Shared-epitope HLA-DRB1 alleles and sex ratio in Italian patients with rheumatoid arthritis

Adenosine Deaminase Activity and HLA-DRB as Diagnostic Markers for Rheumatoid Arthritis

BACKGROUND

Rheumatoid Arthritis (RA) is a chronic multi systemic disorder with the unclarified ethiopathology. Although several markers have been presented for recognition of RA, but none of them has been specific. New markers such as HLA typing and activity of Adenosine Deaminase (ADA) isoenzymes could be useful and specific.

OBJECTIVE

The aim of this study is to evaluate the pattern of ADA isoenzymes activity and HLA typing in both RA patients and healthy cases.

METHODS

Blood samples were collected from 55 RA patients and 60 healthy subjects, over a period of 6 months. Levels of C-reactive Protein (CRP), Rheumatoid Factor (RF) and ADA (ADA1, ADA2, total ADA) were measured using AVITEX kit and HITACHI Auto Analyzer. In addition, HLA-DRB1*01,*04 and *10 was detected using PCR-SSP.

RESULTS

ADA activity, particularly ADA2 level, was significantly higher among RA group (Pv <0.05). The concentrations of tADA in patients with RF and CRP positive were significantly higher (Pv <0.05). The allele prevalence of DRB1*01 was significantly higher in RA patients (13.1%) compared with control group (5.5%, respectively) (P <0.05, Bonferroni adjustment P<0.003). Calculated sensitivity and specificity for diagnostic tests in this study are listed as: CRP (75%), RF (80%), ADA (84%) and RF (90%), ADA (83%), CRP (72%), respectively.

CONCLUSION

Increased tADA level and the frequency of DRB1*10 and *01 caused susceptibility to RA.

TMEM187-IRAK1 Polymorphisms Associated with Rheumatoid Arthritis Susceptibility in Tunisian and French Female Populations: Influence of Geographic Origin

Polymorphisms have been identified in the Xq28 locus as risk loci for rheumatoid arthritis (RA). Here, we investigated the association between three polymorphisms in the Xq28 region containing TMEM187 and IRAK1 (rs13397, rs1059703, and rs1059702) in two unstudied populations: Tunisian and French. The rs13397 G and rs1059703 T major alleles were significantly increased in RA patients (n = 408) compared with age-matched controls (n = 471) in both Tunisian and French women. These results were confirmed by a meta-analysis replication study including two independent Greek and Korean cohorts. The rs1059702 C major allele was significantly associated with RA, only with French women. In the French population, the GTC haplotype displayed a protective effect against RA, while the ATC, GCC, and GTT haplotypes conferred significant risk for RA. No association for these haplotypes was found in the Tunisian population. Our results replicated for the first time the association of the three Xq28 polymorphisms with RA risk in Tunisian and French populations and suggested that RA susceptibility is associated with TMEM187-IRAK1 polymorphisms in women. Our data further support the involvement of X chromosome in RA susceptibility and evidence ethnicities differences that might be explained by differences in the frequencies of SE HLA-DRB1 alleles between both populations.

Meta-analyses of the association of HLA-DRB1 alleles with rheumatoid arthritis among Arabs

AIM

Various studies incorporating Arab populations have reported on specific associations between HLA-DRB1 variants and rheumatoid arthritis (RA). We sought to provide an overview on the association of HLA-DRB1 with RA in Arabs using meta-analysis tools.

METHODS

Data on allele counts and frequencies were compiled from the relevant literature (published before 16 February 2016) and the associations of 13 -DRB1 variants with RA were assessed; relationships were defined in terms of odds ratios (ORs) with a 95% confidence interval.

RESULTS

Based on a collection of six studies, risk conferring or protective allele associations were derived from allele counts in 475 RA patients and 1213 controls. Two HLA-DRB1 alleles (-DRB1*04, *10) significantly conferred an increased risk for RA (OR > 2; P < 0.0001). Conversely, four alleles (-DRB1*03, *07, *11 and *13) significantly conferred a protective effect against RA (OR < 1; P < 0.05). No significant associations with RA were found for seven -DRB1 variants (-DRB1*01, *08, *09, *12, *14, *15 and *16).

CONCLUSION

With increased statistical power and effect size over individual studies, we present a more robust profile on the association of HLA-DRB1 variants with RA in the Arab ethnicity, and contribute to the global geo-ethnic picture in this context.

