Allopurinol reduces antigen-specific and polyclonal activation of human T cells

Allopurinol Prevents Cirrhosis-Related Complications: A Quadruple Blind Placebo-Controlled Trial

BACKGROUND

Complications associated with liver cirrhosis are various and potentially fatal. The treatment options to counteract hepatic decompensation are limited. Therefore, the study aimed to explore the use of allopurinol in preventing the recurrence of liver cirrhosis-related complications.

METHODS

One hundred patients with hepatic decompensation were randomized into 1:1 ratio to receive either allopurinol 300 mg or placebo tablets once daily for 6 months. The primary endpoint was the incidence of cirrhosis-related complications (overt ascites, spontaneous bacterial peritonitis, variceal bleeding, hepatorenal syndrome, and hepatic encephalopathy).

RESULTS

Six months following treatment, allopurinol reduced the relative risk (RR) of any first complication experienced after enrollment by 56% (hazard ratio [HR] 0.44; 95% confidence interval [CI], 0.27-0.62); P ˂ .001). Allopurinol decreased the RR of overt ascites by 67% (HR 0.33; 95% CI, 0.0098-0.94); P = .039] and reduced the RR of spontaneous bacterial peritonitis by about 75% (HR 0.25; 95% CI, 0.05-0.76; P = .01). Likewise, allopurinol was linked to an 80% reduction in the RR of developing hepatorenal syndrome (HR 0.2; 95% CI, 0.04-0.87; P = .033).

CONCLUSION

Allopurinol significantly decreased the recurrence of overall liver cirrhosis-related complications. Therefore, allopurinol may constitute a promising agent for patients with hepatic decompensation. These positive outcomes could be a result of its ability to reduce bacterial translocation and inflammation.

CLINICALTRIALS

GOV IDENTIFIER

NCT005545670.

Peripheral T Cell Populations are Differentially Affected in Familial Mediterranean Fever, Chronic Granulomatous Disease, and Gout

Both innate errors of immunity, such as familial Mediterranean fever (FMF) and chronic granulomatous disease (CGD), and the common inflammatory disease gout are characterized by episodes of sterile inflammatory attacks in the absence of an infection. While these disorders encompass distinct pathologies due to differentially affected metabolic pathways and inflammasome activation mechanisms, their common features are the excessive production of interleukin (IL)-1ß and innate immune cell hyperreactivity. On the other hand, the role of T cells and innate-like lymphocytes such as gamma delta (γδ) T cells in these pathologies is ill-defined. In order to widen our understanding of T cell involvement in CGD, FMF and gout pathology, we developed multicolour immunophenotyping panels for flow cytometry to characterize γδ T cells as well as CD4 and CD8 T cell populations in terms of their cytokine production, activation status, memory or naive phenotypes, exhaustion status, homing receptor expression, and cytotoxic activity. Our study is the first deep immunophenotyping analysis of T cell populations in CGD, FMF, and gout patients. We found that CGD affects the frequencies and activation status of T cells, while gout impairs the cytokine production capacity of Vδ2 T cells. FMF was characterized by decreased percentages of regulatory T cells in circulation and attenuated IFN-γ production capacity by Vδ2 T cells. Autoinflammatory syndromes and congenital defects of phagocyte differentially affect T cell compartments. Future studies are warranted to assess whether these phenotypical changes are relevant for disease pathology.

Senescent CD4+CD28null cells are increased in chronic hyperuricemia, show aberrant effector phenotypes, and are reversed after allopurinol therapy: a proof-of-concept pilot study

To characterize CD4⁺CD28^null cells in chronic hyperuricemia and investigate whether allopurinol could restore CD28 expression and the balance of T helper phenotypes. Asymptomatic individuals with chronic hyperuricemia and ultrasonographic findings evocative of urate deposition in the joints. Age- and gender-matched normouricemic individuals were also studied. Oral allopurinol at 150 mg/day for 4 weeks, followed by 300 mg/day through week 12. Color-flow cytometry on peripheral blood mononuclear cells (PBMC) with antibodies against CD4, CD28, T-bet (Th1), GATA-3 (Th2), and RORγt (Th17). Six patients (five men, median age of 53 years) and seven controls were studied. At baseline, hyperuricemic patients had more CD4⁺CD28^null/CD4⁺ cells than normouricemic subjects (36.8% vs. 6.1%; p = 0.001), with a predominance of T-bet⁺ cells (98.5% vs. 6.6%; p = 0.001) and few RORγt⁺ cells (0.7% vs. 89.4%; p = 0.014). In hyperuricemic patients, the number of CD4⁺ cells/10,000 PBMC was similar before and after allopurinol (3378 vs. 3954; p = 0.843). Conversely, CD4⁺CD28^null cells decreased from 36.8% (23.0-43.7) to 15.8% (4.7-28.1; p = 0.031). CD4⁺CD28^nullT-bet⁺ cells decreased from 98.5% (95.0-99.4) to 88.3% (75.2-98.9; p = 0.062), CD4⁺CD28^nullGATA-3⁺ cells increased from 0% (0-4.0) to 2.8% (0.1-15.6; p = 0.156), and CD4⁺CD28^nullRORγt⁺ cells increased from 0.7% (0.4-7.0) to 4.5% (1.3-28.1; p = 0.031). The CD4⁺CD28^null cell subset is abnormally expanded in chronic hyperuricemia, despite the absence of overt urate-related disease. Allopurinol may partially restore CD28 expression on CD4⁺ cells while enhancing the homeostatic balance of T helper phenotypes. ClinicalTrials.gov, number NCT04012294.

