Drug-Induced Acute Interstitial Nephritis

Diagnosis, management, and outcomes of immune checkpoint inhibitor induced acute interstitial nephritis: A single-center experience

BACKGROUND

Immune checkpoint inhibitor (ICI)-associated acute interstitial nephritis (AIN) is a recognized complication of immunotherapy (IO), but literature on its management and outcomes is limited.

METHODS

We retrospectively reviewed patients who received ICIs and developed biopsy-proven or clinically-suspected ICI-associated AIN at the University of Virginia Comprehensive Cancer Center from 2012-2023. We analyzed baseline characteristics and clinical outcomes, including treatment interruption and rechallenge rates. Acute kidney injury (AKI) was defined as a ≥ 1.5-fold increase in baseline creatinine under seven days, a two-fold increase above the upper limit of normal, or an increase by ≥0.3 mg/dL. Kidney function returning to within 0.3 mg/dL or less than twice baseline was considered complete (CRc) and partial (PRc) recovery, respectively.

RESULTS

We identified 12 cases of ICI-AIN: four by biopsy (33%) and eight (67%) by clinical suspicion. Two patients received anti-CTLA-4 and anti-PD1, six received anti-PD1 alone, and four received chemo-immunotherapy. The majority (58%) of patients developed AIN within the first 5 cycles. Eight patients developed ≥ Grade 3 AKI, and six developed multiple irAEs. ICI was permanently discontinued in seven patients (58%) and temporarily interrupted in four (30%). The CRc and PRc rates were 67% and 8%, respectively. Upon AIN onset, the best disease response was stable disease in five patients, partial response in three, and progressive disease in three. Median overall survival was 4.87 years, and progression-free survival was 1.5 years.

CONCLUSIONS

Rechallenge with IO after kidney irAE may be possible in some patients but requires careful evaluation on an individual basis.

Pembrolizumab-induced nephrotoxicity in a patient with breast cancer

The introduction of immunotherapy has revolutionized the treatment and improved outcomes of multiple types of cancer. Although breast cancer is a less immune-responsive tumor type, the incorporation of pembrolizumab into chemotherapy regimens in the neoadjuvant and first-line metastatic setting for the triple-negative disease has improved outcomes. However, the use of this type of treatment is associated with a spectrum of adverse events. Although rarely affected, kidneys can be a target for immunotherapy, leading to irreversible injury if not recognized and addressed early. A 52-year-old woman presented with clinical stage II right breast cancer diagnosed at an outside facility. Neoadjuvant docetaxel/carboplatin/pembrolizumab every 3 weeks was started. Given the partial response on MRI after the 4th cycle, treatment was switched to doxorubicin/cyclophosphamide. However, pembrolizumab was held in cycle 2 due to the rash and then resumed in cycle 3 after the resolution of symptoms. Elevated creatinine was noted 3 weeks after the last dose of pembrolizumab without improvement despite adequate fluid resuscitation. Diagnostic workup was unremarkable except for pyuria and minimal albuminuria on urinalysis. In the absence of other risk factors and the temporal relationship between pembrolizumab administration and the onset of acute kidney injury (AKI), immune-related nephrotoxicity was the underlying diagnosis. After initiation of corticosteroids, creatinine decreased back to baseline without the need for kidney biopsy. An addendum to the original pathology report from the outside facility surfaced 5 months after starting treatment, revealing that the second breast lesion had a Fluorescence in situ hybridization (FISH) test performed that was positive. Given this fact, therapy was changed to two cycles of neoadjuvant paclitaxel/carboplatin/trastuzumab/pertuzumab, with approximately 8 weeks between the last pembrolizumab dose and the first dose of trastuzumab. Thereafter, she underwent a right breast mastectomy which showed residual invasive carcinoma with negative margins and lymph nodes. She completed 1 year of trastuzumab. Immune-related AKI is a rare, but potentially serious complication associated with an increase in mortality. Further research is needed in the development and early detection. There is promising research in the development of noninvasive biomarkers which has the added benefit of identifying patients who can be re-challenged with immunotherapy.

Proton Pump Inhibitors and Kidney Disease: Fact or Fiction?

BACKGROUND

Proton pump inhibitors (PPIs) are commonly prescribed medications for dyspepsia and gastroesophageal reflux. There are concerns about their use in the development of chronic kidney disease (CKD).

SUMMARY

The available published literature fails to support an association with PPI and the development of CKD. Placebo-controlled trials demonstrate no difference in the incidence of CKD between placebo and PPI. If one examines the data according to the Bradford Hill perspective incorporating temporal relationship, the strength of association, dose-response relationship, replacement of findings, cessation of exposure, specificity of the association, and consistency with other knowledge, one can only conclude that there is no consistent relationship between PPI use and the development of CKD, or its progression.

KEY MESSAGES

There is insufficient evidence to link PPI exposure with the development or progression of CKD.

Drug-induced Interstitial Nephritis in a Patient with Ulcerative Colitis Treated with 5-Aminosalicylic Acid

This report describes the case of a 76-year-old man with ulcerative colitis who developed interstitial nephritis after starting 5-Aminosalicylic acid (5-ASA) therapy. The patient experienced an initial improvement in symptoms, but developed fatigue, anorexia, and severe renal dysfunction 2.5 months later. Renal biopsy confirmed drug-induced interstitial nephritis, and conservative treatment with fluid replacement and the discontinuation of 5-ASA improved the patient's condition. Clinicians should monitor patients receiving 5-ASA therapy for potential adverse effects, particularly renal injury, and promptly investigate symptoms of renal dysfunction. Early recognition and discontinuation of the offending agent may prevent further damage and improve patient outcomes.

Generation of a drug-induced renal injury list to facilitate the development of new approach methodologies for nephrotoxicity

Drug-induced renal injury (DIRI) causes >1.5 million adverse events annually in the USA alone. Although standard biomarkers exist for DIRI, they lack the sensitivity or specificity to detect nephrotoxicity before the significant loss of renal function. In this study, we describe the creation of DIRIL - a list of drugs associated with DIRI and nephrotoxicity - from two literature datasets with DIRI annotation, confirmed using FDA drug labeling. DIRIL comprises 317 orally administered drugs covering all 14 anatomical, therapeutic and chemical (ATC) classification categories. Of the 317 drugs, 171 were DIRI-positive and 146 were DIRI-negative. DIRIL will be a relevant and invaluable resource for discovery of new approach methods (NAMs) to predict the occurrence and possible severity of DIRI earlier in drug development.

