59 research outputs found
Association between interleukin-10 polymorphisms and Alzheimer's disease: a systematic review and meta-analysis
It has been hypothesized that polymorphisms of interleukin (IL)-10 genes affect the risk of developing late onset Alzheimer's disease (AD). However, results of different studies are often inconsistent. Our aim was to investigate by meta-analysis the association of the common polymorphisms comprehensively defining the genetic variability of the IL-10 gene with AD risk. Fifteen studies investigating the association between IL-10 polymorphisms (-1082,-819,-592) and AD were found and analyzed. The model-free approach was applied to meta-analyze these case-control genetic association studies. Available data suggested an association between-1082 polymorphism and AD risk with a marginal statistical significance (GG versus AG/AA: pooled odds ratio [OR]: 0.82, 95% confidence interval CI: 0.65-1.02) and evidence of a moderate degree of between-study heterogeneity (χ 2 = 27.13, d.f. = 13, p = 0.01, I 2 = 52%). For the-819 and-592 polymorphisms, we did not find an association with AD, but significant between-study heterogeneity made genotype data pooling unacceptable. Analysis by IL-10 haplotype showed that the-1082G/-819C/-592C haplotype is associated with a lower risk of AD, although with a marginal statistical significance, probably due to the low number of studies included (GCC versus other genotypes: OR: 0.61, 95% CI: 0.32-1.15; I 2: 85%). Current findings suggest a possible association between-1082 A > G polymorphism and the risk of developing AD; this effect is more evident in the oldest patients. The high degree of between-study heterogeneity, due to several underpowered studies and to other methodological problems of individual studies underlies the need for further methodologically adequate studies. © 2012-IOS Press and the authors. All rights reserved
When and how to treat acute hepatitis C?
Background: Appropriate treatment of acute hepatitis C is still a matter of controversy due to the lack of large controlled trials. Aim: To assess the effectiveness of interferon as treatment for acute hepatitis C by meta-analysis. Methods: MEDLINE search (1985-2002) was supplemented with manual searches of reference lists. Studies were included if they were controlled trials comparing interferon to no treatment and if they included patients with either post-transfusion or sporadic acute hepatitis C. Twelve trials were analyzed (414 patients). The outcome assessed was the sustained virological response (SVR) rate (undetectable hepatitis C virus RNA in serum at least 6 months after cessation of therapy). Results: Interferon significantly increased the SVR (risk difference 49%; 95% confidence interval 32.9-65%) in comparison to no treatment. The risk difference of SVR increased from 5 to 90% when trials were ordered by increasing interferon weekly dose. Delaying therapy by 8-12 weeks after the onset of disease does not compromise the SVR rate. Conclusions: Current evidence is sufficient to recommend interferon treatment of patients with acute hepatitis C. A later initiation of therapy yields the same likelihood of response as early treatment. A daily induction dose during the 1st month is the best option of treatment. © 2003 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved
The importance of the interactions between KIRs and HLA ligands in the development of human autoimmune and viral diseases
Killer immunoglobulin-like receptors (KIRs) regulate the activation of
natural killer cells through their interaction with human leucocyte antigens
(HLA). KIR and HLA loci are highly polymorphic, and certain
KIR/HLA combinations have been found to protect against viral infections
or to predispose to autoimmune disorders. In particular, some
activating KIR profiles may be detrimental in autoimmune pathogenesis,
and specific KIR genes may be particularly aggressive in the clearance
of different microorganisms, protecting individuals in the control of a
given pathogen. Here we reviewed a growing body of evidence purporting
the influence of KIR polymorphism and KIR-HLA interaction in the
development of the main human autoimmune and viral diseases
Oxidative stress inhibits IFN-alpha-induced antiviral gene expression by blocking the JAK-STAT pathway.
Abstract
BACKGROUND/AIMS:
Unresponsiveness to IFN-alpha is common in chronic hepatitis C. Since conditions associated with an increased oxidative stress (advanced age, steatosis, fibrosis, iron overload, and alcohol consumption) reduce the likelihood of response, we hypothesized that oxidative stress may affect the antiviral actions of IFN-alpha.
METHODS:
We examined in a human hepatocellular carcinoma cell line (Huh-7) the effect of hydrogen peroxide (H2O2), as a generator of oxidative stress, on the IFN-alpha signaling pathway.
RESULTS:
Pretreatment of Huh-7 cells with 0.5-1 mM H2O2 resulted in the suppression of the IFN-alpha-induced antiviral protein MxA and of IRF-9 mRNA expression. The reduced expression of these genes was associated to H2O2 -mediated suppression of the IFN-alpha-induced assembly of signal transducer and activator of transcription (STAT) factors to specific promoter motifs on IFN-alpha-inducible genes. This was accomplished by preventing the IFN-alpha-induced tyrosine phosphorylation of STAT-1 and STAT-2 through the inactivation of the upstream receptor associated tyrosine kinases, JAK-1 and Tyk-2. The suppression was fast, occurring within 5mins of pretreatment with H2O2, and did not require protein synthesis.
