Medication-Induced Interstitial Nephritis in the 21st Century

NSAID: Current limits to prescription

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to alleviate pain and inflammation in conditions like arthritis, migraines, and post-operative recovery. Their mechanism involves inhibiting prostaglandins that contribute to inflammation. NSAIDs are categorized based on their structure, selectivity for COX-1 and COX-2 enzymes, and plasma half-life. They are effective in treating osteoarthritis, spondyloarthritis, and rheumatoid arthritis but might carry an elevated risk of adverse events. Despite their effectiveness, NSAIDs have limitations and risks that warrant cautious consideration. Extensive research has investigated their side effects, and this review aims to examine the current limitations of oral NSAID therapy, including safety profiles, specific scenarios where their use may not be appropriate, and gaps in knowledge. By critically evaluating these aspects, healthcare practitioners can make informed decisions about prescribing NSAIDs, optimizing patient outcomes while minimizing potential risks. This narrative review summarizes existing knowledge and underscores the importance of risk-benefit assessments in NSAID prescribing. Ultimately, the goal is to enhance the rational use of NSAIDs, maximizing benefits while mitigating adverse effects.

Drug stewardship in chronic kidney disease to achieve effective and safe medication use

People living with chronic kidney disease (CKD) often experience multimorbidity and require polypharmacy. Kidney dysfunction can also alter the pharmacokinetics and pharmacodynamics of medications, which can modify their risks and benefits; the extent of these changes is not well understood for all situations or medications. The principle of drug stewardship is aimed at maximizing medication safety and effectiveness in a population of patients through a variety of processes including medication reconciliation, medication selection, dose adjustment, monitoring for effectiveness and safety, and discontinuation (deprescribing) when no longer necessary. This Review is aimed at serving as a resource for achieving optimal drug stewardship for patients with CKD. We describe special considerations for medication use during pregnancy and lactation, during acute illness and in patients with cancer, as well as guidance for the responsible use of over-the-counter drugs, herbal remedies, supplements and sick-day rules. We also highlight inequities in medication access worldwide and suggest policies to improve access to quality and essential medications for all persons with CKD. Further strategies to promote drug stewardship include patient education and engagement, the use of digital health tools, shared decision-making and collaboration within interdisciplinary teams. Throughout, we position the person with CKD at the centre of all drug stewardship efforts.

The diagnosis of acute interstitial nephritis caused by infection versus antibiotic-induced interstitial nephritis: a narrative review

Acute interstitial nephritis (AIN) is a significant contributor to acute kidney injury and can be attributed to a variety of factors, including but not limited to allergens or drugs, infections, autoimmune or systemic diseases, and idiopathic forms of the disease. In some cases, AIN requires a therapeutic action according to a single specific etiology by handling the offending agent and applying an immunosuppressant. Although AIN can be diagnosed through renal biopsy, it is not able to pinpoint the precise cause when multiple causes are suspected to be present simultaneously. Such situations arise when a patient suffering from infection develops AIN during antibiotic therapy, the exact causative factor of which becomes a challenge for the clinicians to determine. This is attributed to the different approaches employed in different etiologies, wherein clinicians are required to maintain the current antibiotic therapy or augment the dose in cases of infection as AIN etiology, without resorting to immunosuppressant therapy as the primary objective is infection killing. In contrast, antibiotics as an etiology for AIN require an alternative drug from the antibiotics group, along with an immunosuppressant. In the interim, delaying the identification of the precise cause may result in interstitial fibrosis and chronic kidney disease. This narrative review highlights certain findings that can be typical of infection-associated ATIN compared with antibiotic-associated ATIN based on clinical history and physical examination, clinical presentation of different antibiotic drug classes, histopathological features, classical and novel biomarkers, serum and urine cytokines and chemokines, cellular biomarkers, and genetic biomarkers. Although these findings cannot provide conclusive and clear recommendations that can be useful in the clinical practice, they can entice researchers to conduct original research on these features to discover clear recommendations.

Impact of Proton Pump Inhibitors on Kidney Function and Chronic Kidney Disease Progression: A Systematic Review

Proton pump inhibitors (PPIs) are widely prescribed medications for the management of various gastrointestinal disorders, primarily gastroesophageal reflux disease (GERD) and peptic ulcers. However, recent concerns have emerged regarding their potential adverse effects on kidney function and their role in the progression of chronic kidney disease (CKD). This systematic review aims to comprehensively analyze the existing literature to assess the impact of PPI use on kidney function and CKD progression. We took information from PubMed, PubMed Central (PMC), and Google Scholar articles from the last 10 years, from 2013 to 2023, and looked for links between PPI use and a number of kidney-related outcomes. These included acute kidney injury, a drop in the estimated glomerular filtration rate (eGFR), and new cases of CKD. The findings of this systematic review highlight the need for a thorough evaluation of the benefits and risks associated with PPI use, particularly in patients with pre-existing kidney conditions, in order to inform clinical decision-making and improve were taken out and looked at to see if there were any links between PPI use and different kidney-related events, such as acute kidney injury, a drop in the estimated eGFR, and the development of CKD. The review also explores potential mechanisms underlying PPI-induced nephrotoxicity. The findings of this systematic review highlight the need for a thorough evaluation of the benefits and risks associated with PPI use, particularly in patients with pre-existing kidney conditions, in order to inform clinical decision-making and improve patient care. Further research is warranted to better understand the complex interplay between PPIs, kidney function, and CKD progression.

Immune checkpoint inhibitors and their interaction with proton pump inhibitors-related interstitial nephritis

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and outcomes, leading to an expanding use in millions of patients worldwide. However, they can cause a spectrum of immune-related adverse events (irAEs). Essentially, any organs can be affected by irAEs, which have emerged as therapy-limiting side effects. In the kidneys, ICI-associated acute interstitial nephritis (ICI-AIN) leads to acute kidney injury (AKI) in 2%-5% of patients on ICI therapy. AKI associated with ICI therapy pathologically presents with AIN in nearly 90% of the cases, but the pathophysiology of ICI-AIN remains to be defined. The generation of autoreactive T cells in patients receiving AIN-inducible drugs, such as proton pump inhibitors (PPIs), is one of the leading theories, supported by a higher incidence of ICI-AIN in patients on these AIN-inducible drugs. In this review, we will discuss our understanding of the incidence, potential pathophysiological mechanisms, clinical presentations, risk factors, diagnosis, and management of PPI-related AIN and its interaction with ICI therapy.

Clinical Characteristics and Outcomes of Drug-Induced Acute Kidney Injury Cases

Introduction

Drug-induced acute kidney injury (DI-AKI) is a frequent adverse event. The identification of DI-AKI is challenged by competing etiologies, clinical heterogeneity among patients, and a lack of accurate diagnostic tools. Our research aims to describe the clinical characteristics and predictive variables of DI-AKI.