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.

Tubulointerstitial Nephritis and Uveitis: A Case Report

Tubulointerstitial nephritis and uveitis (TINU) is a rare disease of unknown pathogenesis that is characterized by tubulointerstitial nephritis and uveitis. Currently, there are over 250 reported cases of TINU syndrome. TINU syndrome typically presents with mild uveitis and nephritis that is self-limited; however, in this case, the symptoms were severe making it different from previous case reports. We present a case of a 29-year-old female with a history of cytomegalovirus (CMV) with a recent diagnosis of bilateral uveitis who was admitted for worsening systemic symptoms. Laboratory testing revealed acute renal insufficiency along with hematuria and proteinuria. A kidney biopsy revealed tubulointerstitial nephritis, and the patient was initiated on corticosteroids for the diagnosis of TINU. The patient's renal function recovered to baseline after a prolonged three-month course of systemic steroids but had a recurrence of her uveitis with steroid taper requiring initiation of steroid-sparing therapies. TINU syndrome should be considered in patients presenting with uveitis and renal dysfunction. Prompt diagnosis is necessary to preserve renal function with corticosteroids. The prognosis for patients with TINU is variable, with a frequently recurring and relapsing course. More research is needed to determine the optimal treatment.

Acute interstitial nephritis caused by ANCA-associated vasculitis: a case based review

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) typically manifests as rapidly progressive glomerulonephritis with crescent formation. In this report, we present a local case of myeloperoxidase (MPO)-AAV-associated acute interstitial nephritis (AIN), showing slight pauci-immune glomerulonephritis and positive MPO-ANCA. This case is characterized by foot process effacement of podocytes in the glomerulus, a favorable prognosis, and an absence of crescentic formation. To further understand this condition, we conducted a comprehensive literature search on Google Scholar and PubMed, employing both free text words and MeSH terms related to "AAV and AIN." This search yielded 24 cases, which we analyzed for their clinical features, laboratory findings, renal pathological characteristics, and therapeutic outcomes. AAV-associated interstitial nephritis predominantly affects elderly patients and is often associated with anemia, proteinuria, hematuria, and nonspecific manifestations, including fever, anorexia, fatigue, edema, and weight loss. Most of the cases in our review were MPO-ANCA-positive and exhibited isolated interstitial inflammation. These patients typically presented with relatively lower levels of serum creatinine, 24-h urine protein levels, and MPO-ANCA titers. All patients in our study received immunosuppressive therapy, including glucocorticoids, immunosuppressants, and rituximab, with the majority achieving clinical remission. Isolated AIN in the context of AAV is a rare occurrence, but it displays distinct clinical, laboratory, and pathological features. Patients with this presentation show a positive response to immunosuppressive treatment. Nevertheless, the establishment of definitive therapy guidelines for AAV-associated AIN remains uncertain and necessitates further investigation to develop comprehensive treatment guidelines. AIN, particularly when lacking typical glomerulus lesions, may represent a novel subgroup within MPO-AAV warranting additional research and clinical attention. Key Points • This study contributes valuable scientific insights by highlighting that MPO-AAV-associated interstitial nephritis, even without crescentic formation, can exhibit podocyte foot process effacement and respond well to treatment. • The presence of AIN, independent of crescentic glomerulonephritis, suggests the potential emergence of a new subclass within MPA-AAV. • Notably, some cases of MPO-AAV-associated AIN may present with normal levels of Scr (Table 5, cases 5, 6, and 17). • This observation highlights the importance of considering renal biopsy, diagnosis, and therapy in a timely manner to prevent the development of chronic kidney disease (CKD).

Risk Factors for Teicoplanin-Associated Acute Kidney Injury in Patients with Hematological Malignancies: Focusing on Concomitant Use of Tazobactam/Piperacillin

Patients with hematological malignancies (HM) often receive tazobactam/piperacillin (TAZ/PIPC) and glycopeptide antibiotics for febrile neutropenia. The effect of concomitant use of TAZ/PIPC on risk of teicoplanin (TEIC)-associated acute kidney injury (AKI) remains unclear. We investigated the impact of concomitant TAZ/PIPC use on TEIC-associated AKI in HM patients and identified the risk factors. In this retrospective, single-center, observational cohort study, 203 patients received TEIC, 176 of whom satisfied the selection criteria and were divided into TEIC cohort (no TAZ/PIPC; n = 118) and TEIC + TAZ/PIPC cohort (n = 58). AKI was defined as serum creatinine increase ≥0.3 mg/dL within 48 h or ≥50% from baseline. Incidence of AKI in TEIC cohort before and after propensity score matching was 9.3 and 5.9%, respectively, and that in TEIC + TAZ/PIPC cohort was 10.3 and 11.8%. AKI incidence and risk were not significantly different between two cohorts before (p = 0.829; odds ratio (OR) 1.122, 95% confidence interval (CI) 0.393-3.202) and after matching (p = 0.244; OR 2.133, 95% CI 0.503-9.043). Logistic regression analysis with factors clinically or mechanistically potentially related to TEIC-associated AKI, including concomitant TAZ/PIPC use, as independent variables identified baseline hemoglobin level as the only significant risk factor for TEIC-associated AKI (p = 0.011; OR 0.484, 95% CI 0.276-0.848). In HM patients treated with TEIC, concomitant TAZ/PIPC use did not increase AKI risk whereas lower hemoglobin levels had higher risk for TEIC-associated AKI development, suggesting the necessity to monitor serum creatinine when using TEIC in patients with anemia.

New-Onset Acute Interstitial Nephritis Post-SARS-CoV-2 Infection and COVID-19 Vaccination: A Panoramic Review

The 2019 coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has posed a considerable challenge to global healthcare. Acute interstitial nephritis (AIN) post SARS-CoV-2 infection and vaccination has been reported, but its clinical features and pathogenesis remained unclear. We reviewed so far the largest 22 cases of AIN post SARS-CoV-2 infection and 36 cases of AIN following COVID-19 vaccination. The onset of AIN was mainly related to messenger RNA vaccines (52.8%). Apart from fever, proteinuria (45.5%) was the main manifestation of AIN post SARS-CoV-2 infection, left acute kidney injury (AKI, 63.9%) in patients post COVID-19 vaccination. The potential mechanism of vaccination induced AIN was conjugating vaccines with proteins to form a hapten, which activated dendritic cells and promoted a cascade immunological reaction leading to AIN.

