Presentation, diagnosis, and treatment outcome of tuberculous-mediated tubulointerstitial nephritis

A prediction model for prognosis of nephrotic syndrome with tuberculosis in intensive care unit patients: a nomogram based on the MIMIC-IV v2.2 database

Background

Currently, a scarcity of prognostic research exists that concentrates on patients with nephrotic syndrome (NS) who also have tuberculosis. The purpose of this study was to assess the in-hospital mortality status of NS patients with tuberculosis, identify crucial risk factors, and create a sturdy prognostic prediction model that can improve disease evaluation and guide clinical decision-making.

Methods

We utilized the Medical Information Mart for Intensive Care IV version 2.2 (MIMIC-IV v2.2) database to include 1,063 patients with NS complicated by TB infection. Confounding factors included demographics, vital signs, laboratory indicators, and comorbidities. The Least Absolute Shrinkage and Selection Operator (LASSO) regression and the diagnostic experiment the receiver operating characteristic (ROC) curve analyses were used to select determinant variables. A nomogram was established by using a logistic regression model. The performance of the nomogram was tested and validated using the concordance index (C-index) of the ROC curve, calibration curves, internal cross-validation, and clinical decision curve analysis.

Results

The cumulative in-hospital mortality rate for patients with NS and TB was 18.7%. A nomogram was created to predict in-hospital mortality, utilizing Alb, Bun, INR, HR, Abp, Resp., Glu, CVD, Sepsis-3, and AKI stage 7 days. The area under the curve of the receiver operating characteristic evaluation was 0.847 (0.812-0.881), with a calibration curve slope of 1.00 (0.83-1.17) and a mean absolute error of 0.013. The cross-validated C-index was 0.860. The decision curves indicated that the patients benefited from this model when the risk threshold was 0.1 and 0.81.

Conclusion

Our clinical prediction model nomogram demonstrated a good predictive ability for in-hospital mortality among patients with NS combined with TB. Therefore, it can aid clinicians in assessing the condition, judging prognosis, and making clinical decisions for such patients.

Linalool prevents kidney damage by inhibiting rifampicin-induced oxidative stress and apoptosis

Today, kidney diseases are increasing day by day and life quality is decreasing. In hospitalized patients of all ages, acute kidney injury (AKI) is commonly observed and associated with high rates of morbidity and mortality. Rifampicin (RF) or rifampin is an antibiotic drug from the rifamycin group with a bactericidal effect. RF causes acute kidney injury, often anemia, thrombocytopenia, liver damage and side effect such as cell death. RF causes tissue damage by means of oxidative stress and apoptosis. Thus, in this study, it was examined whether linalool (LN) which had antinociceptive, antimicrobial, antioxidant and anti-inflammatory effects, was beneficial for kidney damage in order to eliminate the side effects of RF. NGAL mRNA, creatinine (Cr), blood urea nitrogen (BUN), Caspase 9 (CAS-9) and nuclear factor-κB (NF-κB) levels increased in the group treated with RF compared to the control group, while the levels of albumin, uric acid and total protein were decreased in the RF-treated group. NGAL mRNA, BUN, Cr, CAS-9 and NF-κB levels decreased significantly in RF+LN administered rats, while it was observed that there was an increase in the levels of albumin, uric acid and total protein. From the results obtained, it was observed that LN was determined to be very effective in preventing tissue damage in kidneys caused by oxidative stress by RF.

Interferon-gamma Release Assay-positive Granulomatous Interstitial Nephritis in a Patient with a History of Diffuse Large B Cell Lymphoma

Tuberculosis is a common etiology of granulomatous interstitial nephritis (GIN). However, the absence of evidence of lung involvement and lack of mycobacterial isolation in cultures make the etiological diagnosis and treatment decision challenging. We herein report a 46-year-old man with severe renal failure, a persistent fever, and a history of lymphoma. A renal biopsy exhibited GIN. Despite no evidence of tuberculosis except for a positive interferon-gamma release assay (IGRA), the patient was successfully treated with anti-tuberculosis drugs. Our case suggests that anti-tuberculosis therapy should be considered for patients with IGRA-positive GIN after excluding other etiologies.

