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European Journal of Pharmaceutical... Jul 2024Uric acid, the metabolic product of purines, relies on xanthine oxidase (XOD) for production. XOD is a target for the development of drugs for hyperuricemia (HUA) and...
Uric acid, the metabolic product of purines, relies on xanthine oxidase (XOD) for production. XOD is a target for the development of drugs for hyperuricemia (HUA) and gout. Currently, treatment options remain limited for gout patients. 3, 4-Dihydroxy-5-nitrobenzaldehyde (DHNB) is a derivative of the natural product protocatechualdehyde with good biological activity. In this work, we identify a DHNB thiosemicarbazide class of compounds that targets XOD. 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazone can effectively inhibit XOD activity (IC50 value: 0.0437 μM) and exhibits a mixed inhibitory effect. In a mouse model of acute hyperuricemia, a moderate dose (10 mg/kg.w) of 3,4-dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide effectively controlled the serum uric acid content and significantly inhibited serum XOD activity. In addition, 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide showed favorable safety profiles, and mice treated with the target compound did not show any symptoms of general toxicity following a single dose of 500 mg/kg. In the allopurinol group, 50 % of the mice died. These results provide a structural framework and mechanism of XOD inhibition that may facilitate the design of hyperuricemia and gout treatments.
Topics: Animals; Hyperuricemia; Male; Semicarbazides; Mice; Benzaldehydes; Gout; Xanthine Oxidase; Uric Acid; Humans
PubMed: 38653341
DOI: 10.1016/j.ejps.2024.106778 -
Frontiers in Pharmacology 2024The human umbilical artery (HUA), rat-isolated right atrium, and rat-isolated vas deferens present a basal release of 6-nitrodopamine (6-ND). The basal release of 6-ND...
The human umbilical artery (HUA), rat-isolated right atrium, and rat-isolated vas deferens present a basal release of 6-nitrodopamine (6-ND). The basal release of 6-ND from these tissues was significantly decreased (but not abolished) when the tissues were pre-incubated with N-nitro-L-arginine methyl ester (L-NAME). In this study, the effect of the pharmacological modulation of the redox environment on the basal release of 6-ND was investigated. The basal release of 6-ND was measured using Liquid chromatography with tandem mass spectrometry (LC-MS/MS). Pre-incubation (30 min) of the tissues with GKT137831 (1 μM) caused a significant increase in the basal release of 6-ND from all tissues. In the HUA, pre-incubation with diphenyleneiodonium (DPI) (100 μM) also caused significant increases in the basal release of 6-ND. Preincubation of the HUA with hydrogen peroxide (HO) (100 μM) increased 6-ND basal release, whereas pre-incubation with catalase (1,000 U/mL) significantly decreased it. Pre-incubation of the HUA with superoxide dismutase (SOD) (250 U/mL; 30 min) also significantly increased the basal release of 6-ND. Preincubation of the HUA with either allopurinol (100 μM) or uric acid (1 mM) had no effect on the basal release of 6-ND. Pre-treatment of the HUA with L-NAME (100 μM) prevented the increase in the basal release of 6-ND induced by GKT137831, diphenyleneiodonium, and HO. The results obtained indicate a major role of endogenous H2O2 and peroxidases as modulators of 6- ND biosynthesis/release and a lack of peroxynitrite contribution.
PubMed: 38645555
DOI: 10.3389/fphar.2024.1348876 -
Arthritis Research & Therapy Apr 2024Little is known about long-term clinical outcomes or urate-lowering (ULT) therapy use following pegloticase discontinuation. We examined ULT use, serum urate (SU),...
BACKGROUND/PURPOSE
Little is known about long-term clinical outcomes or urate-lowering (ULT) therapy use following pegloticase discontinuation. We examined ULT use, serum urate (SU), inflammatory biomarkers, and renal function following pegloticase discontinuation.
