IL-1β Allele Research Articles

Impact of interleukin-1 gene polymorphisms on the severity of COVID-19

The severity of Coronavirus Disease 2019 (COVID-19) has been closely linked to an exacerbated proinflammatory response and cytokine storm. Interleukin-1 (IL-1), a pivotal proinflammatory cytokine, plays a crucial role in the development of acute respiratory distress syndrome (ARDS) and multiorgan dysfunction. Single nucleotide polymorphisms within the IL-1 gene have been shown to modulate IL-1 cytokine levels. This study aimed to investigate the association of IL-1 gene polymorphisms (IL-1 + 3953C > T, IL-1β -511 T > C, and IL-1Ra) with the severity of COVID-19. Genotyping of IL-1 gene polymorphisms (IL-1 + 3953C > T, IL-1β -511 T > C) were performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while IL-1Ra genotyping was done by Random Amplification of Polymorphic DNA (RAPD). PCR-RFLP data were validated through Sanger sequencing (SeqStudio Genetic Analyzer). Data analysis was carried out by SPSS-v21 and SHesis (online version). The frequency of the T allele of the IL-1 + 3953C > T polymorphism was found to be higher in mild cases as compared to severe cases, demonstrating a significant protective effect against COVID-19 severity (P = 0.001). However, no significant associations were observed for IL-1β -511 T > C and IL-1Ra polymorphisms (P > 0.05). In haplotype analysis (between IL-1 + 3953C > T, and IL-1β -511 T > C gene polymorphisms), individual with CT haplotype showed a higher risk of severity (OR = 1.8, P = 0.001), while individuals with TT haplotype showed significant protection against severity (P = 0.001). Our findings suggest that the T allele of IL-1β + 3953C > T polymorphism may confer protective effect against the severity of COVID-19.

Evaluation of the Association between Genetic Polymorphism of Interleukin-1 Beta (–511C/T and +3953C/T) and Cervical Cancer Susceptibility

Cervical cancer (CC) is the leading cause of cancer-related mortality among women, primarily caused by persistent human papillomavirus (HPV) infection, especially in developing countries. A proinflammatory cytokine, emerging as a major facilitator of carcinogenesis, is termed interleukin-1 beta (IL-1β), which characterizes host-environment interactions. Numerous epidemiological studies have revealed that IL-1β gene polymorphisms have been associated with numerous malignancies, but in the context of CC, results of these studies were inconclusive. Thus, our study aimed to explore the relationship between IL-1β polymorphisms (-511C/T and +3953C/T) and CC susceptibility. Genotyping was conducted on 192 CC patients and 200 healthy controls through polymerase chain reaction-restricted fragment length polymorphism. HPV analysis was done through real-time polymerase chain reaction, and the serum concentration of IL-1β was measured by enzyme-linked immunosorbent assay. Women with CT and TT genotypes of IL-1β -511C/T had a threefold increased risk of CC (odds ratio [OR], 3.60; 95% confidence interval [CI], 2.132-6.063; p < 0.001 vs. OR, 3.34; 95% CI, 1.952-5.713; p < 0.001) compared to controls. Women with the T allele of IL-1β -511C/T polymorphism were associated with increased CC susceptibility (OR, 2.00; 95% CI, 1.51-2.66; p = 0.0001) compared to controls. No significant difference was found between patients and controls in the genotype or allele frequencies of IL-1β +3953C/T polymorphism (OR, 0.93; 95% CI, 0.56-1.55; p = 0.86 vs. OR, 0.95; 95% CI, 0.72-1.26; p = 0.74). There was no significant association found between IL-1β -511C/T promoter (OR, 2.41; 95% CI, 0.46-12.76; p = 0.28 vs. OR, 1.64; 95% CI, 0.13-21.10; p = 0.7) and +3953C/T (OR, 3.76; 95% CI, 0.44-31.82; p = 0.19 vs. OR, 0.21; 95% CI, 0.01-3.92; p = 0.25) polymorphisms in tobacco chewers and smokers compared to controls. The level of serum concentration of IL-1β was significantly higher in cases compared to controls. Our results conclude that IL-1β -511C/T polymorphism is associated with CC susceptibility.

Pro-inflammatory and anti-inflamatory cytokine genes polymorphisms and susceptibility to Japanese encephalitis disease in the North Indian population.

Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in many regions of Asia. Cytokines, including pro-inflammatory and anti-inflammatory are key regulators playing a detrimental role in the host response to JE infection, pathogenesis and disease outcome. Evidently, the host's cytokine response is genetically determined, representing the complexity of interindividual differences regarding immune response to viral infection. The current study assesses the association of single nucleotide polymorphisms of classical interleukin IL-1β and IL-10 with JEV susceptibility and disease severity in north Indian population. We performed a case-control study using 85 JE patients and 85 healthy controls. Polymorphisms in the IL-1β (-511 C/T) and IL-10 (-1082 A/G) genes were genotyped using PCR-RFLP. All continuous variables were expressed as mean±standard deviation, and categorical variables were expressed in percentage. The mRNA level of IL-1β and IL-10 were found significantly increased in JE patients. In severe JE patients, IL-1β mRNA level was significantly higher with heterozygous (C/T) and homozygous (C/C) genotype compared to wild (T/T) genotype and mRNA level of IL-10 was higher in heterozygous genotype (A/G) compared to wild genotype (A/A). The C/T and C/C genotypes of IL-1β were significantly associated with higher risk of JE infection (p<0.05, OR=7.25 and 4.40) whereas, the A/G genotype of IL-10 was associated with a reduced risk of JEV infection (p<0.05, OR=0.30). The C allele of IL-1β was associated with fever and neck stiffness (p<0.05) and CT genotype was associated with disease severity and worse outcomes in JE patients. Along with this, IL-10 polymorphism was found associated with fever, and AG genotype was found to be associated with worse disease outcomes such as neurological sequelae (p<0.05). Mutant allele and genotype at IL-1β (-511 C/T) and IL-10 (-1082 A/G) gene polymorphism show increased expression of IL-1β and IL-10 in JE patients which contribute to disease severity as well as adverse outcomes of disease. Overall this is the first report from northern India, which shows the association of IL-1β and IL-10 polymorphisms with JEV infection.

Frequency of Cytokine Gene Polymorphism in Full-Term Newborns with Hypoxic Events

Background. An infant brain damage is an extremely urgent problem, this pathology is difficult to prevent, and subsequently it manifests itself with a variety of neurological consequences. Various mechanisms are involved in neurodamage; cytokines, as well as genes that control their activity, are under a great concern today. However, there is little data about their role as predictors of the brain damage among children after hypoxia. Aim of the research. To identify the frequency of cytokine gene polymorphism: interleukin (IL)-1β(C-511T), IL-1β(C3953T), IL-4(C589T), IL-6(C174G), IL-10(C819T), IL-10(G1082A) among newborns with hypoxic events. Materials and methods. The study involved 128 full-term newborn patients with hypoxic events: the first group (n = 48) included newborns who experienced chronic intrauterine hypoxia (CVH), the second group (n = 80) included newborns born in asphyxiation. Control group (52) included babies born without asphyxia and not suffering from CVH. A retrospective analysis of case-records was carried out. The material for molecular genetic analysis was DNA samples isolated from umbilical cord blood leukocytes using DNA Express Blood reagents (Scientific and Production Company LITECH, Moscow). Results. Compared to the control group (p = 0.03) children born in asphyxia had their T allele IL-1β (C-511T) prevailed. The group of newborn who had CVH had their TT genotype (p = 0.04) and the T IL-1β allele (C-511T) (p = 0.01) prevailed compared to the control group. In the same study group while studying the polymorphism of the IL-1β gene, the T allele (p = 0.03) at the point C3953T prevailed, in contrast to the control group. Conclusion. Due to the fact that cytokines are part of a reaction cascade leading to the secondary brain damage, under the action of hypoxia, it was found that among newborns undergoing asphyxia and chronic intrauterine hypoxia the increased frequencies of carriage of IL-1β-511TT and IL-1β-3953TT genotypes, and IL-1β-511T and IL-1β-3953T alleles increase the risk of neurodamage.