Urinary tract tuberculosis misdiagnosed and treated as renal carcinoma in the presence of diffuse interstitial nephritis: a case report

Background

Urinary tract tuberculosis (UTTB) is a common form of extrapulmonary tuberculosis (TB) which can infrequently present as renal carcinoma, leading to serious errors in the diagnosis and treatment of UTTB.

Case presentation

A 76-year-old Syrian man presented with gross hematuria as the main symptom. A urinary endoscopic examination and pelvic multi-slice computed tomography imaging increased the suspicion of a speared renal mass in the right urinary tract. The patient was treated for renal cancer. After nephrectomy and ureterctomy, the histopathology of the resected mass confirmed the diagnosis of UTTB and interstitial nephritis.

Conclusion

This case should serve to increase the attention of clinicians to perform an accurate diagnosis step by step. This is especially important if they have a patient similar to the case described here who presents with a renal mass, to avoid serious results such as the loss of an essential organ system.

Serologic and urinary characteristics of laboratory-confirmed genitourinary tuberculosis at a tertiary hospital in the Philippines

Background

Genitourinary tuberculosis (GUTB) is known to cause high rates of structural organ damage, however, literature on its biochemical manifestations is limited. Additionally, local studies in the Philippine setting, where cases are rampant, are few and dated. This study aimed to determine the serologic and urinary profile of patients with GUTB admitted at a tertiary hospital within January 2009 to March 2020 and their association with short-term outcomes.

Methods

This retrospective study included 112 patients with laboratory-confirmed GUTB (i.e., positivity in acid-fast smear, polymerase chain reaction, culture, or histology). Demographic data, clinical characteristics, laboratory and radiologic findings, histopathology reports, treatment, and short-term outcomes were recorded.

Results

Bladder (54.5%) and kidney (36.4%) were the most affected organs. The male:female ratio was 1:1.15, and the mean age was 35.79 ± 18.29 years. Weakness (14.29%) was the most common chief complaint. A majority presented with anemia (83.04%), while several had leukocytosis (41.96%) and thrombocytosis (26.79%). Hypoalbuminemia (58.10%), impairment of renal function (36.94%), and electrolyte abnormalities such as hyponatremia (50.93%), hypercalcemia (20.19%), and hypokalemia (21.82%) were common. Proteinuria (67.96%) and pyuria (67.96%) were the most frequent abnormal findings, followed by hematuria (51.46%), acidic urine (45.63%) and low specific gravity (31.07%). Age, leukocytosis, and the need for pressors were all significantly associated with mortality (p values of <0.001, 0.010, and <0.001, respectively).

Conclusions

The young age at presentation with severe clinical and laboratory manifestations may reflect local epidemiology as TB continues to be widespread in the country. Apart from the more commonly cited abnormalities in literature, multiple electrolyte imbalances and urinary concentration defects were also observed in many cases, possibly indicating tubulointerstitial involvement—a complication increasingly mentioned in case reports. As several patient characteristics were found to be associated with the high mortality rates observed in the study, further research is recommended to explore predictive modeling.

Idiopathic granulomatous interstitial nephritis and isolated renal sarcoidosis: Two diagnoses of exclusion

Granulomatous interstitial nephritis is a rare finding in renal biopsy caused by drugs, infections, and inflammatory or autoimmune diseases. Idiopathic cases account for 18% of granulomatous interstitial nephritis in native kidneys. Sarcoidosis and drugs are the most common causes of granulomatous interstitial nephritis in Western countries, while in India tuberculosis prevails. Few cases of renal sarcoidosis without extrarenal involvement, that is, isolated renal sarcoidosis, have been reported. The diagnostic criteria of isolated renal sarcoidosis remain, however, unclear. Extrarenal sarcoidosis and other etiologies of granulomatous interstitial nephritis, in particular drug-related, have to be excluded. Some of these patients may develop extrarenal manifestations during follow-up. Changes in calcium and vitamin D metabolism are frequently observed in renal sarcoidosis and support its diagnosis. While non-necrotizing granulomas are a feature of sarcoidosis and drug-induced granulomatous interstitial nephritis, they also prevail in tuberculosis-associated granulomatous interstitial nephritis. Granulomatous interstitial nephritis caused by sarcoidosis and drugs usually responds to steroid therapy. A poor response to steroids may indicate an infectious etiology such as tuberculosis and should lead to a review of the initial diagnosis. This article gives an overview of the various etiologies of granulomatous interstitial nephritis, their frequency and histopathological characteristics, as well as potential biomarkers associated with renal sarcoidosis.