Nephrotoxicity of Amoxicillin and Third-Generation Cephalosporins: An Updated Review

Because of their broad-spectrum bactericidal activity, amoxicillin (AMX) and third-generation cephalosporins (TGC) are widely used for the prophylaxis and treatment of established infections. They are considered relatively safe, but several recent reports have suggested substantial nephrotoxicity, especially with AMX use. Considering the importance of AMX and TGC for clinical practice, we conducted this up-to-date review, using the PubMed database, which focuses specifically on the nephrotoxicity of these molecules. We also briefly review the pharmacology of AMX and TGC. Nephrotoxicity of AMX may be driven by several pathophysiological mechanisms, such as a type IV hypersensitivity reaction, anaphylaxis, or intratubular and/or urinary tract drug precipitation. In this review, we focused on the two main renal adverse effects of AMX, namely acute interstitial nephritis and crystal nephropathy. We summarize the current knowledge in terms of incidence, pathogenesis, factors, clinical features, and diagnosis. The purpose of this review is also to underline the probable underestimation of AMX nephrotoxicity and to educate clinicians about the recent increased incidence and severe renal prognosis associated with crystal nephropathy. We also suggest some key elements on the management of these complications to avoid inappropriate use and to limit the risk of nephrotoxicity. While renal injury appears to be rarer with TGC, several patterns of nephrotoxicity have been reported in the literature, such as nephrolithiasis, immune-mediated hemolytic anemia, or acute interstitial nephropathy, which we detail in the second part of this review.

Renal Manifestations of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome: A Systematic Review of 71 Cases

Unlike other adverse drug reactions, visceral organ involvement is a prominent feature of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and correlates with mortality. The aim of this study was to systematically review cases published in PubMed-indexed, peer-reviewed journals in which patients had renal injury during the episode of DRESS syndrome (DS). We found 71 cases, of which 67 were adults and 56% were males. Female sex was associated with higher mortality. Chronic kidney disease (CKD) was present in 14% of patients who developed acute kidney injury (AKI) during DS. In 21% of cases, the kidneys were the only visceral organ involved, while 54% of patients had both liver and kidney involvement. Eosinophilia was absent in 24% of patients. The most common classes of medication associated with renal injury in DS were antibiotics in 34%, xanthine oxidase inhibitors in 15%, and anticonvulsants in 11%. Among antibiotics, vancomycin was the most common culprit in 68% of patients. AKI was the most common renal manifestation reported in 96% of cases, while isolated proteinuria or hematuria was present in only 4% of cases. In cases with AKI, 88% had isolated increase in creatinine and decrease in glomerular filtration (GFR), 27% had AKI concomitantly with proteinuria, 18% had oliguria, and 13% had concomitant AKI with hematuria. Anuria was the rarest manifestation, occurring in only 4% of patients with DS. Temporary renal replacement therapy was needed in 30% of cases, and all but one patient fully recovered renal function. Mortality of DS in this cohort was 13%, which is higher than previously reported. Medication class, latency period, or pre-existing CKD were not found to be associated with higher mortality. More research, particularly prospective studies, is needed to better recognize the risks associated with renal injury in patients with DS. The development of disease-specific biomarkers would also be useful so DS with renal involvement can be easier distinguished from other eosinophilic diseases that might affect the kidney.

Identification and validation of urinary CXCL9 as a biomarker for diagnosis of acute interstitial nephritis

BackgroundAcute tubulointerstitial nephritis (AIN) is one of the few causes of acute kidney injury with diagnosis-specific treatment options. However, due to the need to obtain a kidney biopsy for histological confirmation, AIN diagnosis can be delayed, missed, or incorrectly assumed. Here, we identify and validate urinary CXCL9, an IFN-γ-induced chemokine involved in lymphocyte chemotaxis, as a diagnostic biomarker for AIN.MethodsIn a prospectively enrolled cohort with pathologist-adjudicated histological diagnoses, termed the discovery cohort, we tested the association of 180 immune proteins measured by an aptamer-based assay with AIN and validated the top protein, CXCL9, using sandwich immunoassay. We externally validated these findings in 2 cohorts with biopsy-confirmed diagnoses, termed the validation cohorts, and examined mRNA expression differences in kidney tissue from patients with AIN and individuals in the control group.ResultsIn aptamer-based assay, urinary CXCL9 was 7.6-fold higher in patients with AIN than in individuals in the control group (P = 1.23 × 10-5). Urinary CXCL9 measured by sandwich immunoassay was associated with AIN in the discovery cohort (n = 204; 15% AIN) independently of currently available clinical tests for AIN (adjusted odds ratio for highest versus lowest quartile: 6.0 [1.8-20]). Similar findings were noted in external validation cohorts, where CXCL9 had an AUC of 0.94 (0.86-1.00) for AIN diagnosis. CXCL9 mRNA expression was 3.9-fold higher in kidney tissue from patients with AIN (n = 19) compared with individuals in the control group (n = 52; P = 5.8 × 10-6).ConclusionWe identified CXCL9 as a diagnostic biomarker for AIN using aptamer-based urine proteomics, confirmed this association using sandwich immunoassays in discovery and external validation cohorts, and observed higher expression of this protein in kidney biopsies from patients with AIN.FundingThis study was supported by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) awards K23DK117065 (DGM), K08DK113281 (KM), R01DK128087 (DGM), R01DK126815 (DGM and LGC), R01DK126477 (KNC), UH3DK114866 (CRP, DGM, and FPW), R01DK130839 (MES), and P30DK079310 (the Yale O'Brien Center). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Acute interstitial nephritis due to dolutegravir: The first case reported

Kidney disease is frequent in HIV-patients. We present a case of a 44-year-old woman, with known uncontrolled HIV infection and chronic kidney disease due to HIV-associated nephropathy. After starting dolutegravir, the patient developed eosinophilia and worsening kidney function. A kidney biopsy confirmed the diagnosis of acute interstitial nephritis. Given the time relation with dolutegravir introduction, it was deemed the culprit medication. Dolutegravir was stopped, and corticosteroids were initiated, with moderate improvement in renal function. To our knowledge, this is the first reported case of acute interstitial nephritis to dolutegravir, which should raise awareness of previously undocumented renal effects of antiretroviral therapy.

