Vitamin D receptor gene polymorphism influences lipid profile in patients with juvenile idiopathic arthritis

Polymorphic Variants in the Vitamin D Receptor and Clinical Parameters of Rheumatoid Arthritis Patients Undergoing Anti-TNF Treatment

Vitamin D levels have been related to the severity and progression of various autoimmune disorders. In this study, we aimed to investigate the impact of genetic variability in the vitamin D receptor (VDR) gene on disease susceptibility and progression in patients with rheumatoid arthritis (RA) treated with tumor necrosis factor (TNF) inhibitors. The study comprises 121 RA patients subjected to anti-TNF therapy genotyped for four VDR polymorphic variants: rs1544410 (BsmI), rs2228570 (FokI), rs731236 (TaqI), and rs7975232 (ApaI). There was no significant association between RA susceptibility and VDR genetic variants. The study results revealed that patients with the rs2228570 CC genotype were characterized by lower vitamin D3 levels (p = 0.028) than those with the T allele. Also, the vitamin D3 levels (p = 0.029) and age at diagnosis (p = 0.017) were significantly lower in rs7975232 A allele carriers compared to CC homozygotes. However, after 6 months of therapy, the A allele seemed to be related to lower disease activity score 28 (DAS28) values (p = 0.030) and more common in patients who achieved remission (p = 0.004) compared to the CC genotype. Concerning other investigated polymorphisms, patients carrying rs1544410 AA and rs731236 CC homozygosity had lower C-reactive protein (CRP) levels before therapy (p = 0.009). In conclusion, VDR rs2228570 and rs7975232 polymorphic variants were found to be related to vitamin D3 levels. Moreover, the genotyping of rs7975232 was also useful in evaluating disease onset and disease activity after 6 months of therapy with TNF inhibitors in RA patients.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

Is There a Feasible Link between Vitamin D Receptor Genotypic and Allelic Frequencies with Analytical Biomarkers of Rheumatoid Arthritis Disease?

Rheumatoid arthritis (RA) is one of the most widespread autoimmune disorders and it has a genetic background with a variety of genes affecting the degradation of the immune system. Along these lines, we assessed the relationship between the BsmI, and FokI VDR polymorphisms and inflammable records identified with infections activity. Such as interleukins (IL-6, IL-8), hypoxia inducible factor-alpha (HIF-α), soluble receptor of advanced glycation end product (sRAGE), oxidized low-density lipoprotein cholesterol (oxLDL), neutrophil gelatinase-associated lipocalin (NGAL) and procollagen N-propeptide of type III collagen (P3NP) and the allelic frequencies of BsmI VDR rs1544410 and FokI VDR rs2228570 polymorphism on the RA. Total of 131 subjects [70 RA patients and 61 age and sex matched apparently healthy controls (HC)] were monitored for inflammatory biomarkers using ELISA. All patients were screened for the BsmI and FokI using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The all biomarkers were significantly higher in RA patients in comparison with HC. There were positive correlations between NGAL, oxLDL and s-RAGE, oxLDL. On BsmI, 'GG' and 'AG' genotypes were significantly associated with high RA activity as well as the frequency of genotypes 'AG & GG" were higher in high activity RA as compared to low RA activity. However on FokI, was observed that in high activity patients the frequency of 'CC' & 'CT' was more prevalent as compared to low activity ones. These outcomes support the immunoregulatory role of vitamin D which is associated with several inflammatory diseases, signifying a credible anti-inflammatory role in perturbation of the RA.