Acute tubulointerstitial nephritis in a patient with early bronchial tuberculosis

Patients with chronic kidney disease (CKD) are commonly at high risk of tuberculosis (TB). Conversely, TB rarely causes tubulointerstitial nephritis. A 75-year-old Japanese man who was undergoing periodic follow-ups for CKD stage G3aA3 with membranous nephropathy was diagnosed with acute kidney injury (AKI) (estimated glomerular filtration rate [eGFR]: 15 mL/min/1.73 m²) without prerenal AKI. He reported developing recent-onset cough 3 weeks prior to presenting to us. Renal biopsy revealed acute tubulointerstitial nephritis along with known membranous nephropathy. CD4⁺ helper T cells comprised most lymphocytes in the tubulointerstitium. Results of the interferon-gamma release assay, sputum smear test, polymerase chain reaction (PCR), and culture test were positive for TB. Chest computed tomography revealed thickening of the left bronchial wall; therefore, a diagnosis of early bronchial TB was made; his urine culture and PCR were negative for TB. At four months after TB treatment with no immunosuppressive therapy, his eGFR improved to 50 mL/min/1.73 m², and based on this progress, the AKI was diagnosed as tuberculosis-associated tubulointerstitial nephritis (TATIN). Although TATIN typically occurs with chronic or miliary tuberculosis, it is very rare in early bronchial TB. Identification of TATIN is important in kidney diseases of unknown etiology, and treatment with anti-TB drugs is necessary.

[Subacute kidney injury in a 40-year-old female Northern African patient]

Eine 40-jährige Patientin aus Eritrea stellte sich zur Abklärung einer unklaren progredienten Niereninsuffizienz vor. Die konservative Diagnostik war nicht wegweisend. Die Nierenbiopsie zeigte eine interstitielle Nephritis, deren Genese sich aufgrund einer leeren Medikamentenanamnese nicht zuordnen ließ. Im Rahmen der Abklärung ergab sich ein Rezidiv der bereits 2015 therapierten Urogenitaltuberkulose. Bei Vorliegen einer interstitiellen Nephritis sollte neben einer Medikamentenanamnese auch an eine Genese im Rahmen von systemischen Infektionen oder Systemerkrankungen gedacht werden.

[Renal granulomatous nephritis: Histopathological point of view]

Granulomatous interstitial nephritis (NIG) is a rare form of interstitial nephritis that can be related to acute or chronic clinical presentation. NIG is characterized by granulomas located to the renal interstitium and composed of either epithelioid histiocytes with giant cells and/or of foreign body reaction. The symptoms are unspecific and associate varying degrees of renal failure with abnormal urinanalysis. Extra-renal signs may point to systemic disease. Pathological examination from kidney percutaneous biopsy or surgical resection is required to assert NIG diagnosis and to guide the etiological research. The main causes of NIG are sarcoidosis, drug reactions, mycobacterial infections and crystalline nephropathies. Sarcoidosis is characterized by non-necrotic and well-formed giant cell epithelioid interstitial granulomas. Drug reactions have less well-defined granulomas with inconstant eosinophils. The presence of caseous necrosis within giant cell and epithelioid granulomas leads to infectious NIG diagnosis (tuberculosis and fungal infection). Identification of crystals within foreign body reaction can be improved by polarized light study. Xanthogranulomatous pyelonephritis and malakoplakia are rarer causes of NIG characterized by patches of histiocytes associated with inconstant giant cells. Differential diagnoses of NIG are represented by granulomatous reactions centered on glomeruli and vessels (vasculitis and emboli of cholesterol crystals). Less than 10% of NIG are idiopathic. The prognosis and the treatment vary according to the cause. The factors of poor renal prognosis are chronic irreversible tubulo-interstitial injury (tubular atrophy and interstitial fibrosis).

Serum Creatinine as a Potential Biomarker for the Diagnosis of Tuberculous Pleural Effusion

BACKGROUND

Previous studies have revealed the disadvantages of traditional methods for the diagnosis of tuberculous pleural effusions (TPEs) and have created interest in exploring other effective biomarkers. Many studies have focused on the correlation between pulmonary diseases and serum creatinine (Cr), a representative biomarker of renal function, but little is known about the direct relationship between Cr and TPE. Our study aimed to explore whether Cr can act as a biomarker for the diagnosis of TPE and to evaluate the correlation between Cr and TPE.

