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Marrington R, MacKenzie F. Understanding the limitations of your assay using EQA data with serum creatinine as an example. Clin Chem Lab Med 2024; 0:cclm-2024-0027. [PMID: 38565134 DOI: 10.1515/cclm-2024-0027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVES Laboratories need to take into consideration the specificity and imprecision of assays not only in verification, but also of quality assessment. This study investigates the composition of serum used in EQA materials by comparing material from a single and multiple donors (pooled material), across multiple methods, using creatinine as an example. METHODS Sixteen different serum matrices were distributed as 36 specimens through the UK NEQAS for Acute and Chronic Kidney Disease Scheme from March 2022 to March 2023. Male-only and female-only serum was used as single donations, pooled donations, unmanipulated or with added exogenous creatinine. Specimens were distributed to primarily UK participants (approximately n=500) for creatinine analysis. Data has been reviewed by method compared to the enzymatic creatinine method principle mean. RESULTS From the 16 different matrices, only the enzymatic creatinine assay systems from Roche Cobas and Siemens Atellica met the minimum acceptable bias goal, from biological data, of 5.6 %, in all specimens. Pooled material showed less variation in bias across all methods. CONCLUSIONS Since Laboratories invest a lot of time and money in quality management, they need to know the limitations of their assays so that they are not investigating 'apparent' EQA/IQC problems which are purely due to non-specific, imprecise assay, rather than an analytical issue in their laboratory. When large numbers of individual donations are combined, interferents are essentially diluted out. Therefore, if EQA material is of this type it will be very difficult to determine the actual assay's bias and variability.
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Affiliation(s)
- Rachel Marrington
- Birmingham Quality (UK NEQAS), 1732 University Hospitals Birmingham NHS Foundation Trust , Birmingham, UK
| | - Finlay MacKenzie
- Birmingham Quality (UK NEQAS), 1732 University Hospitals Birmingham NHS Foundation Trust , Birmingham, UK
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2
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Stevens PE, Ahmed SB, Carrero JJ, Foster B, Francis A, Hall RK, Herrington WG, Hill G, Inker LA, Kazancıoğlu R, Lamb E, Lin P, Madero M, McIntyre N, Morrow K, Roberts G, Sabanayagam D, Schaeffner E, Shlipak M, Shroff R, Tangri N, Thanachayanont T, Ulasi I, Wong G, Yang CW, Zhang L, Levin A. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024; 105:S117-S314. [PMID: 38490803 DOI: 10.1016/j.kint.2023.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 03/17/2024]
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3
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Chakraborty S, Bhattacharya I, Mitra RK. Solvation Plays a Key Role in Antioxidant-Mediated Attenuation of Elevated Creatinine Level: An In Vitro Spectroscopic Investigation. J Phys Chem B 2023; 127:8576-8585. [PMID: 37769128 DOI: 10.1021/acs.jpcb.3c05334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
An elevated level of creatinine (CRN) is a mark of kidney ailment, and prolonged retention of such condition could lead to renal failure, associated with severe ischemia. Antioxidants are clinically known to excrete CRN from the body through urine, thereby reducing its level in blood. The molecular mechanism of such an exclusion process is still illusive. As the excretion channel is urine, solvation of the solute is expected to play a pivotal role. Here, we report a detailed time-domain and frequency-domain terahertz (THz) spectroscopic investigation to understand the solvation of CRN in the presence of two model antioxidants, mostly used to treat elevated CRN level: N-Acetyl-l-cysteine (NAC) and ascorbic acid (ASC). FTIR spectroscopy in the mid-infrared region and UV absorption spectroscopy measurements coupled with quantum chemical calculations [at the B3LYP/6-311G++(d,p) level] reveal that both NAC and ASC form HBonded complexes with CRN and rapidly undergo a barrier-less proton transfer process to form creatinium ions. THz measurements provide explicit evidence of the formation of highly solvated complexes compared with bare CRN, which eventually enables its excretion through urine. These observations could provide a foundation for designing more beneficial drugs to resolve kidney diseases..
