The presence of the HLA-DRB1 shared epitope correlates with erosive disease in Chilean patients with rheumatoid arthritis

Does non-erosive rheumatoid arthritis exist? A cross-sectional analysis and a systematic literature review

OBJECTIVE

To evaluate the prevalence and factors associated with non-erosive rheumatoid arthritis (RA).

METHODS

First, a cross-sectional analytical study was performed. Non-erosive disease, defined as the absence of any erosion on X-rays after 5 years of RA, was evaluated in 500 patients. Further and additional evaluations including ultrasonography (US) and computed tomography (CT) were performed in those patients meeting the eligibility criteria. The Spearman correlation coefficient, kappa analysis, and Kendall׳s W test were used to analyze the data. Second, a systematic literature review (SLR) was performed following the PRISMA guidelines.

RESULTS

Of a total of 40 patients meeting the eligibility criteria for non-erosive RA, eight patients were confirmed to have non-erosive RA by the three methods. A positive correlation between non-erosive RA and shorter disease duration, antinuclear antibodies positivity, lower rheumatoid factor (RF) and C-reactive protein titers, lower global visual analog scale values, toxic exposures, and lower disease activity-(RAPID3) was found. In addition, an inverse correlation with anticyclic citrullinated peptide antibodies (ACPA) positivity and medication use was observed. From the SLR, it was corroborated that factors associated with this subphenotype were shorter disease duration, younger disease onset, negative ACPA and RF titers, low cytokine levels, and some genetic markers.

CONCLUSION

Non-erosive RA is rare, occurring in less than 2% of cases. These findings improve on the understanding of RA patients who present without erosions and are likely to have less severe disease.

Shared epitope and radiologic progression are less prominent in elderly onset RA than young onset RA

The aim of this study was to determine the influence of HLA-DRB1 and HLA-DQB1 genes on the disease susceptibility and the disease severity in elderly onset rheumatoid arthritis (EORA) compared with young onset rheumatoid arthritis (YORA) in Korean patients. Genetic analysis of HLA-DRB1 and HLA-DQB1 alleles was performed in three groups. Group 1 included 63 patients who were diagnosed with (rheumatoid arthritis) RA after the age of 60 (EORA). Group 2 consisted of 109 patients who were diagnosed with RA before the age of 60 (YORA). Group 3 involved 133 normal controls. The shared-epitope-coding alleles included the members of the HLA-DRB1*04 allele group (*0401, *0404, *0405, *0408, *0410), HLA-DRB1*01 allele group (*0101,*0102), HLA-DRB1*1001, and HLA-DRB1*1402. The disease severity was assessed by the modified total sharp score (mTSS). The shared-epitope-coding alleles were more frequently observed in the RA patients than in the normal controls. The shared-epitope-coding alleles were less frequently found in EORA group than YORA group (31/63 (49.2%) in group 1, 72/109 (66.1%) in group 2, 45/133 (33.8%) group 3, p = 0.02). Although the mTSS of the group 1 was higher than group 2 at symptom onset, the overall mean mTSS of the group 1 was lower than that of group 2 (26.8 vs. 57.5, p < 0.05). HLA-DQ*04 showed the higher frequency in the patients group than in normal controls (p < 0.001). And HLA-DQ*04 was less commonly found in the patients with EORA than YORA (p < 0.05). The influence of shared epitope and HLA-DQ*04 alleles may be less significant on disease susceptibility in EORA. The presence of shared-epitope-coding alleles did not appear to influence on disease severity in EORA patients as well as in YORA patients. Radiologic deterioration in EORA group was less severe than in YORA group. The presence of shared epitope and radiologic progression are less prominent in EORA patients than YORA patients.

Association of rheumatoid factor production with FcgammaRIIIa polymorphism in Taiwanese rheumatoid arthritis

Fcgamma receptors (FcgammaR) impact upon the development of inflammatory arthritis through immune complex stimulation and proinflammatory cytokine production. FcgammaRIIa, FcgammaRIotaIotaIotaa and FcRgammaIIIb polymorphisms were genotyped in 212 rheumatoid arthritis (RA) patients and 371 healthy control subjects using an allelic-specific polymerase chain reaction (PCR). No significant skewing in the distribution of FcgammaRIIa H/R131, FcgammaRIIIa F/V158 and FcgammaRIIIb NA1/NA2 was found between RA patients and healthy control subjects. However, a significant skewing distribution of the FcgammaRIIIa F/V158 polymorphism was observed between rheumatoid factor (RF)-positive versus RF-negative RA patients (P = 0.01). The low-affinity FcgammaRIIIa F158 allele seems to have a protective role in RF production, in comparison with the FcgammaRIIIa V158 allele (P = 0.004; OR = 0.485; 95% CI: 0.293-0.803). A high frequency of FcgammaRIIIa F/F158 was identified in RA patients with negative RF compared with RF-positive patients (for FF158 versus FV158 + VV158; P = 0.002; OR = 0.372; 95% CI: 0.194-0.713). In addition, no association was found between FcgammaRIIa H/R131, FcgammaRhoIIIa F/V158 and FcgammaRIIIb NA1/NA2 polymorphisms and other clinical parameters. The results of this study suggest that three activating FcgammaRs polymorphisms lack association with RA but FcgammaIIIa F/V158 polymorphism may influence RF production and IgG RF immune complex handling in Taiwanese RA patients.

