HLA Class ii sequence polymorphisms and susceptibility to rheumatoid arthritis in greeks. the hla–drβ shared-epitope hypothesis accounts for the disease in only a minority of greek patients

Epidemiology of rheumatoid arthritis: genetic and environmental influences

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic systemic disease characterized by articular involvement and extra-articular manifestations. The incidence and prevalence of the disease vary across populations, and there is an ongoing debate on whether a change of RA occurrence over time exists or is due to methodological issues and other biases. Moreover, the disease's onset is related to an interaction of genetic and environmental factors that influence its expression.

AREAS COVERED

This review explores the latest knowledge on RA epidemiology and the possible risk factors associated with its presentation to identify potential warning signs that may in the future help disease management.

EXPERT OPINION

Current epidemiological evidence suggests a significant impact of smoking, sex hormones, and lifestyle status in RA occurrence. However, the association between these variables has not yet been thoroughly studied. Still, their effect must be interpreted as they may present subsequently integral indicators for a more rational approach of the disease.

The changing incidence of rheumatoid arthritis over time in north-west Greece: data from a referral centre

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown aetiology that affects approximately 1% of the population. The disease presents a temporal variability in different geographic areas. We investigated RA incidence over a 40-year-period in a defined area of north-west Greece, with a total population of about 400 000 inhabitants.

METHOD

This incidence study was based on retrospective review of clinical records among adults with RA newly diagnosed from 1980 to 2019 at the referral university hospital of Ioannina. An incident case was defined as any patient diagnosed with RA based on the 1987 American College of Rheumatology criteria, over 16-years-old, and resident in the study area for at least 1 year before diagnosis.

RESULTS

Out of 1411 cases diagnosed, women constituted a 2.65-fold higher number than men, with a lower mean age at diagnosis. The overall age-adjusted annual incidence rate (95% confidence interval) was 9.5 (8.5-10.5) for the total observation period, 11.7 (10.7-13.0) in 1980-1989, 10.4 (9.4-10.8) in 1990-1999, 9.8 (8.9-10.8) in 2000-2009, and 6.1 (5.3-6.9) in 2010-2019, presenting a statistically significant decline over time, along with a constant decrease in rheumatoid factor (RF)-positive incidence for both sexes.

CONCLUSION

Our findings suggest a decrease in the incidence of RA over 40 years in a geographically defined Greek population. Also, the progressive decrease in the incidence of RF-positive disease may relate to less severe expression of RA in Greek patients. These trends could be explained by different clinical, serological, and genetic factors reported in Greece compared to northern European countries.

Shared epitope and polymorphism of MICA and NKG2D encoding genes in Greek and Polish patients with rheumatoid arthritis

The present study aimed to analyse and compare the distribution of MICA (rs1051792) and NKG2D/KLRK1 (rs1154831, rs1049174, rs2255336) polymorphisms in 61 Greek and 100 Polish patients with rheumatoid arthritis in relation to the presence of the HLA-DRB1 shared epitope and clinical parameters. Genotyping of selected polymorphism was performed using real-time PCR. HLA-DRB1 shared epitope alleles segregated differently in Greek and Polish patients but in both populations were detected in over 60% of cases. The rs1051792-A variant was more common among SE-positive Polish patients (p = 0.003) while the rs1049174-G allele was more frequently observed in Greeks than in Poles (p < 0.001). Moreover, among Greek patients, the rs1051792-GG homozygotes more frequently presented with anti-CCP antibodies and rheumatoid factor (RF), while carriers of the rs1049174-G variant and rs1154831-CC homozygotes were characterized by lower disease activity scores (p < 0.05 in all cases). These results imply that, in addition to the HLA-DRB1 SE alleles, MICA and NKG2D polymorphisms may also play a role in rheumatoid arthritis.

Crosslinks Between Human Leukocyte Antigen DRB1*01 and Human Leukocyte Antigen DRB1*13 Allelic Variants and Occurrence of Rheumatoid Arthritis in Patients From Federation of Bosnia and Herzegovina

Objectives

This study aims to analyze human leukocyte antigen A (HLA-A), human leukocyte antigen B (HLA-B), human leukocyte antigen C (HLA-C), HLA-DRB1*, HLA-DRB3*, HLA-DRB4*, HLA-DRB5*, HLA-DQB1* loci expression in patients with rheumatoid arthritis (RA) in the Federation of Bosnia and Herzegovina.

Patients and methods

Deoxyribonucleic acid was isolated from peripheral blood of 48 RA patients (22 males, 26 females; mean age 36 years; range 2 to 63 years) and 104 healthy control individuals (52 males, 52 females; mean age 43 years; range 2 to 76 years). Deoxyribonucleic acid samples were analyzed using polymerase chain reaction-sequence-specific primers and sequence specific oligonucleotides methods.

