IL-21R gene polymorphisms and serum IL-21 levels predict virological response to interferon-based therapy in Asian chronic hepatitis C patients

Association between Interleukin-21 and Interleukin-21 receptor gene polymorphisms with susceptibility to chronic hepatitis B virus infection and HBV spontaneous clearance in Iranian population

Hepatitis B virus (HBV) infection is a major public health concern due to the infection often leads to chronic infection, liver cirrhosis and also liver cancer. The host immune response to HBV infection and also genetic background play significant role in outcome of infection. Single nucleotide polymorphisms (SNPs) are the most important kind of variation in genetic sequences that caused by point mutations. As cytokines have major roles in viral infections, it seems that cytokine gene polymorphisms are independently associated with response to viral infections. Interleukin 21 (IL-21) plays an influential role in both innate and adaptive immune responses. Its specific receptor, IL-21R, produced and located on the surface of T, B and natural killer (NK) cells and is critical for the proliferation and differentiation of these immune effector cells. Many studies confirmed that the IL-21 involved in response to viral infections. We aimed to investigate the association of G/T IL-21 (rs2055979) and C/T IL-21R (rs3093390) gene polymorphisms with chronic hepatitis B virus infection and HBV spontaneous clearance in Iranian population.

METHODS

In this study, blood samples were gathered from 320 patients with chronic HBV and 310 healthy controls and also 120 HBV spontaneous clearance individuals. Following genomic DNA extraction, genotypes of the selected SNPs determined by PCR and restriction fragment length polymorphism (RFLP) method. The results were analyzed by SPSS software using Chi-square, Logistic Regression, ANOVA and Independent Samples t-Test.

RESULTS

According to our results, in IL-21R (rs3093390 C/T) gene polymorphism, allele frequency of T is statistically different in the HBV spontaneous clearance group compared to chronic HBV cases. But there is no significant difference between G/T IL-21 (rs2055979) and C/T IL-21R (rs3093390) genotypes distribution in three groups. Also we found that higher serum aspartate transaminase (AST) level in HBV spontaneous clearance group is significantly associated with TT genotype of IL-21 (rs2055979) compared to GG genotype (P value = 0.006).

DISCUSSION

Our results showed that T allele frequency in IL-21R (rs3093390 C/T) gene polymorphism could consider as a host genetic factor for HBV spontaneous clearance. Probably we can serve it as a potential prognostic genetic marker for spontaneous clearance of HBV infection.

Role of interleukin-21 and interleukin-21 receptor polymorphisms in the treatment of HBeAg-positive chronic hepatitis B patients with peginterferon

The aim of this study was to evaluate the relationship between interleukin-21 (IL-21) and interleukin-21 receptor (IL-21R) polymorphisms and the response to peginterferon alfa (PEG-IFN α) therapy in HBeAg-positive chronic hepatitis B (CHB) patients.A total of 143 HBeAg-positive CHB patients treated for 48 weeks with PEG-IFN α and followed up for 24 weeks post-treatment were retrospectively evaluated. Genotypes analysis was performed for IL-21 polymorphisms rs907715, rs2221903, and IL-21R polymorphisms rs3093301 and rs2285452. Serum IL-21 levels were measured by enzyme-linked immunosorbent assay.The end of virological response (EVR) rate was 46.9% (67/143) at the end of treatment, the sustained virological response (SVR) rate was 43.4% (62/143) and the complete response (CR) rate was 32.1% (46/143) at 24 weeks post-treatment. Patients who carried IL-21 rs 2221903 genotype AA had a rather higher rate of EVR (response rate: 52.4%, odds ratio [OR] 0.42, 95% confidence interval [CI]: 0.19-0.91, P = .021), SVR (response rate: 47.6%, OR 0.43, 95% CI: 0.19-0.95, P = .028), and CR (response rate: 38.1%, OR 0.31, 95% CI: 0.12-0.79, P = .014) when compared to those had AG genotype. Meanwhile, IL-21rs 2221903 genotype AA was also independently associated with markedly reduced HBsAg levels (>1og10 IU/mL) after 24 weeks treatment and low HBsAg levels (<100 IU/mL) at the end of treatment. IL-21 rs907715 AG/GG genotype was independently associated with SVR (OR: 2.92, 95% CI: 0.98-8.6, P = .039; OR: 3.23, 95% CI: 1.0-10.4, P = .039). Patients with IL-21 rs907715 AG/GG genotype had higher serum IL-21 levels than those with rs907715 AA genotype (P = .021).IL-21 rs2221903 and rs907715 polymorphisms were significantly associated with the treatment response to PEG-IFN α among Chinese HBeAg-positive CHB patients.