591-P: Macrophage IL-1beta–Dependent VEGF-A Expression Is Required for Inflammatory Arteriogenesis and Wound Healing in Type 2 Diabetes

Impaired wound healing in patients with diabetes mellitus (DM) is a major source of morbidity and mortality. Current treatments for diabetic wounds are modestly effective at promoting healing. Recently, we identified an important role for inflammatory macrophage VEGF-A production in consequent angiogenesis/arteriogenesis required for adequate wound healing. We sought to understand the impact of diabetes on inflammatory angiogenesis and consequent healing. We hypothesized that diabetes mellitus (DM) results in reduced inflammatory macrophage VEGF-A expression with consequent impairments in angiogenesis-dependent wound healing. Mice with experimental diabetes demonstrated profound delays both in wound healing using a dermal punch biopsy model and in perfusion recovery using the femoral artery ligation model of hind limb ischemia. VEGF-A expression is highly upregulated in “classic inflammatory” macrophages relative to “alternatively activated” or wound healing macrophages. This is supported by a strong association between IL-1β and VEGF-A expression. In order to understand whether this relationship between IL-1β and VEGF-A was causal, we generated a novel mouse with a LoxP flanked IL-1β allele to create an inducible macrophage deletion of IL-1β. Myeloid IL-β deletion resulted in severely impaired macrophage VEGF-A expression and consequent decreases in angiogenesis and wound healing, consistent with the experimental model of DM. Moreover, macrophages from diabetic mice demonstrated reduced expression of IL-1R signaling complex components along with consequent reductions in VEGF-A expression. Defining inflammatory macrophages as key, early drivers of angiogenesis supports a paradigm shift away from inflammation-suppression for adequate wound healing, allowing for macrophage reprograming strategies that promote appropriate inflammation-dependent healing responses. Disclosure C.S. Mantsounga: None. Funding National Institutes Health (1R01HL139795)

Association of genetic polymorphisms of IL1β -511 C>T, IL1RN VNTR 86bp, IL6 -174 G>C, IL10 -819 C>T and TNFα -308 G>A, involved in symptomatic patients with dengue in Brazil.

In this study, single nucleotide polymorphisms (SNP) of interleukin (IL) 1β -511C>T, IL1RN VNTR 86bp, IL6 -174G>C, IL10 -819C>T and TNFα -308G>A were analyzed by PCR-RFLP with symptoms of dengue with the clinical features. 196 individuals admitted to the São José Infectious Diseases Hospital with suspected dengue infection. Dengue was confirmed in 111 of the patients. The control group consisted of 85 other individuals confirmed without dengue. It was demonstrated that the presence the T allele of IL1β (P<0.05) was associated with susceptibility to developing the disease. Other results also suggested that the polymorphism in the combinations IL6×IL1β (C and T alleles, respectively), IL1β (T allele)×IL1RN (*2/*2 genotype), IL6 (C allele)×TNFα (A allele), IL10 (C/T genotype)×TNFα (A/A genotype) (P<0.01, P=0.01, P<0.05 and P=0.03, respectively) were associated with predisposition to developing the disease and its symptoms. In summary, the findings of this study in a Brazilian population point out the importance of studies of combinations of polymorphisms in the development of dengue, which can increase the risk of dengue infection and its severity.

Polymorphisms of interleukin-1β and MUC7 genes in burning mouth syndrome.

The objectives of the present study are to compare polymorphisms of the IL-1β and MUC7 genes between patients with burning mouth syndrome (BMS) and controls and to investigate relationships between these polymorphisms and clinical characteristics in BMS patients. Forty female BMS patients and 40 gender- and age-matched controls were included. Genomic DNA was extracted from saliva samples. Single-nucleotide polymorphisms of IL-1β -511 and +3954 and variation in number of tandem repeat (VNTR) polymorphism of MUC7 were analyzed. Relationships between genotypic polymorphism data and clinical characteristics in BMS patients were also analyzed. There were no significant differences in the genotypes of IL-1β -511 and +3954 and of MUC7 between the groups. There were no significant differences in symptom duration and intensity of BMS patients according to their IL-1β and MUC7 genotypes. The T allele of IL-1β -511 showed associations with psychometry results in BMS patients: paranoid ideation (P=0.014), Global Severity Index (P=0.025), and Positive Symptom Total (P=0.008). The genotypic polymorphisms of IL-1β -511 and +3954, and of MUC7 VNTR, had no direct associations with the development of BMS. However, the T allele of IL-1β -511 may increase the risk of BMS by increasing psychological asthenia. The genotypic polymorphisms of IL-1β -511 may increase the risk for the development of BMS by increasing psychological asthenia.

