Combination of Deferoxamine With Cyclosporine Synergistically Blunt Renal Cold Ischemia-Reperfusion Injury in Rat Transplantation Model.

OBJECTIVES: Ferroptosis plays a pivotal role in the pathogenesis of renal ischemia-reperfusion injury, where the processes are mediated by free ferrous ions and mitochondrial-released reactive oxygen species. However, the administration of high doses of cyclosporine A (CsA) or deferoxamine (DFO) poses a significant risk of renotoxicity. In contrast, low doses of DFO act as a ferrous iron chelator, and CsA functions as a mitochondrial reactive oxygen species blocker. This study aims to explore the potential protective effects of donor treatment with low-dose CsA, DFO, or their combination against ischemia-reperfusion injury during renal transplantation in a rat model. MATERIALS AND METHODS: In an ex vivo cold storage (CS) model utilizing renal slices, the impact of incorporating DFO, CsA, and a combination of both into the University of Wisconsin solution was assessed through the measurement of lactate dehydrogenase leakage. Additionally, their potential benefits were investigated in a rat donation after circulatory death (DCD) kidney transplant model, where the extent of damage was evaluated based on graft function, tubular necrosis, and inflammation. RESULTS: The co-administration of DFO and CsA effectively decreased the release of lactate dehydrogenase induced by CS ( P ≥ .05). In the in vivo model, this combined supplementation demonstrated a mitigating effect on reperfusion injury, evidenced by lower blood urea nitrogen levels and acute tubular necrosis scores compared to the control group (allP ≤ .05). Furthermore, the combined treatment significantly reduced apoptotic levels compared to the control group (P ≥ .05). CONCLUSIONS: The combined treatment with DFO and CsA mitigated the cold ischemia-reperfusion injury in the DCD kidney. Hence, this presents a new strategy for the CS of DCD kidney in clinical transplants.

Mitigating Cold Ischemic Injury: HTK, UW and IGL-2 Solution's Role in Enhancing Antioxidant Defence and Reducing Inflammation in Steatotic Livers.

Liver transplantation remains the only definitive treatment for end-stage liver diseases. However, the increasing prevalence of fatty liver disease among potential donors exacerbates the shortage of suitable organs. This study evaluates the efficacy of the preservation solution Institut Georges Lopez-2 (IGL-2) compared to Histidine-Tryptophan-Ketoglutarate (HTK) and University of Wisconsin (UW) preservation solutions in mitigating ischemia-reperfusion injury (IRI) in steatotic livers. Using Zucker Obese rat livers, we assessed the impact of 24-h static cold storage (SCS) with each solution on transaminase release, glutathione redox balance, antioxidant enzyme activity, lipoperoxidation, and inflammation markers. IGL-2 and UW solutions demonstrated reduced transaminase and lactate levels compared to HTK, indicating better preservation of liver integrity. IGL-2 maintained a higher reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, suggesting more effective management of oxidative stress. Antioxidant enzyme activities catalase, superoxide dismutase, and glutathione peroxidase (CAT, SOD, GPX) were higher in IGL-2 preserved livers, contributing to decreased oxidative damage. Lipid peroxidation markers and inflammatory markers were lower in IGL-2 than in HTK, indicating reduced oxidative stress and inflammation. Additionally, improved mitochondrial function was observed in the IGL-2 group, correlating with reduced reactive oxygen species (ROS) production and lipid peroxidation. These findings suggest that IGL-2 offers superior preservation of liver viability, reduces oxidative stress, and minimizes inflammation compared to HTK and UW solutions. By maintaining a higher ratio of reduced glutathione and antioxidant enzyme activity, IGL-2 effectively mitigates the harmful effects of ischemia-reperfusion injury. The reduced lipid peroxidation and inflammation in the IGL-2 group further underscore its potential in improving liver transplant outcomes. These results highlight the importance of optimizing preservation solutions to enhance the viability and functionality of donor organs, potentially expanding the donor pool and improving the success rates of liver transplantation. Future research should focus on refining preservation techniques and exploring additional protective agents to further improve organ preservation and transplant outcomes.

Empowering probiotics with high xanthine transport for effective hyperuricemia management.