Genetic Predisposition to Rheumatoid Arthritis in a Tuscan (Italy) Ancient Human Remain

Rheumatoid arthritis (RA) is currently believed to have originated in America, and after the discovery of this continent in 1492, to have been exported to the Old World. We evaluated the genetic predisposition to RA in the “Braids Lady” from Arezzo (Italy), a partially mummified woman's body dating back to the end of 1500 AD which presents the anatomical and pathological features of this disease. The study of the polymorphic HLA-DRB1 locus, which includes alleles strongly associated with RA onset, has received much attention over recent years, especially the loci codifying for the DR1 and DR4 antigens, widely represented in the Mediterranean population, and for DR14, widespread among Native Americans. Molecular analysis was performed on extracts of DNA from the mummy, firstly from histological bone sections and then from the whole bone. Two different HLA typing techniques, PCR-sequence-specific oligonucleotides (PCR-SSO) and PCR-sequence-specific primers (PCR-SSP), were employed to identify HLA-DRB alleles. Both genotyping methods showed that the “Braids Lady” carried the DRB1*0101 allele, the serological equivalent of the DR1 antigen. Although the possession of RA risk factor genes cannot be considered a diagnostic marker, the positive result of the Italian mummy for DRB1*0101 and the RA features present, support the idea that this pathology was present in the Old World from at least the mid-16th century. A pathogenetic hypothesis of RA which might well explain its worldwide diffusion is the “molecular mimicry”, resulting from a cross-reactive antibody response between certain microbial antigens and shared epitopes of specific HLA-DR1, DR4 and DR14 susceptibility alleles, the frequency of which varies among different ethnic groups.

Characteristics and relationship of periodontal disease with juvenile idiopathic and rheumatoid arthritis

Background:

Rheumatoid arthritis (RA) is the most prevalent chronic inflammatory disease of the joints. It is correlated with periodontal disease due to similar factors that exist in both diseases. The present study assessed the relationship of periodontal disease with RA and juvenile idiopathic arthritis (JIA).

Materials and Methods:

In this case-control study, 30 RA and 30 JIA patients along with similar number of matched controls were selected among patients referred to Imam Khomeini Hospital, Tehran, Iran. Periodontal parameters including pocket depth (PD), clinical attachment level (CAL), O’Leary and Bay plaque index (PI) and bleeding on probing (BOP) were determined in cases and controls. Erythrocyte sedimentation rate, number of painful and inflamed joints and severity of disease were evaluated in RA and JIA patients. Mann-Whitney U-test nonparametric, Spearman and Pearson's correlation coefficients, and Chi-square tests were used as statistical analysis (α = 0.05).

Results:

PD (4.17 vs. 3.6 mm; P < 0.0001), CAL (4.89 vs. 4.18 mm; P < 0.002), percentage of sites with PD >4 mm (58.83% vs. 44.33%; P < 0.002), percentage of sites with CAL >3 mm (74.13% vs. 64.4%; P < 0.001), percentage of sites with BOP (9.67% vs. 6.87%; P < 0.0001) and PI index (85.73% vs. 80.63%; P < 0.0001) were significantly higher in RA patients than controls. In this group, direct and significant correlations were found between serologic findings, disease severity and number of painful and inflamed joints with periodontal factors. In JIA patients, no significant relationships were found between JIA findings and periodontal parameters.

Conclusion:

Considering the limitations of this study, there was a relationship between RA and periodontal disease. Severity of periodontal disease increases in patients with RA, while no increased risk of periodontal disease or its severity was observed among JIA patients.

Distribution of HLA-DRβ1 alleles among well-characterized rheumatoid arthritis patients from Western India

An association between human leukocyte antigen-DRβ1*04 and rheumatoid arthritis (RA) has been known for more than 25 years. It has been observed in many different populations, and it accounts for approximately one-third of the genetic component of RA susceptibility. Our aim was to study the distribution of HLA-DRβ1 alleles in well-characterized RA patients from Western India. Polymerase chain reaction-based sequence-specific oligonucleotide probing (PCR-SSOP) technique was used to identify HLA-DRβ1 alleles among 80 clinically well-defined patients and 90 normal controls from same ethnicity. A significant increase in the frequency of DRβ1*04 was observed among RA patients (PF% 30 vs. 7.7, OR 4.959, p value 0.00018), whereas DRβ1*03 and *14 were significantly decreased among patients when compared with controls (DRβ1*03, PF% 8.75 vs. 26.6, OR 0.2637, p value 0.00253; DRβ1*14, PF% 17.5 vs. 30.0, OR 0.4949, p value 0.05722). Our results suggest that DRβ1*04 was strongly associated with well-characterized RA patients from Western India, whereas DRβ1*03 and *14 may be protective alleles for RA. The identification of susceptible allele in patients with RA may help physician to make early decisions regarding initiation of early intensive therapy with disease modifying anti-rheumatic drugs and biological agents to decrease disability in RA patients.