Methods

We analyzed data from the Drug-Induced Renal Injury Consortium (DIRECT) study (NCT02159209), an international, multicenter, observational cohort study of enriched clinically adjudicated DI-AKI cases. Cases met the primary inclusion criteria if the patient was exposed to at least 1 nephrotoxic drug for a minimum of 24 hours prior to AKI onset. Cases were clinically adjudicated, and inter-rater reliability (IRR) was measured using Krippendorff's alpha. Variables associated with DI-AKI were identified using L1 regularized multivariable logistic regression. Model performance was assessed using the area under the receiver operating characteristic curve (ROC AUC).

Results

A total of 314 AKI cases met the eligibility criteria for this analysis, and 271 (86%) cases were adjudicated as DI-AKI. The majority of the AKI cases were recruited from the United States (68%). The most frequent causal nephrotoxic drugs were vancomycin (48.7%), nonsteroidal antiinflammatory drugs (18.2%), and piperacillin/tazobactam (17.8%). The IRR for DI-AKI adjudication was 0.309. The multivariable model identified age, vascular capacity, hyperglycemia, infections, pyuria, serum creatinine (SCr) trends, and contrast media as significant predictors of DI-AKI with good performance (ROC AUC 0.86).

Conclusion

The identification of DI-AKI is challenging even with comprehensive adjudication by experienced nephrologists. Our analysis identified key clinical characteristics and outcomes of DI-AKI compared to other AKI etiologies.

Detection of potential drug-drug interactions for risk of acute kidney injury: a population-based case-control study using interpretable machine-learning models

Background: Acute kidney injury (AKI), with an increase in serum creatinine, is a common adverse drug event. Although various clinical studies have investigated whether a combination of two nephrotoxic drugs has an increased risk of AKI using traditional statistical models such as multivariable logistic regression (MLR), the evaluation metrics have not been evaluated despite the fact that traditional statistical models may over-fit the data. The aim of the present study was to detect drug-drug interactions with an increased risk of AKI by interpreting machine-learning models to avoid overfitting. Methods: We developed six machine-learning models trained using electronic medical records: MLR, logistic least absolute shrinkage and selection operator regression (LLR), random forest, extreme gradient boosting (XGB) tree, and two support vector machine models (kernel = linear function and radial basis function). In order to detect drug-drug interactions, the XGB and LLR models that showed good predictive performance were interpreted by SHapley Additive exPlanations (SHAP) and relative excess risk due to interaction (RERI), respectively. Results: Among approximately 2.5 million patients, 65,667 patients were extracted from the electronic medical records, and assigned to case (N = 5,319) and control (N = 60,348) groups. In the XGB model, a combination of loop diuretic and histamine H₂ blocker [mean (|SHAP|) = 0.011] was identified as a relatively important risk factor for AKI. The combination of loop diuretic and H₂ blocker showed a significant synergistic interaction on an additive scale (RERI 1.289, 95% confidence interval 0.226-5.591) also in the LLR model. Conclusion: The present population-based case-control study using interpretable machine-learning models suggested that although the relative importance of the individual and combined effects of loop diuretics and H₂ blockers is lower than that of well-known risk factors such as older age and sex, concomitant use of a loop diuretic and histamine H₂ blocker is associated with increased risk of AKI.

Genome-Wide Association Study in Acute Tubulointerstitial Nephritis

SIGNIFICANCE STATEMENT

Polymorphisms of HLA genes may confer susceptibility to acute tubulointerstitial nephritis (ATIN), but small sample sizes and candidate gene design have hindered their investigation. The first genome-wide association study of ATIN identified two significant loci, risk haplotype DRB1*14-DQA1*0101-DQB1*0503 (DR14 serotype) and protective haplotype DRB1*1501-DQA1*0102-DQB1*0602 (DR15 serotype), with amino acid position 60 in the peptide-binding groove P10 of HLA-DR β 1 key. Risk alleles were shared among different causes of ATIN and HLA genotypes associated with kidney injury and immune therapy response. HLA alleles showed the strongest association. The findings suggest that a genetically conferred risk of immune dysregulation is part of the pathogenesis of ATIN.

BACKGROUND

Acute tubulointerstitial nephritis (ATIN) is a rare immune-related disease, accounting for approximately 10% of patients with unexplained AKI. Previous elucidation of the relationship between genetic factors that contribute to its pathogenesis was hampered because of small sample sizes and candidate gene design.

METHODS

We undertook the first two-stage genome-wide association study and meta-analysis involving 544 kidney biopsy-defined patients with ATIN and 2346 controls of Chinese ancestry. We conducted statistical fine-mapping analysis, provided functional annotations of significant variants, estimated single nucleotide polymorphism (SNP)-based heritability, and checked genotype and subphenotype correlations.

RESULTS

Two genome-wide significant loci, rs35087390 of HLA-DQA1 ( P =3.01×10 -39 ) on 6p21.32 and rs2417771 of PLEKHA5 on 12p12.3 ( P =2.14×10 -8 ), emerged from the analysis. HLA imputation using two reference panels suggested that HLA-DRB1*14 mainly drives the HLA risk association . HLA-DRB1 residue 60 belonging to pocket P10 was the key amino acid position. The SNP-based heritability estimates with and without the HLA locus were 20.43% and 10.35%, respectively. Different clinical subphenotypes (drug-related or tubulointerstitial nephritis and uveitis syndrome) seemed to share the same risk alleles. However, the HLA risk genotype was associated with disease severity and response rate to immunosuppressive therapy.

CONCLUSIONS

We identified two candidate genome regions associated with susceptibility to ATIN. The findings suggest that a genetically conferred risk of immune dysregulation is involved in the pathogenesis of ATIN.

The Spectrum of Biopsy-Proven Kidney Diseases, Causes, and Renal Outcomes in Acute Kidney Injury Patients

INTRODUCTION

Acute kidney injury (AKI) is a group of highly heterogeneous, complicated clinical syndromes. Although kidney biopsy plays an irreplaceable role in evaluating complex AKI, a few studies have focused on the clinicopathology of AKI biopsies. This study analyzed the pathological disease spectrum, causes, and renal outcomes of biopsied AKI patients.

METHODS

We retrospectively included 2,027 AKI patients who underwent kidney biopsies at a national clinical research center of kidney diseases from 2013 through 2018. To compare the biopsied AKI cases without and with coexisting glomerulopathy, patients were classified into acute tubular/tubulointerstitial nephropathy-associated AKI (ATIN-AKI) and glomerular disease-associated AKI (GD-AKI) groups.

RESULTS

Of 2,027 biopsied AKI patients, 65.1% were male, with a median age of 43 years. A total of 1,590 (78.4%) patients had coexisting GD, while only 437 (21.6%) patients had ATIN alone. The AKI patients with GD mainly (53.5%) manifested as stage 1 AKI, while most ATIN-AKI patients (74.8%) had stage 3 AKI. In the ATIN-AKI group, 256 (58.6%) patients had acute interstitial nephritis (AIN), and 77 (17.6%) had acute tubular injury (ATI). ATIN-AKI was mainly caused by drugs in 85.5% of AIN and 63.6% of ATI cases, respectively. In AKI patients with coexisting GD, the leading pathological diagnoses in over 80% of patients were IgA nephropathy (IgAN, 22.5%), minimal change disease (MCD, 17.5%), focal segmental glomerulosclerosis (FSGS, 15.3%), lupus nephritis (LN, 11.9%), membranous nephropathy (MN, 10.2%), and ANCA-associated vasculitis (AAV, 4.7%). A total of 775 patients were followed up within 3 months after renal biopsy; ATIN-AKI patients achieved statistically higher complete renal recovery than the GD-AKI patients (83.5% vs. 70.5%, p < 0.001).