Study of vitamin D status and vitamin D receptor polymorphisms in a cohort of Italian patients with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis of children and adolescents. Autoimmune mechanisms are suspected to have a central role in its development. Vitamin D is an immuno-modulator in a variety of conditions, including autoimmune diseases. Low levels of vitamin D have commonly been found in JIA patients, but the influence of this hormone insufficiency in JIA pathogenesis is still unclear. Vitamin D receptor (VDR) mediates a great majority of vitamin D biological activities; specific polymorphisms of the VDR gene have been associated with different biologic responses to vitamin D. In this study, we analysed clinical characteristics of a cohort of 103 Italian JIA patients. The distribution of VDR polymorphisms in affected patients versus healthy controls was evaluated, as well as if and how these polymorphic variants associate with different disease presentations (active disease vs non-active disease), different JIA subtypes, serum levels of 25-hydroxy-vitamin D and parathyroid hormone (PTH), and lumbar spine Z-score values (osteopenia vs normal bone mineral density). A great majority of our JIA patients (84.5%) showed a suboptimal vitamin D status, in many cases (84.1%) not solved by vitamin D supplementation. Vitamin D status resulted to be independent of VDR genotypes. ApaI genotypes showed a highly significant different distribution between JIA patients and unaffected controls, with both the TT genotype and the T allele significantly more frequent in patient group.

Association of vitamin D receptor genetic variants with bone mineral density and inflammatory markers in rheumatoid arthritis

BACKGROUND AND AIMS

Vitamin D receptor (VDR) genetic variants are considered to have a role in the pathogenesis of rheumatoid arthritis (RA). This study examines an association of FokI, BsmI, ApaI and TaqI with RA, as well as with bone mineral density (RA with normal bone mineral density, RA-NBMD; RA with associated osteopenia, RA-OSTP; and RA with associated osteoporosis, RA-OP) and inflammatory markers.

MATERIALS AND METHODS

VDR genetic variants were tested in 248 subjects using the PCR-RFLP method.

RESULTS

Significant differences were observed in the distribution of FokI genotypes between RA patients (p < 0.001), or subgroups (RA-NBMD, RA-OSTP, RA-OP) (p = 0.035, p = 0.02, p < 0.001, respectively) and controls. Prevalence of FokI f allele was significantly higher in RA group (p < 0.001) and subgroups (p = 0.003, p = 0.021, p < 0.001, respectively) compared to controls. An increased susceptibility to RA-OSTP was revealed in BsmI/ApaI Ba (AC) haplotype carriers (p = 0.012). A significantly higher erythrocyte sedimentation rate values were obtained in FokI FF compared to Ff + ff carriers (54.57 ± 23.73 vs. 22.83 ± 12.42; p < 0.001) within the RA-NBMD subgroup.

CONCLUSION

The results of the study indicate an association of RA with FokI genetic variant and increased susceptibility to RA in f allele carriers, as well as to RA-OSTP in BsmI/ApaI Ba (AC) haplotype carriers.

The association of CAT-262C/T polymorphism with catalase activity and treatment response in juvenile idiopathic arthritis

Oxidative stress is believed to be of great importance for both the etiology and the persistence of juvenile idiopathic arthritis (JIA). The aim of this study was to investigate the association of -262C/T polymorphism of the catalase (CAT) gene with JIA, as well as to evaluate whether this polymorphism can influence plasma CAT activity and outcome in JIA patients treated with etanercept. A total of 154 subjects (60 JIA patients and 94 healthy volunteers) were screened for CAT-262C/T gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma CAT activity was determined using the spectrophotometric method according to Goth, prior to and 12 months after anti-TNF (etanercept) therapy. Clinical outcome was assessed using the JIA ACR (American College of Rheumatology) response criteria. The genotype and allele frequency distributions of CAT-262C/T polymorphism in the patients were significantly different from those of the controls (p = 0.014, p = 0.006). The TT genotype (polymorphic homozygous) was associated with a 4.36-fold higher likelihood of having JIA (95% CI 1.545-12.323, p = 0.005) as compared to the CC genotype (wild-type). At month 12 of treatment, JIA patients, carriers of the CC genotype, showed significantly higher plasma CAT activity (p = 0.004) and achieved the JIA ACR 70 response more often (p = 0.003) than the patients, carriers of the CT/TT genotype. This is the first study implying the possible association of CAT-262C/T polymorphism with JIA. The results suggest the potential protective effect of the CC genotype, with regard to CAT activity and treatment outcome.