METHODS
We conducted a retrospective analysis of gout patients who discontinued pegloticase using the Rheumatology Informatics System for Effectiveness (RISE) registry from 1/2016 to 6/2022. We defined discontinuation as a gap ≥ 12 weeks after last infusion. We examined outcomes beginning two weeks after last dose and identified ULT therapy following pegloticase discontinuation. We evaluated changes in lab values (SU, eGFR, CRP and ESR), comparing on- treatment (≤ 15 days of the second pegloticase dose) to post-treatment.
RESULTS
Of the 375 gout patients discontinuing pegloticase, median (IQR) laboratory changes following discontinuation were: SU: +2.4 mg/dL (0.0,6.3); eGFR: -1.9 mL/min (- 8.7,3.7); CRP: -0.8 mg/L (-12.8,0.0); and ESR: -4.0 mm/hr (-13.0,0.0). Therapy post-discontinuation included oral ULTs (86.0%), restarting pegloticase (4.5%), and no documentation of ULT (9.5%), excluding patients with multiple same-day prescriptions (n = 17). Oral ULTs following pegloticase were: 62.7% allopurinol, 34.1% febuxostat. The median (IQR) time to starting/restarting ULT was 92.0 days (55.0,173.0). Following ULT prescribing (≥ 30 days), only 51.0% of patients had SU < 6 mg/dL. Patients restarting pegloticase achieved a median SU of 0.9 mg/dL (IQR:0.2,9.7) and 58.3% had an SU < 6 mg/dL.
CONCLUSION
Pegloticase treats uncontrolled gout in patients with failed response to xanthine oxidase inhibitors, but among patients who discontinue, optimal treatment is unclear. Based on this analysis, only half of those starting another ULT achieved target SU. Close follow-up is needed to optimize outcomes after pegloticase discontinuation.
Topics: Humans; Uric Acid; Retrospective Studies; Gout; Biomarkers; Kidney; Polyethylene Glycols; Urate Oxidase
PubMed: 38609967
DOI: 10.1186/s13075-024-03318-5 -
Frontiers in Pharmacology 2024Accumulating evidence suggests that hyperuricemia is a pathological factor in the development and progression of chronic kidney disease. However, the potential benefit...
Accumulating evidence suggests that hyperuricemia is a pathological factor in the development and progression of chronic kidney disease. However, the potential benefit afforded by the control of uric acid (UA) is controversial. Individual studies show discrepant results, and most existing meta-analysis, especially those including the larger number of studies, lack a placebo or control group as they aim to compare efficacy between drugs. On these grounds, we performed a me-ta-analysis restricted to studies including the action of any anti-gout therapies referenced to a control or placebo arm. This approach allows for a clearer association between UA reduction and renal effect. Of the twenty-nine papers included, most used allopurinol and febuxostat and, therefore, solid conclusions could only be obtained for these drugs. Both were very effective in reducing UA, but only allopurinol was able to significantly improve glomerular filtration rate (GFR), although not in a dose-dependent manner. These results raised doubts as to whether it is the hypouricemic effect of anti-gout drugs, or a pleiotropic effect, what provides protection of kidney function. Accordingly, in a correlation study that we next performed between UA reduction and GFR improvement, no association was found, which suggests that additional mechanisms may be involved. Of note, most trials show large inter-individual response variability, probably because they included patients with heterogeneous phenotypes and pathological characteristics, including different stages of CKD and comorbidities. This highlights the need to sub classify the effect of UA-lowering therapies according to the pathological scenario, in order to identify those CKD patients that may benefit most from them. CRD42022306646 https://www.crd.york.ac.uk/prospero/.
PubMed: 38601468
DOI: 10.3389/fphar.2024.1373258 -
The Journal of Pediatric Pharmacology... Apr 2024Allopurinol-induced drug reaction syndrome with eosinophilia and systemic symptoms (A-DRESS) is a well-described condition in adults, whereas it is uncommon among...