CONCLUSIONS

Most biopsied AKI patients have coexisting GD, while ATIN alone is seen less frequently. ATIN-AKI is mainly caused by drugs. In GD-AKI patients, IgAN, MCD, FSGS, LN, MN, and AAV are the leading diagnoses. Compared to AKI patients without GD, patients with GD suffer from worse renal function recovery.

Facing the Challenge of Drug-Induced Acute Interstitial Nephritis

BACKGROUND

Acute interstitial nephritis (AIN) is one of the chief causes of acute kidney injury (AKI). AIN might be produced by drugs, infections, autoimmune diseases, or can be idiopathic. Among these etiologies, drug-induced AIN (DI-AIN) is the dominant one in many countries. Even when DI-AIN is suspected, identification of the putative drug is challenging.

SUMMARY

DI-AIN is an increasingly common cause of AKI. Diagnosis continues to pose a challenge for physicians due to nonspecific clinical symptoms, and the fact that it can be triggered by a wide variety of medications. Furthermore, the gold standard for the diagnosis is kidney biopsy. All these aspects render the diagnosis more difficult. The withdrawal of the causative drug of DI-AIN is the centerpiece of the treatment, and if early restoration of original kidney function is not obtained, several studies support the treatment with steroids especially when they are started quickly.

KEY MESSAGES

Almost all drugs have the potential to produce drug-induced acute interstitial nephritis (DI-AIN); however, antibiotics, nonsteroidal anti-inflammatory agents, and proton pump inhibitors account for the majority of the reported cases. DI-AIN is produced by an idiosyncratic delayed type IV hypersensitivity reaction, but the precise pathophysiological mechanism remains to be elucidated. DI-AIN symptoms are nonspecific, and most of the patients will present mild symptoms including malaise, nausea, and vomiting. The classical triad, associating fever, rash, and eosinophilia, is seldom present. Nonoliguric acute kidney injury is the main renal manifestation of DI-AIN. Tubular nonnephrotic range proteinuria is usually present. Diagnosis of DI-AIN relies on maintaining a high index of suspicion in those patients at greater risk, but kidney biopsy is required to confirm diagnosis. Histologically, AIN is characterized by the presence of an extensive interstitial infiltrate, mainly composed of lymphocytes and monocytes, but eosinophils, plasma cells, histiocytes, and polymorphonuclear cells can also be found. The withdrawal of the presumed causative drug of DI-AIN is the mainstay of the treatment. When there is no evidence of kidney function recovery after an interval of 5-7 days since interrupting the treatment with the suspected drug, several studies support the treatment with steroids, especially when they are promptly started. Early corticosteroids would decrease the inflammatory infiltrates of the kidney interstitium, thus preventing the risk of subsequent fibrosis.

Incidence, risk factors and prognosis of acute kidney injury in patients treated with immune checkpoint inhibitors: a retrospective study

Immune checkpoint inhibitors (ICIs) change the prognosis of many cancer patients. With the increasing use of ICIs, immune-related adverse events are occurring, including acute kidney injury (AKI). This study aimed to assess the incidence of AKI during ICI treatment and its risk factors and impact on mortality. Patients treated with ICIs at the First Medical Center of the Chinese PLA General Hospital from January 1, 2014, to December 30, 2019, were consecutively enrolled, and risk factors affecting AKI development in patients treated with ICIs were analyzed using univariate and multivariate logistic regression. Medical record surveys and telephone inquiry were used for follow-up, and Kaplan-Meier survival analysis and Cox regression were used to analyze independent risk factors for death. Among 1615 patients, 114 (7.1%) had AKI. Multivariate logistic regression analysis showed that anemia, Alb < 30 g/L, antibiotic use, diuretic use, NSAID use and proton pump inhibitor use were independent risk factors for AKI development in patients treated with ICIs. Stage 2 or 3 AKI was an independent risk factor for nonrecovery of renal function after AKI onset. Multivariate Cox regression analysis showed that anemia, Alb < 30 g/L, AKI occurrence, and diuretic use were independent risk factors for death in patients treated with ICIs, while high baseline BMI, other tumor types, ACEI/ARB use, and chemotherapy use were protective factors for patient death. AKI occurs in 7.1% of patients treated with ICIs. Anemia, Alb < 30 g/L, and combined medication use are independent risk factors for AKI in patients treated with ICIs. Anemia, Alb < 30 g/L, AKI occurrence, and diuretic use were independent risk factors for death in patients treated with ICIs.

Adverse Renal Effects of Anticancer Immunotherapy: A Review

Simple Summary

The immune system has a natural ability to work against cancer cells; however, in many cases this ability is insufficient, and cancers develop methods enabling them to escape from the supervision of immune cells. Novel therapeutic methods used in neoplastic diseases are based on encouraging immune cells to fight against cancer. In some cases, boosted by this approach, the immune system may damage not only tumor cells, but also other cells, tissues and organs in the human body. Kidney involvement, for example, is directly dangerous for patients’ health and may have an impact on human body homeostasis and the excretion of xenobiotics. However, renal function impairment in patients treated with immunotherapy is thought to be relatively rare but may be severe. Knowledge of early diagnosis and proper management are essential for physicians utilizing immunotherapy in daily clinical practice.

Abstract

Modern oncological therapy utilizes various types of immunotherapy. Immune checkpoint inhibitors (ICIs), chimeric antigen receptor T cells (CAR-T) therapy, cancer vaccines, tumor-targeting monoclonal antibodies (TT-mAbs), bispecific antibodies and cytokine therapy improve patients’ outcomes. However, stimulation of the immune system, beneficial in terms of fighting against cancer, generates the risk of harm to other cells in a patient’s body. Kidney damage belongs to the relatively rare adverse events (AEs). Best described, but still, superficially, are renal AEs in patients treated with ICIs. International guidelines issued by the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) cover the management of immune-related adverse events (irAEs) during ICI therapy. There are fewer data concerning real occurrence and possible presentations of renal adverse drug reactions of other immunotherapeutic methods. This implies the need for the collection of safety data during ongoing clinical trials and in the real-life world to characterize the hazard related to the use of new immunotherapies and management of irAEs.

Vedolizumab-Induced Acute Interstitial Nephritis in Ulcerative Colitis

Vedolizumab is used in the treatment of inflammatory bowel disease and is generally well tolerated. We report a 20-year-old man who presented with right flank pain on a background of ulcerative colitis. He was on vedolizumab with his last dose 1 week before the onset of symptoms. Kidney function tests revealed a serum creatinine of 171 μmoL/L and a C-reactive protein of 74 mg/L. Kidney biopsy demonstrated focal acute interstitial nephritis. He was prescribed oral prednisolone and achieved complete recovery of renal function within 3 weeks. At the follow-up after 4 months, his renal function remains normal.