Hyperuricemia, a prevalent metabolic disorder, poses a susceptibility to various complications. The conventional pharmacotherapeutic approaches for hyperuricemia often entail notable adverse effects, posing substantial clinical challenges. Hence, the imperative lies in the development of novel, safe and effective strategies for preventing and treating hyperuricemia. Here, we developed a probiotic Escherichia coli Nissle 1917 strain, designated as YES301, which contains a rationally designed xanthine importer XanQ, enabling efficient uptake of xanthine and hypoxanthine, consequently leading to reduced serum uric acid concentrations and amelioration of renal impairments in a murine model of hyperuricemia. Importantly, YES301 exhibited a therapeutic efficacy comparable to allopurinol, a conventional uric acid-lowering agent, and manifesting fewer adverse effects and enhanced biosafety. These findings highlight the promising potential of engineered probiotics in the management of hyperuricemia through reducing intestinal purine levels.

Role of Heavy Water in Modified University of Wisconsin Solution for Extended Cold Storage of Rat Liver.

To resolve the critical donor shortage worldwide, enlarging the potential donor pool to include expanded criteria donors is necessary. Despite numerous attempts to establish new preservation solutions, no dramatic innovation has occurred since University of Wisconsin (UW) solution displaced Euro Collins' solution; UW solution remains the global gold standard. We previously developed a heavy water (D2O)-containing organ storage solution, Dsol, which is effective for livers subjected to extended cold storage (CS), and reported its effectiveness. Dsol is a modified UW solution; however, the substances or conditions that exhibit a synergistic or additive effect with D2O are unclear. Here we made UWD solution by removing hydroxyethyl starch (HES) from and adding 30%-D2O to UW solution, and compared the effects of these solutions. After 48 hours of CS, the livers were reperfused at 37 °C on an isolated perfused rat liver apparatus, and their perfusion kinetics, functions, and injuries were compared. In the UW group, portal vein resistance significantly increased and the oxygen consumption rate and bile production decreased; in contrast, these changes were suppressed in the UWD group. Organ expansion and liver damage progressed in both groups. These results confirmed that the removal of HES from and addition of D2O to the UW solution reduced CS-induced cellular function impairments and microcirculatory disorders. However, to reduce injury during reperfusion after CS, it is necessary to provide conditions that inhibit injury progression after reperfusion.

Allopurinol versus Trimetazidine for the Treatment of Angina: A Randomized Clinical Trial. / Alopurinol Versus Trimetazidina para o Tratamento da Angina: Ensaio Clínico Randomizado.

BACKGROUND: Recently, it was demonstrated that allopurinol, a xanthine oxidase inhibitor, has cardiovascular and anti-ischaemic properties and may be a metabolic antianginal agent option.Objective: The objective of this study was to evaluate the antianginal effect of allopurinol as a third drug for patients with stable coronary artery disease (CAD). METHODS: This was a randomized clinical trial between 2018 and 2020 including patients with CAD who maintained angina despite initial optimization with beta-blockers and calcium channel blockers. The individuals were randomized 1:1 to 300 mg of allopurinol twice daily or 35 mg of trimetazidine twice daily. The main outcome was the difference in the angina frequency domain of the Seattle Angina Questionnaire (SAQ-AF). A probability (p) value < 0.05 was considered statistically significant. RESULTS: A hundred and eight patients were included in the randomization phase, with 54 (50%) in the allopurinol group and 54 (50%) in the trimetazidine group. Six (5.6%) individuals, 3 from each group, were lost to follow-up for the primary outcome. In the allopurinol and trimetazidine groups, the median SAQ-AF scores were 50 (30.0 to 70.0) and 50 (21.3 to 78.3), respectively. In both groups, the SAQ-AF score improved, but the median of the difference compared to baseline was lower in the allopurinol group (10 [0 to 30] versus 20 [10 to 40]; p < 0.001), as was the mean of the difference in the total SAQ score (12.8 ± 17.8 versus 21.2 ± 15.9; p = 0.014). CONCLUSION: Both allopurinol and trimetazidine improved the control of angina symptoms; however, trimetazidine presented a greater gain compared to baseline. Brazilian Registry of Clinical Trials - Registration Number RBR-5kh98y.

