Clinical significance of serum interleukin-6 and −174 G/C promoter polymorphism in Rheumatoid arthritis patients

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

The association between interleukin-6 promoter polymorphisms and rheumatoid arthritis by ethnicity: A meta-analysis of 33 studies

OBJECTIVE

We performed a meta-analysis to determine the effect Interleukin-6 (IL-6) promoter polymorphism (-174 G>C, -572 G>C, and -597 G>A) have on the development rheumatoid arthritis (RA) by ethnicity.

MATERIAL AND METHODS

PubMed, EBSCO, LILACS, and Scopus databases were searched for studies exploring the association between any IL6 polymorphisms and RA until November 2018. Genotype distributions were extracted and, depending on the level heterogeneity, determined by the ψ²-based Q test and the Inconsistency Index (I²), fixed-effects or random-effects models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models.

RESULTS

From 708 identified publications, 33 were used in this analysis. For the -174 polymorphism, Asians (OR_heterozygous=7.57, 95%CI: 2.28-25.14, OR_homozygous=5.84, 95%CI: 2.06-16.56, OR_dominant=7.21, 95%CI: 2.30-22.63, OR_recessive=5.04, 95%CI: 1.78-14.28, OR_allelic=6.60, 95%CI: 2.26-19.28, p<.05) and Middle East countries (OR_heterozygous=2.30, 95%CI: 1.10-4.81, OR_dominant=2.27, 95%CI: 1.22-4.22, OR_allelic=2.29, 95%CI: 1.24-4.23, p<.05) were associated with a significant risk of developing RA. Whereas, for Latinos, the C-allele was associated with a benefit (OR_homozygous=0.26, 95%CI: .08-.82, OR_recessive=.25, 95%CI: .08-.80, p<.05). For the -572 polymorphism, Asians demonstrated a significant association for the homozygous and recessive genetic models (8 studies, OR_homozygous=1.56, 95%CI: 1.16-2.09, OR_recessive=1.63, 95%CI: 1.08-2.45, p<.05). For the -597 polymorphism, no association was observed.

CONCLUSIONS

Here, the -174 G>C polymorphism increased the risk of developing RA in Asians and Middle East populations. Interestingly, for Latinos, the polymorphism was associated with a benefit. For the -572 polymorphism, only the Asian population showed an increased risk of developing RA for the CC genotype.

Interleukin-6 and Serum/Fecal Calprotectin as Useful Specific Markers for Monitoring Rheumatic Diseases: A Pilot Study

OBJECTIVE

Some conventional laboratory tests are routinely used for the prediction of systemic autoimmune disease activity, such as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); however, they can give false-negative results, pointing out the need to identify more specific markers.

METHODS

We evaluated biomarkers in 21 Italian patients naïve to treatment with a diagnosis of autoimmune rheumatic disease according to the 2010 American College of Rheumatology/European League Against Rheumatism Classification Criteria for Rheumatoid Arthritis during 6 months of therapeutic treatments.

RESULTS

We found a significant difference in interleukin-6 (IL-6), CRP, ESR, platelet count, and fecal calprotectin in diagnosed patients compared with healthy participants and a significant decrease in these values during follow-up, except for IL-6 and platelet count.

CONCLUSION

We found that CRP, ESR, and fecal calprotectin seemed to be related to autoimmune rheumatic disorders and to be associated with therapy, whereas serum calprotectin and IL-6 did not seem to be associated with disease improvement after the start of treatment, along with leukocyte count and platelet count.

Evaluating the Relationship Between Serum Level of Interleukin-6 and Rheumatoid Arthritis Severity and Disease Activity

AIM

The aim of this study was to evaluate the relationship between Interleukin-6 (IL-6) serum level and the severity and activity of Rheumatoid Arthritis (RA).

METHODS

In this cross-sectional study, 120 RA patients referred to the rheumatology clinic, the patients were diagnosed by rheumatologists according to ACR / EULAR 2010 criteria. Based on DAS28 score the patients were divided into 4 groups: Remission, Mild, Moderate and Severe. Each group contained 30 patients. Serum levels of Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), anti-Cyclic Citrullinated Peptide (anti-CCP) and Rheumatoid Factor (RF) and serum levels of IL-6, were measured. The relationship between these factors was measured and compared to the relationship between IL-6 and these factors, and the activity of the disease was evaluated based on DAS-28.

RESULTS

This study showed that the serum level of IL-6 has a significant relationship with RA activity according to DAS-28 (P value <0.001). There is also a significant relationship between the ESR level, the number of painful joints, and the number of swollen joints, and the severity of the disease based on VAS.

CONCLUSION

Generally the findings of this study indicate that serum level of IL-6 plays an important role in the severity and activity of RA disease and can be considered as a determining factor in evaluating the severity of RA in RA patients and it is a good guide for a step up or down of treatment.

