Pro-inflammatory cytokines in stable chronic alcoholics: relationship with fat and lean mass

Serum albumin and white matter hyperintensities

People living with HIV and those diagnosed with alcohol use disorders (AUD) relative to healthy individuals commonly have low levels of serum albumin, substantiated as an independent predictor of cardiovascular events. White matter hyperintensities (WMH)-a neuroimaging feature of cerebral small vessel disease-are also related to cardiovascular disease. Despite consensus regarding associations between high levels of urine albumin and WMH prevalence, and low serum albumin levels and impaired cognitive functioning, relations between serum albumin and WMH burdens have rarely been evaluated. Here, a sample including 160 individuals with AUD, 142 living with HIV, and 102 healthy controls was used to test the hypothesis that serum albumin would be inversely related to WMH volumes and directly related to cognitive performance in the two diagnostic groups. Although serum albumin and periventricular WMH volumes showed an inverse relationship in both AUD and HIV groups, this relationship persisted only in the HIV group after consideration of traditional cardiovascular (i.e., age, sex, body mass index (BMI), nicotine use, hypertension, diabetes), study-relevant (i.e., race, socioeconomic status, hepatitis C virus status), and disease-specific (i.e., CD4 nadir, HIV viral load, HIV duration) factors. Further, serum albumin contributed more significantly than periventricular WMH volume to variance in performance on a verbal learning and memory composite score in the HIV group only. Relations in both HIV and AUD groups between albumin and hematological red blood cell markers (e.g., hemoglobin, hematocrit) suggest that in this sample, serum albumin reflects hematological abnormalities. Albumin, a simple serum biomarker available in most clinical settings, may therefore help identify periventricular WMH burden and performance levels in specific cognitive domains in people living with HIV. Whether serum albumin contributes mechanistically to periventricular WMH in HIV will require additional investigation.

Association between lean body mass and hypertension: A cross-sectional study of 50 159 NHANES participants

Increasing attention has been paid to the association between lean body mass (LBM) and hypertension in recent years, but the previous findings have often been contradictory. Therefore, the authors investigated the association between LBM and hypertension through a cross-sectional study in the United States. To investigate the relationship between LBM and hypertension, the authors conducted weighted multivariable logistic regression models. The authors used the restricted cubic spline regression model to determine if there was a nonlinear correlation. In order to locate the inflection point, the authors built a two-part linear regression model using a recursive method. In the full adjustment model, LBM was positively associated with hypertension, with ORs (95% CI) of 1.19 (1.02, 1.38). In the further linear trend test, the ORs (95% CI) for Q2, Q3, and Q4 were 0.76 (0.60, 0.95), 0.62 (0.47, 0.80), and 0.66 (0.48, 0.91), respectively, compared to Q1, which suggested that the association between LBM and hypertension might be non-linear. The authors performed the restricted cubic spline curve to confirm this non-linear relationship and found the inflection point of 43.21 kg with an opposite relationship in which LBM and hypertension exhibited a negative correction of 0.66 (0.50, 0.86) before the inflection point and a positive correlation of 1.20 (1.03, 1.39) after the inflection point. Our study highlighted a non-linear association between LBM and hypertension in the general US population.

Alcohol use disorder and circulating cytokines: A systematic review and meta-analysis

There has been emerging interest in the role of the immune system in the pathophysiology of alcohol use disorder (AUD) given alcohol consumption stimulates immune cells to secrete peripheral pro- and anti-inflammatory cytokines. We conducted a systematic review and meta-analysis to determine whether an abnormal inflammatory cytokine profile exists in AUD patients compared to controls and whether cytokine levels were correlated with behavioural and psychiatric variables. Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines, a comprehensive search of electronic databases (MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library) was conducted, for AUD-related terms in combination with cytokine-related terms. Patients had to meet established criteria for AUD and be compared with healthy controls. A critical appraisal was completed using the Newcastle-Ottawa Scale. Twenty-four papers met the inclusionary criteria with 46 serum or plasma cytokines measured without immune stimulation whereby 17 studies had sufficient data for inclusion in the meta-analysis. Collectively, AUD patients had greater cytokine concentrations than control patients g = 0.85 [ 95% CI 0.42, 1.29]. Differences in cytokine concentrations between AUD patients and controls varied within-study by stage of illness (R₍₂₎² = 19.56%). The greatest differences were reported when AUD patients were engaging in active drinking g = 0.96 [0.49, 1.43] or were in alcohol withdrawal g = 1.25 [0.71, 1.80]. Baseline findings were moderated within and between studies by cytokine identity R₍₂₎² = 51.10%; R₍₃₎² = 44.89%. Cytokine concentrations were not significantly correlated with self-reported craving for alcohol, but were with alcohol consumption r = 0.22 [-0.05, 0.46]. The relationship between cytokine concentration and consumption was moderated by cytokine identity (R₍₂₎² = 100.00%; R₍₃₎² = 100.00%), and sample age (R₍₂₎² = 0.00%; R₍₃₎² = 95.76%). There is sufficient evidence to support the presence of an abnormal circulating cytokine profile in AUD which may vary with respect to the different stages of AUD illness.

