Incidence of tuberculosis infection in spondyloarthritis patients treated with biological and conventional disease-modifying anti-rheumatic drugs in an endemic area

Introduction: Registries of spondyloarthritis (SpA) patients' follow-up provided evidence that tumor necrosis factor inhibitors (TNFi) increase the incidence of active tuberculosis infection (TB). However, most of these registries are from low burden TB areas. Few studies evaluated the safety of biologic agents in TB endemic areas. This study compares the TB incidence rate (TB IR) in anti-TNF-naïve and anti-TNF-experienced subjects with SpA in a high TB incidence setting.Methods: In this retrospective cohort study, medical records from patients attending a SpA clinic during 13 years (2004 to 2016) in a university hospital were reviewed. The TB IR was calculated and expressed as number of events per 105 patients/year; the incidence rate ratio (IRR) associated with the use of TNFi was calculated.Results: A total of 277 patients, 173 anti-TNF-naïve and 104 anti-TNF-experienced subjects, were evaluated; 35.7% (N = 35) of patients who were prescribed an anti-TNF drug were diagnosed with latent tuberculosis infection (LTBI). Total follow-up time (person-years) was 1667.8 for anti-TNF-naïve and 394.9 for anti-TNF-experienced patients. TB IR (95% CI) was 299.8 (37.4-562.2) for anti-TNF naïve and 1012.9 (25.3-2000.5) for anti-TNF experienced subjects. The IRR associated with the use of TNFi was 10.4 (2.3- 47.9).Conclusions: In this high TB incidence setting, SpA patients exposed to anti-TNF therapy had a higher incidence of TB compared to anti-TNF-naïve subjects, although the TB incidence in the control group was significant.(AU)

Xanthine oxidase inhibitors for prevention of cardiovascular events: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Xanthine oxidase inhibitors (XOI), classified as purine-like (allopurinol and oxypurinol) and non-purine (febuxostat and topiroxostat) XOI, present antioxidant properties by reducing the production of reactive oxygen species derived from purine metabolism. Oxidative stress is an important factor related to endothelial dysfunction and ischemia-reperfusion injury, and may be implicated in the pathogenesis of heart failure, hypertension, and ischemic heart disease. However, there is contradictory evidence regarding the possible cardiovascular (CV) protective effect exerted by XOI. Our objective is to compare the incidence of major adverse cardiovascular events (MACE), mortality, total (TCE) and specific CV events in randomized controlled trials (RCTs) testing XOI against placebo or no treatment. METHODS: PubMed, EMBASE, Web of Science, Cochrane Central, Lilacs databases were searched from inception to Dec 30 2016, along with hand searching. RCTs including exclusively adult individuals, lasting ≥ 4 weeks, with no language restriction, were eligible. Independent paired researchers selected studies and extracted data. Considering the expected rarity of events, Peto and DerSimonian/Laird odds ratios (OR), the latter in case of heterogeneity, were used for analysis. Random-effects meta-regression was used to explore heterogeneity. RESULTS: The analysis of MACE included 81 articles (10,684 patients, 6434 patient-years). XOI did not significantly reduce risk of MACE (ORP = 0.71, 95% CI 0.46-1.09) and death (0.89, 0.59-1.33), but reduced risk of TCE (0.60, 0.44-0.82; serious TCE: 0.64, 0.46 to 0.89), and hypertension (0.54, 0.37 to 0.80). There was protection for MACE in patients with previous ischemic events (0.42, 0.23-0.76). Allopurinol protected for myocardial infarction (0.38, 0.17-0.83), hypertension (0.32, 0.18-0.58), TCE (0.48, 0.31 to 0.75, I2 = 55%) and serious TCE (0.56, 0.36 to 0.86, I2 = 44%). Meta-regression associated increasing dose of allopurinol with higher risk of TCE and serious TCE (P < 0.05). Accordingly, lower doses (≤ 300 mg/day) of allopurinol reduced the risk of TCE, unlike higher doses. Non-purine-like XOI did not significantly reduce or increase the risk of adverse CV events, but confidence intervals were wide. Quality of evidence was generally low to moderate. CONCLUSIONS: Purine-like XOI may reduce the incidence of adverse CV outcomes. However, higher doses of allopurinol (> 300 mg/day) may be associated with loss of CV protection.