Allopurinol-induced drug reaction syndrome with eosinophilia and systemic symptoms (A-DRESS) is a well-described condition in adults, whereas it is uncommon among children. We describe a case of A-DRESS in a 16-year-old male with steroid-dependent nephrotic syndrome. He presented a life-threatening clinical course with persisting fever, skin rash, eosinophilia, lymphadenopathy, distributive shock, and herpesvirus 6 detection. The withdrawal of allopurinol and a combination of intravenous immunoglobulins (IVIGs) and systemic corticosteroids led to the patient's recovery without sequelae. Drug reaction with eosinophilia and systemic symptoms (DRESS) in pediatrics is rare and can present in a severe form. Early diagnosis and timely treatment are critical for prognostic purposes. This report suggests the potentially crucial role of IVIG in the treatment of patients with A-DRESS.
PubMed: 38596415
DOI: 10.5863/1551-6776-29.2.195 -
ACR Open Rheumatology Apr 2024Self-monitored point-of-care urate-measuring devices are an underexplored strategy to improve adherence to urate-lowering therapy and clinical outcomes in gout. This...
OBJECTIVE
Self-monitored point-of-care urate-measuring devices are an underexplored strategy to improve adherence to urate-lowering therapy and clinical outcomes in gout. This study observed patient-led urate self-monitoring practice and assessed its influence on allopurinol adherence, urate control, and health-related quality of life.
METHODS
People with gout (n = 31) and prescribed allopurinol self-monitored their urate concentrations (HumaSens2.0) at baseline and thereafter monthly for 12 months (3 months per quarter). Adherence to allopurinol was measured using medication event monitoring technology (Medication Event Monitoring System cap). Time spent below the target urate concentration (<0.36 mmol/L) was determined. Health-related quality of life was measured using a survey (EuroQoL EQ-5D-5L). Gout flares were recorded. Two-tailed Spearman correlation and the Wilcoxon matched-pairs signed-rank test (P < 0.05) were used for statistical comparisons.
RESULTS
Most participants were male (94%) and had urate concentrations below the target (74%) at baseline. Overall, seven participants demonstrated repeated periods of "missed doses" (two or fewer allopurinol doses missed consecutively) and "drug holidays" (three or more missed doses). Most participants (94%) persisted with allopurinol. Time spent within the target urate concentration increased 1.3-fold (from 79% to 100%; P = 0.346), and the incidence of gout flares decreased 1.6-fold (from 8 to 5; P = 0.25) in the final quarter compared to that in the first quarter of the study. Health-related quality of life was reduced for participants reporting at least one gout flare (median utility values 0.9309 vs 0.9563, P = 0.04).
CONCLUSION
Patient-led urate self-monitoring may support the maintenance of allopurinol adherence and improve urate control, thus reducing the incidence of gout flares. Further research on patient-led urate self-monitoring in a randomized controlled study is warranted.
PubMed: 38591107
DOI: 10.1002/acr2.11666 -
Rheumatology Advances in Practice 2024To examine the cross-sectional association between health literacy and gout characteristics.
OBJECTIVES
To examine the cross-sectional association between health literacy and gout characteristics.
METHODS
In a primary care cohort of adults living with gout, the prevalence of poor health literacy was defined using the Single-Item Literacy Screener (SILS). Multiple logistic regression was used to obtain adjusted odds ratios (ORs) for the cross-sectional associations between health literacy and individual gout characteristics (frequency of flares, age at gout onset, history of oligo-/polyarticular flares, allopurinol use, allopurinol dose and serum urate level) with 95% CIs and adjustment for age, sex, deprivation and further education.
RESULTS
Of 551 participants [mean age 54.4 years (s.d. 11.2), 498 (90.4%) male], 163 (30.1%) reported two or more flares in the previous 12 months. Fifty-one (9.4%) had poor health literacy. Poor health literacy was associated with having two or more flares in the preceding 12 months [adjusted OR 4.10 (95% CI 2.04, 8.19)] and a history of oligo-/polyarticular flares [OR 1.93 (95% CI 1.06, 3.55)]. No associations were identified between health literacy and age at gout onset [OR 0.99 (95% CI 0.96, 1.01)], allopurinol use [OR 0.88 (95% CI 0.46, 1.65)] or dose [OR 1.00 OR (95% CI 1.00, 1.00)] or serum urate [most recent serum urate OR 1.0 (95% CI 1.00, 1.00)].