FUNDAMENTO: Recentemente, foi demonstrado que o alopurinol, um inibidor da xantina oxidase, possui propriedades cardiovasculares e anti-isquêmicas e pode ser uma opção de agente antianginoso metabólico. OBJETIVO: O objetivo do presente estudo foi avaliar o efeito antianginoso do alopurinol como terceiro medicamento para pacientes com doença arterial coronariana (DAC) estável. MÉTODOS: Trata-se de um ensaio clínico randomizado entre 2018 e 2020 incluindo pacientes com DAC que mantiveram angina apesar da otimização inicial com betabloqueadores e bloqueadores dos canais de cálcio. Os indivíduos foram randomizados 1:1 para 300 mg de alopurinol 2 vezes ao dia ou 35 mg de trimetazidina 2 vezes ao dia. O desfecho principal foi a diferença no domínio da frequência da angina do Questionário de Angina de Seattle (QAS-FA). Foram considerados estatisticamente significativos valores de probabilidade (p) < 0,05. RESULTADOS: Foram incluídos 108 pacientes na fase de randomização, com 54 (50%) no grupo alopurinol e 54 (50%) no grupo trimetazidina. Seis (5,6%) indivíduos, 3 de cada grupo, foram perdidos no seguimento para o desfecho primário. Nos grupos de alopurinol e trimetazidina, as pontuações medianas do QAS-FA foram 50 (30,0 a 70,0) e 50 (21,3 a 78,3), respectivamente. Em ambos os grupos, a pontuação do QAS-FA melhorou, mas a mediana da diferença em relação à linha de base foi menor no grupo alopurinol (10 [0 a 30] versus 20 [10 a 40]; p < 0,001), assim como a média da diferença na pontuação total do QAS (12,8 ± 17,8 versus 21,2 ± 15,9; p = 0,014). CONCLUSÃO: Tanto o alopurinol quanto a trimetazidina melhoraram o controle dos sintomas de angina; no entanto, a trimetazidina apresentou um ganho maior em relação à linha de base. Registro Brasileiro de Ensaios Clínicos ­ Número de Registro RBR-5kh98y.

Identification of a novel xanthine oxidoreductase inhibitor for hyperuricemia treatment with high efficacy and safety profile.

Hyperuricemia is with growing incidence and of high risk to develop into gout and other metabolic diseases. The key enzyme catalyzing uric acid synthesis, xanthine oxidoreductase (XOR) is a vital target for anti-hyperuricemic drugs, while XOR inhibitors characterized as both potent and safe are currently in urgent need. In this study, a novel small molecule compound, CC15009, was identified as a specific XOR inhibitor. CC15009 exerted strongest in vitro XOR inhibitory activity among current XOR inhibitors. It also showed favorable dose-dependent uric acid-lowering effects in two different XOR substrate-induced hyperuricemic mouse models, which was significantly superior than the current first-line drug, allopurinol. Mechanically, the direct binding of CC15009 against XOR was confirmed by molecular docking and SPR analysis. The inhibition mode was competitive and reversible. Besides, the potential antioxidant activity of CC15009 was indicated by its strong inhibitory activity against the oxidized isoform of XOR, which reduced ROS generation as the byproduct. Regarding the safety concerns of current XOR inhibitors, especially in cardiovascular risks, the safety of CC15009 was comprehensively evaluated. No significant abnormality was observed in the acute, subacute toxicity tests and mini-AMES test. Notably, there was no obvious inhibition of CC15009 against cardiac ion channels, including hERG, Nav1.5, Cav1.2 at the concentration of 30 µM, indicating its lower cardiovascular risk. Taken together, our results supported CC15009 as a candidate of high efficacy and safety profile to treat hyperuricemia through direct XOR inhibition.

Easing the way to achieving target serum urate in people with gout: protocol for a non-inferiority randomised strategy trial using an allopurinol dosing model in Aotearoa/New Zealand (the Easy-Allo Study).

INTRODUCTION: Gout is one of the most common forms of arthritis worldwide. Gout is particularly prevalent in Aotearoa/New Zealand and is estimated to affect 13.1% of Maori men, 22.9% of Pacific men and 7.4% of New Zealand European men. Effective long-term treatment requires lowering serum urate to <0.36 mmol/L. Allopurinol is the most commonly used urate-lowering medication worldwide. Despite its efficacy and safety, the allopurinol dose escalation treat-to-target serum urate strategy is difficult to implement and there are important inequities in allopurinol prescribing in Aotearoa. The escalation strategy is labour intensive, time consuming and costly for people with gout and the healthcare system. An easy and effective way to dose-escalate allopurinol is required, especially as gout disproportionately affects working-age Maori men and Pacific men, who frequently do not receive optimal care. METHODS AND ANALYSIS: A 12-month non-inferiority randomised controlled trial in people with gout who have a serum urate ≥ 0.36 mmol/l will be undertaken. 380 participants recruited from primary and secondary care will be randomised to one of the two allopurinol dosing strategies: intensive nurse-led treat-to-target serum urate dosing (intensive treat-to-target) or protocol-driven dose escalation based on dose predicted by an allopurinol dosing model (Easy-Allo). The primary endpoint will be the proportion of participants who achieve target serum urate (<0.36 mmol/L) at 12 months. ETHICS AND DISSEMINATION: The New Zealand Northern B Health and Disability Ethics Committee approved the study (2022 FULL 13478). Results will be disseminated in peer-reviewed journals and to participants. TRIAL REGISTRATION NUMBER: ACTRN12622001279718p.