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Affiliation(s)
- Subhadip Chakraborty
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
| | - Indrani Bhattacharya
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
| | - Rajib Kumar Mitra
- Department of Chemical and Biological Sciences, S.N. Bose National Centre for Basic Sciences; Block-JD; Sector-III; Salt Lake, Kolkata 700106, India
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4
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Yang Y, Nan Y, Chen Q, Xiao Z, Zhang Y, Zhang H, Huang Q, Ai K. Antioxidative 0-dimensional nanodrugs overcome obstacles in AKI antioxidant therapy. J Mater Chem B 2023; 11:8081-8095. [PMID: 37540219 DOI: 10.1039/d3tb00970j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to enormous health risks and economic losses. In the absence of specific drugs to treat AKI, hemodialysis remains the primary clinical treatment for AKI patients. The revelation of the pathology opens new horizons for antioxidant therapy in the treatment of AKI. However, small molecule antioxidant drugs and common nanozymes have failed to challenge AKI due to their unsatisfactory drug properties and renal physiological barriers. 0-Dimensional (0D) antioxidant nanodrugs stand out at this time thanks to their small size and high performance. Recently, a number of research studies have been carried out around 0D nanodrugs for alleviating AKI, and their multi-antioxidant enzyme mimetic activities, smooth glomerular filtration barrier permeability and excellent biocompatibility have been investigated. Here, we comprehensively summarize recent advances in 0D nanodrugs for AKI antioxidant therapy. We classify these representative studies into three categories according to the characteristics of 0D nanomaterials, namely ultra-small metal nanodots, inorganic non-metallic quantum dots and polymer nanodots. We focus on the antioxidant mechanisms and their distribution in vivo in each inspiring work, and the purpose and ingenuity of each design are rigorously captured and described. Finally, we provide our reflections and prospects for 0D antioxidant nanodrugs in AKI treatment. This mini review provides unique insights and valuable clues in the design of 0D nanodrugs and other kidney absorbable drugs.
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Affiliation(s)
- Yuqi Yang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410008, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Yayun Nan
- Geriatric Medical Center, People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, 750002, China
| | - Qiaohui Chen
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
- Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
| | - Zuoxiu Xiao
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
- Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
| | - Yuntao Zhang
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
- Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
| | - Huanan Zhang
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
- Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
| | - Qiong Huang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410008, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Kelong Ai
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
- Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China
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5
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Daoud A, Dalhoff KP, Petersen TS. Paracetamol-induced acute kidney injury in the absence of acute liver injury: a retrospective cohort study. TOXICOLOGY COMMUNICATIONS 2022. [DOI: 10.1080/24734306.2022.2117941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Affiliation(s)
- Alaa Daoud
- Department of Clinical Medicine, Faculty of Health and Medical science, Copenhagen University, Copenhagen, Denmark
- Department of Clinical Pharmacology and The Danish Poison Information Centre, Bispebjerg and Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Public Health, Faculty of Health and Medical science, University of Copenhagen, Copenhagen, Denmark
| | - Kim Peder Dalhoff
- Department of Clinical Medicine, Faculty of Health and Medical science, Copenhagen University, Copenhagen, Denmark
- Department of Clinical Pharmacology and The Danish Poison Information Centre, Bispebjerg and Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark
| | - Tonny Studsgaard Petersen
- Department of Clinical Medicine, Faculty of Health and Medical science, Copenhagen University, Copenhagen, Denmark
- Department of Clinical Pharmacology and The Danish Poison Information Centre, Bispebjerg and Frederiksberg Hospital, Copenhagen University Hospital, Copenhagen, Denmark
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6
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Verma A, Figueroa Villalba C, Choucair I, El-Khoury JM. A case of spuriously low serum creatinine concentrations in a patient with acetaminophen poisoning. Clin Chim Acta 2022; 535:195-196. [PMID: 36075459 DOI: 10.1016/j.cca.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/21/2022]
Affiliation(s)
- Anuj Verma
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, United States; Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | | | - Ibrahim Choucair
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Joe M El-Khoury
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, United States.