Chromosome conformation signatures define predictive markers of inadequate response to methotrexate in early rheumatoid arthritis

Background

There is a pressing need in rheumatoid arthritis (RA) to identify patients who will not respond to first-line disease-modifying anti-rheumatic drugs (DMARD). We explored whether differences in genomic architecture represented by a chromosome conformation signature (CCS) in blood taken from early RA patients before methotrexate (MTX) treatment could assist in identifying non-response to DMARD and, whether there is an association between such a signature and RA specific expression quantitative trait loci (eQTL).

Methods

We looked for the presence of a CCS in blood from early RA patients commencing MTX using chromosome conformation capture by EpiSwitch™. Using blood samples from MTX responders, non-responders and healthy controls, a custom designed biomarker discovery array was refined to a 5-marker CCS that could discriminate between responders and non-responders to MTX. We cross-validated the predictive power of the CCS by generating 150 randomized groups of 59 early RA patients (30 responders and 29 non-responders) before MTX treatment. The CCS was validated using a blinded, independent cohort of 19 early RA patients (9 responders and 10 non-responders). Last, the loci of the CCS markers were mapped to RA-specific eQTL.

Results

We identified a 5-marker CCS that could identify, at baseline, responders and non-responders to MTX. The CCS consisted of binary chromosome conformations in the genomic regions of IFNAR1, IL-21R, IL-23, CXCL13 and IL-17A. When tested on a cohort of 59 RA patients, the CCS provided a negative predictive value of 90.0% for MTX response. When tested on a blinded independent validation cohort of 19 early RA patients, the signature demonstrated a true negative response rate of 86 and a 90% sensitivity for detection of non-responders to MTX. Only conformations in responders mapped to RA-specific eQTL.

Conclusions

Here we demonstrate that detection of a CCS in blood in early RA is able to predict inadequate response to MTX with a high degree of accuracy. Our results provide a proof of principle that a priori stratification of response to MTX is possible, offering a mechanism to provide alternative treatments for non-responders to MTX earlier in the course of the disease.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1387-9) contains supplementary material, which is available to authorized users.

IL-21 as a Predictor of Sustained Virologic Response in Patients with Chronic Hepatitis C Virus Infection

Hepatitis C virus (HCV) infection is a significant public health problem. The crucial role of interleukin (IL)-21 in HCV has been established. Thus, we aimed to investigate the association of serum IL-21 levels with the virological response to interferon (IFN)-based therapy in a group of Egyptian patients with chronic hepatitis C (CHC). Clinical data were collected from 58 HCV-positive Egyptian patients treated with IFN/ribavirin therapy and 10 non-HCV-infected healthy subjects. Liver and renal function tests, complete blood count, viral markers, and pretreatment IL-21 levels were determined in all patients and healthy controls. Patients who achieved sustained virologic response (SVR) had higher pretreatment median serum IL-21 levels than those who did not. Thus, this study concluded that higher pretreatment serum IL-21 may be useful in predicting SVR in CHC patients.

Genotype-related variations in proinflammatory and regulatory cytokine levels in treated and treatment-naive HCV-infected patients

Hepatitis C virus (HCV) modulates immune-related inflammatory responses to induce milder reactions leading to virus persistence. In this regard, the present study aimed to investigate the link between the HCV genotypes and the proinflammatory and regulatory cytokine levels. Ninety patients with hepatitis C infection (68 treatment-naive and 22 treated patients) and 76 healthy blood donors were studied. The serum levels of IFN-γ, IL-10, IL-17A, and IL-21 were measured by ELISA in the patients and healthy controls. IL-10, IL-17A, and IL-21 levels were significantly higher in HCV patients than in the healthy controls. The same cytokines were also higher in genotype 3a-infected patients compared with genotype 1a-infected patients. Interestingly, in treated patients, lower serum levels of IL-17A and IL-21 were detected in G3a-infected individuals, but not in those infected with G1a. G3a viral load displayed a significant correlation with IL-21 and IL-17A levels. In addition, G1a viral load correlated with IL-10 levels. In G3a-infected patients, a significant association was found between IL-17A serum levels and ALT. We found differences in IL-21 and IL-17A serum levels among HCV-infected patients which were genotype dependent. Since Th17-associated cytokines are associated with the progression of liver disease in HCV patients, IL-17A and IL-21 can be used as important biological markers for evaluating the immunopathogenesis of chronic hepatitis. Our results suggest that HCV G3a along with immune responses such as cytokines in HCV patients should be taken into account when interpreting clinical data and IFN-based therapeutic response.