CONCLUSIONS
Frequent flares and a history of oligo-/polyarticular flares were associated with poor health literacy. Since health literacy is an important determinant of health outcomes, it is important to consider health literacy when providing information and education to people with gout.
PubMed: 38584855
DOI: 10.1093/rap/rkae034 -
Clinical and Translational Allergy Apr 2024
Correction to HLA-A*24:02 increase the risk of allopurinol-induced drug reaction with eosinophilia and systemic symptoms (DRESS) in HLA-B*58:01 carriers in Korean population; A multicenter cross-sectional case-control study.
PubMed: 38578246
DOI: 10.1002/clt2.12351 -
Schweizer Archiv Fur Tierheilkunde Apr 2024This case report describes the long-term success of a subcutaneous ureteral bypass device in a dog for treatment of a ureteral obstruction. The suspected xanthine...
This case report describes the long-term success of a subcutaneous ureteral bypass device in a dog for treatment of a ureteral obstruction. The suspected xanthine urolithiasis was secondary to treatment with allopurinol for leishmaniasis. The dog presented initially with lethargy, anuria and abdominal pain. Mild azotemia was found on biochemical analysis and abdominal ultrasound revealed bilateral ureteral obstruction. A subcutaneous ureteral bypass was subsequently placed using a standard surgical technique. The dog recovered uneventfully and the azotemia resolved within days. Follow-up examinations were performed every trimester for over three years and no complications like obstruction of the bypass tubes, urinary tract infection or azotemia were recognized during this follow-up period. Allopurinol was replaced with domperidone as long-term treatment against Leishmaniasis which resulted in a mild increase of the leishmania serum antibody titer. The subcutaneous ureteral bypass placement was successful and safe in this dog and is a valuable alternative in cases of ureteral obstruction also in dogs.
Topics: Animals; Dogs; Cats; Ureteral Obstruction; Allopurinol; Azotemia; Urolithiasis; Leishmaniasis; Xanthines; Stents; Cat Diseases; Dog Diseases
PubMed: 38572822
DOI: 10.17236/sat00422 -
BMC Medical Imaging Apr 2024To investigate the feasibility of Diffusion Kurtosis Imaging (DKI) in assessing renal interstitial fibrosis induced by hyperuricemia.
BACKGROUND
To investigate the feasibility of Diffusion Kurtosis Imaging (DKI) in assessing renal interstitial fibrosis induced by hyperuricemia.
METHODS
A hyperuricemia rat model was established, and the rats were randomly split into the hyperuricemia (HUA), allopurinol (AP), and AP + empagliflozin (AP + EM) groups (n = 19 per group). Also, the normal rats were selected as controls (CON, n = 19). DKI was performed before treatment (baseline) and on days 1, 3, 5, 7, and 9 days after treatment. The DKI indicators, including mean kurtosis (MK), fractional anisotropy (FA), and mean diffusivity (MD) of the cortex (CO), outer stripe of the outer medulla (OS), and inner stripe of the outer medulla (IS) were acquired. Additionally, hematoxylin and eosin (H&E) staining, Masson trichrome staining, and nuclear factor kappa B (NF-κB) immunostaining were used to reveal renal histopathological changes at baseline, 1, 5, and 9 days after treatment.
RESULTS
The HUA, AP, and AP + EM group MK and MK values gradually increased during this study. The HUA group exhibited the highest MK value in outer medulla. Except for the CON group, all the groups showed a decreasing trend in the FA and MD values of outer medulla. The HUA group exhibited the lowest FA and MD values. The MK and MK values were positively correlated with Masson's trichrome staining results (r = 0.687, P < 0.001 and r = 0.604, P = 0.001, respectively). The MD and FA were negatively correlated with Masson's trichrome staining (r = -626, P < 0.0014 and r = -0.468, P = 0.01, respectively).
CONCLUSION
DKI may be a non-invasive method for monitoring renal interstitial fibrosis induced by hyperuricemia.
Topics: Rats; Animals; Hyperuricemia; Kidney; Diffusion Tensor Imaging; Diffusion Magnetic Resonance Imaging; Fibrosis
PubMed: 38570748
DOI: 10.1186/s12880-024-01259-8