MATERIALS AND METHODS

Patients with pleural effusions (PEs) were enrolled in this study. By comparing the concentrations of Cr and adenosine deaminase (ADA) in patients with TPEs and non-TPEs, we determined the sensitivity, specificity, Youden index, and area under the curve for these biomarkers. We generated receiver operating characteristic curves and quantifications to evaluate the diagnostic accuracy.

RESULTS

In total, 86 patients (44 with TPE, 25 with malignant pleural effusion (MPE) and 17 with non-tuberculosis infectious PE (NTIPE)) were enrolled in the study. The concentrations of Cr in TPE were significantly higher than those in non-TPE. However, a similar trend was not observed for NTIPE and MPE. The levels of ADA in TPE were significantly higher than those in NTIPE and MPE.

CONCLUSION

Cr has the potential for the diagnosis of TPE to some extent though its accuracy is not as good as that of ADA. Further studies are necessary for Cr to be applied in clinical practice for the diagnosis of TPE.

Acute kidney injury in interstitial nephritis

PURPOSE OF REVIEW

The purpose of this review is to describe the most common causes of acute interstitial nephritis (AIN), the diagnostic work-up and the therapeutic management.

RECENT FINDINGS

Several case series and registries have found an increasing incidence of AIN, especially among older patients. Drug-induced AIN still represents the most common cause. Early withdrawal of the culprit drug together with corticosteroid therapy remain the mainstay of treatment, although recent studies have shown that prolonged treatment beyond 8 weeks does not further improve kidney function recovery.

SUMMARY

AIN is a common cause of acute kidney injury, and therefore, physicians should suspect this entity especially in patients exposed to multiple medications. While immune-allergic reaction to numerous drugs is the most common cause of AIN, other underlying systemic diseases may also be involved, and therefore, every patient should undergo a complete diagnostic evaluation. Kidney biopsy provides the definitive diagnosis of AIN, and certain histologic features may help to identify the underlying condition. In drug-induced AIN, an early discontinuation of the culprit drug is the mainstay of therapy, and unless a rapid recovery of kidney function is observed, a course of glucocorticoid therapy should be initiated.

Granulomatous interstitial nephritis on renal biopsy in human immunodeficiency virus positive patients: Prevalence and causes in Cape Town, South Africa

South Africa continues to be burdened by human immunodeficiency virus (HIV) and tuberculosis (TB). In Cape Town, the epidemic of HIV-TB co-infection is as high as 70%. Granulomatous interstitial nephritis (GIN) has increased in frequency on renal biopsy. This study aimed to determine GIN prevalence and causes in HIV-positive patients as well as renal outcomes, patient survival and associated factors. This observational cohort study reviewed HIV-positive renal biopsies for GIN from 2005 to 2012. Causes of GIN (medications, TB, fungal and other), and baseline characteristics were analysed. A comparison of baseline data, renal function and survival was made between GIN and non-GIN cohorts. There were 45/316 biopsies demonstrating GIN. TB was the likely cause of GIN in 27 (60%) and 9 (20%) were due to a drug. Low estimated glomerular filtration rate was a statistically significant factor associated with mortality in both GIN (P = 0.045) and non-GIN cohorts (P < 0.000). In the GIN group, there were 12 (26.7%) deaths. Mortality for all patients was greatest in the first 6 months (P = 0.057). TB co-infection in both cohorts was associated with a higher mortality. The multivariate logistic regression demonstrated that a higher urine protein/creatinine ratio (uPCR) and lower estimated glomerular filtration rate were statistically associated with death. GIN is common in HIV-positive renal biopsies in Cape Town. TB-GIN was the commonest cause and associated with a high early mortality. GIN should be considered in HIV-positive patients with acute kidney injury, its presence conveys a survival benefit. There is a need for improved diagnostic accuracy and treatment strategies of TB-GIN.

Tuberculosis in the 21st century: A narrative review

Sadly, despite the discovery of the tuberculosis bacillus over a century ago by Robert Koch, tuberculosis remains a major killer and modern day plague. Progress in the eradication of tuberculosis has been very slow and will require determined efforts on multiple fronts to make substantial inroads to lower the currently stagnant incidence of around 2% globally.