Involvement of the Interleukin-23/Interleukin-17 Axis in Chronic Hepatitis C Virus Infection and Its Treatment Responses

Interleukin-23 (IL-23) and its downstream factor IL-17 are the key cytokines involved in immune and inflammatory response in chronic liver diseases. This study aimed to investigate the role and molecular mechanisms of the IL-23/Th17 axis in chronic hepatitis C virus (HCV) infection, and the efficacy of IL-23/Th17 modulation in response to anti-HCV therapy. Sixty-six HCV-infected patients and 20 healthy controls were enrolled. The patients received PegIFNa-2a and ribavirin therapy for at least 48 weeks. The plasma level of IL-23 and the number of IL-17A-, IFN-γ-, and IL-21-producing peripheral blood mononuclear cells (PBMCs) at baseline and 12, 24, and 48 weeks following treatment were determined. The mRNA level of Th17 immune-associated molecules in PBMCs was evaluated by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) following treatment with IL-23 agonist or antagonist. Our data showed that, compared to healthy controls, HCV-infected patients had an increased plasma level of IL-23 and increased frequencies of IL-17A- and IFN-γ-producing PBMCs, whereas the HCV patients exhibited a reduced number of IL-21-producing PBMCs. However, the baseline frequencies of IL-21-producing PBMCs were markedly higher in HCV patients who achieved rapid virological response (RVR) than those without RVR. Additionally, the mRNA expressions of IL-21, IFN-γ, myxovirus resistance protein A (MxA), and suppressor of cytokine signaling 3 (SOCS3) were significantly upregulated in PBMCs, while FoxP3 expression was suppressed by IL-23 agonist. Thus, the IL-23/Th17 axis plays an important role in development of chronic HCV infection and antiviral response. IL-23 may enhance the antiviral activity of interferon-based therapy by modulating the expression of Th17 cells-associated molecules in HCV-infected patients.

Interleukin-21 mediates hepatitis B virus-associated liver cirrhosis by activating hepatic stellate cells

AIM

Interleukin-21 (IL-21) is involved in effective primary hepatic immune response against hepatitis B virus (HBV) and profibrotic function. However, the role of IL-21 in HBV-associated liver cirrhosis is poorly understood. This study aimed to investigate the role of IL-21 in HBV-associated liver cirrhosis and possible mechanisms.

METHODS

The study subjects included 10 healthy controls and 30 patients with HBV-associated liver cirrhosis that categorized into three subgroups based on Child-Pugh score (A, 13; B, 10; C, 7). The frequencies of IL-21(+) CD4(+) T cells were detected by flow cytometry, and the level of IL-21 in plasma was measured by enzyme-linked immunoassay. The distribution of IL-21(+) cells in situ in liver was observed by immunohistochemistry. In addition, the in vitro expression of α-smooth muscle actin (α-SMA), apoptosis and proliferation markers of LX-2 cells were examined by flow cytometry and Cell Counting Kit-8 kit. Finally, the collagen levels in the supernatant were measured by chemiluminescence.

RESULTS

Increased peripheral number of IL-21(+) CD4(+) cells, elevated plasma level of IL-21 and IL-21(+) cell accumulation in liver were observed in patients with HBV-associated liver cirrhosis. In vitro administration of IL-21 was accompanied with increased expression of α-SMA, inhibited LX-2 cells apoptosis and upregulated collagen production by LX-2 cells.

CONCLUSION

IL-21 may contribute to the fibrogenesis of HBV-associated liver cirrhosis by activating the hepatic stellate cells. Therefore, neutralization of IL-21 could be a favorable new therapeutic strategy for liver cirrhosis treatment.

Role of T cell immunity in hepatitis C virus infections

Chronic infections with the hepatitis C virus (HCV) are a major global health issue. Viral replication is restricted to hepatocytes, and occurs for decades at high replication rates. Over the last decade, it became accepted that HCV-specific CD4(+) and CD8(+) T cells are crucial for protective immunity to HCV. However, a characteristic feature of persistent HCV infection is the dysfunctional T cell response, and over recent years enormous progress has been made in understanding the mechanisms that dampen the antiviral T cell responses in blood and liver of chronic HCV patients and also impact disease progression.