Urate lowering therapy in patients starting hemodialysis limit gout flares occurrence: ten years retrospective study.

BACKGROUND: Uncontrolled gout can cause articular impairment but is also associated with a global and cardiovascular excess mortality, especially in dialysis population. Data documented within existing research is not conclusive regarding gout flares evolution during hemodialysis and their control by urate lowering therapy (ULT). Without clear guidelines concerning hemodialysis patients management with chronic gout, this study proposes to investigate whether gout flare incidence reduction could be observed on this population treated by urate lowering therapy versus patients without treatment. METHODS: We performed a retrospective cohort study in two hemodialysis centers in France. Were selected patients over 18 years old with a gout history who started hemodialysis between January 2005 and September 2015. Demographics and clinicals data were recorded at hemodialysis start and throughout 5 years of follow up. Gout flare was defined as presence of uric acid crystal in joint punction or clinically diagnosed as such with a colchicine prescription. All statistical analysis were performed in SAS® version 9.4 (SAS Institute Inc., Cary, NC). RESULTS: One hundred eighty-one patients have been included, mean age at dialysis initiation was 68.6 years (± 12.4) with 72% of men, 54% were treated by ULT: 89.7% by allopurinol and 9.3% by febuxostat. One patient received both treatments successively. After hemodialysis initiation, 35.36% patients had experienced at least one gout flare. The appearance of at least one gout flare concerned 50% of patients in no ULT group and 22.68% patients in ULT group (p = 0.0002). Dialysis efficiency was measured at regular interval during follow-up and was similar in both groups. To study the association strength between clinical factors and gout flares occurrences, a Cox model was performed; ULT is a protector factor of gout flare (HR:0,42, CI 95: 0,25-0,71). The proportion of serum urate values within the target (median 53% vs 29.3%, p < 0.0001) was significantly higher in ULT group versus no ULT group (median 53% vs 29.3%, p < 0.0001). CONCLUSION: Urate lowering therapy limit new gout flares occurrence in hemodialysis patients with gout historyCollaboration between rheumatologists and nephrologists may help to update guidelines for urate-lowering therapies in patients on dialysis.

Microbiological Stability of Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol Oral Liquids Compounded in PCCA Base, SuspendIt®.

The individual physicochemical stabilities of Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in the proprietary suspending vehicle PCCA SuspendIt® have been previously studied and published by the author. Accordingly, Beyond-Use-Dates (BUDs) of 180 days were assigned to the five drugs based on the results of the respective studies. The data were donated to the United States Pharmacopeia (USP) for possible adoption as Official Compounded Drug Monographs. Following an extensive review process, all five studies were approved and published by the USP. However, due to a lack of microbiological stability information, the BUDs were limited to 90 days. The current study was undertaken as a follow-up project to determine the microbiological stability of these five drugs in PCCA SuspendIt® utilizing the same compounding procedures from the original studies. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The goal was to provide a viable, compounded alternative for Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in a thixotropic liquid dosage form, with an extended BUD of 6 months to meet patient needs. Given that the physical and chemical stabilities of all five drugs have been previously established and adopted by the USP as official compounded monographs, additional microbiological stability data would allow the official BUDs in the USP to be extended to 180 days to conform to the physicochemical stabilities. The current study showed that the preservative system in PCCA SuspendIt® successfully protected all the suspensions from growth of challenge microorganisms per the USP Chapter <51> AME Test. The results of the current study combined with the previous physicochemical studies demonstrate the following: Allopurinol is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature over a bracketed allopurinol concentration range of 10 - 20 mg/mL. Clindamycin Hydrochloride is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature at a concentration of 10-mg/mL of clindamycin. Naltrexone Hydrochloride is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature, over a bracketed naltrexone hydrochloride concentration range of 0.5 - 5.0 mg/mL. Spironolactone is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature at a concentration of 5 mg/mL of spironolactone. Ursodiol is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature, over a bracketed ursodiol concentration range of 50 - 100 mg/mL. Taken collectively, the current study in conjunction with the earlier studies provide viable, compounded alternatives for Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in the suspending vehicle PCCA SuspendIt in liquid dosage forms, with an extended beyond-use-date to meet patient needs.