Severe tubulointerstitial nephritis: tracking tuberculosis even in the absence of renal granuloma

Extra-pulmonary tuberculosis is frequently located in the kidneys and, in such cases, could be associated with a granulomatous interstitial nephritis. Granulomas are not always detected, especially in human immunodeficiency virus (HIV)-positive patients. We report here a case of tubulointerstitial nephritis without granulomas in an HIV-negative patient. Since all laboratory tests failed to isolate Mycobacterium tuberculosis in the kidney, a targeted biopsy guided by positron emission tomography-computed tomography was performed on a mediastinal node, revealing a positive culture. After 6 months of treatment, no recovery of the renal injury has been observed.

Single-centre experience of granulomatous interstitial nephritis-time for a new approach?

Background: Differentiating between renal-limited sarcoidosis and tuberculosis (TB) infection as a cause of granulomatous interstitial nephritis (GIN) can be difficult. This series compares clinical features and response to treatment between the different underlying aetiologies in order to propose a management algorithm for GIN to assist with diagnosis and treatment.

Methods: This retrospective study reports on all patients presenting with a histological diagnosis of GIN between 2000 and 2012 at our unit.

Results: Twenty-one patients were identified, 57% were male and the mean age was 53 years. Eight cases were associated with sarcoidosis with evidence of extra-renal disease and five with renal-limited sarcoidosis. Five patients had GIN that may have been related to TB infection or to renal-limited sarcoidosis, and three were idiopathic or drug related. All those with sarcoidosis were treated with steroids and renal function, as measured by estimated glomerular filtration rate (eGFR), improved from a mean of 24 mL/min at baseline to 37 mL/min at 1 year. Baseline eGFR was 19 mL/min in those with possible TB infection. Four received steroids as well as anti-TB drugs. Anti-TB therapy was delayed in four patients by a mean of 22 months due to difficulties in diagnosis. Two patients with TB developed end-stage kidney disease and the remaining three patients had a mean eGFR of 28 mL/min at 1 year.

Conclusions: This series represents the largest cohort of patients with GIN in the UK and supports previous findings that patients with sarcoid have a favourable outcome with steroid treatment. Those with TB have an inferior prognosis, perhaps due to delayed diagnosis. We suggest an algorithm when investigating a diagnosis of GIN with the aim of expediting diagnosis and considering a trial of anti-TB therapy in order to prevent deterioration of renal function.

Long-term outcome in biopsy-proven acute interstitial nephritis treated with steroids

Background: There are no prospective randomized controlled trials describing the outcome of acute interstitial nephritis (AIN) treated with steroids, and retrospective studies are limited.

Methods: We identified adult patients with a diagnosis of AIN without glomerular pathology over a 14-year period. Treated patients all received oral prednisolone and three also recieved IV methylprednisolone. Data were collected retrospectively on estimated glomerular filtration rate (eGFR), change in eGFR from time of biopsy, dependence on renal replacement therapy (RRT) and mortality, and outcomes were analysed according to the treatment prescribed.

Results: A total of 187 eligible patients with AIN were identified and 158 were treated with steroids. There was no difference in median eGFR or dependence on RRT at the time of biopsy. Steroid-treated patients had significantly higher eGFR at all time points post-biopsy up to 24 months, when median eGFR was 43 mL/min in the steroid-treated group and 24 mL/min in the untreated group (P  =  0.01). Fewer patients in the steroid-treated group were dialysis dependent by 6 months (3.2% versus 20.6%, P  =  0.0022) and 24 months (5.1% versus 24.1%, P  =  0.0019).

Conclusions: This large retrospective study suggests a benefit of steroids in treatment of AIN with greater improvement in eGFR and fewer patients progressing to end-stage renal disease.

Etiological diagnosis of granulomatous tubulointerstitial nephritis in the tropics

Background

Granulomatous tubulointerstitial nephritis (GIN) is common due to infections, drugs or sarcoidosis. However, the cause is often difficult to establish and the studies are limited. We studied the etiology of GIN and compared the clinical and histological features and outcome in different etiologies at a tertiary care center in North India.