Latent tuberculosis infection and tuberculosis in patients with rheumatic diseases treated with anti-tumor necrosis factor agents.

The introduction of biological agents, especially the tumor necrosis factor inhibitors (anti-TNF), for the treatment of rheumatic diseases increased the risk of developing tuberculosis (TB). Screening for latent TB infection (LTBI) is strongly recommended before starting therapy with anti-TNF agents. The objective of this study was to identify the prevalence of LTBI and TB among patients with rheumatic diseases on anti-TNF agents. This is a cross-sectional study. The electronic medical records of all adult patients (≥18 years old) undergoing anti-TNF treatment were reviewed. Every patient underwent tuberculin skin test (TST) before starting anti-TNF treatment. In total, 176 patients were included; the mean age was 51.9 ± 12.4 years, 34.7% were males, and 90.9% were white. The underlying diseases were rheumatoid arthritis (RA) in 50.6% (N = 89), ankylosing spondylitis (AS) in 27.8% (N = 49), and psoriatic arthritis (PsA) in 17.6% (N = 31). The prevalence of positive TST was 29.5%. Household contact with TB was significantly associated with a positive TST (p = 0.020). RA patients had lower TST reactions than AS patients (p = 0.022). There were six cases of TB (3.4%) diagnosed during anti-TNF therapy. We demonstrated a high prevalence of positive TST (29.5%) among patients with rheumatic diseases in a region with high TB prevalence. Our data corroborates the ACR's recommendation that patients who live in high TB incidence settings should be tested annually for LTBI.

Effect of different vasodilators on NTPDase activity in healthy and hypertensive patients.

INTRODUCTION: The thrombogenic process that affects the hypertensive patient is associated with regulatory mechanisms present in the vascular endothelium. These mechanisms involve release of an endothelium-derived relaxing factor, ectonucleotidase activity and calcium ion concentration. METHODS: Interference with ENTPDase activity in platelets of hypertensive patients and healthy donors was evaluated for arginine, sodium nitroprusside, and hydralazine. In addition, the kinetic behavior of NTPDase was determined in the presence of the vasodilator that showed the greatest inhibitory influence. RESULTS: Vasodilators decreased NTPDase activity with ATP and ADP as substrates. In controls, hydrolysis was increased in the presence of arginine. Captopril did not affect enzyme activities. The dose response for increasing sodium nitroprusside was biphasic. Kinetic behavior studies were estimated in the presence of sodium nitroprusside, which caused a mixed inhibition. The K(m) values increased and V(max) decreased with increasing sodium nitroprusside concentrations. The IC(50) and K(i) values indicated that the vasodilator was a strong NTPDase inhibitor when tested for the control and hypertensive group, using ATP and ADP as substrate, respectively. CONCLUSION: It is postulated that there was an interaction between vasodilators, NO donors and inhibition of NTPDase.

Previous treatment with ebselen and vitamin E alters adenine nucleotide hydrolysis in platelets from adult rats experimentally demyelinated with ethidium bromide.