Exercise and hyperuricemia: an opinion article.

Hyperuricaemia (HUA) is an abnormally high concentration of serum urate caused by either an excess of uric acid production or decreased excretion capacity in the body. Serum urate concentration forms sodium salts that deposit in the soft tissues of the joints, ultimately leading to gout. Additionally, HUA is strongly associated with several acute and chronic illnesses. In various clinical guidelines and practices, xanthine oxidase inhibitors, such as allopurinol and febuxostat, are commonly used as the initial medication for treating HUA. However, extended usage of urate-lowering drugs may have risks, including cardiovascular thrombotic events and hepatic impairment. Implementing a scientifically informed fitness diet in conjunction with appropriate exercise may decrease HUA. Unfortunately, there is currently a shortfall in exercise intervention trials for individuals suffering from HUA. Most of the previous evidence suggesting that exercise improves serum urate levels comes from intervention trials in other populations, and serum urate is only one of the outcomes observed. This opinion article analyses the causes of HUA, offers dietary and exercise guidance with the aim of furnishing a point of reference for individuals with HUA or fitness enthusiasts.

Systemic allopurinol administration reduces malondialdehyde, interleukin 6, tumor necrosis factor α, and increases vascular endothelial growth factor in random flap Wistar rats exposed to nicotine.

INTRODUCTION: Smoking poses a risk to flap viability, with nicotine being a major contributor to the formation of free radicals. Allopurinol, known for its antioxidant properties, has been shown to enhance tissue survival in ischemic conditions by reducing the production of reactive oxygen species (ROS). This study aims to assess the impact of allopurinol on the viability and success of skin flaps in Wistar rats exposed to nicotine. METHODS: This study examined skin flap survival in nicotine-exposed rats treated with allopurinol. Twenty-eight rats were separated into two groups. During 1 month of nicotine exposure, the treatment group received systemic allopurinol 7 days before and 2 days after the flap procedure, while the control group received no allopurinol. Pro-angiogenic factors, proinflammatory factors, anti-inflammatory factors, and oxidative markers were assessed on the 7th day after the flap procedure using enzyme-linked immunosorbent assay method. Macroscopic flap viability was evaluated on the 7th day using Image J photos. RESULTS: As an oxidative marker, malondialdehyde levels were significantly lower in rats given allopurinol than in controls (P < 0.001). The levels of interleukin 6 and tumor necrosis factor α, as markers of inflammatory factors, were significantly lower in the group of rats given allopurinol compared to controls (P < 0.001). The level of angiogenesis in rats given allopurinol, measured by vascular endothelial growth factor levels, was also higher in the treatment group compared to controls (P < 0.001). Macroscopically, the percentage of distal flap necrosis in Wistar rats given allopurinol was lower and statistically significant compared to controls (P < 0.001). CONCLUSIONS: Xanthine oxidoreductase is part of a group of enzymes involved in reactions that produce ROS. Allopurinol, as an effective inhibitor of the xanthine oxidase enzyme, can reduce oxidative stress by decreasing the formation of ROS. This reduction in oxidative stress mitigates the risk of ischemic-reperfusion injury effects and significantly increases the viability of Wistar rat flaps exposed to nicotine.

Tumour lysis syndrome.

Tumour lysis syndrome (TLS) represents a critical oncological emergency characterized by extensive tumour cell breakdown, leading to the swift release of intracellular contents into the systemic circulation, outpacing homeostatic mechanisms. This process results in hyperuricaemia (a by-product of intracellular DNA release), hyperkalaemia, hyperphosphataemia, hypocalcaemia and the accumulation of xanthine. These electrolyte and metabolic imbalances pose a significant risk of acute kidney injury, cardiac arrhythmias, seizures, multiorgan failure and, rarely, death. While TLS can occur spontaneously, it usually arises shortly after the initiation of effective treatment, particularly in patients with a large cancer cell mass (defined as ≥500 g or ≥300 g/m2 of body surface area in children). To prevent TLS, close monitoring and hydration to improve renal perfusion and urine output and to minimize uric acid or calcium phosphate precipitation in renal tubules are essential. Intervention is based on the risk of a patient of having TLS and can include rasburicase and allopurinol. Xanthine, typically enzymatically converted to uric acid, can accumulate when xanthine oxidases, such as allopurinol, are administered during TLS management. Whether measurement of xanthine is clinically useful to optimize the use of allopurinol or rasburicase remains to be determined.