Frequently reported adverse events of rebamipide compared to other drugs for peptic ulcer and gastroesophageal reflux disease

This study aimed to detect safety signals of rebamipide and search for adverse events (AEs) of rebamipide that are more common than those of other drugs for peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD) in the elderly population. A total of 101,735 AE reports for drugs used to treat PUD and GERD between 2009 and 2018 from the KIDS-KAERS database (KIDS-KD) were used. Disproportionality analysis was performed to calculate the proportional reporting ratio (PRR), reporting odds ratio (ROR), and information component (IC). Drug labels in Korea, Japan, and China were reviewed to identify signals that have been listed. AEs frequently reported in the elderly population were also analyzed. Seriousness and median time to AEs were evaluated for statistically significant AEs. A total of 14 signals were detected, and 4 signals (dry mouth, dermatitis, purpura/petechia, and fluid overload) were not listed on drug labels; however, they may be included as part of other listed AEs. In the elderly population, 11 AEs such as dyspepsia/indigestion/gastrointestinal distress, somnolence, dry mouth, and edema were common. These AEs were not serious and occurred within 2–9 days. This study identified possible AEs of rebamipide, a relatively safe drug.

Rare case of interstitial nephritis in a young adult under IgG therapy

Immunoglobulin replacement therapy is an important therapeutic approach used in different diseases, such as immunodeficiency diseases. We report a case of a 19-year-old female patient with suspected common variable immunodeficiency who started replacement therapy with IgG. During the follow-up, she developed interstitial nephritis and the subsequent workup excluded other diseases or triggers except IgG therapy.

Beta-Lactams Dosing in Critically Ill Patients with Gram-Negative Bacterial Infections: A PK/PD Approach

Beta-lactam antibiotics are often the backbone of treatment for Gram-negative infections in the critically ill. Beta-lactams exhibit time-dependent killing, and their efficacy depends on the percentage of dosing interval that the concentration remains above the minimum inhibitory concentration. The Gram-negative resistance rates of pathogens are increasing in the intensive care unit (ICU), and critically ill patients often possess physiology that makes dosing more challenging. The volume of distribution is usually increased, and drug clearance is variable. Augmented renal clearance and hypermetabolic states increase the clearance of beta-lactams, while acute kidney injury reduces the clearance. To overcome the factors affecting ICU patients and decreasing susceptibilities, dosing strategies involving higher doses, and extended or continuous infusions may be required. In this review, we specifically examined pharmacokinetic models in ICU patients, to determine the desired beta-lactam regimens for clinical breakpoints of Enterobacterales and Pseudomonas aeruginosa, as determined by the European Committee on Antimicrobial Susceptibility Testing. The beta-lactams evaluated included penicillins, cephalosporins, carbapenems, and monobactams. We found that when treating less-susceptible pathogens, especially P. aeruginosa, continuous infusions are frequently needed to achieve the desired pharmacokinetic/pharmacodynamic targets. More studies are needed to determine optimal dosing strategies in the novel beta-lactams.

[Safety in the selection of oral antibiotic treatment in community infections, beyond COVID-19]

Los antibióticos orales son uno de los fármacos más utilizados en la comunidad. Sus efectos adversos son generalmente poco frecuentes y leves, e incluyen toxicidad e interacciones medicamentosas. El mecanismo de producción es variado y no siempre bien conocido. El conocimiento de los efectos adversos con relevancia clínica puede permitir hacer un uso más juicioso de los antibióticos basados en el principio primero no hacer daño, primun non nocere. En esta revisión exploramos los principales efectos adversos de los antibióticos orales con énfasis en los β-lactámicos, macrólidos y fluoroquinolonas.

Beta-Lactams Toxicity in the Intensive Care Unit: An Underestimated Collateral Damage?

Beta-lactams are the most commonly prescribed antimicrobials in intensive care unit (ICU) settings and remain one of the safest antimicrobials prescribed. However, the misdiagnosis of beta-lactam-related adverse events may alter ICU patient management and impact clinical outcomes. To describe the clinical manifestations, risk factors and beta-lactam-induced neurological and renal adverse effects in the ICU setting, we performed a comprehensive literature review via an electronic search on PubMed up to April 2021 to provide updated clinical data. Beta-lactam neurotoxicity occurs in 10-15% of ICU patients and may be responsible for a large panel of clinical manifestations, ranging from confusion, encephalopathy and hallucinations to myoclonus, convulsions and non-convulsive status epilepticus. Renal impairment, underlying brain abnormalities and advanced age have been recognized as the main risk factors for neurotoxicity. In ICU patients, trough concentrations above 22 mg/L for cefepime, 64 mg/L for meropenem, 125 mg/L for flucloxacillin and 360 mg/L for piperacillin (used without tazobactam) are associated with neurotoxicity in 50% of patients. Even though renal complications (especially severe complications, such as acute interstitial nephritis, renal damage associated with drug induced hemolytic anemia and renal obstruction by crystallization) remain rare, there is compelling evidence of increased nephrotoxicity using well-known nephrotoxic drugs such as vancomycin combined with beta-lactams. Treatment mainly relies on the discontinuation of the offending drug but in the near future, antimicrobial optimal dosing regimens should be defined, not only based on pharmacokinetics/pharmacodynamic (PK/PD) targets associated with clinical and microbiological efficacy, but also on PK/toxicodynamic targets. The use of dosing software may help to achieve these goals.

Design, Synthesis, In Vitro and In Vivo Characterization of Selective NKCC1 Inhibitors for the Treatment of Core Symptoms in Down Syndrome

Intracellular chloride concentration [Cl^-]_i is defective in several neurological disorders. In neurons, [Cl^-]_i is mainly regulated by the action of the Na⁺-K⁺-Cl^- importer NKCC1 and the K⁺-Cl^- exporter KCC2. Recently, we have reported the discovery of ARN23746 as the lead candidate of a novel class of selective inhibitors of NKCC1. Importantly, ARN23746 is able to rescue core symptoms of Down syndrome (DS) and autism in mouse models. Here, we describe the discovery and extensive characterization of this chemical class of selective NKCC1 inhibitors, with focus on ARN23746 and other promising derivatives. In particular, we present compound 40 (ARN24092) as a backup/follow-up lead with in vivo efficacy in a mouse model of DS. These results further strengthen the potential of this new class of compounds for the treatment of core symptoms of brain disorders characterized by the defective NKCC1/KCC2 expression ratio.