Many aspects of the relationship between the demyelinating pathology and platelet function need to be elucidated. Thus, the activity of NTPDase and 5'-nucleotidase enzymes was analyzed in platelets from rats demyelinated with ethidium bromide (EB) and previously treated with ebselen (Ebs) and vitamin E (Vit. E). The animals were divided into four groups: for ebselen, the groups were: I-control (saline), II-(saline and Ebs), III-(EB) and IV-(EB and Ebs); and for vitamin E, the groups were: I - control (saline), II-(saline and Vit. E), III-(EB) and IV-(EB and Vit. E). After 3 and 21 days, the blood was collected and the platelets were separated for enzymatic assays. For the treatment with Ebs, the NTPDase activity for ATP substrate was significantly lower in groups II, III and IV (p < 0.05) after 3 days, while after 21 days, a reduction was observed in group III (p < 0.05). ADP hydrolysis was reduced in group II (p < 0.05) and increased in group IV (p < 0.05) after 3 days, while after 21 days there was an increase in group IV (p < 0.05). In the treatment with Vit. E, ATP hydrolysis was lower in groups II, III and IV (p < 0.05) after 3 and 21 days. ADP hydrolysis was increased in group II (p < 0.05) after 3 days, and in group IV (p < 0.05) after 21 days. However, 5'-nucleotidase activity was not altered by the treatments. These findings demonstrate that NTPDase activity in platelets is diminished in demyelinating events and the treatments with Ebs and Vit. E modulated adenine nucleotide hydrolysis.

Malathion, carbofuran and paraquat inhibit Bungarus sindanus (krait) venom acetylcholinesterase and human serum butyrylcholinesterase in vitro.

Carbofuran and malathion, well known pesticides, and paraquat, a world widely used herbicide, were tested on acetylcholinesterase (AChE) from Bungarus sindanus venom and butyrylcholinesterase (BChE) from human serum. The calculated IC(50 )values for inhibition of venom enzyme by malathion, carbofuran and paraquat were 2.5, 0.14, and 0.16 microM, respectively. The values for inhibition of serum butyrylcholinesterase (BChE) were 3.5, 0.09 and 0.18 microM, respectively. Analysis of kinetic data indicated that the inhibition caused by malathion, carbofuran and paraquat was mixed for venom AChE. For BChE from human serum, the inhibition caused by malathion and paraquat was mixed and for carbofuran it was uncompetitive. The present results suggest a commercial paraquat preparation (a popular herbicide) inhibits cholinesterases with similar or higher potency than classical pesticide inhibitors. Furthermore, this inhibition was observed both in human serum and snake venom, a newly studied source of AChE.

Oxidative stress and delta-ALA-D activity in chronic renal failure patients.

In this paper, we studied the influence of uremia and hemodialysis on oxidative parameters and delta-aminolevulinic acid dehydratase (delta-ALA-D) activity in control subjects, patients with chronic renal failure (CRF) on hemodialysis treatment (HD) and in patients not undergoing hemodialysis (ND). An increased lipid peroxidation was observed in the serum of HD and ND patients, as measured by the MDA serum levels. However, the level of MDA from erythrocytes was only elevated in HD patients. Blood catalase activity was increased in HD and ND groups. This study also showed a decreased activity of blood delta-aminolevulinic acid dehydratase (delta-ALA-D) in both groups of patients. This study demonstrated a positive correlation between ALA-D activity and hemoglobin, suggesting that inhibition of this enzyme might enhance anemia in CRF. A negative correlation was found between the alteration in delta-ALA-D activity and oxidative stress, which may indicate that the inhibition of ALA-D can be used as an index of oxidative stress.

Activities of enzymes that hydrolyze adenine nucleotides in platelets from rats experimentally demyelinated with ethidium bromide and treated with interferon-beta.

The activities of the enzymes NTPDase (EC 3.6.1.5, apyrase, CD39) and 5'-nucleotidase (EC 3.1.3.5, CD73) were analyzed in platelets from rats submitted to demyelination by ethidium bromide (EB) and treated with interferon beta (IFN-beta). The following groups were studied: I - control (saline), II - (saline and IFN-beta), III - (EB) and IV - (EB and IFN-beta). After 7, 15 and 30 days, the animals (n=7) were sacrificed and the platelets were separated by the method of Lunkes et al. [Lunkes, G., Lunkes D., Morsch, V., Mazzanti, C., Morsch, A., Miron, V., Schetinger, M.R.C., 2004. NTPDase and 5'-nucleotidase in rats alloxan- induced diabetes. Diabetes Research and Clinical Practice 65, 1-6]. NTPDase activity for ATP and ADP substrates was significantly lower in groups II and III after seven days, when compared to control (p<0.001). At fifteen days, ATP hydrolysis was significantly lower in group III and IV and higher in group II (p<0.001), while there was an activation of ADP hydrolysis in group II (p<0.001), when compared with the control. 5'-nucleotidase activity was significantly higher in group IV (p<0.001) after seven days, and lower in the groups III and IV (p<0.001) after fifteen days in relation to the control. No significant differences were observed in NTPDase and 5'-nucleotidase activities after thirty days. In conclusion, our study demonstrated that the hydrolysis of adenine nucleotides is modified in platelets of rats demyelinated and treated with IFN-beta.

