Saad S. Alzahrani

POLYMORPHISM IN VITAMIN D RECEPTOR AND OSTEOPROTEGERIN GENES IN EGYPTIAN RHEUMATOID ARTHRITIS PATIENTS WITH AND WITHOUT OSTEOPOROSIS

Abstract1α,25-Dihydroxyvitamin D3 upregulates the expression of the receptor activator of nuclear factor kB ligand (RANKL), and downregulates osteoprotegerin (OPG) expression. We tested the effects of polymorphisms in the vitamin D receptor gene (VDR), and OPG gene in rheumatoid arthritis (RA) patients and healthy controls and their relationship to bone mineral density (BMD) and development of osteoporosis. Three hundred and fifty women were evaluated, 200 women having RA and 150 healthy control. The subjects were genotyped for polymorphism at BsmI in VDR and A163G in OPG genes by polymerase chain reaction followed by restriction fragment length polymorphism analysis. BMD was also measured. In A163G, the G allele increased the risk for RA and for the development of osteoporosis. We found a significant association between lower hip (BMD-h) and genotype variants of VDR (BsmI) and OPG A163G in RA patients with osteoporosis. Our results suggested that OPG A163G polymorphism was associated with RA susceptibility and with the development of osteoporosis in these patients. Also, VDR and OPG genes are important candidates for osteoporosis in RA patients.

Toll-like receptor 2 and Toll-like receptor 4 polymorphisms and susceptibility to asthma and allergic rhinitis: A case–control analysis

The aim of the study was to investigate whether polymorphisms in genes encoding Toll-like receptors (TLR2 and TLR4) may modify relative risk for development of asthma or allergic rhinitis. The results showed that the genotype and allele frequencies of the TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were not significantly different between asthmatic children or allergic rhinitis when compared to controls (p>0.05 for each) or even when compared further with IgE level. However, it was shown that the mutant allele of TLR2 or TLR4 polymorphisms were significantly associated with the moderate-severe group compared to the mild group in both atopic asthmatics and allergic rhinitis group (p>0.001 for each). In conclusion, our study demonstrates a lack of association of TLR2 and TLR4 polymorphisms with asthma and allergic rhinitis but suggests significant association between these genetic variants and the disease severity.

Association of tumor necrosis factor alpha and its receptor polymorphisms with rheumatoid arthritis in female patients

Rheumatoid arthritis (RA) is a chronic autoimmune disorder associated with altered expression of pro-inflammatory cytokines. We aim to elucidate the association between the -308G/A polymorphism of the TNF-α gene and 196M/R polymorphism in TNFRII gene and susceptibility and severity of RA. One hundred and seventy-two RA patients and one hundred and sixty controls were enrolled in the study. Polymorphisms (SNPs) at position -308 of TNF and -196 of TNFRII genes were determined using restriction fragment length polymorphism-polymerase chain reaction (PCR-RFLP). TNF AA genotype was more prevalent among the patients. GG genotype was significantly more likely to have erosive arthropathy. TNFRII RR genotype was more prevalent among the patients. Our findings suggest that the 308AA genotype of TNF-α and TNFRII 196M/R polymorphism are associated with RA susceptibility. While only the 308GG genotype of TNF-α is associated with RA severity.

Influence of interleukin-4 gene polymorphisms and interleukin-4 serum level on susceptibility and severity of rheumatoid arthritis in Egyptian population.

BACKGROUND Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease in which interleukin-4 (IL-4) plays an important role. This study aimed to investigate the influence of IL-4 variable number of tandem repeats (VNTRs) and IL-4-590 promoter polymorphisms on RA susceptibility, activity and severity in Egyptian population. MATERIALS AND METHODS One hundred and seventy-two RA patients and 172 controls were enrolled in this study. IL-4 VNTR and IL-4-590 promoter polymorphisms were genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Serum IL-4 and anti-cyclic citrullinated peptides (anti-CCPs) antibody concentrations were measured by enzyme linked immunosorbent assay (ELISA). RESULTS Subjects with IL-4-590 TT genotype were significantly more likely to develop RA. IL-4 VNTR 1/1 genotype, IL-4-590 TT and CT genotypes were significantly more associated with erosive RA and positive anti-CCP antibody. RA severity parameters were significantly increased, while, IL-4 level was significantly decreased in RA patients with IL-4 VNTR 1/1 and IL-4-590 TT genotypes. Only patients with IL-4-590 TT genotype showed a significant increase of all RA activity parameters. CONCLUSION IL-4 VNTR and IL-4-590 promoter polymorphisms may be helpful for assessing RA severity in Egyptian population. Moreover, IL-4-590 promoter polymorphism may be associated with increased risk and activity of RA.