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7
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Macdonald DB, Hurrell C, Costa AF, McInnes MDF, O'Malley ME, Barrett B, Brown PA, Clark EG, Hadjivassiliou A, Kirkpatrick IDC, Rempel JL, Jeon PM, Hiremath S. Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury. Can Assoc Radiol J 2022; 73:499-514. [PMID: 35608223 DOI: 10.1177/08465371221083970] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.
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Affiliation(s)
- D Blair Macdonald
- 6363Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Casey Hurrell
- Canadian Association of Radiologists, Ottawa, ON, Canada
| | - Andreu F Costa
- Department of Radiology, Queen Elizabeth II Health Sciences Centre, 3688Dalhousie University, Halifax, NS, Caanada
| | - Matthew D F McInnes
- 6363Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Martin E O'Malley
- Princess Margaret Hospital, Joint Department of Medical Imaging, 7938University of Toronto, Toronto, ON, Canada
| | | | - Pierre Antoine Brown
- Department of Medicine, University of Ottawa, 12365The Ottawa Hospital, Ottawa, ON, Canada
| | - Edward G Clark
- Division of Nephrology, Department of Medicine, 153006University of Ottawa, Ottawa, ON, Canada
| | | | | | - Jeremy L Rempel
- 3158Department of Radiology, University of Alberta Hospital, University of Alberta, Edmonton, AB, Canada
| | - Paul M Jeon
- 7512Memorial University, St John's, NL, Canada
| | - Swapnil Hiremath
- Department of Medicine, University of Ottawa, 12365The Ottawa Hospital, Ottawa, ON, Canada
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8
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Magner K, Ilin JV, Clark EG, Kong JWY, Davis A, Hiremath S. Meta-analytic Techniques to Assess the Association Between N-acetylcysteine and Acute Kidney Injury After Contrast Administration: A Systematic Review and Meta-analysis. JAMA Netw Open 2022; 5:e2220671. [PMID: 35788669 PMCID: PMC9257561 DOI: 10.1001/jamanetworkopen.2022.20671] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
IMPORTANCE The most suitable analytic method to systematically analyze numerous trials with contradictory results is unclear. Multiple trials assessing the use of N-acetylcysteine (NAC) for prevention of contrast-induced acute kidney injury (CI-AKI) have had contradictory results with recent trials confirming a lack of benefit. OBJECTIVE To systematically review the literature on NAC for the prevention of CI-AKI, and to explore the heterogeneity, publication bias, and small-study effect to determine the most suitable analytic method in a setting where the literature is contradictory. DATA SOURCES Medline, Embase, and Cochrane Central Register of Controlled Trials databases were used to find randomized clinical trials (RCTs) comparing NAC with any other prophylactic agent or placebo in adults. STUDY SELECTION The search included studies published in English from database inception to January 2020. Two independent reviewers screened the studies, extracted data, and performed the risk of bias assessment. DATA EXTRACTION AND SYNTHESIS A meta-analysis was conducted about the effect of NAC on CI-AKI, the need for dialysis, and mortality. Fixed and random effects analyses were also performed. Funnel plots and the trim and fill method were used for assessment of publication bias. Metaregression was performed to explore the heterogeneity and subgroup analysis to examine the association between NAC and CI-AKI when studies were categorized according to sample size and number of events. RESULTS A total of 101 trials were included in this meta-analysis. The median sample size was 112 (range, 20 to 4993). Twenty-nine trials had a sample size of 200 or more, and only 3 trials had a sample size of 500 or more. Forty-five trials reported the need for kidney replacement therapy, and 41 trials reported mortality as an outcome. NAC seemed to show a benefit, with a pooled OR of 0.72 (95% CI, 0.63-0.82) using random effects model and a pooled OR of 0.82 (95% CI 0.76-0.90) using a fixed effects model. However, there was significant heterogeneity (I2 = 37.6; P < .001) and significant publication bias, which was reduced only when restricting to large RCTs (N ≥ 500). The clinical outcomes (ie, the need for kidney replacement therapy and mortality) revealed little heterogeneity and no publication bias, and each provided a robust neutral summary result. CONCLUSIONS AND RELEVANCE In this meta-analysis, NAC was associated with a benefit in the prevention of CI-AKI. However, because of substantial publication bias and other biases, standard meta-analytic techniques resulted in significant heterogeneity and a spurious, or factitious, association, even when using a random effects model. When the analysis was restricted to RCTs with a large sample size to account for publication bias or restricted to trials with clinical outcomes, this issue was reduced and resulted in more robust and neutral effect sizes.