CONCLUSIONS:
In conclusion, oxidative stress impairs IFN-alpha signaling and might cause resistance to the antiviral action of IFN-alpha in chronically HCV infected patients with high level of oxidative stress in the liver
HLA-C1 ligands are associated with increased susceptibility to systemic lupus erythematosus
Recently, the role of killer cell immunoglobulin-like receptor (KIR) in autoimmune diseases has received increasing attention. The present study was undertaken to determine the association of KIR genes and the human leukocytes antigen (HLA) ligands with Systemic Lupus Erythematosus (SLE) and accompanying oxidative stress. Presence or absence of 17 KIR and 5 HLA loci was performed using the polymerase chain reaction-sequence specific primer (PCR-SSP) method by case-control study. A total of 45 SLE patients, and 60 healthy controls, all of Sicilian descent, were enrolled. Plasma values of the anti-oxidant molecule Taurine were determined in all subjects by capillary electrophoresis UV detection. The carrier frequency of the KIR2DS2 gene was significantly increased in SLE patients compared to healthy controls (73.3 versus 45.0%; OR = 3.36; 95% CI = 1.46-7.74; p = .005) suggesting a role of KIR2DS2 gene in the susceptibility to disease. We also observed a strong positive association between the presence of HLA-C1 ligands group and the disease (82.2% in SLE patients versus 41.7% in controls; OR = 6.47, 95% CI = 2.58-16.26; p < .0001). Stepwise logistic regression analysis supported the effect of the HLA-C1 ligands in SLE patients (OR = 7.06, 95% CI = 0.07-2.19; p = .002), while the KIR genes were no longer significant. Interestingly, we found that SLE patients HLA-C1 positive showed significantly decreased plasma levels of antioxidant activity marker Taurine (69.38 ± 28.49 μmol/L) compared to SLE patients HLA-C1 negative (108.37 ± 86.09 μmol/L) (p = .03). In conclusion, HLA-C1 ligands group was significantly associated with an increased risk of SLE as well as an increased oxidative stress status overall in SLE patients
GM Allotypes and COVID-19. A Pilot Study Performed on Sicilian Patients
Several studies suggest that genetic variants that influence the onset, maintenance and resolution of the immune response might be fundamental in predicting the evolution of COVID-19. In the present paper, we analysed the distribution of GM allotypes (the genetic markers of immunoglobulin γ chains) in symptomatic and asymptomatic COVID-19 patients and in healthy controls, all born and residing in Sicily. Indeed, the role played by GM allotypes in immune responses and infection control is well known. Our findings show that the GM23 allotype is significantly reduced in healthy controls. Interestingly, in a previous study, Sicilians carrying the GM23 allotype were associated with the risk of developing a symptomatic Human Cytomegalovirus infection. However, a note of caution should be considered, due to the small sample size of patients and controls
HLA and killer cell immunoglobulin-like receptor (KIRs) genotyping in patients with acute viral encephalitis
Introduction: The HLA genes, as well as the innate immune KIR genes, are considered relevant determinants of viral outcomes but no study, to our knowledge, has evaluated their role in the clinical setting of acute viral encephalitis. Results: Subjects with acute viral encephalitis in comparison to subjects without acute viral encephalitis showed a significantly higher frequency of 2DL1 KIR gene and AA KIR haplotypes and of HLA-C2 and HLA-A-Bw4 alleles. Subjects without acute viral encephalitis showed a higher frequency of interaction between KIR2DL2 and HLAC1. Multiple logistic regression analysis showed the detrimental effect of HLA-A haplotype and HLA-C1, HLA-A-BW4 HLA-B-BW4T alleles, whereas multiple logistic regression showed a protective effect of AB+BB KIR haplotype and a detrimental effect of interaction between KIR3DL1 and HLA-A-Bw4. Discussion: Our findings of a lower frequency of activating receptors in patients with acute encephalitis compared to controls could result in a less efficient response of NK cells. This finding could represent a possible pathogenetic explanation of susceptibility to acute symptomatic encephalitis in patients with viral infection from potentially responsible viruses such as Herpes virus. Materials and Methods: 30 Consecutive patients with symptomatic acute viral encephalitis and as controls, 36 consecutive subjects without acute encephalitis were analyzed. The following KIR genes were analyzed, KIR2DL1, 2DL2, 2DL3, 2DL5, 3DL1, 3DL2, 3DL3, 2DL4, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DS1, 2 pseudogenes (2DP1 and 3DP1) and the common variants of KIR2DL5 (KIR2DL5A, KIR2DL5B)
HLA and killer cell immunoglobulin-like receptor (KIRs) genotyping in patients with acute ischemic stroke
Introduction: In humans, a major component of natural killer (NK) and T cell target recognition depends on the surveillance of human leukocyte antigen (HLA) class I molecules by killer immunoglobulin-like receptors (KIRs). Aims: To implement the knowledge about the immunological genetic background of acute ischemic stroke susceptibility in relation to the frequency of the KIR genes and HLA alleles. Methods: Subjects with acute ischemic stroke and subjects without stroke were genotyped for the presence of KIR genes and of the three major KIR ligand groups, HLA-C1, HLA-C2, and HLA-Bw4, both HLA-B and HLA-A loci. Results: Between November 2013 and February 2016, consecutive patients with acute ischemic stroke were recruited. As healthy controls, we enrolled subjects without acute ischemic stroke. Subjects with acute ischemic stroke in comparison with controls showed a higher frequency of 2DL3, 2DL5B, 2DS2, and 2DS4 KIR genes and a lower frequency of HLA-B-Bw4 I alleles. Subjects without acute ischemic stroke showed a higher frequency of interaction between KIR 2DS2 and HLAC2. We also observed a higher frequency of 2DL3 and 2 DL4 KIR genes in subjects with atherosclerotic (LAAS) subtype. Multiple logistic regression analysis showed a protective effect towards stroke of HLA-B-Bw4 I and interaction between KIR 2DL2 and HLAC1 and 2DS2-HLAC2 and a detrimental effect of 2DL2-HLA-C1-A interactions. Conclusion: Our findings of a higher frequency of activating KIR genes seem to be consistent with findings previously reported patients with coronary syndrome. This higher frequency of "proinflammatory" genes in subjects with ischemic stroke could also explain the immunoinflammatory activation of the acute phase of stroke
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