Ethnicity may be a reason for lipid changes and high Lp(a) levels in rheumatoid arthritis

There are so many studies that suggest the changes in lipid profiles and lipoprotein (a) [Lp(a)] are associated with early atherosclerosis in rheumatoid arthritis (RA). But there are some opposite studies also. Because of marked ethnicity differences in the distribution of Lp(a), we aimed to investigate the associations of Lp(a) levels and lipid changes in Turkish RA patients. There were 30 women and 20 men, a total of 50 patients with RA (mean age 47.6 +/- 13.2 years), included and 21 healthy women and 14 healthy men (mean age 45.7 +/- 14.5 years) were recruited as a control (C) group. Serum Lp(a), total cholesterol (TC), triglyceride (TG), HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) levels were analysed for each group. Analysis of six different studies was performed. In the RA and C groups, mean serum Lp(a) levels were 39.7 +/- 64.4 and 10.5 +/- 13.4 mg/dl, respectively (P=0.001). Mean TC levels were 189.2 +/- 142.5 and 174.0 +/- 29.3 mg/dl (P=0.294), mean TG levels were 121.4 +/- 65.4 and 106.5 +/- 80.0 mg/dl (P=0.030), mean HDL-C levels were 44.5 +/- 10.0 and 47.7 +/- 4.8 mg/dl (P=0.014) and mean LDL-C levels were 94.3 +/- 35.3 and 102.0 +/- 24.6 mg/dl (P=0.98), respectively. Analysis of the six studies showed Lp(a) level was higher and HDL level was lower in RA patients than in healthy controls. Patients with RA may have altered lipid profiles from one country to another one. Especially in Turkey, higher serum Lp(a), lower HDL-C and higher TG levels may be found in RA patients instead of some findings of other countries showing different results. Ethnicity may be a reason for these findings.

Association of tumor necrosis factor α polymorphism, but not the shared epitope, with increased radiographic progression in a seropositive rheumatoid arthritis inception cohort

OBJECTIVE

To determine whether the tumor necrosis factor alpha (TNFA) -308 guanine-to-adenosine polymorphism and/or the shared epitope (SE) is associated with radiographic damage in patients with early rheumatoid arthritis (RA).

METHODS

The cohort consisted of 189 patients with early seropositive RA (median 5.6 months since symptom onset) who had active disease, no previous disease-modifying antirheumatic drug treatment, and >or=2 sets of scored radiographs of the hands/wrists and forefeet. TNFA -308 polymorphism was analyzed by polymerase chain reaction pyrosequencing. The SE was defined as presence of any 1 of the following HLA-DRB1 alleles: *0101, *0102, *0401, *0404, *0405, *0408, *0410, *1001, *1402, or *1406. Radiographic progression was assessed by the total Sharp score.

RESULTS

Using a weighted least-squares regression analysis, patients with the -308 TNFA AA plus AG genotypes (n=49) had significantly higher rates of progression in erosion scores (median 0.84 versus 0.48 units/year), joint space narrowing (JSN) scores (0.42 versus 0.04), and total Sharp scores (1.70 versus 0.61) compared with patients with the TNFA GG genotype (n=140). Presence of the SE (n=137) was associated with significantly lower progression rates (per year) for total Sharp scores (median 0.9 versus 1.25 units/year) and JSN scores (0.04 versus 0.41), but not for erosion scores (0.50 versus 0.61) compared with patients without the SE (n=52). In a least-squares multiple linear regression model, the presence of the AA plus AG genotypes was associated with a significantly higher progression rate after adjusting for the presence of the SE, interaction between the SE and the AA plus AG genotypes, baseline log C-reactive protein level, Health Assessment Questionnaire Disability Index, total Sharp score, swollen joint count, and presence of osteophytes (osteoarthritis). There was a strong linkage disequilibrium between DRB1*0301 and TNFA polymorphism (D'=0.84, r2=0.45, P<0.001).