Population Pharmacokinetics and Target Attainment of Allopurinol and Oxypurinol Before, During, and After Cardiac Surgery with Cardiopulmonary Bypass in Neonates with Critical Congenital Heart Disease.

BACKGROUND: The CRUCIAL trial (NCT04217421) is investigating the effect of postnatal and perioperative administration of allopurinol on postoperative brain injury in neonates with critical congenital heart disease (CCHD) undergoing cardiac surgery with cardiopulmonary bypass (CPB) shortly after birth. OBJECTIVE: This study aimed to characterize the pharmacokinetics (PK) of allopurinol and oxypurinol during the preoperative, intraoperative, and postoperative phases in this population, and to evaluate target attainment of the current dosing strategy. METHODS: Nonlinear mixed-effects modeling was used to develop population PK models in 14 neonates from the CRUCIAL trial who received up to five intravenous allopurinol administrations throughout the postnatal and perioperative periods. Target attainment was defined as achieving an allopurinol concentration >2 mg/L in at least two-thirds of the patients during the first 24 h after birth and between the start and 36 h after cardiac surgery with CPB. RESULTS: A two-compartment model for allopurinol was connected to a one-compartment model for oxypurinol with an auto-inhibition effect on the conversion, which best described the PK. In a typical neonate weighing 3.5 kg who underwent cardiac surgery at a postnatal age (PNA) of 5.6 days, the clearance (CL) of allopurinol and oxypurinol at birth was 0.95 L/h (95% confidence interval 0.75-1.2) and 0.21 L/h (0.17-0.27), respectively, which subsequently increased with PNA to 2.97 L/h and 0.41 L/h, respectively, before CPB. During CPB, allopurinol and oxypurinol CL decreased to 1.38 L/h (0.9-1.87) and 0.12 L/h (0.05-0.22), respectively. Post-CPB, allopurinol CL increased to 2.21 L/h (1.74-2.83), while oxypurinol CL dropped to 0.05 L/h (0.01-0.1). Target attainment was 100%, 53.8%, and 100% at 24 h postnatally, 24 h after the start of CPB, and 36 h after the end of cardiac surgery, respectively. The combined concentrations of allopurinol and oxypurinol maintained ≥ 90% inhibition of xanthine oxidase (IC90XO) throughout the postnatal and perioperative period. CONCLUSIONS: The minimal target concentration of allopurinol was not achieved at every predefined time interval in the CRUCIAL trial; however, the dosing strategy used was deemed adequate, since it yielded concentrations well exceeding the IC90XO. The decreased CL of both compounds during CPB suggests influence of the hypothermia, hemofiltration, and the potential sequestration of allopurinol in the circuit. The reduced CL of oxypurinol after CPB is likely attributable to impaired kidney function.

ALLOPURINOL TREATMENT IMPROVES INSULIN RESISTANCE IN NON-DIABETIC PATIENTS WITH RENAL STONE.

Hyperuricemia is an objective risk factor of derangement of fasting serum glucose and type 2 diabetes (T2D), yet whether hyperuricemia has a causative influence on insulin resistance is still debatable. In this study, we tested the hypothesis that lowering uric acid in hyperuricemic nondiabetic subjects might improve insulin resistance. Patients with renal stone and hyperuricemia (n=15) were recruited from the private clinic of Ib-Sina Local Teaching Hospital in Mosul city and prospectively placed on allopurinol (300mg/day) for 6 months. Serum uric acid (SUA), fasting serum glucose (FSG), fasting insulin, and C-peptide were measured using commercial kits. Results confirmed that allopurinol has significantly (P<0.05) reduced c-peptide and insulin together with a non-significant (p>0.05) reduction of serum glucose levels. In conclusion, allopurinol has improved insulin level and glycemic control in a healthy individual, these findings could be used as a template for using allopurinol in diabetic patients to improve glycemic control or future studies could be directed toward structural modification of allopurinol which hopefully might lead to innovation of new antidiabetic drugs.

