is often drug-induced, is a frequent cause of kidney injury. However, ATIN associated with ANCA without any glomerular lesions has been rarely reported, and drug-induced ATIN associated with ANCA is not well recognized. Here we present a case of an older woman with ATIN associated with myeloperoxidase-ANCA (MPO-ANCA) following cimetidine treatment. Case presentation A 70-year-old woman was admitted to our hospital due to acute kidney injury and mild proteinuria. She had a one-year history of chronic thyroiditis and dyslipidemia, for which she was taking levothyroxine sodium and atorvastatin, respectively. Two weeks before admission she had started cimetidine, methylmethionine sulfonium chloride, and itopride hydrochloride for gastric discomfort persistent since a month. She had experienced fatigue for two weeks and later appetite loss. The patient demonstrated a positive titer for MPO-ANCA (192 IU/mL) and a positive drug-induced lymphocyte stimulation test for cimetidine. She underwent two kidney biopsies that revealed ATIN without any glomerular lesions. Despite discontinuation of cimetidine on admission, renal injury continued with the presence of high MPO-ANCA titer. Oral steroid treatment was closely related with the recovery of her renal function and disappearance of MPO-ANCA. Conclusions In this case, ATIN presented as sustained renal insufficiency and high MPO-ANCA titer despite withdrawal of cimetidine. Therefore, we reason that the development of ANCA-associated ATIN was caused by cimetidine. Serologic follow-up with measurement of MPO-ANCA titers and renal biopsy are recommended when the clinical history is inconsistent with the relatively benign course of drug-induced ATIN.

Urinary Cytokines Reflect Renal Inflammation in Acute Tubulointerstitial Nephritis: A Multiplex Bead-Based Assay Assessment

Background: Acute tubulointerstitial nephritis (ATIN) diagnosis lays on histological assessment through a kidney biopsy, given the absence of accurate non-invasive biomarkers. The aim of this study was to evaluate the accuracy of different urinary inflammation-related cytokines for the diagnostic of ATIN and its distinction from acute tubular necrosis (ATN). Methods: We included 33 patients (ATIN (n = 21), ATN (n = 12)), and 6 healthy controls (HC). We determined the urinary levels of 10 inflammation-related cytokines using a multiplex bead-based Luminex assay at the time of biopsy and after therapy, and registered main clinical, analytical and histological data. Results: At the time of biopsy, urinary levels of I-TAC/CXCL11, CXCL10, IL-6, TNFα and MCP-1 were significantly higher in ATIN compared to HC. A positive correlation between the extent of the tubulointerstitial cellular infiltrates in kidney biopsies and the urinary concentration of I-TAC/CXCL11, MIG/CXCL9, CXCL10, IL17, IFNα, MCP1 and EGF was observed. Notably, I-TAC/CXCL11, IL-6 and MCP-1 were significantly higher in ATIN than in ATN, with I-TAC/CXCL11 as the best discriminative classifier AUC (0.77, 95% CI 0.57–0.95, p = 0.02). A combinatory model of these three urinary cytokines increased the accuracy in the distinction of ATIN/ATN compared to the individual biomarkers. The best model resulted when combining the three cytokines with blood eosinophil and urinary leukocyte counts (LR = 9.76). Follow-up samples from 11ATIN patients showed a significant decrease in I-TAC/CXCL11, MIG/CXCL9 and CXCL10 levels. Conclusions: Urinary I-TAC/CXCL11, CXCL10, IL6 and MCP-1 levels accurately distinguish patients developing ATIN from ATN and healthy individuals and may serve as novel non-invasive biomarkers in this disease.

Aetiology, course and treatment of acute tubulointerstitial nephritis in paediatric patients: a cross-sectional web-based survey