Interaction between TGF-β1 (869C/T) polymorphism and biochemical risk factor for prediction of disease progression in rheumatoid arthritis.

OBJECTIVES Rheumatoid arthritis (RA) is a chronic inflammatory disease. Transforming growth factor-β1 (TGF-β1) may be a promising candidate gene for susceptibility and severity in RA. We aimed to determine whether TGF-β1 polymorphism is associated with susceptibility to RA and progression of joint destruction, as well as to identify the interaction between TGF-β1 polymorphism and biochemical risk factor. METHODS A total of 160 RA patients and 168 healthy unrelated controls were tested for the TGF-β1 (869C/T) polymorphism using polymerase chain reaction. RESULTS The TGF-β1 T allele was associated with susceptibility to RA. Within the RA group, TGF-β1 T allele carriers had a significant increased risk to develop osteoporosis (OR=4.4, 95% CI=-2. 4-8.1, P<0.001), as well as more likely to develop bone erosion (OR=1.7, 95% CI=0. 99-2.7, P=0. 034). Better prediction was achieved when the TGF-β1 TT genotype was used in combination with either elevated, rheumatoid factor (RF) or C-reactive protein (CRP) (OR=6.8, 3.7 respectively). Also, they increased the risk to develop bone erosion in patients with rheumatoid arthritis (OR=3.3, 9.8, P=0.017, 0.001 respectively). CONCLUSION Our results suggest that TGF-β1 TT genotype may determine the development of osteoporosis and bone erosion in RA. Also, our results points to a synergism between TGF-β1 TT genotype and elevated serum RF or elevated CRP that lead to the development of osteoporosis and bone erosion in patients with rheumatoid arthritis.

Association between genes encoding components of the IL-4/IL-4 receptor pathway and dermatitis in children.

OBJECTIVE To determine whether IL-4, IL-4Rα and STAT6 polymorphisms are associated with susceptibility to dermatitis in Egyptian children. METHODS We genotyped three groups of children, consisting of 106 atopic dermatitis (AD) children, 95 non-AD children, and 100 of healthy controls, for IL-4 (-590 C/T), (-33 C/T), IL-4Rα (I50V), (Q576R) and STAT6 (2964 G/A), (2892 C/T) gene polymorphisms using PCR-RFLP assay. Total serum IgE and serum IL-4 levels were detected by ELISA. RESULTS There was a non-significant association of IL-4 -590 C/T, -33 C/T polymorphisms in the children with non-AD or those with AD when compared with the controls. We identified a significant association between IL-4Rα I50V, Q576R polymorphisms and dermatitis susceptibility in AD (p=0.002, <0.001 respectively), whereas no such association was observed in non-AD group (p=0.52, 0.99 respectively). A significant association between STAT6 polymorphisms and both types of dermatitis was found. Patients who were carriers of IL4 -590C, IL-4Rα I50V G, STAT6 2964 A and STAT6 2892 T had an increased risk of AD [OR and 95% CI: 3.2 (2.5-4.2), p=0.005]. Furthermore, there was no relation between each polymorphism and serum IL-4 level (p>0.05 for each) while homozygosity for the risk alleles of IL-4, IL-4Rα and STAT6 SNPs were significantly associated with increased total IgE levels in all subjects. CONCLUSION In Egyptian children, the IL-4Rα and the STAT6 polymorphism may play a role in susceptibility to AD. In addition, gene-gene interaction between the IL-4, the IL-4Rα and the STAT6 significantly increases an individuals susceptibility to AD.

Association of serum cytokines levels, interleukin 10 -1082G/A and interferon-γ +874T/A polymorphisms with atopic asthma children from Saudi Arabia.

The aim of this study was to clarify the role of IL-4, IL-10, IL-13 and interferon (IFN) -γ levels in atopic asthma patients by studying the relation between their serum levels and severity of the disease. The effect of IL-10 -1082G/A and IFN-γ +874T/A SNPs was also studied. The study included 200 atopic children with asthma and 50 age- and gender matched healthy children as controls. The levels of both IL-4 and IL-13 were significantly (p<0.001) higher, while IFN-γ was significantly (p<0.001) lower in patients compared to that of the controls. There was a significant effect of gene polymorphisms of IL-10 (p<0.05) and IFN-γ (p<0.001) in occurrence of atopic asthma and increased IgE level. Polymorphism of IFN-γ gene had an effect on the serum level of IFN-γ. In conclusion, IFN-γ gene polymorphism at position +874 and IL-10 gene polymorphism at position -1082A/G are genetic determinants which contribute to susceptibility to atopic asthma in children from Saudi Arabia.