Interactions of early adversity with stress-related gene polymorphisms impact regional brain structure in females.

Early adverse life events (EALs) have been associated with regional thinning of the subgenual cingulate cortex (sgACC), a brain region implicated in the development of disorders of mood and affect, and often comorbid functional pain disorders, such as irritable bowel syndrome (IBS). Regional neuroinflammation related to chronic stress system activation has been suggested as a possible mechanism underlying these neuroplastic changes. However, the interaction of genetic and environmental factors in these changes is poorly understood. The current study aimed to evaluate the interactions of EALs and candidate gene polymorphisms in influencing thickness of the sgACC. 210 female subjects (137 healthy controls; 73 IBS) were genotyped for stress and inflammation-related gene polymorphisms. Genetic variation with EALs, and diagnosis on sgACC thickness was examined, while controlling for race, age, and total brain volume. Compared to HCs, IBS had significantly reduced sgACC thickness (p = 0.03). Regardless of disease group (IBS vs. HC), thinning of the left sgACC was associated with a significant gene-gene environment interaction between the IL-1β genotype, the NR3C1 haplotype, and a history of EALs (p = 0.05). Reduced sgACC thickness in women with the minor IL-1β allele, was associated with EAL total scores regardless of NR3C1 haplotype status (p = 0.02). In subjects homozygous for the major IL-1β allele, reduced sgACC with increasing levels of EALs was seen only with the less common NR3C1 haplotype (p = 0.02). These findings support an interaction between polymorphisms related to stress and inflammation and early adverse life events in modulating a key region of the emotion arousal circuit.

Gene polymorphisms of theMMP1, MMP9, MMP12, IL-1βandTIMP1and the risk of primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is the main cause of irreversible blindness worldwide. Matrix metalloproteinases (MMPs) and their regulators (TIMPs and ILs) have been extensively studied as POAG risk factors. Recent reports have showed several single-nucleotide polymorphisms (SNPs) for MMPs, TIMPs and ILs encoding genes in patients with POAG. The aim of this study was to investigate association of the -1607 1G/2G MMP1, -the 1562 C/T MMP9, the -82 A/G MMP12, the -511 C/T IL-1β and the 372 T/C TIMP1 gene polymorphisms with POAG occurrence and to investigate their impact on main clinical features. In the present case-control study, we examined group of 511 unrelated Caucasian subjects consist of 255 patients with POAG (mean age 70 ± 15) and 256 controls (mean age 67 ± 16). Determination of genes polymorphic variants was made using polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). The odds ratios (ORs) and 95% confidence intervals (CIs) for each genotype and allele were calculated. Presented study showed statistically significant increase in the POAG development risk of the -1607 2G/2G MMP1 genotype (OR 1.75; 95% CI, 1.11-2.75; p = 0.014) and for the -1607 2G MMP1 allele (OR 1.35; 95% CI, 1.05-1.73; p = 0.017), as well as for the -1562 C/T MMP9 genotype (OR 1.74; 95% CI, 1.17-2.59; p = 0.006) and the -1562 T MMP9 allele (OR 1.55; 95% CI, 1.10-2.17; p = 0.012) in patients with POAG in comparison with healthy control group. We also observed positive association of the -511 T/T IL-1β genotype (OR 2.60; 95% CI, 1.41-4.80; p = 0.002) as well as the -511 T IL-1β allele occurrence with an increased POAG development risk (OR 1.47; 95% CI, 1.13-1.90; p = 0.003). Furthermore, we found an association of the -1607 1G/2G MMP1, -1562 C/T MMP9 (anova, p < 0.001) and the -511 C/T IL-1β gene polymorphism (anova, p < 0.05) with decreased retinal nerve fibre layer (RNFL) thickness in patients with POAG group. Results displayed also an association of the 372 T/C TIMP1 gene polymorphism with normal range RNFL (anova, p < 0.001). We observed an association of decreased RA value (rim area) with the -82 A/G MMP12 (anova, p < 0.001). Normal RA value was observed in patients with POAG group connected with the 372 T/C TIMP1 (anova, p < 0.05) and the -511 C/T IL-1β (anova, p < 0.05) genes polymorphisms occurrence. Finally, results showed an association of the -1562 C/T MMP9 (anova, p < 0.001) gene polymorphism with decreased cup/disc index in patients with POAG group. In conclusion, we suggest that the -1607 1G/2G MMP1, -1562 C/T MMP9, -511 C/T IL-1β gene polymorphisms can be considered as an important risk factors associated with POAG.