The Emerging Role of the Innate Immune Response in Idiosyncratic Drug Reactions

Idiosyncratic drug reactions (IDRs) range from relatively common, mild reactions to rarer, potentially life-threatening adverse effects that pose significant risks to both human health and successful drug discovery. Most frequently, IDRs target the liver, skin, and blood or bone marrow. Clinical data indicate that most IDRs are mediated by an adaptive immune response against drug-modified proteins, formed when chemically reactive species of a drug bind to self-proteins, making them appear foreign to the immune system. Although much emphasis has been placed on characterizing the clinical presentation of IDRs and noting implicated drugs, limited research has focused on the mechanisms preceding the manifestations of these severe responses. Therefore, we propose that to address the knowledge gap between drug administration and onset of a severe IDR, more research is required to understand IDR-initiating mechanisms; namely, the role of the innate immune response. In this review, we outline the immune processes involved from neoantigen formation to the result of the formation of the immunologic synapse and suggest that this framework be applied to IDR research. Using four drugs associated with severe IDRs as examples (amoxicillin, amodiaquine, clozapine, and nevirapine), we also summarize clinical and animal model data that are supportive of an early innate immune response. Finally, we discuss how understanding the early steps in innate immune activation in the development of an adaptive IDR will be fundamental in risk assessment during drug development. SIGNIFICANCE STATEMENT: Although there is some understanding that certain adaptive immune mechanisms are involved in the development of idiosyncratic drug reactions, the early phase of these immune responses remains largely uncharacterized. The presented framework refocuses the investigation of IDR pathogenesis from severe clinical manifestations to the initiating innate immune mechanisms that, in contrast, may be quite mild or clinically silent. A comprehensive understanding of these early influences on IDR onset is crucial for accurate risk prediction, IDR prevention, and therapeutic intervention.

Proton pump inhibitors use and risk of chronic kidney disease and end-stage renal disease

INTRODUCTION

A possible association between long-term proton pump inhibitors (PPI) use and chronic kidney disease (CKD) has been recently described. Due to the potential health risk of this association, in the absence of proper clinical trials, we have decided to carry out a systematic review followed by meta-analysis.

EVIDENCE ACQUISITION

PubMed, Cochrane Library, and Lilacs databases were searched. Studies that reported an association between PPI use and CKD or End-stage Renal Disease (ESRD) published until December 23, 2019, were included. All selected studies present high quality according to the New-Castle-Ottawa. The risk ratio (RR) and confidence interval (CI) were pooled using a random-effects model in CKD outcome analysis and fixed effects model for ESRD. A total of 10 observational studies were selected.

EVIDENCE SYNTHESIS

Compared to patients who did not use PPI, the RR for CKD associated with PPI use was 1.35 (95% CI 1.15-1.56) with P<0.001, and the RR for ESRD associated with PPI use was 1.49 (95% CI 1.41-1.56) with P<0.001.

CONCLUSIONS

This study indicates the presence of a significant association between PPI use and an increased risk of CKD and ESRD and reiterates the need for the medical prescription of this class of drugs to be made following the guidelines of the FDA.

Florid Interstitial Hemorrhages: A Novel Feature of Amoxicillin-Clavulanate-Induced Acute Tubulointerstitial Nephritis

Patient: Male, 33-year-old

Final Diagnosis: Amoxicillin-Clavulanate induced acute tubulointerstitial nephritis

Symptoms: Hematuria

Medication:—

Clinical Procedure: Bone marrow biopsy • renal biopsy

Specialty: Nephrology • Pathology

PD-1 immunobiology in glomerulonephritis and renal cell carcinoma

BACKGROUND

Programmed cell death protein (PD)-1 receptors and ligands on immune cells and kidney parenchymal cells help maintain immunological homeostasis in the kidney. Dysregulated PD-1:PD-L1 binding interactions occur during the pathogenesis of glomerulopathies and renal cell carcinoma (RCC). The regulation of these molecules in the kidney is important to PD-1/PD-L1 immunotherapies that treat RCC and may induce glomerulopathies as an adverse event.

METHODS

The expression and function of PD-1 molecules on immune and kidney parenchymal cells were reviewed in the healthy kidney, PD-1 immunotherapy-induced nephrotoxicity, glomerulopathies and RCC.

RESULTS

PD-1 and/or its ligands are expressed on kidney macrophages, dendritic cells, lymphocytes, and renal proximal tubule epithelial cells. Vitamin D3, glutathione and AMP-activated protein kinase (AMPK) regulate hypoxic cell signals involved in the expression and function of PD-1 molecules. These pathways are altered in kidney disease and are linked to the production of vascular endothelial growth factor, erythropoietin, adiponectin, interleukin (IL)-18, IL-23, and chemokines that bind CXCR3, CXCR4, and/or CXCR7. These factors are differentially produced in glomerulonephritis and RCC and may be important biomarkers in patients that receive PD-1 therapies and/or develop glomerulonephritis as an adverse event CONCLUSION: By comparing the functions of the PD-1 axis in glomerulopathies and RCC, we identified similar chemokines involved in the recruitment of immune cells and distinct mediators in T cell differentiation. The expression and function of PD-1 and PD-1 ligands in diseased tissue and particularly on double-negative T cells and parenchymal kidney cells needs continued exploration. The possible regulation of the PD-1 axis by vitamin D3, glutathione and/or AMPK cell signals may be important to kidney disease and the PD-1 immunotherapeutic response.

Acute kidney injury following the use of different proton pump inhibitor regimens: A real-world analysis of post-marketing surveillance data

BACKGROUND AND AIM

Recent evidence has concerned acute kidney injury (AKI) after the proton pump inhibitor (PPI) application. There are few real-world studies to compare the occurrences, clinical features, and prognosis of AKI related to various PPI regimens. We aimed to evaluate and compare the links between different PPIs and AKI in a large population by investigating the Food and Drug Administration Adverse Event Reporting System (FAERS) until recently.

METHODS

Disproportionality analysis and Bayesian analysis were used in data mining to screen the suspected AKI after different PPIs based on the FAERS from January 2004 to December 2019. The times to onset, fatality, and hospitalization rates of PPI-associated AKI were also investigated.

RESULTS

We identified 19 522 PPI-associated AKIs, which appeared to influence more middle-aged patients than elderly ones (53.04% vs 33.94%). Women were more affected than men (55.42% vs 44.58%). Lansoprazole appeared a stronger AKI association than other PPIs, based on the highest reporting odds ratio (reporting odds ratio = 20.8, 95% confidence interval = 20.16, 21.46), proportional reporting ratio (proportional reporting ratio = 15.55, χ²  = 73 899.68), and empirical Bayes geometric mean (empirical Bayes geometric mean = 15.15, 95% confidence interval = 14.76). The median time to AKI onset was 446 (interquartile range [IQR] 16-2176) days after PPI administration. PPIs showed a significant difference in average time to AKI onset (P < 0.001), with the shortest of 9 (IQR 3-25) days for rabeprazole and the longest of 1221 (IQR 96.5-2620) days for esomeprazole. PPI-associated AKI generally led to a 5.69% fatality rate and an 8.94% hospitalization rate. The highest death rate occurred in rabeprazole (15.35%).

CONCLUSIONS

Based on the FAERS database, we profiled AKI related to various PPIs with more details in occurrences, clinical characteristics, and prognosis. Concern should be paid for PPIs when applied to patients with a tendency for AKI.