Methods

Renaö biopsies from GIN cases diagnosed from January 2004 to April 2014 were retrieved. Stain for acid fast bacilli was performed in all biopsies. Etiological diagnosis was based on clinical features, extra-renal manifestations, radiology, history of drug intake and demonstration of infective agent. Tissue PCR for tubercular DNA was performed in seven biopsies.

Results

Seventeen GIN patients [mean age 35 ± 15 years; males 11] were identified. Tuberculosis was the commonest etiology followed by idiopathic, sarcoidosis and fungal. Both tuberculosis and sarcoidosis patients presented with subnephrotic proteinuria and raised serum creatinine. Acid fast bacilli were demonstrated in 1/9 and necrosis was demonstrated in 3/9 granulomas in tuberculosis. Tissue PCR for tubercular DNA was positive in six TB patients and negative in one sarcoidosis patient. Patients responded well to appropriate therapy.

Conclusion

Etiological diagnosis of GIN is essential for timely and appropriate therapy. Tuberculosis is the commonest etiology (53%) in the tropics. Necrosis in granuloma, demonstration of acid fast bacilli, blood interferon gamma release assay and urine culture is not sensitive for the diagnosis of tuberculosis in GIN. Our findings suggest that tissue PCR for tuberculosis performed in an appropriate clinical setting is useful in the diagnostic evaluation of GIN.

An implication of relationship between tuberculosis and primary nephrotic syndrome

PURPOSE

There have been few observations on the concurrence of tuberculosis (TB) and primary nephrotic syndrome (PNS). We try to define their relationship from multiple aspects.

METHODS

Patients with PNS (n = 386), secondary nephrotic syndrome (SNS, n = 60), pneumonia (n = 196), and TB (n = 156) were enrolled. Through a novel evaluation system, the evidence of TB infection (clinical, laboratory, and radiographic evidence) was classified into 5 levels: lack of evidence (level 0), mild-to-moderate evidence (level 1-2), strong evidence (level 3-4). Additionally, whether TB infection was primary or secondary to long-term steroid therapy for PNS was recorded.

RESULTS

Through the evaluation system, 42.24% (68/161) of PNS inpatients had evidence of TB level 1-4, more than those in SNS (23.33%, P = .788) or pneumonia (22.45%, P = .004); 9.32% (15/161) PNS inpatients had evidence of level 3-4, who should be considered as having TB; 13 of the 15 patients had TB before the onset of PNS; 61.75%(96/153) PNS inpatients were abnormal on chest imaging. In the TB group, 28.21% (44/156) patients had abnormal urinalysis, more than those in the pneumonia group (8.16%, 16/196, P&lt;0.001). TB-related symptoms were seldom seen in PNS inpatients (cough 26.1%, fever 6.8%; night sweats, fatigue, and weight loss were negative).

CONCLUSIONS

Around 10% of PNS in children has an association with TB infection that preceded the onset of PNS.

Extrapulmonary tuberculosis presented as fever of unknown origin in two patients with endstage kidney disease not on dialysis: usefulness of 18-FDG-PET/CT in the diagnostic localization of fever of unknown origin

Tuberculosis is one of the common causes of fever of unknown origin in patients with chronic kidney disease (CKD). Extrapulmonary tuberculosis is more common in CKD patients, and is, unfortunately, often underdiagnosed despite extensive assessments. Recently, fluorine-18-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has been available in the diagnosis of malignancy, inflammatory and infectious diseases, and has become a useful diagnostic tool. Here, we present two cases of endstage kidney disease who presented with fever of unknown origin at the time of dialysis initiation. In both cases, although interferon-gamma-releasing assay was positive, combined conventional diagnostic modalities such as computed tomography and gallium-citrate scintigraphy failed to detect the sites infected with tuberculosis. By contrast, extrapulmonary lesions were detected by FDG-PET/CT and successfully treated with combined anti-tuberculous drugs. Diagnosis of extrapulmonary tuberculosis was confirmed by biopsy of the affected lymph node and lumbar spine, followed by PCR of the biopsied specimen. These cases highlight the importance of considering tuberculosis as one of the differential diagnoses in pre-dialysis CKD patients with persistent fever, and the usefulness of FDG-PET/CT in the detection of infectious sites of extrapulmonary tuberculosis.

