Autoantibodies and immunoglobulins in alcoholic steatosis and cirrhosis

AHR rs4410790 genotype and IgG levels: Effect modification by lifestyle factors

Inflammation is a multifaceted marker resulting from complex interactions between genetic and lifestyle factors. Emerging evidence suggests Aryl hydrocarbon receptor (AHR) protein may be implicated in the regulation of immune system and inflammatory responses. To investigate whether rs4410790 genotype (TT, TC, CC) near AHR gene is related to serum IgG levels, a marker of chronic inflammation, and whether lifestyle factors modifies the relationship, we conducted a cross-sectional study by recruiting 168 Korean adults. Participants responded to a lifestyle questionnaire and provided oral epithelial cells and blood samples for biomarker assessment. Among these participants, C allele was the minor allele, with the minor allele frequency of 40%. The rs4410790 TT genotype was significantly associated with elevated IgG levels compared with TC/CC genotypes, after adjusting for potential confounders (p = 0.04). The relationship varied significantly by levels of alcohol consumption (P interaction = 0.046) and overweight/obese status (P interaction = 0.02), but not by smoking status (P interaction = 0.64) and coffee consumption (P interaction = 0.55). Specifically, higher IgG levels associated with the TT genotype were evident in frequent drinkers and individuals with BMI≥23kg/m2, but not in their counterparts. Thus, rs4410790 genotype may be associated with IgG levels and the genetic predisposition to higher IgG levels may be mitigated by healthy lifestyle factors like infrequent drinking and healthy weight.

Global prevalence, incidence, and outcomes of alcohol related liver diseases: a systematic review and meta-analysis

BACKGROUND

Alcohol related liver disease (ARLD) is one of the major chronic liver diseases worldwide. This review aimed to describe the global prevalence, incidence, and outcomes of ARLD.

METHODS

Medline, Embase, The Cochrane Library, and China National Knowledge Infrastructure (CNKI) were searched from inception to May 31, 2022. The language was restricted to English or Chinese. According to the criteria, articles describing the basic characteristics of the population were selected. Two reviewers extracted the data independently.

RESULTS

A total of 372 studies were identified: 353 were used for prevalence analysis, 7 were used for incidence analysis, and 114 were used to for outcome analysis. The prevalence of ARLD worldwide was 4.8%. The prevalence in males was 2.9%, which was higher than female (0.5%). Among the ethnic groups, the percentage was highest in Caucasians (68.9%). Alcoholic liver cirrhosis comprised the highest proportion in the disease spectrum of ARLD at 32.9%. The prevalence of ascites in ARLD population was highest (25.1%). The ARLD population who drinking for > 20 years accounted for 54.8%, and the average daily alcohol intake was 146.6 g/d. About 59.5% of ARLD patients were current or former smokers, and 18.7% were complicated with hepatitis virus infection. The incidence was 0.208/1000 person-years. The overall mortality was 23.9%, and the liver-related mortality was 21.6%.

CONCLUSION

The global prevalence of ARLD was 4.8% and was affected by sex, region, drinking years, and other factors. Therefore, removing the factors causing a high disease prevalence is an urgent requisite.

TRIAL REGISTRATION

PROSPERO Nr: CRD42021286192.

Serum levels of immunoglobulins (IgG, IgA, IgM) in a general adult population and their relationship with alcohol consumption, smoking and common metabolic abnormalities

The present study investigated serum immunoglobulin (Ig) concentrations in relation to demographic factors, common habits (alcohol consumption and smoking) and metabolic abnormalities in an adult population-based survey including 460 individuals. Serum levels of interleukin (IL)-6, a marker of inflammation, were also determined. After adjusting for confounders, male sex was associated positively with IgA levels and negatively with IgM levels. Age was associated positively with IgA and IgG levels. Smoking was associated negatively with IgG levels. Heavy drinking was associated positively with IgA levels. Metabolic abnormalities (obesity and metabolic syndrome) were associated positively with IgA levels. Abdominal obesity and hypertriglyceridaemia were the components of metabolic syndrome associated most strongly with serum IgA. Heavy drinkers with metabolic syndrome showed particularly high serum IgA levels. Serum IL-6 levels were correlated positively with IgA and IgG concentrations. It is concluded that sex, age, alcohol consumption, smoking and common metabolic abnormalities should be taken into account when interpreting serum levels of IgA, IgG and IgM.

Autoantibodies in mothers of children with neonatal liver disease

OBJECTIVES

Neonatal lupus erythematosus (NLE) is associated with maternal anti-Ro/La autoantibodies. It is characterized by heart block and/or cutaneous skin lesions, and occasionally liver disease. This study was performed to determine whether idiopathic neonatal cholestasis (INC) represents NLE without its cardiac or cutaneous findings.