The impact of alcohol use disorders on pulmonary immune cell inflammatory responses to Streptococcus pneumoniae

Community-acquired pneumonia due to Streptococcus pneumoniae occurs commonly in alcohol use disorders (AUDs). Pneumonia in the AUD patient is associated with poorer outcomes, and specific therapies to mitigate disease severity in these patients do not exist. Numerous investigations have attributed increased severity of pneumonia in AUDs to aberrant function of the alveolar macrophage (AM), a lung immune cell critical in host defense initiation. No studies have examined the response of human AMs to S. pneumoniae in AUDs. We hypothesized that the inflammatory mediators released by AMs after S. pneumoniae stimulation would differ quantitatively in individuals with AUDs compared to non-AUD participants. We further postulated that AM inflammatory mediators would be diminished after exposure to the antioxidant, N-acetylcysteine (NAC). For comparison, responses of peripheral blood mononuclear cells (PBMCs) to pneumococcal protein were also examined. Otherwise healthy participants with AUDs and smoking-matched controls underwent bronchoalveolar lavage and peripheral blood sampling to obtain AMs and PBMCs, respectively. Freshly collected cells were cultured with increasing doses of heat-killed S. pneumoniae protein, with and without exposure to N-acetylcysteine. Cell culture supernatants were collected, and inflammatory mediators were measured, including interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. IFN-γ and IL-6 were significantly higher in unstimulated AM cell culture supernatants from subjects with AUDs. After stimulation with pneumococcal protein, a dose-response and time-dependent increase in pro-inflammatory cytokine production by both AMs and PBMCs was also observed; differences were not observed between AUD and non-AUD subjects. Addition of NAC to pneumococcal-stimulated AMs and PBMCs was generally associated with diminished cytokine production, with the exception of IL-1β that was elevated in AM culture supernatants from subjects with AUDs. Our observations suggest that AUDs contribute to basal alterations in AM pro-inflammatory cytokine elaboration, but did not support consistent differences in pneumococcal-stimulated AM or PBMC inflammatory mediator secretion that were referable to AUDs.

Relationship between leptin concentration and body fat with peripheral blood mononuclear cells cytokines among obese and overweight adults

BACKGROUND

Overweight and obesity has been suggested to be well correlated with altered levels of pro-inflammatory cytokines.

AIM

The purpose of this study is to assess the relationship of body fat mass (BFM), body fat percentage (BFP) and leptin levels with peripheral blood mononuclear cells (PBMCs) cytokines among obese and overweight adults.

METHODS

Eighty-two overweight and obese individuals were divided into two BMI-category groups (BMI <30 and BMI ≥30 kg/m²) in this study. Balanced blocked randomization was used based on their sex and BMI ranges. Fasting blood samples, PBMCs cytokines, leptin and anthropometric indices were measured and PBMCs were cultured.

RESULTS

Mean of leptin concentrations were 23.14 ± 4.07 and 28.25 ± 4.35 pg/ml among individuals with BMI <30 and BMI ≥30 kg/m², respectively. The mean values of anthropometric measurements (all P < 0.001), the concentrations of TNF-α (P = 0.028) and IFN-γ (P = 0.029) were significantly higher among obese individuals. BFP had a significant positive correlation with leptin (P < 0.001, r = 0.445) and TGF-β (P = 0.03, r = 0.243). BFM has significant positive correlation with leptin (P < 0.001, r = 0.521). Leptin had a positive significant correlation with IFN-γ (p = 0.03, r = 0.251).

CONCLUSIONS

Regarding these results, we proved that BFP, BFM and leptin levels have significant correlations with some PBMC cytokines. Focusing on such strategies may lead to promises for alleviating obesity and its co-morbidities.

Osteoporosis and fractures in liver disease: Relevance, pathogenesis and therapeutic implications

It is being increasingly recognized that patients with liver disease develop bone loss that can be severe enough to lead to atraumatic fractures and thus markedly diminish life quality and expectancy. The estimated prevalence for liver-related osteoporosis is between 20-420/100000 of the general population, and fractures between 60-880/100000. It should be kept in mind that up to 40% of patients with chronic liver disease may experience a fracture. The pathogenic mediators include fibronectin, insulin like growth factor-I, and various cytokines, but decreased vitamin D and/or treatment with corticosteroids contribute to worsening bone health. Despite the advances in bone biology that have shed some light on the pathogenesis of this bone loss, treatment options remain nonspecific and tightly linked to treatments of other forms of osteoporosis. Thus, treatment should include calcium and vitamin D supplementation in all patients with chronic liver disease. Therapy with bisphosphonates should be considered, especially in patients receiving corticosteroids. This review focuses on the prevalence of this entity as well as the evidence available with regard to the pathogenesis of bone loss in liver disease, the diagnostic steps required in all patients, and the therapeutic options available.