Risk and preventive factors of low‐dose aspirin‐induced gastroduodenal injuries: A comprehensive review

The risk of peptic ulcer complications, particularly bleeding, is increased in association with the use of low-dose aspirin (LDA). Risk factors for upper gastrointestinal (GI) ulcer or bleeding among LDA users include a history of prior GI events, older age, chronic renal failure, combined antithrombotic therapy and nonsteroidal anti-inflammatory drugs (NSAIDs). Helicobacter pylori and aspirin seem to be independent risk factors for peptic ulcer and bleeding. The studies report conflicting findings about the effect of H. pylori infection on NSAID-related ulcers, and proton-pump inhibitors (PPIs) seem to be superior to eradication only to prevent recurrent ulcer bleeding with LDA. Previous studies indicate that hypoacidity related to corpus atrophy, as well as taking PPIs and co-treatment with angiotensin type 1 receptor blockers (ARBs) and statins seem to reduce peptic ulcer among LDA users. In addition, the interleukin-1β (IL-1β)-511 T allele and angiotensinogen (AGT)-20 CC, which work as the high-producer allele of IL-1β and AGT, are significantly associated with ulcer or ulcer bleeding. The SLCO1B1*1b haplotype, which has the highest transport activity, may diminish the preventive effect of statins or ARBs. The data are still lacking and further prospective studies are needed to identify the specific risk or protective factors for upper GI ulcer and its complications associated with LDA.

Effect of TNF-α and IL-1β genetic variants on the development of myocardial infarction in Turkish population

Tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) genetic variants which resulting in TNF-α and IL-1 overproduction may increase susceptibility to autoimmune diseases such as atherosclerosis. We have studied the association of TNF-α G308A and IL-1β (+3953) C/T polymorphism with myocardial infarction in Turkish population. 143 patients with myocardial infarction and 213 age-matched healthy controls were included in the study. In univariant analysis, the frequencies of IL-1β, TNF-α genotype or allele, and haplotype of C:A and T:A were significantly elevated in patients when compared with those of controls. GA genotype of TNF-α, T allele of IL-1β and A of TNF-α allele seem to be risk factors for myocardial infarction. In contrast, CC genotype of IL-1β and GG genotype of TNF-α have protective effect against myocardial infarction. In multivariate logistic regression analysis, TNF-α A allele, gender and smoking were associated with myocardial infarction. In conclusion, we can state that TNF-α A allele might be associated with myocardial infarction.

Allelic polymorphism in IL-1 beta and IL-1 receptor antagonist (IL-1Ra) genes in inflammatory bowel disease.

Recent reports have shown that allele 2 of the IL-1 receptor antagonist (IL-1Ra) gene is over-represented in ulcerative colitis (UC). Healthy individuals carrying allele 2 of this gene have increased production of IL-1Ra protein. Since the final outcome of the biological effects of IL-1 beta may depend on the relative proportion of these two cytokines, we have studied if a TaqI polymorphism in the IL-1 beta gene, which is relevant to IL-1 beta protein production, may be involved in the genetic susceptibility to UC and Crohn's disease (CD), in association with the established IL-1Ra gene polymorphism. Polymorphisms in the closely linked genes for IL-1 beta and IL-1Ra were typed in 100 unrelated Dutch patients with UC, 79 with CD, and 71 healthy controls. The polymorphic regions in exon 5 of the IL-1 beta gene and in intron 2 of the IL-1Ra gene, were studied by polymerase chain reaction (PCR)-based methods. The IL-1 beta allele frequencies in UC and CD patients did not differ from those in healthy controls. In order to study if the IL-1 beta gene polymorphism might participate synergistically with the IL-1Ra gene polymorphism in susceptibility to UC and CD, individuals were distributed into carriers and non-carriers of allele 2 of the genes encoding IL-1 beta and IL-1Ra, in each of the patient groups and controls. Results indicated a significant association of this pair of genes, estimated by the odds ratio (OR) after performing Fisher's exact test, in the UC group (P = 0.023, OR = 2.81), as well as in the CD group (P = 0.01, OR = 3.79). Thus, non-carriers of IL-1 beta allele 2 were more often present in the subgroup of patients carrying the IL-1Ra allele 2. By contrast, no association of these alleles was detected in the group of healthy controls (P = 1.00, OR = 0.92). These results suggest that the IL-1 beta/IL-1Ra allelic cluster may participate in defining the biological basis of predisposition to chronic inflammatory bowel diseases.