Enhanced NTPDase and 5'-nucleotidase activities in diabetes mellitus and iron-overload model.

The activity of the enzymes NTPDase and 5'-nucleotidase was studied in both diabetes mellitus and an associated model of iron-overload. Rats were divided in five groups: citrate (CC), saline (S), diabetic (D), iron-overload (IO), and diabetic iron-overload (DIO). Diabetes was induced with alloxan (150 mg/kg), and iron-overload was induced with iron-dextran (10 intramuscular applications of +/-80 mg/kg). The enzymatic activities were evaluated in the platelets. The results demonstrated an increase in the activity of NTPDase with substrates ATP and ADP (60% and 120%, respectively; P<0.001), and 5'-nucleotidase (60%, P<0.001). This increase was more intense in the IO and DIO groups. The results obtained in vitro showed an activation in ATP, ADP, and AMP hydrolysis between 1 microM and 1,000 microM ferric nitrate concentrations, being more pronounced at 100 microM and decreasing at 1,000 microM. We concluded that diabetes mellitus in association with iron-overload increased the hydrolysis of adenine nucleotides in platelets, contributing to the abnormalities found in these pathological conditions.

Inhibition of two different cholinesterases by tacrine.

Kinetic parameters of the effect of tacrine as a cholinesterase inhibitor have been studied in two different sources: snake venom (Bungarus sindanus) acetylcholinesterase (AChE) and human serum butyrylcholinesterase (BChE). Tacrine inhibited both venom acetylcholinesterase (AChE) as well as human serum butyrylcholinesterase (BChE) in a concentration-dependent manner. Kinetic studies indicated that the nature of inhibition was mixed for both enzymes, i.e. Km values increase and Vmax decrease with the increase of the tacrine concentration. The calculated IC50 for snake venom and for human serum were 31 and 25.6 nM, respectively. Ki was observed to be 13 nM for venom acetylcholinesterase (AChE) and 12 nM for serum butyrylcholinesterase (BChE). KI (constant of AChE-ASCh-tacrine complex into AChE-ASCh complex and tacrine) was estimated to be 20 nM for venom and 10 nM for serum butyrylcholinesterase (BChE), while the gammaKm (dissociation constant of AChE-ASCh-tacrine complex into AChE-tacrine complex and ASCh) were 0.086 and 0.147 mM for snake venom AChE and serum BChE, respectively. The present results suggest that this therapeutic agent used for the treatment of Alzheimer's disease can also be considered an inhibitor of snake venom and human serum butyrylcholinesterase. Values of Ki and KI show that tacrine had more affinity with these enzymes as compared with other cholinesterases from the literature.

Enzymes that hydrolyze adenine nucleotides in chronic renal failure: relationship between hemostatic defects and renal failure severity.

The activities of the enzymes NTPDase (E.C.3.6.1.5, apyrase, ATP diphosphohydrolase, ecto-CD 39) and 5'-nucleotidase (E.C.3.1.3.5, CD 73) were analyzed in platelets from patients with chronic renal failure (CRF), both undergoing hemodialysis treatment (HD) and not undergoing hemodialysis (ND), as well as from a control group. The results showed an increase in platelet NTPDase activity in CRF patients on HD treatment (52.88%) with ATP as substrate (P<0.0001). ADP hydrolysis was decreased (33.68% and 39.75%) in HD and ND patients, respectively. In addition, 5'-nucleotidase activity was elevated in the HD (160%) and ND (81.49%) groups when compared to the control (P<0.0001). Significant correlation was found among ATP, ADP and AMP hydrolysis and plasma creatinine and urea levels (P<0.0001). Patients were compared statistically according the time of hemodialysis treatment. We found enhanced NTPDase and 5'-nucleotidase activities between 49 and 72 months on HD patients. Our result suggests the existence of alterations in nucleotide hydrolysis in platelets of CRF patients. Possibly, this altered nucleotide hydrolysis could contribute to hemostasis abnormalities found in CRF.