Results

The most frequent allelic groups in RA patients were HLA-DRB1*01 (odds ratio=2.795; 95% confidence interval: 1.441-5.421; p=0.004) and HLA-DRB1*04 (odds ratio=2.573; 95% confidence interval: 1.214-5.453; p=0.023). Among RA patients, the most frequent genotype for the allelic group HLA-DRB1*, in the light of the common epitopes theory, was observed for DRB1*01/DRB1*13. This genotype indicates an increased incidence and relative risk (odds ratio=11.09).

Conclusion

The most common genotype in our RA patients was DRB1*01/DRB1*13, which showed increased frequency and a high relative risk. This genotype variant may be considered a predisposing factor for the development of RA.

Treatment of rheumatoid arthritis: Unraveling the conundrum

Rheumatoid arthritis (RA) is a heterogeneous disease with a complex and yet not fully understood pathophysiology, where numerous different cell-types contribute to a destructive process of the joints. This complexity results into a considerable interpatient variability in clinical course and severity, which may additionally involve genetics and/or environmental factors. After three decades of focused efforts scientists have now achieved to apply in clinical practice, for patients with RA, the "treat to target" approach with initiation of aggressive therapy soon after diagnosis and escalation of the therapy in pursuit of clinical remission. In addition to the conventional synthetic disease modifying anti-rheumatic drugs, biologics have greatly improved the management of RA, demonstrating efficacy and safety in alleviating symptoms, inhibiting bone erosion, and preventing loss of function. Nonetheless, despite the plethora of therapeutic options and their combinations, unmet therapeutic needs in RA remain, as current therapies sometimes fail or produce only partial responses and/or develop unwanted side-effects. Unfortunately the mechanisms of 'nonresponse' remain unknown and most probable lie in the unrevealed heterogeneity of the RA pathophysiology. In this review, through the effort of unraveling the complex pathophysiological pathways, we will depict drugs used throughout the years for the treatment of RA, the current and future biological therapies and their molecular or cellular targets and finally will suggest therapeutic algorithms for RA management. With multiple biologic options, there is still a need for strong predictive biomarkers to determine which drug is most likely to be effective, safe, and durable in a given individual. The fact that available biologics are not effective in all patients attests to the heterogeneity of RA, yet over the long term, as research and treatment become more aggressive, efficacy, toxicity, and costs must be balanced within the therapeutic equation to enhance the quality of life in patients with RA.

The Prevalence of Rheumatoid Arthritis in the South of Jordan

The aim of this study is to evaluate the prevalence of rheumatoid arthritis in the south of Jordan. The study was carried out between January, 2005 and December, 2008; 2,220 adults aged between 16 and 75 years were evaluated for the presence of rheumatoid arthritis disease according to the American Rheumatism Association 1987 criteria. The results showed that the prevalence of rheumatoid arthritis was 0.36% in the general population; the prevalence in males was 0.34% and in females it was 0.39%. In conclusion, the prevalence of rheumatoid arthritis is extremely low in the south of Jordan with a slight female predominance. American Rheumatism Association criteria continued to be the most useful criteria for the diagnosis of rheumatoid arthritis.

Antineutrophil cytoplasmic antibodies testing in a large cohort of unselected greek patients

Objective. To retrospectively evaluate ANCA testing in a cohort of unselected Greek in- and outpatients. Methods. In 10803 consecutive serum samples, ANCA were tested by indirect immunofluorescence (IIF) and ELISA. ELISA in inpatients was performed only on IIF positive sera. Results. Low prevalence (6.0%) of IIF positive samples was observed. Among these samples, 63.5% presented perinuclear (p-ANCA), 9.3% cytoplasmic (c-ANCA) and 27.2% atypical (x-ANCA) pattern. 16.1% of p-ANCA were antimyeloperoxidase (anti-MPO) positive, whereas 68.3% of c-ANCA were antiproteinase-3 (anti-PR3) positive. Only 17 IIF negative outpatients' samples were ELISA positive. ANCA-associated vasculitides (AAV), connective tissue disorders and gastrointestinal disorders represented 20.5%, 23.9%, and 21.2% of positive results, respectively. AAV patients exhibited higher rates of MPO/PR3 specificity compared to non-AAV (93.8% versus 8%). Conclusions. This first paper on Greek patients supports that screening for ANCA by IIF and confirming positive results by ELISA minimize laboratory charges without sacrificing diagnostic accuracy.

Prognostic Factors of Radiological Damage in Rheumatoid Arthritis: A 10-year Retrospective Study

Objective.

To describe the longterm clinical and radiological outcomes in rheumatoid arthritis (RA) in a cohort in northwestern Greece; and to investigate predictive factors of radiological damage at the 10-year followup in patients with RA.