CONCLUSION

This study showed an association between the TNFA -308 polymorphism and progression of radiographic damage in patients with early seropositive RA. This association appeared to be independent of the SE, but might be dependent on other genetic variants in linkage disequilibrium with the -308 TNFA A allele and DRB1*0301. Further studies should be conducted to validate these results in both longitudinal observational cohorts and randomized clinical trials.

Interaction between RANKL and HLA-DRB1 genotypes may contribute to younger age at onset of seropositive rheumatoid arthritis in an inception cohort

OBJECTIVE

To determine whether the RANKL and HLA-DRB1 "shared epitope" (SE) genotypes contribute to the development of rheumatoid arthritis (RA).

METHODS

We studied 237 patients with early RA (within 15 months of symptom onset) who were seropositive for rheumatoid factor. HLA-DRB1 genotyping was performed using the polymerase chain reaction (PCR)-based oligonucleotide probe assay. RANKL polymorphisms were analyzed using PCR pyrosequencing for SNP1 and fluorescence-based PCR for the presence or absence of the TAAA insertion.

RESULTS

The presence of SE-containing DRB1*04 alleles was associated with an earlier age at RA onset (mean +/- SD 47 +/- 12.7 years versus 53 +/- 12.5 years in SE- patients; P = 0.0004). The 2 novel RANKL polymorphisms were in strong linkage disequilibrium (P < 0.0001) and were associated with earlier ages at disease onset (e.g., for the CC versus CT/TT genotypes, 44 +/- 13.5 years versus 51 +/- 12.7 years; P = 0.0080). The mean age at disease onset in SE+ patients with the RANKL-CC genotype (35 +/- 7.2 years) was a mean of 18 years younger than in SE- patients with RANKL-CT/TT (53 +/- 12.5 years; P < 0.0001) and was 17 years younger than in SE- patients with RANKL-CC (52 +/- 13.2 years; P = 0.0005). The proportion of patients with both the SE and RANKL risk alleles was highest (23%) in those who developed RA during their third decade of life (ages 20-30 years), with a declining trend among those who developed RA during their fourth (16%), fifth (5%), and sixth or later (0%) decades. Interestingly, 92% of the patients diagnosed as having RA between ages 20 and 30 years carried at least 1 of the RA-associated DRB1*04 alleles, suggesting a strong influence of the SE in the early onset of RA. The majority of patients who developed RA symptoms in their third to fifth decades (74 of 119 [62%]) carried at least 1 copy of the DRB1*04 alleles; in contrast, fewer than half of the patients who developed RA in their sixth decade or later (50 of 118 [42%]) had DRB1*04 alleles. RANKL genotypes were not associated with erosive disease at baseline or with the yearly progression rate of radiographic joint damage.

CONCLUSION

This study provides the first evidence that novel RANKL polymorphisms were associated with an earlier age at RA onset in SE+, but not SE-, patients and that an interaction between SE-containing HLA-DRB1 and RANKL polymorphisms increased the disease penetrance, resulting in a mean age at RA onset that was 18-20 years younger. Our results also suggested genetic differences between patients with early-onset and those with late-onset RA.

Genotypes and phenotypes: should genetic markers and clinical predictors drive initial treatment decisions in rheumatic diseases?

Using patients' genetic and phenotypic profiles to identify the best available drug therapy for individual cases remains a clinical aspiration. Considerable recent research has developed this theme in rheumatoid arthritis (RA). Seven reports have evaluated how the high-risk epitope and other genes influence RA susceptibility and severity. There is strong evidence that the shared epitope influences susceptibility, but inconclusive evidence concerning whether it effects severity. The interleukin-1 gene cluster and IL-4/IL-4 genes influence erosive disease, but their effects are mainly in late RA. A further ten studies examined links with erosive disease. Fewer reports evaluated phenotypes: six studies examined outcome predictions using rheumatoid factor and antikeratin/anticyclic citrullinated peptide antibodies and two looked at conventional clinical measures. Anticyclic citrullinated peptide antibodies are useful in establishing the diagnosis of RA, but rheumatoid factor potentially provides the most useful prognostic information. The value of genotyping RA patients in defining their clinical course and determining the most suitable treatment remains unproven.

Clinical epidemiology: diagnostic and prognostic tests

Recent studies of diagnostic and prognostic tests have commonly examined serological tests and new imaging techniques. Antifilaggrin antibodies have been found to be highly specific for the diagnosis of rheumatoid arthritis (RA), but uncertainty remains about the sensitivity of this test, particularly in early RA. Magnetic resonance imaging and ultrasound continue to be explored as methods to detect synovitis and erosions in RA. Several recent studies have confirmed the association between the human leukocyte antigen DRB1 shared epitope and worse radiographic outcomes in patients with RA. Interlaboratory variation in detecting autoantibodies remains a concern, as does overuse of tests for antineutrophil cytoplasmic autoantibodies.