Enzymes that hydrolyze adenine nucleotides in platelets from breast cancer patients.

The activities of NTPDase (EC 3.6.1.5, apyrase, CD39) and 5'-nucleotidase (EC 3.1.3.5, CD73) enzymes were analyzed in platelets from breast cancer patients. Initially, patients were compared in terms of length (years) of tamoxifen use. The following groups were studied: breast cancer patients who did not use tamoxifen, patients using tamoxifen for 1-48 months, patients using tamoxifen for 49-84 months, and controls (healthy subjects). Results demonstrated that adenosine triphosphate (ATP) hydrolysis was enhanced (F(3,114)=8.53; P<0.001) and adenosine diphosphate (ADP) hydrolysis was reduced (F(3,106)=5.09, P=0.002) as a function of tamoxifen use, while adenosine monophosphate (AMP) hydrolysis was unchanged. Next, patients were compared statistically according to disease stage, determined by the tumor-node-metastasis (TNM) staging system for classifying breast tumor. ATP hydrolysis was significantly elevated in patients with stage I and II breast cancer (F(4,113)=4.35; P=0.003), but was normal in patients with stage III and IV cancer. ADP hydrolysis was reduced in stages II to IV (F(4,105)=3.88, P=0.006) and AMP hydrolysis was elevated in stage II (F(4,105)=3.45 P=0.01), but was normal in stages III and IV. Platelet aggregation time was similar in all patients regardless of tamoxifen use or disease stage. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were also within the normal range and similar among all groups. Similarly, fibrinogen and fibrin degradation product (FDP) were unchanged in all groups. In conclusion, our study demonstrated for the first time that hydrolysis of adenine nucleotides is modified in platelets from breast cancer patients taking tamoxifen.

NTPDase and 5'-nucleotidase activities in rats with alloxan-induced diabetes.

Diabetes is associated with a hypercoagulable state. In this study, we investigated the potential effects of alloxan-induced diabetes on the activities of the enzymes NTPDase (E.C. 3.6.1.5, apyrase, ATP diphosphohydrolase, ecto/CD39) and 5'-nucleotidase (E.C. 3.1.3.5, CD73) that can control the levels of ADP and adenosine, two substances that regulates platelet aggregation. In the alloxan-treated rats, NTPDase activity was significantly increased by 88 and 35% with ATP as substrate and by 156 and 58% with ADP as substrate in platelets and synaptosomes, respectively (P< 0.05). AMP hydrolysis was increased by 142% (platelets) and 70% (synaptosomes) in diabetic rats compared to control. These results demonstrate that alloxan-induced diabetes interferes with ATP, ADP, and AMP hydrolysis in platelets and synaptosomes. Taken together, these results may indicate that in diabetic rats both NTPDase and 5'-nuleotidase from the central nervous system (CNS) and platelets respond similarly with increased activity. Thus, we speculate that platelets could be used as a potential peripheral marker of central alterations in NTPDase and 5'-nucleotidase activities in diabetes.