INFLAMMATION AND IMPACT OF VINCRISTINE AND ENTEROSORPTION USE IN CHEMICALLY INDUCED COLON CARCER IN RATS

Background. The increasing incidence of colon malignant tumors is one of the most urgent matters of contemporary medicine. In the study of carcinogenesis of the colon the attention is paid to the state of the body’s immune system and activation of inflammatory processes in experimental animals. Objective. The aim of the study was to estimate the level of markers of inflammation in the serum of experimental animals with chemically induced carcinogenesis and their dynamics in case of administration of the cytostatic Vincristine secondary to AUT-M carbon enterosorbent. Methods. The study was performed on white male rats. Animals were modeled for colon cancer by administration of 1.2-dimethylhydrazine hydrochloride at a dose of 7.2 mg/kg body weight for 30 weeks. AUT-M enterosorbent was administered intragastrically daily during 7 and 21 days after modeling of carcinogenesis at a dose of 1 ml of suspension (corresponding to 0.2 g of drug weight) per 100 g of animal body weight. The antitumor drug was administered to the animals with induced carcinogenesis intragastrically daily during 14 days at a dose of 0.23 mg/kg of body weight after a 21-day detoxification therapy. The activity of inflammatory processes was evaluated by the content of pro-inflammatory interleukin 6 and anti-inflammatory interleukin 4, C-reactive protein in the serum of experimental animals. Results. It was established that introduction of 1.2-dimethylhydrazine hydrochloride in the rats caused changes in the cytokine profile and the content of C-reactive protein. In the affected animals an increase in the content of pro-inflammatory interleukin 6, C-reactive protein, as well as a decrease in the content of anti-inflammatory interleukin 4 was evidenced in all periods of the study. AUT-M enterosorbent contributed to normalization of these parameters. The cytostatic Vincristine had a negligible effect on development of inflammatory processes in the studied animals. Conclusions. In cases of induced carcinogenesis, an imbalance in the content of pro- and anti-inflammatory cytokines, an increase in the content of acute-phase C-reactive protein was established. The positive effect of the cytostatic Vincristine secondary to a previous detoxification therapy with AUТ-M sorbent during a progressive development of inflammatory processes in the presence of modeled carcinogenesis was evidenced.

The Association Between Interleukin-6 Promoter Polymorphisms and Rheumatoid Arthritis by Ethnicity: A Meta-Analysis of 33 Studies

OBJECTIVE

We performed a meta-analysis to determine the effect Interleukin-6 (IL-6) promoter polymorphism (-174 G>C, -572 G>C, and -597 G>A) have on the development rheumatoid arthritis (RA) by ethnicity.

MATERIAL AND METHODS

PubMed, EBSCO, LILACS, and Scopus databases were searched for studies exploring the association between any IL6 polymorphisms and RA until November 2018. Genotype distributions were extracted and, depending on the level heterogeneity, determined by the ψ2-based Q test and the Inconsistency Index (I2), fixed-effects or random-effects models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models.

RESULTS

From 708 identified publications, 33 were used in this analysis. For the -174 polymorphism, Asians (ORheterozygous=7.57, 95%CI: 2.28-25.14, ORhomozygous=5.84, 95%CI: 2.06-16.56, ORdominant=7.21, 95%CI: 2.30-22.63, ORrecessive=5.04, 95%CI: 1.78-14.28, ORallelic=6.60, 95%CI: 2.26-19.28, p<.05) and Middle East countries (ORheterozygous=2.30, 95%CI: 1.10-4.81, ORdominant=2.27, 95%CI: 1.22-4.22, ORallelic=2.29, 95%CI: 1.24-4.23, p<.05) were associated with a significant risk of developing RA. Whereas, for Latinos, the C-allele was associated with a benefit (ORhomozygous=0.26, 95%CI: .08-.82, ORrecessive=.25, 95%CI: .08-.80, p<.05). For the -572 polymorphism, Asians demonstrated a significant association for the homozygous and recessive genetic models (8 studies, ORhomozygous=1.56, 95%CI: 1.16-2.09, ORrecessive=1.63, 95%CI: 1.08-2.45, p<.05). For the -597 polymorphism, no association was observed.

CONCLUSIONS

Here, the -174 G>C polymorphism increased the risk of developing RA in Asians and Middle East populations. Interestingly, for Latinos, the polymorphism was associated with a benefit. For the -572 polymorphism, only the Asian population showed an increased risk of developing RA for the CC genotype.

Interleukin 6 gene polymorphism is associated with protein serum level and disease activity in Polish patients with rheumatoid arthritis

Interleukin 6 (IL-6) is a pro-inflammatory cytokine involved in the development of rheumatoid arthritis (RA). The present study aimed to determine the possible association of the IL6 (rs1800795, G > C) polymorphism with RA susceptibility, disease progression and protein serum levels. Distribution of IL6 alleles and genotypes was similar in RA patients and controls. As expected, patients before induction of anti-tumour necrosis factor agents had significantly higher IL-6 levels as compared with controls (P = 0.002). The CC homozygous patients were characterised with the highest average concentrations of this pro-inflammatory cytokine before treatment (P = 0.028), and they also more frequently presented with more active disease (P = 0.048). These results imply that the IL6 rs1800795 CC homozygosity may play a rather unfavourable role in RA.