A putative xanthine dehydrogenase is critical for Borrelia burgdorferi survival in ticks and mice

Borrelia burgdorferi is a pathogenic bacterium and the causative agent of Lyme disease. It is exposed to reactive oxygen species (ROS) in both the vertebrate and tick hosts. While some mechanisms by which B. burgdorferi ameliorates the effects of ROS exposure have been studied, there are likely other unknown mechanisms of ROS neutralization that contribute to virulence. Here, we follow up on a three gene cluster of unknown function, bb_0554, bb_0555, and bb_0556, that our prior unbiased transposon insertional sequencing studies implicated in both ROS survival and survival in Ixodes scapularis. We confirmed these findings through genetic knockout and provide evidence that these genes are co-transcribed as an operon to produce a xanthine dehydrogenase. In agreement with these results, we found that B. burgdorferi exposure to either uric acid (a product of xanthine dehydrogenase) or allopurinol (an inhibitor of xanthine dehydrogenase) could modulate sensitivity to ROS in a bb_0554-bb_0556 dependent manner. Together, this study identifies a previously uncharacterized three gene operon in B. burgdorferi as encoding a putative xanthine dehydrogenase critical for virulence. We propose renaming this locus xdhACB.

The Prospective Effect of Allopurinol on the Oxidative Stress Index and Endothelial Dysfunction in Covid-19

SARS-CoV-2 by the direct cytopathic effect or indirectly through the propagation of pro-inflammatory cytokines could cause endothelial dysfunction (ED) and oxidative stress (OS). It has been reported that OS is triggered by various types of viral infections, including SARS-CoV-2. Into the bargain, allopurinol is regarded as a potent antioxidant that acts through inhibition of xanthine oxidase (XO), which is an essential enzyme of purine metabolism. Herein, the present study aimed to find the potential protective effects of allopurinol on the biomarkers of OS and ED in patients with severe Covid-19. This single-center cohort study recruited 39 patients with mild-moderate Covid-19 compared with 41 patients with severe Covid-19. Nineteen patients with severe Covid-19 were on the allopurinol treatment because of underlying chronic gout 3 years ago compared with 22 Covid-19 patients not on this treatment. The recruited patients were allocated into three groups: group I, mild-moderate Covid-19 on the standard therapy (n = 39); group II, severe Covid-19 patients on the standard therapy only (n = 22); and group III, severe Covid-19 patients on the standard therapy plus allopurinol (n = 19). The duration of the study was 3 weeks from the time of hospitalization till the time of recovery. In addition, inflammatory biomarkers (D-dimer, LDH, ferritin, CRP, procalcitonin), neutrophil-lymphocyte ratio (NLR), endothelin-1 (ET-1), uric acid and oxidative stress index (OSI), CT scan score, and clinical score were evaluated at the time of admission and discharge regarding the effect of allopurinol treatment adds to the standard treatment of Covid-19. Allopurinol plus standard treatment reduced LDH, ferritin, CRP, procalcitonin, and ET-1 serum level significantly (P < 0.05) compared with Covid-19 patients on standard treatment. Besides, neutrophil (%), lymphocyte (%), and neutrophil-lymphocyte ratio (NLR) were reduced in patients with severe Covid-19 on standard treatment plus allopurinol compared with Covid-19 patients on standard treatment alone (P < 0.01). OSI was higher in patients with severe Covid-19 than mild-moderate Covid-19 patients (P = 0.00001) at admission. At the time of discharge, the oxidative status of Covid-19 patients was significantly improved compared with that at admission (P = 0.01). In conclusion, Covid-19 severity is linked with high OS and inflammatory reaction with ED development. High uric acid in patients with severe Covid-19 is correlated with high OS and inflammatory biomarkers. Allopurinol with standard treatment in patients with severe Covid-19 reduced oxidative and inflammatory disorders with significant amelioration of ED and clinical outcomes.