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.

Update on Therapeutic Drug Monitoring of Beta-Lactam Antibiotics in Critically Ill Patients—A Narrative Review

Beta-lactam antibiotics remain one of the most preferred groups of antibiotics in critical care due to their excellent safety profiles and their activity against a wide spectrum of pathogens. The cornerstone of appropriate therapy with beta-lactams is to achieve an adequate plasmatic concentration of a given antibiotic, which is derived primarily from the minimum inhibitory concentration (MIC) of the specific pathogen. In a critically ill patient, the plasmatic levels of drugs could be affected by many significant changes in the patient’s physiology, such as hypoalbuminemia, endothelial dysfunction with the leakage of intravascular fluid into interstitial space and acute kidney injury. Predicting antibiotic concentration from models based on non-critically ill populations may be misleading. Therapeutic drug monitoring (TDM) has been shown to be effective in achieving adequate concentrations of many drugs, including beta-lactam antibiotics. Reliable methods, such as high-performance liquid chromatography, provide the accurate testing of a wide range of beta-lactam antibiotics. Long turnaround times remain the main drawback limiting their widespread use, although progress has been made recently in the implementation of different novel methods of antibiotic testing. However, whether the TDM approach can effectively improve clinically relevant patient outcomes must be proved in future clinical trials.

Association Between Proton Pump Inhibitor Exposure and Acute Kidney Injury After Cardiac Surgery

OBJECTIVE

To evaluate the association of preoperative proton pump inhibitor (PPI) exposure with incident acute kidney injury (AKI) after cardiac surgery.

PATIENTS AND METHODS

The Severance cardiac surgery cohort included 9860 cardiac surgery patients aged 18 years or older. The National Health Insurance Service-senior cohort included 2933 patients aged 60 years or older who underwent cardiac surgery. Preoperative PPI exposure was defined as a PPI prescription within 3 weeks prior to cardiac surgery. Primary outcomes were postoperative AKI and AKI requiring dialysis (AKI-dialysis).

RESULTS

In the Severance cardiac surgery cohort after propensity score matching for PPI exposure, incident AKI (44.0% [472 of 1073] vs 40.5% [1304 of 3219]) and AKI-dialysis (5.8% [62 of 1073] vs 3.7% [119 of 3219]) were more common in patients exposed to PPI than in those who were not. Hospital and intensive care unit stay durations were longer among PPI-exposed than PPI-nonexposed patients. Multivariable conditional logistic analyses revealed that PPI exposure was significantly associated with incident AKI (adjusted odds ratio [AOR], 1.21; 95% CI, 1.03 to 1.42; P=.02) and AKI-dialysis (AOR, 1.74; 95% CI, 1.15 to 2.63; P=.009). The National Health Insurance Service-Senior cohort had similar results, revealing a significant association between PPI exposure and incident AKI-dialysis (AOR, 1.87; 95% CI, 1.25 to 2.81; P=.003). Discontinuation of PPI prior to operation was associated with a lower odds of AKI development in both cohorts.

CONCLUSION

Preoperative PPI exposure may be a modifiable risk factor for AKI among patients undergoing cardiac surgery.

A Synopsis of Current Theories on Drug-Induced Nephrotoxicity

The overriding goal of the treatment of patients is its effectiveness and safety. However, all medications currently being used also exert some adverse pharmaceutical reactions, which may be regarded as an unintended but inevitable cost of pharmacotherapy. The kidney, as the main organ that eliminates xenobiotics, is an organ especially predisposed and vulnerable to the toxic effects of drugs and their metabolites during their excretion from the body. Moreover, some drugs (e.g., aminoglycosides, cyclosporin A, cisplatin, amphotericin B, and others) have a "preferential" nephrotoxicity potential, and their use is associated with an increased risk of kidney damage. Drug nephrotoxicity is, therefore, both a significant problem and a complication of pharmacotherapy. It should be noted that, currently, there is no generally recognized definition of drug-induced nephrotoxicity and no clear criteria for its diagnosis. This review briefly describes the epidemiology and diagnosis of drug-induced nephrotoxicity and characterizes its pathomechanisms, including immunological and inflammatory disturbances, altered kidney blood flow, tubulointerstitial injury, increased lithogenesis-crystal nephropathy, rhabdomyolysis, and thrombotic microangiopathy. The study also lists the basic drugs with nephrotoxicity potential and provides a short overview of the preventive methods for reducing the risk of drug-related kidney damage developing.

Risk Factors for Nephrotoxicity in Methicillin-Resistant Staphylococcus aureus Bacteraemia: A Post Hoc Analysis of the CAMERA2 Trial

BACKGROUND

Clinical risk factors for nephrotoxicity in Staphylococcus aureus bacteraemia remain largely undetermined, despite its common occurrence and clinical significance. In an international, multicentre, prospective clinical trial (CAMERA2), which compared standard therapy (vancomycin monotherapy) to combination therapy (adding an anti-staphylococcal beta-lactam) for methicillin-resistant S. aureus bacteraemia, significantly more people in the combination therapy arm experienced acute kidney injury compared with those in the monotherapy arm (23% vs 6%).

OBJECTIVE

The aim of this post hoc analysis was to explore in greater depth the risk factors for acute kidney injury from the CAMERA2 trial.

METHODS

Among participants of the CAMERA2 trial, demographic-related, infection-related and treatment-related risk factors were assessed for their relationship with acute kidney injury by univariable and multivariable logistic regression. Acute kidney injury was defined by a modified-KDIGO (Kidney Disease: Improving Global Outcomes) criteria (not including urinary output).

RESULTS

Of the 266 participants included, age (p = 0.04), randomisation to combination therapy (p = 0.002), vancomycin area under the concentration-time curve (p = 0.03) and receipt of (flu)cloxacillin as the companion beta-lactam (p < 0.001) were significantly associated with acute kidney injury. On a multivariable analysis, concurrent use of (flu)cloxacillin increased the risk of acute kidney injury over four times compared with the use of cefazolin or no beta-lactam. The association of vancomycin area under the concentration-time curve with acute kidney injury also persisted in the multivariable model.