Sarilumab: Review of a Second IL-6 Receptor Antagonist Indicated for the Treatment of Rheumatoid Arthritis

Major Objectives: To review the efficacy, safety, and economics of sarilumab, an interleukin-6 (IL-6) receptor antagonist, in the treatment of rheumatoid arthritis (RA). Data Sources: PubMed (1966 to January 2018), Clinicaltrials.gov (January 2018), and Scopus (1970 to January 2018) were searched using sarilumab, Kevzara, REGN88, and SAR153191. Study Selection and Data Extraction: Human studies published in peer-reviewed publications in English were the primary sources for efficacy and safety. Data Synthesis: Data from randomized, double-blind, controlled, published clinical studies weeks demonstrated statistically significantly higher American College of Rheumatology (ACR) 20, ACR50, and Disease Activity Score-28 (DAS28) remission response rates and improvements in DAS28 and Health Assessment Questionnaire–Disability Index scores for sarilumab monotherapy versus adalimumab monotherapy (P < 0.05) and for sarilumab versus placebo in patients receiving methotrexate or other conventional synthetic disease-modifying antirheumatic drugs (DMARDs); P < 0.05. The ACR20 and ACR50 response rates were, respectively, 56-72% and 35-46% for sarilumab, 58% and 30% for adalimumab, and 33-34% and 15-18% for placebo. DAS28 remission rates were 20-34% for sarilumab, 7% for adalimumab, and 7-10% for placebo. Sarilumab has a higher risk for neutropenia than tocilizumab, the other IL-6 inhibitor, but a lower risk for dyslipidemia, injection site reactions, and gastrointestinal perforation. The acquisition costs of sarilumab are expected to be similar to those of most other biologic DMARDs. Conclusion: Sarilumab is an alternative to biologic DMARDs or targeted synthetic DMARDs in patients with moderate to severely active RA who have not responded adequately to prior conventional synthetic DMARDs or tumor necrosis factor-α inhibitors.

Impact of secondhand smoking on disease activity in women with rheumatoid arthritis

Smoking is an established risk factor for the development and severity of rheumatoid arthritis (RA) with prominent production of cytokines. The aim of the work was to study the possible effect of secondhand exposure on disease activity in non-smoking female RA patients. This cross-sectional study include 100 women with RA attending the rheumatology outpatient clinic and were grouped according to the non-smoking status into those not exposed to smoking and those considered secondhand smokers (SHS). Disease activity score in 28 joints (DAS28) was calculated and the patients' global assessment (PGA) score were assessed. The mean age of the patients was 45.2 ± 12.1 years and disease duration was 8.3 ± 6 years. Their DAS28 score was 4.3 ± 0.93 with a PGA score of 1.47 ± 1.36. Forty-seven of the patients were SHS and 53 were non-exposed. The secondhand smokers were significantly younger (41.6 ± 11.7 years) than the non-smokers (48.3 ± 11.6 years) (p = 0.005), and the DAS28 was significantly higher (4.6 ± 0.84 versus 4.1 ± 0.97; p = 0.02) compared to non-smokers. The disease duration and medications received were comparable. There is evidence pointing to the important role of secondhand smoking on disease activity in RA female patients. Studying the effect of secondhand smoking in view of the cytokine milieu could help confirm the relation to the disease pathogenesis. Taking into consideration the risk of cardiovascular disease and interplay with other potential factors should be well thought of. It is essential to draw patients' attention to the expected hazardous effect of passive smoking.

The association between interleukin 6 -174 G/C gene polymorphism and the risk of osteoporosis: A meta-analysis

Objectives

This study aimed to investigate the association between the IL6 −174 G/C gene polymorphism and the risk of osteoporosis by performing a meta-analysis.

Methods

Published literature from PubMed and Embase databases was searched for eligible publications. The following information was extracted from each study: Name of first author, year of publication, country of origin, sample size of cases and controls, and size of each allele. The combined odds ratio (ORs) and 95% confidence intervals (95%CIs) for the association between the IL6 −174 G/C gene polymorphism and the risk of osteoporosis were assessed using a random or fixed effects model. A comprehensive meta-analysis (CMA) 2.0 was used to analyse the data.

Results

Twelve studies (4923 cases/3431 controls) were included in this meta-analysis. The results indicated that IL6 −174 G/C gene polymorphism was associated with an increased (G vs C, OR 95%CI = 1.29 [1.03–1.62], p = 0.029) and decreased risk of osteoporosis (C vs G, OR 95%CI = 0.77 [0.62–0.97], p = 0.029; CC vs GG + GC, OR 95%CI = 0.58 [0.39–0.88], p = 0.010).

Conclusion

The IL6 −174 G/C gene polymorphism was shown to be positively correlated with osteoporosis risk.