Urine interleukin-9 and tumor necrosis factor-α for prognosis of human acute interstitial nephritis

BACKGROUND

We previously demonstrated that urine interleukin (IL)-9 and tumor necrosis factor (TNF)-α can distinguish acute interstitial nephritis (AIN) from other causes of acute kidney injury. Here we evaluated the role of these biomarkers to prognosticate kidney function in patients with AIN.

METHODS

In a cohort of participants with biopsy-proven, adjudicated AIN, we tested the association of histological features and urine biomarkers (IL-9 and TNF-α) with estimated glomerular filtration rate measured 6 months after diagnosis (6 m-eGFR) controlling for eGFR before AIN and albuminuria. We also evaluated subgroups in whom corticosteroid use was associated with 6 m-eGFR.

RESULTS

In the 51 (93%) of the 55 participants with complete data, median (interquartile range) eGFR before and 6 m after AIN were 41 (27-69) and 28 (13-47) mL/min/1.73 m2, respectively. Patients with higher severity of interstitial fibrosis had lower 6 m-eGFR, whereas those with higher tubulointerstitial infiltrate had higher 6 m-eGFR. IL-9 levels were associated with lower 6 m-eGFR only in the subset of patients who did not receive corticosteroids [6m-eGFR per doubling of IL-9, -6.0 (-9.4 to -2.6) mL/min/1.73 m2]. Corticosteroid use was associated with higher 6 m-eGFR [20.9 (0.2, 41.6) mL/min/1.73 m2] only in those with urine IL-9 above the median (>0.66 ng/g) but not in others.

CONCLUSIONS

Urine IL-9 was associated with lower 6 m-eGFR only in participants not treated with corticosteroids. Corticosteroid use was associated with higher 6 m-eGFR in those with high urine IL-9. These findings provide a framework for IL-9-guided clinical trials to test efficacy of immunosuppressive therapy in patients with AIN.

Drug rash with eosinophilia and systemic symptoms and severe renal injury induced by proton pump inhibitor therapy: A case report

INTRODUCTION

Proton pump inhibitors (PPIs) are widely prescribed and generally well tolerated but can rarely cause severe allergic reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS). We report a case of DRESS and renal injury induced by PPIs, and describe the therapeutic process.

PATIENT CONCERNS

The patient was a 66-year-old female who complained of fever, pruritus, desquamation, erythema multiforme, and anuria caused by omeprazole taken for 2 weeks to treat abdominal distention.

DIAGNOSIS

The clinical history revealed a similar episode of PPI-induced fever, eosinophilia, and acute kidney injury more than 1 year ago. The present laboratory tests revealed eosinophilia and oliguric renal failure. The renal biopsy was performed subsequently and proved the diagnosis of PPI-induced DRESS.

INTERVENTIONS

After the suspected diagnosis of PPI-induced DRESS, omeprazole was discontinued and methylprednisolone infusion (40 mg qd) was initiated. Because of oliguric renal failure, the patient received intermittent hemodialysis.

OUTCOMES

The patient initially responded to omeprazole discontinuation, hemodialysis, and glucocorticoids but later died from severe infection during the tapering of glucocorticoid therapy.

CONCLUSION

Clinicians should remain on high alert for potential life-threatening complications when prescribing PPIs. If unexplained renal injury develops in a patient taking a PPI, renal biopsy may help in identifying the pathogenesis and might facilitate timely intervention.

Drug-induced interstitial nephritis as a result of sodium valproate and triamterene

we presented a case of drug-induced interstitial nephritis in a 43-year-old woman, having the history of renal calculi, as a result of sodium valproate and triamterene. Renal biopsy was used to confirm the diagnosis, however, due to poor prognosis along with discontinuation of drugs, she was treated with corticosteroids.

Renal disorders in rheumatologic diseases: the spectrum is changing (part 2. Arthridides)

This review is devoted to rheumatologic diseases mainly characterized by different types of arthritis. They may involve also different organs, including the kidney, but renal disease is more frequently caused by the nephrotoxicity of drugs to relieve pain or to interfere with the pathophysiology of the underlying disease. Rheumatoid arthritis is the prototype of arthropathies. This autoimmune disease mainly attacks joints, tendons and ligaments but can also involve internal organs including the kidney. Psoriatic arthritis is a complex disease in which psoriasis, a chronic inflammatory disease, is associated with the development of peripheral arthritis or spondylitis. The disease or its treatment may lead to kidney complications. Gout is a form of inflammatory arthritis which is characterized by an increase in the serum uric acid deposits in and around the joints of the extremities, the so called tophi. The disease is often associated with a metabolic syndrome with diabetes, obesity, hypertension, and cardiovascular disease. Kidney injury is frequent. It may be caused by kidney stones, urinary tract obstruction, tubulointerstitial and vascular lesions leading to CKD and renal failure.

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.

Drug-induced tubulointerstitial nephritis: hypersensitivity and necroinflammatory pathways

More than 250 drugs carry a small but important dose-independent risk of initiating a delayed-type hypersensitivity reaction that leads to acute tubulointerstitial nephritis (TIN). Clinical manifestations are often non-specific, making epidemiological studies challenging. In severe cases, if cessation of the offending drug is not followed by a prompt improvement in renal function, corticosteroid therapy appears to enhance renal recovery rates. Other drugs, classified as potential nephrotoxins, may induce dose-dependent acute tubular necrosis. Studies over the past decade have identified a unique form of tubular cell death called "necroptosis" that is accompanied by a specific and significant interstitial inflammatory response to certain insults, including some nephrotoxins. Insights into the molecular basis of this necroinflammatory pathway have emerged. There is still a paucity of pediatric data on these two distinct types of drug-induced TIN. Early recognition is essential to minimize the risk of chronic kidney damage.

Nefritis tubulointersticial aguda. Revisión bibliográfica

La nefritis tubulointersticial aguda hace referencia a un tipo de daño renal que afecta principalmente el intersticio y ocasiona la lesión renal aguda, potencialmente reversible. Su curso puede ser subclínico, con deterioro progresivo hasta evolucionar hacia la insuficiencia renal crónica. La nefritis tubulointersticial aguda tiene múltiples etiologías, las más frecuentes son los medicamentos, productos herbales, las infecciones y las enfermedades autoinmunes. Las principales manifestaciones clínicas son la poliuria, polaquiuria, nocturia, dolor lumbar, microhematuria y leucocituria, aunque puede ser totalmente asintomática. El tratamiento depende de la causa de base y los esteroides juegan un papel importante cuando la condición es de origen medicamentoso o autoinmune. El pronóstico generalmente es bueno, si el problema se identifica de forma oportuna y se trata adecuadamente.

Recurrent acute interstitial nephritis: what lies beneath

Background

Acute interstitial nephritis (AIN) is an emerging cause of acute kidney disease. While this disease usually follows an acute course, it may occasionally recur, representing a major challenge for the clinician.

Methods

We performed a retrospective, observational cohort study in 13 nephrology departments belonging to the Spanish Group for the Study of Glomerular Diseases. Patients with biopsy-proven AIN between 1996 and 2018 were included.