CONCLUSIONS

For participants receiving vancomycin for S. aureus bacteraemia, use of (flu)cloxacillin and increased vancomycin area under the concentration-time curve were risk factors for acute kidney injury. These represent potentially modifiable risk factors for nephrotoxicity and highlight the importance of avoiding the use of concurrent nephrotoxins.

Lifestyle-Related Risk Factors for the Incidence and Progression of Chronic Kidney Disease in the Healthy Young and Middle-Aged Population

The prevalence of chronic kidney disease (CKD) increased by 88% from 1990 to 2016. Age of onset of lifestyle-related diseases (such as hypertension, diabetes mellitus, obesity, dyslipidemia, and hyperuricemia), which are risk factors for incident CKD, is lower now compared with the past. Thus, we aimed to evaluate the risk factors for the incidence and progression of CKD in the young and middle-aged population. There are differences in the risk for CKD among the young, middle-aged, and elderly populations. We aimed to assess obesity (which is basic component of metabolic syndrome), waist circumference, and abdominal adiposity, which are predictive factors of CKD in the younger population. Furthermore, we described the management and clinical evidence of hypertension, diabetes mellitus, dyslipidemia, and hyperuricemia for young and middle-aged patients, along with diet management and nutrients associated with kidney function. Kidney function in the young and middle-aged population is mostly normal, and they are considered a low-risk group for incident CKD. Thus, we expect this review to be useful in reducing the prevalence of CKD.

Bland Urine Sediment in a Child with Acute Kidney Injury

Tubulointerstitial nephritis (TIN) or acute interstitial nephritis (AIN) is a renal lesion characterized by inflammatory infiltrate limited to the renal interstitium and tubules. Three-fourths of the cases are drug induced, other causes being systemic and autoimmune diseases, and infections. Various drugs have been implicated, the most common being antibiotics such as β-lactams. Cephalosporins causing AIN have been reported uncommonly, particularly in children. Although renal biopsy confirms the diagnosis, urinalysis provides pertinent diagnostic clues against the backdrop of the clinico-laboratory profile. The presence of white blood cells, white cell casts, and red blood cells in urine sediment have been described in literature. However, a relatively normal urinalysis may be present in some cases and may pose a diagnostic challenge. We present a case of ceftriaxone-induced AIN in a child with bland urine sediment at initial presentation. To the best of our knowledge, this is the first report of ceftriaxone-induced AIN in the pediatric age group.

The role of kidney biopsy in immune checkpoint inhibitor nephrotoxicity

Immune checkpoint inhibitors, medications that boost host immune response to tumor cells, are now at the forefront of anti-cancer therapy. While efficacious in the treatment of patients with advanced cancer, immune checkpoint inhibitors can lead to serious autoimmune side effects involving any organ in the body. Immune checkpoint inhibitor nephrotoxicity is an increasingly recognized cause of acute kidney injury in patients with cancer. This review discusses the clinical and histopathologic diagnosis of immune checkpoint inhibitor nephrotoxicity, highlighting the need for more reliable non-invasive diagnostic testing. We focus on the controversy surrounding the role of kidney biopsy in diagnosis and management of suspected immune checkpoint inhibitor toxicity with inclination toward pursuing kidney biopsy in certain outlined circumstances. Finally, we briefly discuss treatment of immune checkpoint inhibitor nephrotoxicity and the decision to re-challenge immunotherapy in patients who experience these adverse events.

Characteristics of risk factors for acute kidney injury among inpatients administered sulfamethoxazole/trimethoprim: a retrospective observational study

Background

Sulfamethoxazole/trimethoprim (SMX/TMP) potentially increases the serum creatinine levels, resulting in acute kidney injury (AKI). However, the clinical characteristics of the AKI associated with SMX/TMP and the risk factors for its development have not been fully characterized.

Methods

A retrospective cohort observational analysis was conducted on adult inpatients who started SMX/TMP treatment at the Tokyo Women’s Medical University, Yachiyo Medical Center, from April 2018 to March 2020. The primary outcome was AKI, defined as an increase in serum creatinine level of ≥ 50% from baseline. Multivariate logistic regression analysis was used to determine the risk factors for the AKI associated with SMX/TMP.

Results

Of the 281 patients, 32 (11.4%) developed AKI. The multivariate logistic regression analysis identified that body mass index (BMI) (odds ratio [OR] = 0.86, 95% confidence interval [95% CI] 0.76–0.97, p < 0.01), presence of hypertension (OR = 2.69, 95% CI 1.11–6.49, p = 0.02), SMX/TMP daily dose (OR = 1.16, 95% CI 1.03–1.30, p = 0.02), and concomitant loop diuretic use (OR = 2.91, 95% CI 1.08–7.78, p = 0.04) were the associated risk factors for AKI in patients who were administered SMX/TMP.

Conclusions

This study showed that low BMI, hypertension, high-dose SMX/TMP, and concomitant loop diuretic use increased the risk of AKI in patients administered SMX/TMP. Clinicians should consider monitoring the renal function in patients at a high risk of AKI.

Interstitial nephritis without glomerulonephritis in ANCA-associated vasculitis: a case series and literature review

The typical nephrological presentation of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is rapidly progressive glomerulonephritis. AAV-associated interstitial nephritis without apparent glomerular lesions was rare. We reported three local cases of AAV-associated interstitial nephritis without glomerulonephritis confirmed by renal biopsy. Then, a literature search was conducted in PubMed using free text words and MeSH terms related to "AAV and interstitial nephritis". Fifteen cases were included, and their demographics, clinical manifestations, laboratory data, renal pathological features, and treatment response were summarized. AAV-associated interstitial nephritis usually affects elderly patients. The common symptoms include fever, arthralgias, and edema. These patients were mostly MPO-ANCA positive. Pathological lesions in the kidney showed diffuse infiltration of inflammatory cells, edema, tubulitis, and fibrosis in the interstitial area. Various immunosuppressive treatments, including glucocorticoids, immunosuppressants, and rituximab, were used, and most of the patients achieved clinical remission. AAV-associated interstitial nephritis is rare but shows a characteristic clinical phenotype, serological results, and pathogenic lesions. Immunosuppressive therapy showed good efficacy in these patients.