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Affiliation(s)
- Kate Magner
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Edward G. Clark
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Kidney Research Institute, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Jennifer W. Y. Kong
- Kidney Research Institute, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Alexandra Davis
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Swapnil Hiremath
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Kidney Research Institute, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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9
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Macdonald DB, Hurrell CD, Costa AF, McInnes MDF, O’Malley M, Barrett BJ, Brown PA, Clark EG, Hadjivassiliou A, Kirkpatrick IDC, Rempel J, Jeon P, Hiremath S. Canadian Association of Radiologists Guidance on Contrast-Associated Acute Kidney Injury. Can J Kidney Health Dis 2022; 9:20543581221097455. [PMID: 35646375 PMCID: PMC9134018 DOI: 10.1177/20543581221097455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 03/28/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose Iodinated contrast media is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after iodinated contrast administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow-up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. Information sources Published literature, including clinical trials, retrospective cohort series, review articles, and case reports, along with expert opinions from radiologists and nephrologists across Canada. Methods The leadership of the CAR formed a working group of radiologists and nephrologists with expertise in contrast administration and patient management related to contrast-associated AKI. We conducted a comprehensive review of the published literature to evaluate the evidence about contrast as a cause of AKI, and to inform evidence-based recommendations. Based on the available literature, the working group developed consensus recommendations. Key Findings The working group developed 21 recommendations, on screening, choice of iodinated contrast media, prophylaxis, medication considerations, and post contrast administration management. The key changes from the 2012 guidelines were (1) Simplification of screening to a simple questionnaire, and not delaying emergent examinations due to a need for creatinine measurements (2) Prophylaxis considerations only for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 (3) Not recommending the routine discontinuation of any drugs to decrease risk of AKI, except metformin when eGFR is less than 30 mL/min/1.73 m2 and (4) Not requiring routine follow up serum creatinine measurements post iodinated contrast administration. Limitations We did not conduct a formal systematic review or meta-analysis. We did not evaluate our specific suggestions in the clinical environment. Implications Given the importance of iodinated contrast media use in diagnosis and management, and the low risk of AKI after contrast use, these guidelines aim to streamline the processes around iodinated contrast use in most clinical settings. As newer evidence arises that may change or add to the recommendations provided, the working group will revise these guidelines.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Paul Jeon
- Memorial University of Newfoundland, Saint John’s, NL, Canada
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10
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Sandilands EA, Rees JM, Raja K, Dhaun N, Morrison EE, Hickson K, Wraight J, Gray T, Briody L, Cameron S, Thompson AP, Johnston NR, Uren N, Goddard J, Treweeke A, Rushworth G, Webb DJ, Bateman DN, Norrie J, Megson IL, Eddleston M. Acetylcysteine has No Mechanistic Effect in Patients at Risk of Contrast-Induced Nephropathy - A Failure of Academic Clinical Science. Clin Pharmacol Ther 2022; 111:1222-1238. [PMID: 35098531 PMCID: PMC9306485 DOI: 10.1002/cpt.2541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/10/2022] [Indexed: 11/25/2022]
Abstract