Extrato da casca de Syzygium cumini no controle da glicemia e estresse oxidativo de ratos normais e diabéticos / Syzygium cumini bark extract in controling glycemia and oxidative stress of normal and diabetic rats

O Syzygium cumini, também conhecido como Jamboläo é amplamente utilizado na medicina popular para o tratamento da diabetes melito. Este estudo verificou a eficiência do extrato da casca de Syzygium cumini sobre os níveis glicêmicos e estresse oxidativo de ratos normais e diabéticos induzidos por aloxano. Os animais foram divididos em grupo controle (C), controle tratado (CT), diabético controle (DC) e diabético tratado (DT). A administraçäo oral do extrato aquoso da casca de Jamboläo, na dose de 1g/kg de peso vivo, por um período de trinta dias, näo resultou em uma reduçäo significativa na glicemia e nos níveis de hemoglobina glicosilada. Neste estudo, o tratamento com o extrato demonstrou um aumento dos níveis de substâncias reativas ao ácido tiobarbitúrico (TBA-RS) no plasma dos ratos do grupo DT (P<0,05), comparado com o C. A atividade da catalase nos rins dos ratos do grupo DC diminuiu significativamente (P<0,01) e no fígado houve uma elevaçäo significativa dessa enzima no grupo DC (P<0,01). Estes resultados indicam que o extrato da casca do Jamboläo näo possui efeito hipoglicemiante em ratos diabéticos induzidos pelo aloxano. O efeito antioxidante desta planta näo foi suficiente para diminuir significativamente a produçäo de TBA-RS. A diminuiçäo da atividade da catalase nos rins pode ser devida à exaustäo ou inibiçäo desta enzima e seu aumento, no fígado, devido ao estresse oxidativo, ocasionado pelo estado diabético

Enzymes that hydrolyze adenine nucleotides in diabetes and associated pathologies.

The activities of the enzymes NTPDase (E.C. 3.6.1.5, apyrase, ATP diphosphohydrolase, ecto-CD39) and 5'-nucleotidase (E.C. 3.1.3.5, CD73) were analyzed in platelets of type 2 diabetic, hypertensive and type 2 diabetic/hypertensive patients. The results showed an increase in platelet NTPDase activity in type 2 diabetic (34% and 72%), hypertensive (32% and 70%) and type 2 diabetic/hypertensive patients (30% and 55%) when compared to control (P<.01) with ATP and ADP as substrate, respectively. 5'-Nucleotidase activity was elevated in the hypertensive (60%) and type 2 diabetic/hypertensive (53%) groups when compared to the control and type 2 diabetic group (P<.01). No differences in sensitivity to inhibitors was detected between the platelets of controls and type 2 diabetic/hypertensive patients. No effects on the enzyme activities were observed when pharmacological doses of propranolol, captopril, furosemide, chlorpropamide, acetylsalicylic acid and glibenclamide were administered. Furthermore, changes in platelet adhesiveness and reactivity were found in all groups tested. In conclusion, we may postulate that NTPDase and 5'-nucleotidase from platelets are altered in patients with type 2 diabetes and hypertension. Probably, such alterations are involved in compensatory physiological responses in these diseases and are related to other important mechanisms of thromboregulation.

In vitro effects of L-arginine and guanidino compounds on NTPDase1 and 5'-nucleotidase activities from rat brain synaptosomes.

Tissue accumulation of arginine (Arg), N-acetylarginine (NA), argininic acid (AA) and homoarginine (HA) occurs in hyperargininemia, an inborn error of the urea cycle. In the present study, we investigated the in vitro effects of Arg, NA, AA and HA on NTPDase1 and 5'-nucleotidase activities from synaptosomal cerebral cortex of rats. The results showed that Arg enhances NTPDase1 activity at the high concentrations tested (1.5 and 3.0mM) for both the ATP and ADP nucleotides. Activation was also observed with other guanidino compounds tested: NA, AA and HA activated ATP and ADP hydrolysis in all experiments at the concentration of 25 microM. Besides this, NA and AA activated ATP hydrolysis at a lower concentration (1 microM). In another set of experiments, we verified the effect of Arg on purified apyrase at pH 8.0 and 6.5 and observed an increase in the enzyme activity at all Arg concentrations tested (0.01-3.0mM). In contrast, Arg and the other guanidino compounds tested did not alter 5'-nucleotidase activity. These results suggest that changes in nucleotide hydrolysis may be involved in the brain dysfunction caused by hyperargininemia amongst other potential pathophysiological mechanisms involved in this condition.