Incidence, Pathogenesis, and Management of Proton Pump Inhibitor-Induced Nephrotoxicity

Proton pump inhibitors are widely used in the treatment of various acid-related diseases and are among the most commonly used drugs. Studies estimate that 25-70% of proton pump inhibitors are prescribed for inappropriate treatments, doses, and indications, where the benefits of proton pump inhibitor use may be less than the risk of adverse drug reactions for many patients. Acute interstitial nephritis is an immune-mediated atypical kidney injury in the long-term use of proton pump inhibitors that causes problems for clinicians and patients. In this review, we summarize the current knowledge of proton pump inhibitors inducing acute interstitial nephritis, chronic kidney disease, and even end-stage renal disease in terms of incidence, pathogenesis, factors, clinical features, and diagnosis. We discuss how these factors change under conditions of acute interstitial nephritis, chronic kidney disease, and end-stage renal disease. The purpose of this review is to assess the current evidence to help clinicians and patients interpret the potential causal relationship between proton pump inhibitor intake and nephrotoxicity. This prompts clinicians to consider the appropriate dose and duration of proton pump inhibitor therapy to avoid inappropriate use.

Several Alkaloids in Chinese Herbal Medicine Exert Protection in Acute Kidney Injury: Focus on Mechanism and Target Analysis

Objectives

Acute kidney injury (AKI) is a loose set of kidney diseases accompanied by a variety of syndromes, which is a serious threat to human life and health. Some alkaloids are derived from various Chinese herbs have been widely concerned in the improvement of AKI. This review provides the research progress of alkaloids in AKI experimental models and discusses the related molecular mechanisms. Key Findings. Alkaloids can protect AKI through various mechanisms including antioxidant stress, improvement of mitochondrial damage, reduction of cell death, induction of autophagy, and inhibition of inflammation. These mechanisms are mainly related to the activation of Nrf2/HO-1 signaling pathway, inhibition of ferroptosis and apoptosis, regulation of PINK1/Parkin pathway, inhibition of TLR4/NF-κB pathway and NLRP3 inflammatory bodies, upregulation of Klotho protein level and so on. In addition, there are a few alkaloids that have certain toxicity on the kidney.

Conclusion

Alkaloids have been shown to significantly improve AKI, but only in pharmacological studies. This paper summarizes the main experimental models currently used in AKI research and describes some representative alkaloids based on recent research. Their potential roles in the prevention and treatment of AKI through different mechanisms are highlighted.

Urine testing to differentiate glomerular from tubulointerstitial diseases on kidney biopsy

Background

Differentiating between glomerular and tubulointerstitial diseases can guide selection of appropriate patients for kidney biopsy. The aim of this study is to identify urine tests that can differentiate between these histological diagnoses.

Methods

In this sub-study of a prospectively enrolled cohort of participants with urine samples concurrent with their kidney biopsy, we tested the association of 24 features on urinalysis, urine sediment microscopy, and biomarkers of glomerular and tubular injury and inflammation with histological diagnosis of glomerular or tubulointerstitial disease. We selected a combination of features associated with glomerular disease using stepwise forward and backward regression, and LASSO algorithm after dividing the cohort into training (70%) and test (30%) sets.

Results

Of 359 participants, 121 had glomerular, 89 had tubulointerstitial diseases, and 149 were classified as mixed. Compared to patients with tubulointerstitial diseases, those with glomerular diseases had more dipstick hematuria (3+ vs. 1+, P < 0.001) and urine albumin (1.25 vs. 0.09 mg/mg, P < 0.001). Patients with glomerular diseases had higher levels of tubular health biomarkers (Uromodulin, 1.22 vs. 0.92, P = 0.03). In a multivariable model, higher urine albumin, dipstick blood, and urine uromodulin were independently associated with higher odds of glomerular diseases (test set AUC, 0.81 (0.69, 0.93)).

Conclusion

Urine tests, including urine albumin, dipstick blood, and urine uromodulin, were associated with the histological diagnosis of glomerular disease. These findings can help clinicians differentiate between glomerular and tubulointerstitial diseases and guide clinical decisions regarding a kidney biopsy.

Drug-Induced Acute Kidney Injury

Medications are a common cause of AKI especially for patients admitted to hospital wards and the intensive care unit. Although drug-related kidney injury occurs through different mechanisms, this review will focus on three specific types of tubulointerstitial injury. Direct acute tubular injury develops from several medications, which are toxic to various cellular functions. Their excretory pathways through the proximal tubules contribute further to AKI. Drug-induced AKI may also develop through induction of inflammation within the tubulointerstitium. Medications can elicit a T cell-mediated immune response that promotes the development of acute interstitial nephritis leading to AKI. Although less common, a third pathway to kidney injury results from the insolubility of drugs in the urine leading to their precipitation as crystals within distal tubular lumens, causing a crystalline-related AKI. Intratubular obstruction, direct tubular injury, and localized inflammation lead to AKI. Clinicians should be familiar with the pathogenesis and clinical-pathologic manifestations of these forms of kidney injury. Prevention and treatment of AKI relies on understanding the pathogenesis and judiciously using these agents in settings where AKI risk is high.

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.

Analysis of Risk Factors for Perioperative Acute Kidney Injury and Management Strategies

Acute kidney injury (AKI) is a serious clinical syndrome, and one of the common comorbidities in the perioperative period. AKI can lead to complications in surgical patients and is receiving increasing attention in clinical workup. In recent years, the analysis of perioperative risk factors has become more in-depth and detailed. In this review, the definition, diagnosis, and pathophysiological characteristics of perioperative AKI are reviewed, and the main risk factors for perioperative AKI are analyzed, including advanced age, gender, certain underlying diseases, impaired clinical status such as preoperative creatinine levels, and drugs that may impair renal function such as non-steroidal anti-inflammatory drugs (NASIDs), ACEI/ARB, and some antibiotics. Injectable contrast agents, some anesthetic drugs, specific surgical interventions, anemia, blood transfusions, hyperglycemia, and malnutrition are also highlighted. We also propose potential preventive and curative measures, including the inclusion of renal risk confirmation in the preoperative assessment, minimization of intraoperative renal toxin exposure, intraoperative management and hemodynamic optimization, remote ischemic preadaptation, glycemic control, and nutritional support. Among the management measures, we emphasize the need for careful perioperative clinical examination, timely detection and management of AKI complications, administration of dexmedetomidine for renal protection, and renal replacement therapy. We aim that this review can further increase clinicians' attention to perioperative AKI, early assessment and intervention to try to reduce the risk of AKI.