Association study of human leukocyte antigen-DRB1 alleles with rheumatoid arthritis in south Tunisian patients

The aim of this study is to explore relationship between HLA-DRB1 alleles and the susceptibility and clinical features of rheumatoid arthritis (RA) in the south Tunisian population. We studied 142 RA patients and 123 controls matched for age, sex, and ethnicity. HLA-DRB1 genotyping and HLA-DRB1*04 subtypes were performed using polymerase chain reaction/sequence-specific primers. Association was assessed based on the χ (2) test and odds ratio with 95% confidence interval. For multiple comparisons, p value was corrected (p (c)) with Bonferroni test. Two alleles, HLA-DRB1*04 (p=0.045, p(c)=NS) and HLA-DRB1*10 (p=0.021, p(c)=NS), were found to have increased frequencies in RA patients compared to controls. In contrast HLA-DRB1*08 allele was found to have a decreased frequency in patients compared to controls (p=0.044, p(c)=NS). Molecular subtyping of the most prevalent allele (DRB1*04) revealed increased frequencies of HLA-DRB1*04:05 in patients compared to controls (p=0.013, p(c)=NS) whereas HLA-DRB1*04:02 showed a protective effect (p=0.005, p(c)=0.04). Moreover, stratified analyses indicated statistically significant associations between HLA-DRB1*04 allele and anti-cyclic peptides antibodies positivity (ACPA(+)) and rheumatoid factor positivity (RF(+); p(c)=0.03, for both subgroups), HLA-DRBI*10 and ACPA(+) and the presence of another autoimmune disease (p(c)=0.05 and p(c)=0.007, respectively), and HLA-DRB1*04:05 and RF(+) and erosion (p(c)=0.005 and p(c)=0.049; respectively). A significant decrease in the frequency of the DRB1*04:02 allele was observed in patients with ACPA(+) and RF(+) subgroups (p(c)=0.04 and p(c)=0.02, respectively). Our results showed that there was a trend of positive association of HLA-DRB1*04 and HLA-DRB1*10 with RA as such and significant associations with the disease severity in the south Tunisian population.

Frequency of HLA-DRB1 alleles in rheumatoid arthritis patients in Zahedan, southeast Iran

BACKGROUND AND OBJECTIVES

Analysis of the role of different alleles of human leukocyte antigen (HLA) in rheumatoid arthritis (RA) patients is necessary in many populations and geographical areas. The aim of the present study was to investigate the frequency of HLA-DRB1 alleles in RA patients, comparing with that in control group in southeast Iran.

DESIGN AND SETTING

Case-control study of rheumatoid arthritis patients referred to rheumatology clinic at university hospital.

PATIENTS AND METHODS

The frequency of HLA-DRB1 alleles was determined in 79 RA patients and 93 healthy subjects in Zahedan, southeast Iran. HLA-DRB1 allele types were identified by polymerase chain reaction with sequence-specific primer (PCR-SSP).

RESULTS

The HLA-DRB1FNx0110 allele showed a significantly higher frequency in patients with RA (OR=2.698, 95% CI=1.087-6.699, P=.045), while the frequency of DRB1FNx0103 allele in these subjects was significantly lower than that in the control group (OR=0.447, 95% CI=0.2285-0.8729, P=.021). The frequencies of DRB1FNx0101, DRB1FNx0104, DRB1FNx0107, DRB1FNx0109, DRB1FNx0111, DRB1FNx0113, DRB1FNx0114, DRB1FNx0115, DRB1FNx0116 were not significantly different between RA subjects and the control group.

CONCLUSION

The data suggest that the DRB1FNx0110 allele is a risk factor and DRB1FNx0103 is protective for RA in this population.

Relationship Between Cyclic Citrullinated Peptide Antibodies Positivity and HLA-DRB1 Shared Epitope Alleles in Patients with Rheumatoid Arthritis in Turkey

Objective: The most characteristic genetic risk factors for rheumatoid arthritis (RA), the HLA-DRB1 shared epitope (SE) alleles, encode for a common amino acid sequence in the peptide-presenting part of the HLA class II molecule. These SE alleles have been described recently to be a risk factor for the development of antibodies against citrullinated proteins in RA. The current study was performed to investigate the association between the cyclic citrullinated peptide antibodies (anti-CCP) and HLA-DR1 HLA-DRB1 shared epitope alleles in patients with RA in Turkey.

Materials and Methods: Sixty patients with RA who were newly diagnosed or under conventional treatment in our clinic and 60 healthy volunteers as controls were enrolled in the study. In patients with RA anti-CCP levels were investigated with enzyme-linked immunosorbent assay and HLA-DRB1 subtyping and SE was assessed by polymerase chain reaction. Only anti-CCP was measured in healthy volunteers.

Results: SE was positive in 50% of the patients with RA. Amongst the SE carriers, 30% of them were carrying double copy of SE. While anti-CCP was positive in 73,3% of patients with RA, this ratio was 0% in healthy volunteers. We determined that the existence of SE increases the positivity of anti-CCP (OR=4,3, 95% [CI], P=0.04 ), and a significant relationship was found between the anti-CCP positivity and the RF positivity. (OR=5,3, 95% [CI] P<0.05).