Neutralizing the free radicals could alleviate the disease severity following an infection by positive strand RNA viruses

Free radical release due to oxidative stress is gaining importance in the field of viral pathogenesis. Recent studies suggest the involvement of oxidative stress and ROS levels in regulating disease virulence during RNA virus infection. Most of the RNA virus infections lead to vascular dysfunction and disease severity. However, the biology of free radicals in maintaining vascular endothelium integrity is not completely understood. In the present review, we discuss some of the common features in positive-strand RNA virus infections such as dengue and SARS-CoV-2 and suggest that anti-oxidant therapy could pave the way to develop therapeutic strategies in combating emerging and re-emerging RNA viruses.

Identification of Inflammation-Related Biomarker Pro-ADM for Male Patients With Gout by Comprehensive Analysis

Objective

Gout is a local inflammatory disease caused by the deposition of monosodium urate (MSU) crystals in joints or adjacent tissues. When some gout occurs without hyperuricemia, or its clinical symptoms and signs are not typical, the diagnosis of gout will be delayed, so there is an urgent need to find a new biomarker to predict and diagnose of gout flare. Our research attempts to find the key genes and potential molecular mechanisms of gout through bioinformatics analysis, and collected general data and blood biochemical samples of patients with gout and healthy, then analyzed and compared the expression of factors regulated by key genes.

Method

GSE160170 were downloaded from GEO database for analysis. The data were normalized to identify the differentially expressed genes (DEGs), then GO and KEGG enrichment analysis were applied. Protein-protein interaction (PPI) networks and hub genes between DEGs were identified. Then collect general information and blood samples from male patients with acute gout, hyperuricemia and healthy. ELISA method was used to detect pro-ADM levels of different groups, and the data was input into SPSS statistical software for analysis.

Result

We identified 266 DEGs (179 up-regulated and 87 down-regulated) between gout patients and healthy controls. GO analysis results show that DEGs are mostly enriched in inflammatory response, growth factor activity, cytokine activity, chemokine activity, S100 protein binding and CXCR chemokine receptor binding. KEGG pathway analysis showed that DEGs are mainly related to Chemokine signaling pathway and Cytokine-cytokine receptor interaction. ADM, CXCR1, CXCR6, CXCL3, CCL3, CCL18, CCL3L3, CCL4L1, CD69, CD83, AREG, EREG, B7RP1, HBEGF, NAMPT and S100B are the most important hub genes in the PPI network. We found that the expression of pro-ADM in the gout group and hyperuricemia group was higher than that in the healthy group, and the difference was statistically significant.

Conclusion

In this study, a series of bioinformatics analyses were performed on DEGs to identify key genes and pathways related to gout. Through clinical verification, we found that pro-ADM can be used as an inflammation-related biomarker for acute attacks of gout, providing new ideas for the diagnosis and treatment of gout.

Xanthine oxidase inhibition in SARS-CoV-2 infection: the mechanism and potency of allopurinol and febuxostat in COVID-19 management

The number of coronavirus disease 2019 (COVID-19) infection cases has been increasing globally, including in Indonesia. Definitive therapy for COVID-19 has not yet been found; hence, repurposed drugs for COVID-19 have been considered and have been practiced by several researchers in the world. This literature review investigates the action of xanthine oxidase as a component of the biomolecular pathway against severe acute respiratory syndrome-related coronavirus-2, the cause of COVID-19, and describes the mechanism and potential of uric acid drugs (allopurinol and febuxostat) as prophylaxis and curative therapy for COVID-19. 

Role of T cells in the pathogenesis and treatment of gout

Though macrophages and neutrophils are considered to be the principal immune cells involved in gout inflammation, recent studies highlight an emerging role of T cell subsets in the pathogenesis of gout. Some studies found that abnormal functions of several T cell subsets and aberrant expressions of their signature cytokines existed in gouty arthritis. Additionally, recent studies also suggested that therapeutic strategies by targeting pro-inflammatory T cell subsets or their related cytokines could ameliorate monosodium urate (MSU) crystals-induced arthritis in mice. The important role of T cells in gouty arthritis may provide some explanation for the absence of acute gout attacks among individuals with severe hyperuricemia or clinical evidence of MSU crystals deposition. Nevertheless, the molecular mechanisms underlying the role of those T cell subsets in gouty arthritis and their role in the initiation, progression and resolution of gouty arthritis are largely elusive, which need to be elaborated in future research. Uncovering the role of those T cell subsets in gout may transform our understanding of gout and facilitate new promising preventive or therapeutic strategies for gouty arthritis.