METHODS

Sera were obtained for autoantibody analysis from mothers of children with INC (N = 11), biliary atresia (N = 25), other liver disease excluding viral hepatitis (liver disease control subjects, N = 14), and healthy children (normal control subjects [NC], N = 22).

RESULTS

The characteristic serologic findings of NLE, high titer antibodies to Ro and/or La, were absent in mothers from all groups. An unexpected finding was the prevalence of autoantibodies in mothers of infants with liver disease of any type. The frequency of maternal antinuclear antibodies at > or = 1:120 dilution was greater than the estimated frequency in the general population (22% vs. 9%, P = 0.044). The frequency of maternal low titer autoantibodies to 52 kD Ro detected by ELISA was significantly greater than in the NC group (31% vs. 5%, P = 0.014).

CONCLUSIONS

The majority of cases of INC do not represent NLE. The frequent presence of autoantibodies in mothers of infants in all neonatal liver disease groups raises the possibility that maternal serologic autoimmunity is associated with neonatal liver disease.

Time-course changes of serum immunoglobulins (IgA, IgG, IgM) after liver transplantation for alcoholic cirrhosis

BACKGROUND

Serum immunoglubulin increase is a hallmark of liver disease. Serum IgA is specifically increased in alcoholic liver disease, which has been considered an IgA-associated disorder. No previous studies have been focused on the time-course changes of serum immunoglobulins (IgG, IgA, IgM) after liver transplantation.

AIM OF THE STUDY

To investigate the outcome of serum immunoglobulin levels in alcoholic cirrhosis after liver transplantation, with special focus on IgA values.

PATIENTS AND METHODS

A total of 18 patients, liver transplanted in our center because of alcoholic cirrhosis were included in the study. Serum immunoglobulins were assayed by nephelometry before transplantation and at different intervals after the procedure from the intraoperative period to more than a year after transplantation.

RESULTS

A rapid drop in IgA, IgG and IgM concentration was observed during the surgical procedure, particularly after donor liver reperfusion, and during the first days after transplantation. Mild transient hypogammaglobulinemia (IgG) was present. After a subsequent moderate re-increase, serum immunoglobulins (particularly IgA and IgG) remained stable within normal or near-normal limits during the following months after liver transplantation.

CONCLUSIONS

Liver transplantation for alcoholic cirrhosis is followed by a decrease in serum IgA, IgG and IgM. In the short term, low IgG levels may be observed. In the long term, serum levels of IgA and IgG become normal or near-normal.

Impaired immunoglobulin M production by incubation of hybridoma cells with ethanol

Several reports have presented results that demonstrate suppression of the immune system by ethanol. Using a hybridoma cell model, we studied the effects of ethanol on cell proliferation and on the production of immunoglobulin M (IgM) antibodies. The number of cells decreased while incubated with as little as 25 mM ethanol but not in a clonal subline incapable of IgM production, indicative of an increased vulnerability associated with the antibody-producing machinery. Levels of antibodies in cell culture supernatants were monitored by -heavy-chain-specific and -light-chain-specific enzyme-linked immunosorbent assays. We found a significant decrease in antibody concentration at 200 mM ethanol compared with findings for nonexposed cells. In addition, lower -chain compared with -chain values were monitored at ethanol concentrations of 50 mM and higher. This difference suggests irregular composition of the antibodies in the supernatant. Determination of IgM levels within the hybridoma cells revealed a linear increase in antibody concentrations by as much as three times the control levels with increasing ethanol concentrations when correlated with cell numbers. Analysis of the mRNA levels of two ethanol-inducible stress proteins, the 78-kilodalton glucose-regulated protein (GRP78) and the 70-kilodalton heat-shock protein (HSC70), by quantitative Northern hybridization yielded increased mRNA in a nonlinear fashion. The results demonstrate that ethanol impairs IgM composition, whereas antibody production within hybridoma cells is increased and the assembling machinery is activated, indicating compensating processes.

Modern approach to alcoholic liver disease

The pathogenesis of alcoholic liver disease is unclear. The recent literature on pathogenic factors, including direct effects of ethanol and its proximate metabolite acetaldehyde, associated nutritional factors, the formation of acetaldehyde-protein adducts, associated immune alterations, and the potential for liver injury due to coexisting hepatitis virus infection, is highlighted. The therapy of patients with advanced alcoholic liver injury, especially alcoholic hepatitis, is also controversial. It seems reasonable that all patients should receive adequate nutrition even if parenteral or enteral supplementation is required. Corticosteroid administration may benefit those patients with alcoholic hepatitis who have coexisting spontaneous hepatic encephalopathy and no gastrointestinal bleeding. For patients with complications from end-stage alcoholic cirrhosis, liver transplantation should be considered, as the patient with alcoholic cirrhosis does as well after liver transplantation as those patients with other forms of end-stage liver disease.