[Fanconi syndrome in a 22-year-old African patient]

Acquired Fanconi syndrome can occur in patients with monoclonal gammopathy or after exposure to heavy metals or drug agents such as ifosfamide, and some antiretroviral therapies. Fanconi syndrome is characterized by a dysfunctional of the proximal tubular responsible in its complete form for polyuria, hypokalemia, glycosuria, hypophosphatemia and low molecular weight proteinuria. We report the case of a 22-year-old patient hospitalized with an acute renal failure secondary to a tubulo-interstitial nephritis associated with a complete Fanconi syndrome in a context of a poor general condition and fever. We described and analyzed the process leading to the diagnosis.

Changes in the aetiology, clinical presentation and management of acute interstitial nephritis, an increasingly common cause of acute kidney injury

Acute interstitial nephritis (AIN) is an important cause of acute kidney injury that has experienced significant epidemiological and clinical changes in the last years. The classical presentation, mostly induced by antibiotics and accompanied by evident hypersensitivity manifestations (skin rash, eosinophilia, fever) has been largely replaced by oligosymptomatic presentations that require a higher index of suspicion and are increasingly recognized in the elderly, having non-steroidal anti-inflammatory agents and proton pump inhibitors as frequent offending drugs. Drug-induced AIN continues to be the commonest type, but it requires a careful differential diagnosis with other entities (tubulointerstitial nephritis with uveitis syndrome, IgG4-related disease, drug reaction with eosinophilia and systemic symptom syndrome, sarcoidosis and other systemic diseases) that can also induce AIN. Cortico-dependant, relapsing AIN is a recently recognized entity that poses an important therapeutic challenge. Although corticosteroids are widely used in drug-induced AIN to speed kidney function recovery and avoid chronic kidney disease, their efficacy has not been tested by randomized controlled trials. New diagnostic tests and biomarkers, as well as prospective therapeutic studies are needed to improve AIN diagnosis and management.

Renal failure due to granulomatous interstitial nephritis in native and allograft renal biopsies: experience from a tertiary care hospital

Granulomatous interstitial nephritis is a rare cause of renal failure in both native and allograft renal biopsies. Drugs and sarcoidosis are the commonest causes of granulomatous interstitial nephritis as reported in Western countries. Unlike the west, tuberculosis is the commonest cause of granulomatous interstitial nephritis in Indian subcontinent. The etiological factors, clinical course, glomerular and tubulointerstitial changes associated with granulomatous interstitial nephritis have been analyzed in the present study along with the outcome in patients with granulomatous interstitial nephritis.

Rifampicin-induced acute kidney injury during the initial treatment for pulmonary tuberculosis: a case report and literature review

A 47-year-old man diagnosed with pulmonary tuberculosis was referred to our hospital. Rifampicin, isoniazid, pyrazinamide and ethambutol were administered, and the patient's symptoms promptly improved. On the 19th hospital day, he developed acute kidney injury with a fever and chills. Renal biopsy specimens indicated tubulointerstitial nephritis. Suspecting rifampicin-induced acute kidney injury, we discontinued the rifampicin and administered levofloxacin in its place. The patient's serum creatinine level subsequently gradually improved. We herein report this case and review eight cases reported in Japan. We found that the rifampicin toxicity appeared at both the initial administration and readministration. All eight patients presented with proteinuria.

Widespread tuberculosis including renal involvement

Renal and urogenital disease is a prevalent finding of extrapulmonary Mycobacterium tuberculosis. Patients can present with unusual complaints not immediately suspicious for tuberculosis. We describe a 38-year-old man who presented with vomiting and an acute kidney injury. Imaging studies showed nodules throughout the lungs, retroperitoneum, abdominal viscera, and kidneys. Asymmetrical hydronephrosis was found on renal imaging. A classic beaded ureteral appearance (ureteritis cystica) was found during retrograde pyelography. The patient was screened and found to have a negative purified protein derivative skin test, negative acid-fast bacilli of sputum in three samples, and an indeterminate QuantiFERON Gold test. Evaluation of the urine for acid-fast bacilli was negative in four separate samples. A fifth urine sample for acid-fast bacilli was positive. A renal biopsy showed granulomatous interstitial nephritis with multiple areas of caseous necrosis. The patient was diagnosed with active tuberculosis and started on traditional four-drug antituberculous medical therapy. Kidney function remained marginal but did mildly improve with volume expansion and urinary drainage.