BackgroundAcute tubulointerstitial nephritis (TIN) is a significant cause of acute renal failure in paediatric and adult patients. There are no large paediatric series focusing on the aetiology, treatment and courses of acute TIN.Patients, design and settingWe collected retrospective clinical data from paediatric patients with acute biopsy-proven TIN by means of an online survey. Members of four professional societies were invited to participate.ResultsThirty-nine physicians from 18 countries responded. 171 patients with acute TIN were included (54% female, median age 12 years). The most frequent causes were tubulointerstitial nephritis and uveitis syndrome in 31% and drug-induced TIN in 30% (the majority of these caused by non-steroidal anti-inflammatory drugs). In 28% of patients, no initiating noxae were identified (idiopathic TIN). Median estimated glomerular filtration rate (eGFR) rose significantly from 31 at time of renal biopsy to 86 mL/min/1.73 m2 3–6 months later (p<0.001). After 3–6 months, eGFR normalised in 41% of patients (eGFR ≥90 mL/min/1.73 m2), with only 3% having severe or end-stage impairment of renal function (<30 mL/min/1.73 m2). 80% of patients received corticosteroid therapy. Median eGFR after 3–6 months did not differ between steroid-treated and steroid-untreated patients. Other immunosuppressants were used in 18% (n=31) of patients, 21 of whom received mycophenolate mofetil.ConclusionsDespite different aetiologies, acute paediatric TIN had a favourable outcome overall with 88% of patients showing no or mild impairment of eGFR after 3–6 months. Prospective randomised controlled trials are needed to evaluate the efficacy of glucocorticoid treatment in paediatric patients with acute TIN.

MO160COVID-19 INFECTION AND ACUTE TUBULOINTERSTITIAL NEPHRITIS

Background COVID-19 infection manifests as pneumonia associated with multiple organ failure, and death. Acute kidney injury is a risk factor for mortality. There is limited scientific literature on COVID-19 infection and allergic tubulointerstitial nephritis, its clinical course and short- and long-term prognosis. Method We performed a retrospective study where medical records of 60 patients with histological diagnosis of allergic tubulointerstitial nephritis from January 2009 to November 2020. In these patients, we studied the incidence of COVID-19 infection, clinical characteristics and prognosis from March to the actual date. Results Of 60 patients with allergic tubulointerstitial nephritis, 6 (10%) patients were diagnosed with COVID-19. The first case, an 85-year-old woman with a history of metastatic melanoma treated with nivolumab and allergic tubulointerstitial nephritis by immunobiological agents in 2018, diagnosed with mild COVID-19 infection in April 2020 without deterioration of renal function in controls at 3 and 6 months of follow-up. The second case, a 51-year-old woman with a history of large B-cell lymphoma with plasmacytic differentiation and progression to multiple myeloma of lambda light chains and allergic tubulointerstitial nephritis due to chemotherapy since 2019, admitted for acute pyelonephritis and PRES syndrome secondary to first dose of bortezomib complicated with COVID-19 nosocomial pneumonia and acute pancreatitis treated with corticosteroids and broad spectrum antibiotic therapy; she died of abdominal refractory septic shock. The third patient, a 64-year-old man without prior renal impairment, was admitted for severe COVID-19 pneumonia and acute kidney injury secondary to acute tubulointerstitial nephritis of uncertain etiology that required orotracheal intubation and continuous veno-venous hemodiafiltration for a week who received methylprednisolone in bolus for 3 days and continued treatment with corticosteroid therapy with complete recovery of renal function and improvement in proteinuria at 3 months of follow-up. The fourth patient, an 82-year-old woman with acute kidney injury AKIN 3 secondary to acute allergic tubulointerstitial nephritis related to ciprofloxacin complicated with severe COVID-19 nosocomial pneumonia, who died despite ventilatory support and high-dose steroids therapy and tocilizumab. The fifth patient, a 75-year-old with a history of metastatic lung adenocarcinoma treated with immunobiological agents and allergic tubulointerstitial nephritis in 2018, admitted in march 2020 for mild COVID-19 pneumonia treated with steroids and hydroxychloroquine without deterioration of respiratory and kidney function. The sixth patient, an 86-years-old man with acute kidney injury AKIN 3 due to acute allergic tubulointerstitial nephritis secondary to proton-binding inhibitors and nosocomial COVID-19 infección with improvement of kidney function with steroids therapy only. Conclusion Our 6 patients with allergic tubulointerstitial nephritis and COVID-19 infection presented different spectrum of the disease. It seems that nosocomial COVID-19 infection in patients admitted with recent diagnosis of acute allergic tubulointerstitial nephritis presented a worse clinical prognosis compared with long-term diagnosed acute tubulointerstitial nephritis. Further studies with a larger sample size are needed.