Results

The study group consisted of 205 patients with AIN, 22 of which developed recurrent AIN (RAIN) after a median of 111 days from diagnosis. RAIN was due to a surreptitious reintroduction of a previously known implicated drug or toxic in six patients (27%), sarcoidosis in two (9%), Sjögren’s syndrome in three (14%), light-chain-mediated AIN in two (9%) and tubulointerstitial nephritis and uveitis syndrome in two (9%), while in the rest of cases (32%), no precise cause could be identified. Microscopic haematuria was more frequent in patients with underlying systemic diseases. The first RAIN episode was treated with a repeated course of corticosteroids in 21 patients (95%). In six cases (27%), azathioprine and mycophenolate mofetil were added as corticosteroid-sparing agents. During a median follow-up of 30 months, 50 patients (27%) with no recurrences and 12 patients (55%) with RAIN reached Stages 4 and 5 chronic kidney disease (CKD). By multivariable logistic regression analysis, RAIN was independently associated with the risk of reaching Stages 4 and 5 CKD, even after adjusting for potential covariables.

Conclusions

RAIN is infrequent but is associated with poor kidney survival. RAIN should prompt clinicians to search for an underlying aetiology other than drug induced. However, in a large percentage of cases, no precise cause can be identified.

Omeprazole use and risk of chronic kidney disease evolution

RATIONALE, AIMS AND OBJECTIVES

In recent years, the use of proton pump inhibitors (PPI), especially omeprazole, has been associated with development of chronic kidney disease (CKD). These drugs are widely used worldwide. Although some studies have found an association between the use of PPI and the onset of acute renal failure and CKD. This study aims to analyze the association between the continuous use of omeprazole and the progression of CKD in adult and elderly individuals.

METHOD

A retrospective cohort study was conducted with patients followed up at a nephrology clinic in Brazil, in 2016 and 2017. Information about clinical and sociodemographic data, health behaviors, and medication use were collected from all patients diagnosed with CKD through consultation of medical charts and the Brazilian health information system (SIS). The participants were allocated into two groups: users and non-users of omeprazole, and the progression of CKD was then evaluated for each group. In the bivariate analysis, the Mann-Whitney U test to compare the quantitative variables between groups, and the Pearson/Fisher two-tailed chi-square test to compare the categorical variables were applied. Multivariate analysis was performed using Cox regression.

RESULTS

A total of 199 CKD patients were attended in the polyclinic, and of these, 42.7% were omeprazole users. There was a higher percentage of CKD progression in users (70.6%) compared to non-users (10.5%). The hazard ratio was 7.34 (CI: 3.94-13.71), indicating a higher risk of progression to worse stages of CKD in omeprazole users than in non-users. As for the other variables, no statistically significant difference was found between groups (p > 0.05).

CONCLUSION

An association between omeprazole use and progression of CKD stage was identified, showing a higher risk of disease evolution among omeprazole users.

Acute toxic kidney injury

Substances toxic to the kidney are legion in the modern world. The sheer number and variety, their mutual interactions and, metabolism within the body are a challenge to research. Moreover, the kidney is especially prone to injury owing to its physiology. Acute kidney injury (AKI) induced by poisonous or primarily nephrotoxic substances, may be community acquired with ingestion or inhalation or nosocomial. Many nephrotoxic plants, animal poisons, medications, chemicals and illicit drugs can induce AKI by varying pathophysiological pathways. Moreover, the epidemiology of toxic AKI varies depending on country, regions within countries, socioeconomic status and health care facilities. In this review, we have selected nephrotoxic insults due to medication, plants, animal including snake venom toxicity, environmental, (agri)chemicals and also illicit drugs. We conclude with a section on diagnosis, clinical presentation and management of poisoning accompanied by various organ dysfunction and AKI.

Co-occurrence of bilateral nodular anterior scleritis and large-vessel arteritis in a patient with TINU syndrome

We present a case of tubulointerstitial nephritis and uveitis (TINU) with nodular anterior scleritis and large-vessel arteritis. A 67-year-old patient was admitted to the hospital with high fever, thoracic pain, and weakness. Bilateral anterior uveitis was seen at that time. Laboratory examination showed acute renal failure. A renal biopsy was performed and showed pathognomonic signs of tubulointerstitial nephritis (TIN). Six months later, she developed ocular inflammation suggestive of nodular scleritis. One year after hospital admission, she presented with large-vessel arteritis. We describe a case of TINU with co-occurrence of scleritis and large-vessel arteritis.

[Pharmacology of non-opioid analgesics]

Due to high prescription rates as well as the frequent use as over the counter drugs, it is of interest to consider non-opioid analgesics when evaluating the quality and appropriateness of a given overall medication. This article sums up the basic pharmacology and main adverse effects of these analgesics. Non-opioids can be further classified according to their additional mechanisms of action besides analgesia. High-dose acetylsalicylic acid, traditional nonsteroidal anti-inflammatory drugs, and coxibs exhibit antipyretic and anti-inflammatory properties. Acetaminophen and metamizole (dipyrone) are analgesics and antipyretic agents, while metamizole exhibits also spasmolytic effects. Capsaicin and intrathecal ziconotide are pure analgesics.

Granulomatous interstitial nephritis: a rare diagnosis with an overlooked culprit

Granulomatous interstitial nephritis (GIN) is a rare entity identified in <1% of native kidney biopsies. The most frequent aetiology is drug-related, followed by systemic granulomatous conditions. Among drugs implicated in GIN, antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are the most frequent. We report the case of a 45-year-old white man referred to a nephrology consult due to chronic kidney disease. He had a history of arterial hypertension with 10 years of evolution, hyperuricaemia, medicated with allopurinol and NSAID abuse for at least 20 years. Urine sediment was blunt, without proteinuria. Renal ultrasound was normal. A kidney biopsy revealed well-defined epithelioid granulomas with glomerular wrinkling and collapse. Infectious and systemic conditions were excluded, favouring the hypothesis of drug-induced GIN, probably related to NSAIDs. Kidney biopsy remains the gold standard for the diagnosis of GIN. Facing a patient with renal failure without significant proteinuria or active sediment, one should look for causes of tubulointerstitial injury.

Diagnosing acute interstitial nephritis: considerations for clinicians

Acute interstitial nephritis (AIN) is a common cause of acute kidney injury (AKI), particularly in hospitalized patients. It can be difficult for clinicians to differentiate between AIN and other common causes of AKI, most notably acute tubular necrosis (ATN) and prerenal injury. Clinicians often struggle with the clinical history and laboratory data available to definitively diagnose AIN. Sometimes they diagnose ATN or AIN based on these flawed data. Thus it is important that clinicians be familiar with the utility of commonly ordered tests used to aid in the diagnosis. Unfortunately, no single test performs particularly well on its own, and until a biomarker is rigorously shown to be diagnostic of AIN, most patients require a kidney biopsy to definitively establish the diagnosis and direct further management.