Contrast‐induced nephropathy (CIN) is a major complication of imaging in patients with chronic kidney disease (CKD). The publication of an academic randomized controlled trial (RCT; n = 83) reporting oral (N)‐acetylcysteine (NAC) to reduce CIN led to > 70 clinical trials, 23 systematic reviews, and 2 large RCTs showing no benefit. However, no mechanistic studies were conducted to determine how NAC might work; proposed mechanisms included renal artery vasodilatation and antioxidant boosting. We evaluated the proposed mechanisms of NAC action in participants with healthy and diseased kidneys. Four substudies were performed. Two randomized, double‐blind, placebo‐controlled, three‐period crossover studies (n = 8) assessed the effect of oral and intravenous (i.v.) NAC in healthy kidneys in the presence/absence of iso‐osmolar contrast (iodixanol). A third crossover study in patients with CKD stage III (CKD3) (n = 8) assessed the effect of oral and i.v. NAC without contrast. A three‐arm randomized, double‐blind, placebo‐controlled parallel‐group study, recruiting patients with CKD3 (n = 66) undergoing coronary angiography, assessed the effect of oral and i.v. NAC in the presence of contrast. We recorded systemic (blood pressure and heart rate) and renal (renal blood flow (RBF) and glomerular filtration rate (GFR)) hemodynamics, and antioxidant status, plus biomarkers of renal injury in patients with CKD3 undergoing angiography. Primary outcome for all studies was RBF over 8 hours after the start of i.v. NAC/placebo. NAC at doses used in previous trials of renal prophylaxis was essentially undetectable in plasma after oral administration. In healthy volunteers, i.v. NAC, but not oral NAC, increased blood pressure (mean area under the curve (AUC) mean arterial pressure (MAP): mean difference 29 h⋅mmHg, P = 0.019 vs. placebo), heart rate (28 h⋅bpm, P < 0.001), and RBF (714 h⋅mL/min, 8.0% increase, P = 0.006). Renal vasodilatation also occurred in the presence of contrast (RBF 917 h⋅mL/min, 12% increase, P = 0.005). In patients with CKD3 without contrast, only a rise in heart rate (34 h⋅bpm, P = 0.010) and RBF (288 h⋅mL/min, 6.0% increase, P = 0.001) occurred with i.v. NAC, with no significant effect on blood pressure (MAP rise 26 h⋅mmHg, P = 0.156). Oral NAC showed no effect. In patients with CKD3 receiving contrast, i.v. NAC increased blood pressure (MAP rise 52 h⋅mmHg, P = 0.008) but had no effect on RBF (151 h⋅mL/min, 3.0% increase, P = 0.470), GFR (29 h⋅mL/min/1.73m², P = 0.122), or markers of renal injury. Neither i.v. nor oral NAC affected plasma antioxidant status. We found oral NAC to be poorly absorbed and have no reno‐protective effects. Intravenous, not oral, NAC caused renal artery vasodilatation in healthy volunteers but offered no protection to patients with CKD3 at risk of CIN. These findings emphasize the importance of mechanistic clinical studies before progressing to RCTs for novel interventions. Thousands were recruited to academic clinical trials without the necessary mechanistic studies being performed to confirm the approach had any chance of working.
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Affiliation(s)
- Euan A Sandilands
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Jessica Mb Rees
- Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - Khuram Raja
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Neeraj Dhaun
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Department of Renal Medicine, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Emma E Morrison
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Kirsty Hickson
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Jonathan Wraight
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Tanya Gray
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Lesley Briody
- Wellcome Trust Clinical Research Facility, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Sharon Cameron
- Wellcome Trust Clinical Research Facility, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Adrian P Thompson
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Neil R Johnston
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Neal Uren
- Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Jane Goddard
- Department of Renal Medicine, Royal Infirmary of Edinburgh, Edinburgh, UK
| | - Andy Treweeke
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Gordon Rushworth
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - David J Webb
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - D Nicholas Bateman
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - John Norrie
- Edinburgh Clinical Trials Unit, University of Edinburgh, Edinburgh, UK
| | - Ian L Megson
- Free Radical Research Facility, University of the Highlands & Islands, Inverness, UK
| | - Michael Eddleston
- Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.,National Poisons Information Service (Edinburgh), Royal Infirmary of Edinburgh, Edinburgh, UK
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