Gene Polymorphism of Interleukin-4, Interleukin-4 Receptor and STAT6 in Children with Atopic Dermatitis in Taif, Saudi Arabia.

ABSTRACT Aim of study: This work was performed to evaluate the level of IL-4, and to clarify the role of IL-4 gene polymorphism at position cytosine –590-to-thyamine (C-590T), IL-4Rα gene polymorphism at position adenine +4679-to-guanine (A+4679G) [isoleucine-50-valine (I50V)] and STAT6 gene polymorphism at position guanine 2964-to-adenine (G2964A) in Saudi children with non-atopic dermatitis (non-AD) and atopic dermatitis (AD) to identify their role in the pathogenesis of these diseases. Subjects and methods: This study included 150 children: 50 healthy children as controls, 50 with non-AD, and 50 with AD. They were subjected to full clinical examination, complete blood picture, skin prick test, and determination of serum interleukin-4 (IL-4) and total immunoglobulin-E (IgE) levels. Detection of interleukin-4 gene (C-590T), interleukin-4 receptor alpha gene (A+4679G) (I50V), and STAT6 gene (G2964A) polymorphisms were performed by PCR-based restriction fragment length polymorphism (PCR-RFLP). Results: There was a significant (P < 0.01) association between genotype and allele frequencies of IL-4Rα (A+4679G) (I50V) polymorphism in the AD group (but not non-AD group). Moreover, there was a significant association between genotype and allele frequencies of the STAT6 (G2946A) polymorphism in the non-AD (P < 0.05) and AD (P < 0.01) groups. On the other hand, there was no significant association between genotype and allele frequencies of the (C-590T) polymorphism in the non-AD group and AD group. There was a significant (P < 0.001) higher total IgE level in patients compared to the controls. Moreover, the mean values of total IgE were significantly different among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively, in all the studied groups. On the other hand, there was no significant difference of serum IL-4 levels among all the studied patients, or among the different allelic variants of (C-590T), (I50V), (G2964A) polymorphisms of IL-4, IL-4Rα, and STAT6 genes, respectively. Conclusion: IL-4Rα gene (I50V) and STAT6 gene (G2964) polymorphisms may play a role in development of eczema; however, the IL-4 gene polymorphism (C-590T) had no relationship with susceptibility to the disease among Saudi children.

CD14 tobacco gene–environment interaction in atopic children

Studying gene-environment interactions may elucidate the complex origins of atopic diseases. The aim of this study was to evaluate the association of CD14 polymorphisms and atopy in Egyptian children and to study whether atopy is influenced by CD14 interaction with tobacco smoke exposure. CD14 -159 C/T and CD14 -550 C/T were genotyped in 500 asthmaic children, 150 allergic rhinitis children and 150 controls. We found that CD14 -159T allele, CD14 -550T allele and CD14 -159T/-550T haplotype were significantly associated with atopic asthma and allergic rhinitis groups. CD14 -159 TT and CD14 -550 TT genotypes associated with elevated IgE levels in children exposed to tobacco smoke. The TT genotype of CD14 -159 C/T and CD14 -550 C/T was associated with higher serum levels of sCD14. The present study indicated that CD14 gene polymorphisms may contribute to susceptibility to atopy in Egyptian children and influenced with tobacco smoke exposure.

Osteopontin as a marker for response to pegylated interferon alpha-2b treatment in chronic HCV Saudi patients

BACKGROUND Many recent studies support the idea that osteopontin (OPN) can be used to predict the success of pegylated interferon (PEG IFN) alpha-2b/ribavirin therapy in chronic HCV patients. OBJECTIVE Our aim was to investigate the role of plasma OPN and its gene polymorphism at nt - 443 in response to PEG IFN in Saudi patients with chronic HCV. METHODS Blood was collected from 87 patients with chronic hepatitis C before treatment, then patients received PEG IFN α2b plus ribavirin combination therapy. Another 25 healthy subjects, matched for age and sex to patients, were enrolled as controls. Single nucleotide polymorphism (SNP) in OPN at nt - 443 and its blood level were analyzed. RESULTS The frequency of patients who reached sustained virological response (SVR) was increased in patients with T/T at nt - 443 than in those with C/C or C/T. Also the frequency of T allele was increased in responders than in non-responders. However, this increase was not statistically significant. The blood level of OPN was significantly increased in non-responders (Mean±SD=37.21±3.9) in comparison to responders (Mean±SD=33.22±4.1). CONCLUSION Osteopontin blood level can be considered as a reliable predictor to PEG IFN α2b plus ribavirin therapy in chronic HCV Saudi Patients.