Genetic predisposition to external apical root resorption

External apical root resorption (EARR) can be an undesirable sequela of orthodontic treatment. Previous studies have suggested that EARR has a substantial genetic component. Linkage and association were examined between polymorphisms of the interleukin IL-1 (IL-1A and IL-1B) genes and EARR in 35 white American families. Buccal swab cells were collected for DNA isolation and analysis. The EARR in the maxillary central incisors, the mandibular central incisors, and the mesial and distal roots of the mandibular first molar were analyzed separately and together by using both linkage and association methods of analysis. Highly significant (P =.0003) evidence of linkage disequilibrium of IL-1B polymorphism with the clinical manifestation of EARR was obtained. The analysis indicates that the IL-1B polymorphism accounts for 15% of the total variation of maxillary incisor EARR. Persons homozygous for the IL-1B allele 1 have a 5.6 fold (95% CI 1.9-21.2) increased risk of EARR greater than 2 mm as compared with those who are not homozygous for the IL-1β allele 1. Data indicate that allele 1 at the IL-1B gene, known to decrease the production of IL-1 cytokine in vivo, significantly increases the risk of EARR. These findings are consistent with an interpretation of EARR as a complex condition influenced by many factors, with the IL-1B gene contributing an important predisposition to this common problem. Defining genetic contributions to EARR is an important factor in understanding the contribution of environmental factors, such as habits and therapeutic biomechanics. (Am J Orthod Dentofacial Orthop 2003;123:242-52)

Polymorphism of the cytokine genes and IgA nephropathy

IgA nephropathy (IgAN) is a form of chronic glomerulonephritis of unknown etiology and pathogenesis. Cytokine gene polymorphisms regulate cytokine production and play a role in immune and inflammatory responses; these immunological responses thus are possibly involved in the etiology and pathogenesis of IgAN. We studied by polymerase chain reaction (PCR) polymorphisms of important cytokine genes of inflammation interleukin-1 (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 receptor antagonist (IL-1Ra) in 167 patients with IgAN and 400 healthy blood donor controls. IgAN patients had been followed up for 6 to 17 (median 11) years from renal biopsy. Carriage of the IL-1beta allele 2 (IL1beta2) or IL-1Ra allele 2 (IL1RN*2) was associated with an increased risk of IgAN. These alleles were highly linked and the odds ratio (OR) of IgAN for carriage of both alleles was 1.8 (95% confidence interval 1.2 to 2.6; P = 0.002). Carriage of the TNF-alpha allele 2 (TNF2) was associated with a decreased risk of IgAN (OR 0.5, range 0.3 to 0.7; P = 0.001). The risk of IgAN was found to be highest in those carrying IL1beta2 and IL1RN*2 but not TNF2 as compared to those who did not carry both of these IL-1 cluster genes and were carriers of TNF2 (OR 5.0 (2.4-10.3); P < 0.001). None of the polymorphisms studied was associated with poor prognosis. Carriage of IL1beta2 and IL1RN*2 together with non-carriage of TNF2 is associated with increased susceptibility, but not with a prognosis of IgAN.