Low serum levels of alpha-interferon, gamma-interferon, and interleukin-2 in alcoholic cirrhosis

The existence of cellular immune deficit in alcoholic cirrhosis, together with the role of alpha- and gamma-interferon and interleukin-2 in the immune system, led us to compare serum levels of these immune system mediators in a group of 40 patients with alcoholic cirrhosis classified according to Child-Pugh's grade of severity of liver disease and 23 healthy volunteers. Serum levels of alpha-IFN, gamma-IFN, and IL-2 were significantly depressed in alcoholic cirrhotics, with no significant differences between the different degrees of hepatic damage. The results suggest a profound alteration in the immune system of alcoholic cirrhotics, which may contribute to the development of the disease and the accompanying immune system deficit.

Autoantibodies to histones and their subfractions in chronic liver diseases

Sera of 78 patients with different chronic liver diseases were examined for the presence of anti-histone activity using an enzyme-linked immunosorbent assay. Eighteen patients had primary biliary cirrhosis (PBC), 20 had chronic active hepatitis, and 40 had cirrhosis. Anti-histone antibodies were detected in 34 patients (43.6%), distributed among all liver disease entities studied. When antibodies of specific isotypes (IgG, IgM, and IgA) were measured, even higher frequencies were noted--50% for IgG and 53.8% for IgA. Antibodies to histone subfractions H1, H2a, H2b, H3, and H4 were also observed in all liver disorders investigated (in 22-32% of patients)--H1 and H3 being the prominent fractions involved. Of the various disease entities examined PBC was the one disclosing the highest frequency of anti-histone antibodies.

Common lupus anti-DNA antibody idiotypes in chronic liver diseases

Chronic liver diseases may be associated with the appearance of antinuclear antibodies. To further analyze the relationship between connective tissue and liver diseases the sera of 88 patients with chronic liver disorders were examined for the presence of common lupus anti-DNA idiotypes (16/6-id, 134-id, and 32/15-id), using an enzyme-linked immunosorbent assay. The 16/6-id was found in 58 (65.9%), the 134-id in 43 (48.9%), and the 32/15-id in 13 (14.8%) of the patients' sera. Distinct diagnostic groups displayed different lupus anti-DNA idiotype profiles. Patients with primary biliary cirrhosis (PBC) and chronic active hepatitis (CAH) had mainly the 16/6 idiotype, while in alcoholic (AC) and in cryptogenic cirrhosis (CC) the 16/6-id and 134-id were the main idiotypes recorded. There was considerable correlation among the different anti-DNA idiotypes but not between any of these idiotypes and an unrelated common anti-HBsAg idiotype. The occurrence of the various idiotypes was not found to be correlated with increased serum immunoglobulin levels. It can be concluded that the similarities between chronic liver diseases and connective tissue diseases are extended also to the presence of specific common anti-DNA antibody idiotypes.

Antibody to G-actin in different categories of alcoholic liver disease: quantification by an ELISA and significance for alcoholic cirrhosis

Autoantibodies to smooth muscle (ASMA), and to actin which is a major determinant of such reactivity, were measured in the serum of 94 patients with three defined categories of alcoholic liver disease, fatty liver, alcoholic hepatitis, and alcoholic cirrhosis, and in controls matched individually by age and sex with the patients. Autoantibody to monomeric G-actin was detected by an ELISA and autoantibody to polymeric F-actin by immunofluorescence staining of fibroblast stress fibers in cultured cells. Values for the ELISA were expressed as a percentage of the value for a strongly reactive standard serum. The mean value for antibody to G-actin in 40 patients with alcoholic cirrhosis (70 +/- 33%) was significantly greater than that for the matched controls (28 +/- 18%), but the mean value for the 30 patients with alcoholic hepatitis (46 +/- 16%) and the 24 with fatty liver (42 +/- 24%) did not differ significantly from the controls. High levels of reactivity with G-actin correlated significantly with HLA B7. ASMA was demonstrable to low titer in 11 of the 94 sera, and positive ASMA reactions by immunofluorescence correlated with high binding values to G-actin in the ELISA. Antibody to F-actin was found in only one serum and no controls. Thus in different liver diseases the reactivity of antibodies to monomeric G-actin and polymeric F-actin may differ, presumably because of specificity for different determinants of the actin molecule. Reactivity to G-actin may distinguish a group of alcoholic subjects in whom a predisposition to autoimmune reactivity is one of the determinants of progression of liver damage to cirrhosis.