Investigation of the direct hepatic effects of intramuscular interleukin-8 injection in an experimental rabbit model

BACKGROUND

The aim of this study was to investigate the effects of intramuscular IL-8 injection on hepatic tissues using an in vivo histopathological animal model.

MATERIAL AND METHODS

Twelve New Zealand white rabbits were used for this randomized, controlled, single-blinded interventional study. For 6 days, 1 gluteus maximus muscle was injected daily with 1 mcg/kg of IL-8 in 6 rabbits (Group A). The remaining 6 rabbits (to determine to normal porto-hepatic morphology of the rabbit genus) were in the sham group (Group B). At the end of the 7th day, all rabbits were killed and livers were meticulously harvested. Microscopically, regional tissues were scored according to portal inflammation, focal necrosis, piecemeal necrosis, and total impact.

RESULTS

Total impact score, portal inflammation, focal necrosis, and piecemeal necrosis were the histopathologic changes present in a higher incidence in the IL-8 group compared with the control group. The differences were significant when the groups were compared according to total impact score, portal inflammation, focal necrosis, and piecemeal necrosis according to Pearson's correlation (p<0.05). The most significant differences were detected at the total impact scores (p=0.002) and the portal inflammation scores (p=0.008).

CONCLUSIONS

Our results showed that IL-8 may damage hepatocytes. This can be the determined target for new therapeutic strategies. Further trials should be designed to obtain definitive results.

Changes in cytokine levels during admission and mortality in acute alcoholic hepatitis

Cytokine levels are raised in acute alcoholic hepatitis. However, there are disparate results regarding the duration of altered plasma levels, and there are also discrepancies about the relation of changes during the first 15 days after admission with short-term (in-hospital) or long-term mortality. In 56 patients with acute alcoholic hepatitis we found that IL-8, IL-4, Interferon-γ (IFN-γ), malondialdehyde and C-reactive protein remained higher in patients than in 18 age- and sex-matched controls at admission, at the 7th day and at the 15th day after admission. Moreover, IL-4 levels (and to a lesser extent, IL-10 and IFN-γ ones) increased along the three determinations. However, comparing patients who died during the admission with those who did not, there were no statistically significant differences, but there was a nearly significant trend for MDA (Z=1.89; p=0.059), with higher levels among those who died. When changes between the first and the second determinations were compared with long-term survival, only IL-8 and IFN-γ showed a relation with mortality. IFN-γ values increased among those who survived and decreased among those who died (p=0.048). IFN-γ values at the first determination also showed a relation with long-term mortality, especially when patients with IFN-γ values in the first quartile were compared with those of the 4th one (log rank=5.64; p=0.018; Breslow=4.64; p=0.031). Besides Interferon-γ, only C-reactive protein showed differences between the first and the 4th quartile regarding mortality (Log rank=4.50; p=0.034; Breslow 4.33; p=0.038). In contrast with other studies, no relation was found between TNF-α or IL-6 and mortality.

A longitudinal analysis of circulating stress-related proteins and chronic ethanol self-administration in cynomolgus macaques

BACKGROUND

Alcoholics have alterations in endocrine and immune functions and increased susceptibility to stress-related disorders. A longitudinal analysis of chronic ethanol intake on homeostatic mechanisms is, however, incompletely characterized in primates.

METHODS

Plasma proteins (n = 60; Luminex) and hormones (adrenocorticotropic hormone [ACTH]; cortisol) were repeatedly measured in adult male cynomolgus monkeys (Macaca fascicularis, n = 10) during a 32-month experimental protocol at baseline, during induction of water and ethanol (4% w/v in water) self-administration, after 4 months, and after 12 months of 22-hour daily concurrent access to ethanol and water.

RESULTS

Significant changes were observed in ACTH, cortisol, and 45/60 plasma proteins: a majority (28/45) were suppressed as a function of ethanol self-administration, 8 proteins were elevated, and 9 showed biphasic changes. Cortisol and ACTH were greatest during induction, and correlations between these hormones and plasma proteins varied across the experiment. Pathway analyses implicated nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) as possible mediators of ethanol-induced effects on immune-related proteins in primates.

CONCLUSIONS

Chronic ethanol consumption in primates leads to an allostatic state of physiological compromise with respect to circulating immune- and stress-related proteins in NF-κB- and STAT/JAK-related pathways in correlation with altered endocrine activity.