Iatrogenic Disease of the Genitourinary Tract

Iatrogenic disease is defined as illness caused by diagnostic procedures or treatment given by health care professionals. More recently described treatment complications involving the genitourinary tract include newly recognized variants of renal carcinoma in the setting of dialysis/end-stage renal disease, treatment effect in genitourinary carcinomas, and medical renal disease caused by drug therapies, including immunotherapy. The objective of this review is to cover iatrogenic inflammatory diseases, pseudotumors and tumors of the kidney, bladder, prostate, testis and paratestis of most interest to surgical pathologists. For this reason, disease caused by the following will not be covered: iatrogenic glomerulonephritis, self-inflicted injury including the introduction of foreign bodies, surgical error, drugs of abuse and herbal medications, and iatrogenic disease in the transplant setting including ischemia/reperfusion injury. Emphasis is placed upon commonly encountered diseases in order to ensure that the review is of utility to practicing pathologists. The clinical context, pathophysiology and histopathology of each disease entity are covered.

Severe acute interstitial nephritis induced by valsartan: A case report

RATIONALE

Angiotensin receptor blocker (ARB) can increase serum creatinine or potassium levels in patients with renal insufficiency, renal artery stenosis, heart failure or hypovolemia, but hardly cause severe kidney injury in patients without any risk factors. A case of severe acute interstitial nephritis (AIN) induced by valsartan was reported here.

PATIENT CONCERNS

A 62-year-old female with nausea for 1 month and acute deterioration of kidney function for 2 weeks was admitted. She had a history of hypertension for 5 months and had taken valsartan 40 mg daily for 4 months. Although the valsartan had been stopped for 2 weeks, the serum creatinine continuously increased after admission. Kidney biopsy demonstrated the eosinophils infiltration in interstitium.

DIAGNOSES

AIN induced by valsartan.

INTERVENTIONS

The patient was treated with glucocorticoid.

OUTCOMES

The serum creatinine decreased gradually and got back to normal level 5 months later. Then therapy of glucocorticoid was stopped. Renal artery stenosis was excluded by computed tomography angiography (CTA).

LESSONS

Although valsartan-induced allergy has been reported previously, AIN was firstly recognized as a severe complication of this drug. We suggest when there is a ARB-associated continuous deterioration of kidney function for patients without renal insufficiency, renal artery stenosis, heart failure or hypovolemia, AIN should be thought of and therapy with glucocorticoid should be considered if necessary.

Acute and Chronic Tubulointerstitial Nephritis of Rheumatic Causes

Tubulointerstitial nephritis (TIN) is the second most common cause of acute intrinsic kidney injury after acute tubular necrosis. Although drug-induced forms of TIN represent the vast majority, rheumatic disease is another common cause and often underdiagnosed. Early diagnosis of acute interstitial nephritis and prompt withdrawal of the culprit medication or a correct treatment can avoid chronic damage and progressive chronic kidney disease. This review highlights the recent updates, clinical features, and treatment in TIN in autoimmune rheumatic disease.

The relationship between proton pump inhibitors and renal disease

Proton pump inhibitors (PPIs) bind to enzyme H⁺/K⁺-ATPase and inhibit its activity in the stomach, thus decreasing the secretion of gastric acid. PPIs may trigger acute interstitial nephritis, a potentially severe adverse event commonly associated with acute kidney injury. Studies have found that prolonged use of PPIs may increase the risk of chronic kidney disease (CKD). The increase in prescription and inadequate use of this class of medication calls for studies on the effects of prolonged PPI therapy on renal function. Therefore, this review aimed to analyze recent studies on the matter and discuss the possible consequences of the long-term use of PPIs on renal function.

High intake of orange juice and cola differently affects metabolic risk in healthy subjects

BACKGROUND

Higher consumption of sugar-containing beverages has been associated with an elevated risk of type 2 diabetes and gout. Whether this equally applies to cola with an unhealthy image and orange juice (OJ) having a healthy image remains unknown.

METHODS

In order to investigate whether OJ and cola differently affect metabolic risk 26 healthy adults (24.7 ± 3.2 y; BMI 23.2 ± 3.3 kg/m²) participated in a 2 × 2-wk intervention and consumed either OJ or caffeine-free cola (20% Ereq as sugar from beverages) in-between 3 meals/d at ad libitum energy intake. Glycemic control, uric acid metabolism and gut microbiota were assessed as outcome parameters.

RESULTS

Fecal microbiota, body weight, basal and OGTT-derived insulin sensitivity remained unchanged in both intervention periods. Levels of uric acid were normal at baseline and did not change with 2-wk cola consumption (-0.03 ± 0.67 mg/dL; p > 0.05), whereas they decreased with OJ intervention (-0.43 ± 0.56 mg/dL; p < 0.01) due to increased uric acid excretion (+130.2 ± 130.0 mg/d; p < 0.001). Compared to OJ, consumption of cola led to a higher daylong glycemia (ΔiAUC: 36.9 ± 83.2; p < 0.05), an increase in glucose variability (ΔMAGE-Index: 0.29 ± 0.44; p < 0.05), and a lower 24 h-insulin secretion (ΔC-peptide excretion: -31.76 ± 38.61 μg/d; p < 0.001), which may be explained by a decrease in serum potassium levels (-0.11 ± 0.24 mmol/L; p < 0.05).

CONCLUSION

Despite its sugar content, regular consumption of large amounts of OJ do not increase the risk of gout but may even contribute to lower uric acid levels. The etiology of impaired insulin secretion with cola consumption needs to be further investigated.

Associations of Proton-Pump Inhibitors and H2 Receptor Antagonists with Chronic Kidney Disease: A Meta-Analysis

BACKGROUND/AIMS

The aim of this meta-analysis was to assess the risks of chronic kidney disease (CKD) and/or end-stage kidney disease (ESRD) in patients who are taking proton-pump inhibitors (PPIs) and/or H2 receptor antagonists (H2RAs).

METHODS

Comprehensive literature review was conducted utilizing MEDLINE and EMBASE databases through April 2017 to identify all studies that investigated the risks of CKD or ESRD in patients taking PPIs/H2RAs versus those without PPIs/H2RAs. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird. The protocol for this study is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42017067252).

RESULTS

Five studies with 536,902 participants were patients were identified and included in the data analysis. When compared with non-PPIs users, the pooled risk ratio (RR) of CKD or ESRD in patients with PPI use was 1.33 (95% CI 1.18-1.51). Pre-specified subgroup analysis (stratified by CKD or ESRD status) demonstrated pooled RRs of 1.22 (95% CI 1.14-1.30) for association between PPI use and CKD and 1.88 (95% CI 1.71-2.06) for association between PPI use and ESRD, respectively. However, there was no association between the use of H2RAs and CKD with a pooled RR of 1.02 (95% CI 0.83-1.25). When compared with the use of H2RAs, the pooled RR of CKD in patients with PPI use was 1.29 (95% CI 1.22-1.36).

CONCLUSIONS

Our study demonstrates statistically significant 1.3-fold increased risks of CKD and ESRD in patients using PPIs, but not in patients using H2RAs.