Genetic polymorphisms of interleukin-1β in association with the development of alcoholic liver disease in Japanese patients

OBJECTIVE: Cytokine interleukin-1β plays a central role in the inflammation process. Serum levels of IL-1β are elevated in patients with alcoholic liver disease (ALD), especially in those with cirrhosis and alcoholic hepatitis. Recently, the presence of genetic polymorphisms of this cytokine was confirmed. The aim of this study was to determine whether IL-1β polymorphisms are associated with the development of ALD. METHODS: We examined the frequency of two polymorphisms in the IL-1β gene located in promoter −511 and exon 5 +3953 locus by restriction fragment length polymorphisms in 142 male patients with ALD, 30 heavy drinkers without ALD, and 218 healthy controls. RESULTS: The carriers of −511 IL-1β allele 2 were present significantly more often in patients with alcoholic cirrhosis than in those with noncirrhotic ALD ( p = 0.026), heavy drinkers without ALD ( p = 0.001), and healthy controls ( p = 0.032). The frequencies of allele 2 and heterozygotes of +3953 polymorphism were both significantly higher in heavy drinkers without ALD than in patients with ALD (allele, p = 0.030; genotype, p = 0.027) and healthy controls (allele, p = 0.047; genotype, p = 0.043). The haplotype, IL-1β −511 allele 2/+3953 allele 1 was associated with the development of alcoholic cirrhosis ( p < 0.05). CONCLUSIONS: These results suggest that IL-1β polymorphisms may be related to the development of ALD in Japanese alcoholics.

Genetic polymorphisms of interleukin-1beta in association with the development of alcoholic liver disease in Japanese patients.

Cytokine interleukin-1beta plays a central role in the inflammation process. Serum levels of IL-1beta are elevated in patients with alcoholic liver disease (ALD), especially in those with cirrhosis and alcoholic hepatitis. Recently, the presence of genetic polymorphisms of this cytokine was confirmed. The aim of this study was to determine whether IL-1beta polymorphisms are associated with the development of ALD. We examined the frequency of two polymorphisms in the IL-1beta gene located in promoter -511 and exon 5 +3953 locus by restriction fragment length polymorphisms in 142 male patients with ALD, 30 heavy drinkers without ALD, and 218 healthy controls. The carriers of -511 IL-1beta allele 2 were present significantly more often in patients with alcoholic cirrhosis than in those with noncirrhotic ALD (p = 0.026), heavy drinkers without ALD (p = 0.001), and healthy controls (p = 0.032). The frequencies of allele 2 and heterozygotes of +3953 polymorphism were both significantly higher in heavy drinkers without ALD than in patients with ALD (allele, p = 0.030; genotype, p = 0.027) and healthy controls (allele, p = 0.047; genotype, p = 0.043). The haplotype, IL-1beta -511 allele 2/+3953 allele 1 was associated with the development of alcoholic cirrhosis (p < 0.05). These results suggest that IL-1beta polymorphisms may be related to the development of ALD in Japanese alcoholics.

IL-1 receptor antagonist (IL-1Ra) plasma levels are co-ordinately regulated by both IL-1Ra and IL-1β genes

The genes in the IL-1 complex code for three proteins, IL-1α, IL-1β and the IL-1 receptor antagonist (IL-1Ra). The severity of a given infection is influenced by the balance between the levels of IL-1β, the major extracellular agonist, and that of IL-1Ra. In healthy individuals, IL-1Ra is readily detectable in plasma but IL-1β levels are usually undetectable. As there are polymorphisms in both of these genes, we have now analyzed whether there are allelic associations between these loci and whether these would have an influence on plasma IL-1Ra levels. In 200 healthy blood donors, the mean plasma IL-1Ra concentration was 681 pg/ml. The IL-1Ra allele 2 (IL1RN*2) had a clear influence on IL-1Ra levels: its carriers had higher levels than the non-carriers (745 ng/ml vs. 627 pg/ml, p < 0.05, t -test). As marker alleles for IL-1β we used two biallelic base-exchange polymorphisms (at positions − 511 and + 3953 relative to the transcriptional start site). The more rare allele of IL-1β − 511 (allele 2) was significantly associated with the presence of IL-1Ra allele 2, but in the case of the IL-1β + 3953, the more rare allele (allele 2) was less frequent in the carriers of the IL-1Ra allele 2. These IL-1β allelisms did not have a direct influence on plasma IL-1Ra levels, but the enhancing effect of IL-1Ra allele 2 on IL-1Ra plasma levels required the presence of the IL-1β − 511 allele 2 or absence of the IL-1β + 3953 allele 2. Taken together, these results indicate that the IL-1β gene participates in the regulation of IL-1Ra production in vivo and that the alleles of IL-1β and IL-1Ra which demonstrate this cooperative effect are often associated.