Cortical bone is more sensitive to alcohol dose effects than trabecular bone in the rat

OBJECTIVE

While chronic alcohol consumption is known to decrease bone mineral content (BMC), bone mineral density (BMD), and negatively modify trabecular bone microarchitecture, the impact of alcohol on cortical microarchitecture is still unclear. The aim of this study was to investigate the effects of various doses of alcohol on bone density, trabecular and cortical parameters and bone strength in rats.

METHODS

Forty-eight male Wistar rats were divided into four groups: control (C), alcohol 25% v/v (A25), alcohol 30% v/v (A30) and alcohol 35% v/v (A35). Rats in the alcohol groups were fed a solution composed of ethanol and water for 17 weeks while the control group drank only water. Bone quality and quantity were evaluated through the analysis of density, trabecular and cortical bone microarchitectural parameters, osteocalcin and N-Telopeptide concentrations and a 3-point bending test.

RESULTS

Bone density along with trabecular and cortical thickness were lower in alcohol groups compared to C. BMD was lower in A35 vs. A30 and cortical thickness was lower in A35 vs. A25 and A30. Pore number was increased by alcohol and the porosity was greater in A35 compared to C. N-Telopeptide concentration was decreased in alcohol groups compared to control whereas no differences were observed in osteocalcin concentrations. Maximal energy to failure was lower in A25 and A35 compared to C.

CONCLUSION

Chronic ethanol consumption increases cortical bone damage in rats and may have detrimental effects on bone strength. These effects were dose-dependent, with greater negative effects proportionate to greater alcohol doses.

Does the simultaneous tumor necrosis factor receptor 2, tumor necrosis factor promoter gene polymorphism represent a higher risk for alcoholic liver disease?

BACKGROUND AND AIM

Tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine that seems to play a crucial role in the pathogenesis of alcoholic liver disease (ALD). TNF-alpha exerts its effects by binding to specific receptors (TNFR); the polymorphism of TNFRII T587G has been associated with increased TNF apoptotic response and its presence may increase the risk to develop liver disease. The aim of this study was to evaluate the prevalence of the TNF-alpha G238A promoter and TNFRII polymorphisms, individually or simultaneously, in ALD.

METHODS

TNF-alpha G238A and TNFRII T587G polymorphisms were studied in 103 unrelated patients with ALD (biopsy confirmed or clinical evidence) and in 76 heavy drinkers without liver disease (NLD). Single nucleotide polymorphism gene was detected by a polymerase chain reaction-restriction fragment length polymorphisms method. All patients had, at least, a 5 year history of alcohol consumption greater than 80 g/day.

RESULTS

TNF-alpha G238A allele frequency was similar in both groups. TNFRII T587G allele frequency was slightly higher in the ALD group than in the NLD group (21 vs. 18%, P=NS). TNF-alpha G238A and TNFRII T587G were simultaneously present in six ALD patients and in none of NLD patients (P=0.04).

CONCLUSION

Although individually there was no association between TNFRII T587G or TNF-alpha G238A polymorphisms and ALD, this study suggests that the presence of both polymorphisms may enhance the susceptibility for ALD. TNF-alpha G238A may increase TNF-alpha production, which when associated with TNFRII T587G, can further exacerbate TNF-alpha response leading to a greater risk of ALD.

Brain atrophy in alcoholics: relationship with alcohol intake; liver disease; nutritional status, and inflammation

OBJECTIVES

Brain atrophy is a common finding in alcoholics. Several mechanisms may be involved, including ethanol itself, malnutrition, liver failure, and, possibly, ethanol-induced hormone and cytokine changes. The aim of this study was to analyse the relation of brain atrophy-assessed by computerized tomography (CT) scan-and the aforementioned alterations.

METHODS

Serum insulin-like growth factor 1 (IGF-1), interleukin (IL)-6, IL-8, IL-10, TNF alpha, PTH, estradiol, free testosterone, and corticosterone were measured in 36 alcoholics, ten of them cirrhotics, who also underwent brain CT, which recorded the presence of cortical atrophy or cerebellar atrophy, Evan's, Huckmann's, cella media, bicaudate, cortical atrophy, bifrontal, and ventricular indices, and diameter of the third ventricle; subjective nutritional assessment, midarm anthropometry, and evaluation of liver function.

RESULTS

Patients showed marked alterations of all the CT indices compared with 12 controls, but poor relations between these indices and the other parameters analysed (IGF-1, handgrip strength and years of addiction with bifrontal index (P < 0.025 in all cases); PTH and Evan's index (r = 0.36, P = 0.032); mean corpuscular volume with cella index and cortical atrophy (P < 0.05). Cerebellar atrophy was associated with a greater daily ethanol consumption (t = 2.19, P = 0.034).

CONCLUSION

Brain atrophy is frequently observed in alcoholics, but relationships with liver function, cytokines, nutritional status, and hormone levels are poor.