Serum anti-CRP antibodies differentiate etiology and predict relapse in acute tubulointerstitial nephritis

INTRODUCTION

Acute tubulointerstitial nephritis (ATIN) is a common cause of acute kidney injury with various etiologies. It has been shown that autoimmune-related ATIN (AI-ATIN) has a higher recurrence rate and a greater likelihood of developing into chronic kidney disease compared with drug-induced ATIN, yet misdiagnosis at renal biopsy is not uncommon.

METHODS

Patients who were clinicopathologically diagnosed as ATIN from January 2006 to December 2015 in Peking University First Hospital were enrolled. Clinical, pathological and follow-up data were collected. Serum samples on the day of renal biopsy were collected and tested for anti-C-reactive protein (CRP) antibodies. CRP and its linear peptides were used as coating antigens to detect antibodies. Statistical analysis was used to assess the diagnostic value of the antibodies.

RESULTS

Altogether 146 patients were enrolled. The receiver operating characteristic-area under the curve of the anti-CRP antibody for the identification of late-onset AI-ATIN was 0.750 (95% confidence interval 0.641-0.860, P < 0.001) and the positivity was associated with ATIN relapse (adjusted hazard ratio = 4.321, 95% confidence interval 2.402-7.775, P < 0.001). Antibodies detected by CRP linear peptide 6 (PT6) were superior with regard to differentiating patients with AI-ATIN, while antibodies detected by peptide 17 (PT17) could predict ATIN relapse. Antibodies detected by these two peptides were positively correlated with the severity of tubular dysfunction and pathological injury.

CONCLUSIONS

Serum anti-CRP antibody could be used to differentiate late-onset AI-ATIN and predict relapse of ATIN at the time of renal biopsy. The CRP linear peptides PT6 and PT17 could be used as coating antigens to detect anti-CRP antibodies, which may provide more information for the clinical assessment of ATIN.

Drug-Induced Nephrotoxicity Assessment in 3D Cellular Models

The kidneys are often involved in adverse effects and toxicity caused by exposure to foreign compounds, chemicals, and drugs. Early predictions of these influences are essential to facilitate new, safe drugs to enter the market. However, in current drug treatments, drug-induced nephrotoxicity accounts for 1/4 of reported serious adverse reactions, and 1/3 of them are attributable to antibiotics. Drug-induced nephrotoxicity is driven by multiple mechanisms, including altered glomerular hemodynamics, renal tubular cytotoxicity, inflammation, crystal nephropathy, and thrombotic microangiopathy. Although the functional proteins expressed by renal tubules that mediate drug sensitivity are well known, current in vitro 2D cell models do not faithfully replicate the morphology and intact renal tubule function, and therefore, they do not replicate in vivo nephrotoxicity. The kidney is delicate and complex, consisting of a filter unit and a tubular part, which together contain more than 20 different cell types. The tubular epithelium is highly polarized, and maintaining cellular polarity is essential for the optimal function and response to environmental signals. Cell polarity depends on the communication between cells, including paracrine and autocrine signals, as well as biomechanical and chemotaxis processes. These processes affect kidney cell proliferation, migration, and differentiation. For drug disposal research, the microenvironment is essential for predicting toxic reactions. This article reviews the mechanism of drug-induced kidney injury, the types of nephrotoxicity models (in vivo and in vitro models), and the research progress related to drug-induced nephrotoxicity in three-dimensional (3D) cellular culture models.

Management of corticosteroid-dependent eosinophilic interstitial nephritis: A case report

INTRODUCTION

Drug-induced acute interstitial nephritis (DI-AIN) is an important cause of acute kidney injury. In renal biopsy specimens, tubulitis with eosinophilic infiltration is suggestive of DI-AIN. Although corticosteroid therapy and discontinuation of the offending drug can improve renal dysfunction in most cases of DI-AIN, some patients experience AIN recurrence, leading to corticosteroid dependency. Corticosteroid-dependent eosinophilic interstitial nephritis presents a difficult dilemma in diagnosis and information regarding optimum management is limited.

PATIENT CONCERNS

A 25-year-old man, who received treatment with carbamazepine, zonisamide, valproate, and lacosamide for temporal lobe epilepsy, showed an increase in serum creatinine level from 0.98 to 1.29 mg/dL over a period of 6 months. Although he exhibited no symptoms, his serum creatinine level continued to increase to 1.74 mg/dL.

DIAGNOSIS

Renal biopsy revealed tubulitis and interstitial inflammatory infiltrates with eosinophils. Immunological and ophthalmological examinations showed no abnormal findings, and thus, his renal dysfunction was presumed to be caused by DI-AIN. Although oral prednisolone (PSL) administration (40 mg/d) and discontinuation of zonisamide immediately improved his renal function, AIN recurred 10 months later. The increase in PSL dose along with discontinuation of valproate and lacosamide improved renal function. However, 10 months later, recurrent AIN with eosinophilic infiltration was confirmed by further biopsy. The patient was therefore diagnosed with corticosteroid-dependent eosinophilic interstitial nephritis.

INTERVENTIONS

To prevent life-threatening epilepsy, carbamazepine could not be discontinued; hence, he was treated with an increased dose of PSL (60 mg/d) and 1500 mg/d of mycophenolate mofetil (MMF).

OUTCOMES

MMF was well tolerated and PSL was successfully tapered to 5 mg/d; renal function stabilized over a 20-month period.

LESSONS

The presence of underdetermined autoimmune processes and difficulties in discontinuing the putative offending drug discontinuation are contributing factors to corticosteroid dependency in patients with eosinophilic interstitial nephritis. MMF may be beneficial in the management of corticosteroid-dependent eosinophilic interstitial nephritis by reducing the adverse effects related to high-dose and long-term corticosteroid use.

Management of acute kidney injury in gastrointestinal tumor: An overview

Gastrointestinal tumors remain a global health problem. Acute kidney injury (AKI) is a common complication during the treatment of gastrointestinal tumors. AKI can cause a decrease in the remission rate and an increase in mortality. In this review, we analyzed the causes and risk factors for AKI in gastrointestinal tumor patients. The possible mechanisms of AKI were divided into three groups: pretreatment, intrafraction and post-treatment causes. Treatment and prevention measures were proposed according to various factors to provide guidance to clinicians and oncologists that can reduce the incidence of AKI and improve the quality of life and survival rate of gastrointestinal tumor patients.