Uric acid increases IL-1β secretion and Caspase-1 activation in PBMCs of Behçet's disease patients: The in vitro immunomodulatory effect of xanthine oxidase inhibitor Allopurinol

Behçet's disease (BD) is a multisystem disease, which shares some features with other diseases belonging to the autoinflammatory disorders panel. Recent studies have postulated that IL-1β/Caspase-1 may play a cardinal role in autoinflammatory diseases. In this study, we aimed to (i) elucidate the mechanism underlying the involvement of xanthine oxidase (XO) and Uric Acid (UA) in BD (ii) study the direct effects of UA and XO inhibitor "Allopurinol" on nitric oxide (NO) and caspase-1-mediated IL-1β release in peripheral blood mononuclear cells (PBMCs) of BD patients. In this context, plasma of BD patients and healthy controls (HC) were used to measure XO activity, UA, advanced oxidized proteins products (AOPP) and NO levels. In Addition, PBMCs of BD patients and HC were treated or not with either UA or Allopurinol. Then we quantified NO and IL-1β levels, and Caspase-1 Activity in the supernatants and lysates of PBMCs, respectively. We showed that plasma levels of XO activity, UA, AOPP and NO are significantly increased in BD patients compared to those of HC. Interestingly, a significant positive correlation between XO and UA was observed in BD patients. Additionally, while UA has markedly increased NO, IL-1β, and Caspase-1 activity levels in PBMCs of BD patients, Allopurinol has exerted an immunomodulatory effect resulting in reduced NO, IL-1β and Caspase-1 levels in PBMCs of BD patients particularly during the active stages. Collectively, our results indicate a potential clinical use of XO as a tool for assessing BD activity, and suggest that the in-vitro immunomodulatory effect of Allopurinol may have a promising therapeutic value in BD management.

Azathioprine with Allopurinol: Lower Deoxythioguanosine in DNA and Transcriptome Changes Indicate Mechanistic Differences to Azathioprine Alone

BACKGROUND

Use of azathioprine (AZA) for inflammatory bowel disease is limited by side effects or poor efficacy. Combining low-dose azathioprine with allopurinol (LDAA) bypasses side effects, improves efficacy, and may be appropriate as first-line therapy. We test the hypothesis that standard-dose azathioprine (AZA) and LDAA treatments work by similar mechanisms, using incorporation of the metabolite deoxythioguanosine into patient DNA, white-blood cell counts, and transcriptome analysis as biological markers of drug effect.

METHODS

DNA was extracted from peripheral whole-blood from patients with IBD treated with AZA or LDAA, and analyzed for DNA-incorporated deoxythioguanosine. Measurement of red-blood cell thiopurine metabolites was part of usual clinical practice, and pre- and on-treatment (12 wk) blood samples were used for transcriptome analysis.

RESULTS

There were no differences in reduction of white-cell counts between the 2 treatment groups, but patients on LDAA had lower DNA-incorporated deoxythioguanosine than those on AZA; for both groups, incorporated deoxythioguanosine was lower in patients on thiopurines for 24 weeks or more (maintenance of remission) compared to patients treated for less than 24 weeks (achievement of remission). Patients on LDAA had higher levels of red-blood cell thioguanine nucleotides than those on AZA, but there was no correlation between these or their methylated metabolites, and incorporated deoxythioguanosine. Transcriptome analysis suggested down-regulation of immune responses consistent with effective immunosuppression in patients receiving LDAA, with evidence for different mechanisms of action between the 2 therapies.

CONCLUSIONS

LDAA is biologically effective despite lower deoxythioguanosine incorporation into DNA, and has different mechanisms of action compared to standard-dose azathioprine.

Combined treatment with benznidazole and allopurinol in mice infected with a virulentTrypanosoma cruziisolate from Nicaragua

We evaluated the effect of chemotherapy with a sequential combined treatment of a low dose of benznidazole and allopurinol, in different schedules of administration, in experimental models of acute and chronicTrypanosoma cruziinfection. Mice were infected with NicaraguaT. cruziisolate, a virulent parasite from an endemic area of Nicaragua, genotyped asTcI (Grossoet al. 2010). We assessed survival rate, IgG levels, histopathological studies and quantified parasitaemia. A 15% survival rate was recorded in untreated mice during the acute phase ofT. cruziinfection. Allopurinol administered immediately after benznidazole treatment was able to reduce parasitaemia and attenuate tissue damage by reducing inflammation.Trypanosoma cruzi-specific antibodies also decreased in 40–50% of the treated mice. The addition of allopurinol during the chronic phase showed the highest beneficial effect, not only by reducing parasitaemia but also by lowering the degree of inflammation and fibrosis.