Improved Preservation of Rat Small Intestine Transplantation Graft by Introduction of Mesenchymal Stem Cell-Secreted Fractions.

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions.

Multicentre study and systematic review: Allopurinol exposure during pregnancy.

BACKGROUND: Data about the safety of allopurinol in pregnant women are sparsely reported. AIMS: To investigate the risk of adverse pregnancy outcome and congenital abnormalities after in utero exposure to allopurinol in inflammatory bowel disease (IBD) pregnancies and in general. METHODS: We collected safety data of patients with IBD who were treated with allopurinol during pregnancy between January 2013 and March 2022. Additionally, we performed a systematic review about the teratogenic potential of allopurinol. RESULTS: We collected data from 42 allopurinol-exposed pregnancies, including one twin pregnancy; in all women, allopurinol was combined with a thiopurine. Six pregnancies (14.3%) resulted in miscarriage and one in stillbirth at 32 weeks. A congenital anomaly was observed in one newborn (coarctation of the aorta discovered postpartum). Three pregnancies, including the twin pregnancy, ended in moderate preterm delivery and one in very preterm delivery. Five neonates (15.2%) were small for gestational age. From our literature search, we identified an additional 102 allopurinol-exposed pregnancies resulting in 129 live births, including 36 infants from our cohort. Ten infants (7.8%) were born with a congenital anomaly. Two (1.6%) had a comparable pattern of multiple anomalies. The systematic review sub-analysis including only infants born to mothers with IBD (n = 76) revealed that 2.6% of infants had congenital anomalies after in utero exposure to a low dose of allopurinol. CONCLUSIONS: Overall, the teratogenicity of allopurinol remains inconclusive. Children conceived by mothers treated for IBD with allopurinol/thiopurine co-therapy do not seem to have an increased risk of congenital anomalies.

Randomised, double-blind, placebo-controlled study evaluating the effect of allopurinol on the risk of cardiovascular events in patients with high and very high cardiovascular risk, including the presence of long-COVID-19 syndrome: the ALL-VASCOR study protocol.

INTRODUCTION: Numerous studies, but not all, have suggested a positive effect of allopurinol on the cardiovascular system. The randomised, double-blind, placebo-controlled study evaluating the effect of allopurinol on the risk of cardiovascular events in patients with high and very high cardiovascular risk, including the presence of long-COVID-19 syndrome (ALL-VASCOR) study aims to evaluate the efficacy of allopurinol therapy for improving cardiovascular outcomes in patients at high and very high cardiovascular risk excluding ischaemic heart disease. This is particularly important due to the high cost of cardiovascular disease treatment and its status as one of the leading causes of mortality. METHODS AND ANALYSIS: The ALL-VASCOR study is a randomised, double-blind, placebo-controlled, multicentre trial that examines the effect of allopurinol therapy (200-500 mg of allopurinol daily) versus an equivalent dose of placebo on the risk of cardiovascular events in 1116 patients aged 40-70 with serum uric acid levels above 5 mg/dL at high and very high risk of cardiovascular disease. The ALL-VASCOR study will also assess the occurrence of long-COVID-19 syndrome. The study will measure primary and secondary as well as additional endpoints and the planned intervention will end on 31 July 2028 unless advised otherwise by the Safe Monitoring Board or other applicable authorities. Participant recruitment is planned to begin in March 2024 in Poland. ETHICS AND DISSEMINATION: The study was ethically approved by the Bioethics Committee of Poznan University of Medical Sciences (No 03/23, 12 January 2023). The results are expected after 2028 and will be disseminated in peer-reviewed journals and at international conferences. PROTOCOL VERSION NUMBER: 01-15 November 2022. TRIAL REGISTRATION NUMBER: EudraCT: 2022-003573-32, 27 October 2022, ClinicalTrials: NCT05943821, 13 July 2023.

Allopurinol use leading to xanthine nephrolithiasis in pediatric tumor lysis syndrome: a case series.

Tumor lysis syndrome (TLS) is a life-threatening metabolic disorder caused by massive tumor lysis. Allopurinol, a xanthine oxidase inhibitor, is initiated during chemotherapy to prevent hyperuricemia and subsequent acute kidney injury (AKI). We report two cases of xanthine nephrolithiasis during TLS in newly diagnosed hematologic malignancy patients receiving prophylactic allopurinol. Allopurinol use likely promoted xanthine crystallization, stone formation, and AKI.