Acute interstitial nephritis secondary to vedolizumab

We present a patient with an acute kidney injury thought secondary to acute interstitial nephritis as a result of vedolizumab maintenance therapy for Crohn's disease. This appears to be a rare but serious side effect in patients receiving this treatment which clinicians should consider in the event of renal dysfunction.

Strong Associations Between Early Tubular Damage and Urinary Cytokine, Chemokine, and Growth Factor Levels in Elderly Males and Females

Acute tubular necrosis is associated with high mortality rates and it is important to develop new biomarkers for tubular damage. The aim of this study was to investigate the effect of early tubular damage on a large number of urinary cytokines, chemokines, and growth factors. We selected 90 urine samples from the Prospective Investigation of the Vasculature in Uppsala Seniors Study (41 males and 49 females). The tubular damage markers cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) were analyzed in the urine samples and urinary cytokine levels were analyzed with 2 multiplex assays (proximity extension assay). After adjustment for sex, body mass index, estimated glomerular filtration rate, smoking, and multiplicity testing using the false discovery rate approach, there remained 26 cytokines that correlated significantly with urine cystatin C, 27 cytokines that correlated with NGAL, and 66 cytokines that correlated with KIM-1. Tubular damage shows a strong association with urinary cytokines, chemokines, and growth factors. Our findings indicate that multiplex proteomics could be a promising new approach to explore the complex effects of tubular damage.

Acute Interstitial Nephritis: A Rare and Unusual Side Effect of Omalizumab

Acute interstitial nephritis (AIN) is a relatively common cause of acute kidney injury with etiologies that include drug therapy, infections, and systemic diseases. Of these etiologies, drug therapy accounts for ~70% of AIN cases. Although any drug can cause AIN, there are no reported cases of AIN caused by omalizumab, a humanized monoclonal antibody that binds to and inhibits circulating immunoglobulin E. In this article, we share the first reported case of AIN following administration of omalizumab for the treatment of moderate to severe persistent asthma.

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.

Iatrogenic Toxicities in the Intensive Care Unit

Drug-induced iatrogenic toxicities are common in critically ill patients and have been associated with increased morbidity and mortality. Early recognition and management of iatrogenic toxicities is essential; however, the diagnosis is usually complicated by the underlying critical illness, comorbidities, and administration of multiple medications. This article reviews several types of iatrogenic toxicities associated with medications that are commonly used in critically ill patients. The mechanism of the iatrogenic toxicities, clinical presentation, and diagnosis, as well as management are discussed.

Immune checkpoint inhibitors-induced nephropathy: a French national survey

Immune checkpoint inhibitors (ICIs), aiming to foster cancer-targeted immune response, proved to be effective in several advanced malignancies at the price of immune-related adverse events affecting various organs, notably the kidneys. Herein, a retrospective descriptive analysis was performed on all biopsy-confirmed cases of ICI-induced nephropathy notified to the French Pharmacovigilance database to date. Data were gathered about patients' characteristics, acute kidney injuries and histopathological features. A total of 63 biopsy-proven cases were included for analysis. Immune-related nephropathy occurred after a mean of 105.5 ± 98.6 (standard deviation) days after the introduction of the ICI. Kidney Disease: Improving Global Outcomes acute kidney injury stage 3 occurred in 36.5% of patients, and the mean peak serum creatinine was 288 µmol/L. Histopathology suggested acute tubule-interstitial nephritis in 52 patients (83%), while signs of acute tubular necrosis were found in 18 (29%) and glomerular involvement in 5 of them (8%). Another immune-related adverse event was documented in 25 patients (39.7%). Patients were treated with corticosteroids in 88.9% of cases. All in all, 27.0% fully recovered, 54.0% partially recovered, 12.7% did not recover. Rechallenge was attempted in 19 patients and one patient relapsed. Three-quarters of patients received a medication known to cause acute tubule-interstitial nephritis. The major limits of this study are those inherent to pharmacovigilance studies, such as its retrospective nature and incomplete data. Although it cannot pretend drawing any pathophysiological conclusion, this study depicts the clinical and histopathological pictures of ICI-induced nephropathies in a large cohort of biopsied patients with all grades of severity.

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.

Cocaine-Induced Acute Interstitial Nephritis: A Comparative Review of 7 Cases

Acute interstitial nephritis is a well-known cause of acute kidney injury, but its association with cocaine use is extremely rare. In this article, we chronicle the case of a patient who developed acute interstitial nephritis secondary to cocaine insufflation. Furthermore, we conducted a systematic literature search of MEDLINE, Cochrane, Embase, and Scopus databases regarding cocaine-induced acute interstitial nephritis. A comprehensive review of the search results yielded a total of 7 case reports only. The data on patient characteristics, clinical features, biochemical profiles, treatment, and outcomes were collected and analyzed. This paper illustrates that acute interstitial nephritis may be added to the list of differentials in patients with acute kidney injury and a history of cocaine use. The therapeutic approach for cocaine-related kidney disease may be different than other etiologies responsible for acute renal insult. Prompt recognition of this entity is crucial because such patients may ultimately develop severe deterioration in renal function.

The Mechanism of Drug Nephrotoxicity and the Methods for Preventing Kidney Damage

Acute kidney injury (AKI) is a global health challenge of vast proportions, as approx. 13.3% of people worldwide are affected annually. The pathophysiology of AKI is very complex, but its main causes are sepsis, ischemia, and nephrotoxicity. Nephrotoxicity is mainly associated with the use of drugs. Drug-induced AKI accounts for 19-26% of all hospitalized cases. Drug-induced nephrotoxicity develops according to one of the three mechanisms: (1) proximal tubular injury and acute tubular necrosis (ATN) (a dose-dependent mechanism), where the cause is related to apical contact with drugs or their metabolites, the transport of drugs and their metabolites from the apical surface, and the secretion of drugs from the basolateral surface into the tubular lumen; (2) tubular obstruction by crystals or casts containing drugs and their metabolites (a dose-dependent mechanism); (3) interstitial nephritis induced by drugs and their metabolites (a dose-independent mechanism). In this article, the mechanisms of the individual types of injury will be described. Specific groups of drugs will be linked to specific injuries. Additionally, the risk factors for the development of AKI and the methods for preventing and/or treating the condition will be discussed.