Conclusion: The results of the present study revealed that Turkish patients with RA carrying SE with HLA-DRB1 genes is significantly related with the production of anti-CCP. The diagnostic sensitivity and specificity of anti-CCP for RA is determined as 73,3% and 100% respectively. (Turk J Rheumatol 2010; 25: 12-8)

Major histocompatibility complex class II (DRB1*, DQA1*, and DQB1*) and DRB1*04 subtypes' associations of Hashimoto's thyroiditis in a Greek population

Hashimoto's thyroiditis (HT) is an autoimmune disease resulting from complex interactions between genetic and environmental factors. The disease is associated with certain human leukocyte antigen (HLA) class II alleles in various populations. We aimed to determine in this study, for the first time in a Greek population, the association of HLA-DRB1*, -DQA1*, and -DQB1* alleles with HT. HLA-DRB1*, -DQA1*, and -DQB1* alleles' and -DRB1*04 subtypes' distribution was evaluated in 125 patients with HT and in 500 healthy control individuals by using a DNA-based sequence-specific primer method. Chi(_)squared tests and Bonferroni correction method were applied in the statistical analysis of the data. Significantly higher frequency of DRB1*04 (24.8% vs 7.7%, P < 0.0001) was observed in HT patients, while HLA-DRB1*07 was significantly decreased (2.8% vs 7.9%, P < 0.05). HLA-DRB1*04 subtyping showed a significant increase of DRB1*0405 (21% vs 7.8%, P < 0.0001) in HT patients. Also significant high frequencies of DQB1*0201 (14.8% vs 8.2%, P < 0.001), DQB1*0302 (18.8% vs 7.0%, P < 0.0001), and DQA1*0301 (25.6% vs 7.8%, P < 0.0001) were recorded in the patient group. Conducting the first research of this kind in a Greek population, our study tries to provide an evaluation of the prevalence of HT relating to HLA-DRB1*0405, and we report a relative risk of 2.7 for HT in a Greek population.

Is there a relationship between juvenile idiopathic arthritis and periodontitis?

AIM

The aim was to compare the prevalence of periodontal conditions in patients with juvenile idiopathic arthritis (JIA) (n=78, age 14.4 years) with those revealed in a healthy control group (n=75, age 15.5 years).

MATERIAL AND METHODS

In both groups, the approximal plaque index (API), the modified sulcular bleeding index (SBI), and the clinical attachment loss (CAL) were determined. Laboratory parameters for JIA activity included the capsule-reactive protein (CRP) and the immunoglobulins A, G, M.

RESULTS

JIA patients had a significantly higher API (64.6%versus 49.9%, p=0.004) and slightly higher mean percentages of sites with CAL>3.5 mm (0.58%versus 0.22%, p=0.041). There was no significant difference in the prevalence of patients and controls who had sites with CAL >3.5 mm (25.6%versus 17.3%, p=0.212). The mean CAL was slightly greater (0.2 mm; p=0.030) in patients with CRP> or =5.0 mg/l compared with patients with CRP<5.0 mg/l. Patients who took non-steroidal anti-inflammatory drugs (NSAIDs) had a significantly decreased SBI (26.2%versus 51.1%, p=0.019).

CONCLUSION

After adjustment for microbial plaque, JIA is not a risk factor for periodontitis.

Human leukocyte antigen DRB1*04 is associated with rheumatoid arthritis in Kuwaiti patients

OBJECTIVES

Rheumatoid arthritis (RA) is a common, complex autoimmune disease known to be associated with inheritance of certain human leukocyte antigen (HLA)-DR alleles in different populations. This study investigated the association of DRB1 alleles in Kuwaiti patients with RA.

MATERIALS AND METHODS

DRB1 alleles were analyzed in 47 Kuwaiti patients and 70 ethnically matched controls using a DNA-based sequence specific primer (SSP) method.

RESULTS

The frequency of DRB1*04 allele was higher in patients compared to the controls (P < 0.012). The association with of HLA-DRB1*04 allele in our patients with RA was accounted for mainly by the seropositive group of patients (P < 0.05). Moreover, five patients were homozygous for DRB1*4 compared to none in the controls. None of the other DRB1 alleles tested was significantly higher in the patients. All patients homozygous for the DRB1*04 allele were females. There was no statistically significant difference in the frequency of DRB1*04 allele in patients classified according to presence of erosive disease or extra-articular manifestations.

CONCLUSION

Our results indicate that in Kuwaiti patients, RA is associated with the presence of DRB1*04 allele. The lack of association with severity or the phenotype of RA is not surprising since this is a hospital-based study where patients tend to have a more severe disease.