Methods.

We studied the disease course and outcome of 144 patients with RA and radiographs of the hands and wrists available at baseline and at 10 years. Baseline measurements and time-averaged measures of swollen joint count (SJC) and inflammatory markers [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)] were tested in univariate analysis, and then those presenting a statistically significant association with either Larsen score at 10 years or annual progression rate were included in 2 logistic regression models in order to determine relevant independent prognostic factors.

Results.

A significant clinical improvement was noted, associated with a decrease of inflammatory markers along the timepoints. Larsen score and the number of erosive joints were increased. In the univariate analysis, both final Larsen score at 10 years and accelerated annual radiological progression rate were significantly associated with baseline radiographic measurements (Larsen score and number of erosive joints), the presence of autoantibodies [anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor of IgA and IgM isotype], disease duration, and time-averaged measures of ESR, CRP, and SJC. In the logistic regression analysis, the baseline Larsen score, anti-CCP antibodies, and time-averaged CRP presented significant and independent associations with Larsen score at 10 years. An accelerated annual radiological progression rate was also predicted by baseline Larsen score and time-averaged measures of SJC and CRP.

Conclusion.

Despite clinical improvement, the radiologic progression of RA continues over time, because of the underlying inflammatory process. Baseline radiographic damage, anti-CCP antibodies, and time-averaged CRP constitute the main predictive factors of poor radiologic outcome in the long term.

Gene expression profiles of systemic lupus erythematosus and rheumatoid arthritis

Gene expression profiling using microarray technology is being employed to define specific molecular mediators and pathways involved in immunobiology, to understand the intricate interplay of genes participating in the pathogenesis, and to develop biomarkers of disease activity in both systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). This review summarizes the latest information on the pathogenesis of SLE and RA and describes the utilization of microarray technology in these systemic autoimmune diseases.

Rituximab therapy in Greek patients with rheumatoid arthritis

OBJECTIVE

An open-label, prospective, uncontrolled study created to investigate clinical response, serological changes and side effects in Greek patients with rheumatoid arthritis (RA), after B-cell depletion with rituximab.

METHODS

Patients with high disease activity (disease activity score [DAS]-28 > 5.1) were selected for treatment with rituximab and received two infusions, 1 gr each, 2 weeks apart. Different disease parameters (visual analog scale, DAS-28, C-reactive protein [CRP], erythrocyte sedimentation rate, health assessment questionnaire, complement (C3), C4, rheumatoid factor [RF], anti-cyclic citrullinated peptide antibody [anti-CCP], swollen joint count, tender joint count, immunoglobulin M [IgM], IgG, IgA) were performed at base line, 2, 4, and 6 months post-treatment. Response was defined according to the American College of Rheumatology (ACR) criteria.

RESULTS

Seventeen patients received therapy. Treatment led to a reduction in various disease parameters. ACR20 was achieved in 41.11% of patients by week 8, 52.94% by week 16, and 82.35% by week 24. ACR50 was achieved in 5.88% by week 8, 41.17% by week 16, and 64.7% by week 24. ACR70 was achieved only by week 24 in 23.52% of patients. Statistical analysis has shown no differences in clinical response, between RF positive/negative patients, and anti-CCP-positive/negative patients, while decline of RF was better correlated with reduction of DAS-28 than with anti-CCP.

CONCLUSIONS

Rituximab is a well tolerated and effective treatment in RA. Response was not correlated to RF or anti-CCP positivity. Decline of RF was associated with clinical response and reduction of DAS-28 and CRP.

The HLA-DRB1 shared epitope is associated with susceptibility to rheumatoid arthritis in African Americans through European genetic admixture

OBJECTIVE

To determine whether shared epitope (SE)-containing HLA-DRB1 alleles are associated with rheumatoid arthritis (RA) in African Americans and whether their presence is associated with higher degrees of global (genome-wide) genetic admixture from the European population.

METHODS

In this multicenter cohort study, African Americans with early RA and matched control subjects were analyzed. In addition to measurement of serum anti-cyclic citrullinated peptide (anti-CCP) antibodies and HLA-DRB1 genotyping, a panel of >1,200 ancestry-informative markers was analyzed in patients with RA and control subjects, to estimate the proportion of European ancestry.

RESULTS

The frequency of SE-containing HLA-DRB1 alleles was 25.2% in African American patients with RA versus 13.6% in control subjects (P = 0.00005). Of 321 patients with RA, 42.1% had at least 1 SE-containing allele, compared with 25.3% of 166 control subjects (P = 0.0004). The mean estimated percent European ancestry was associated with SE-containing HLA-DRB1 alleles in African Americans, regardless of disease status (RA or control). As reported in RA patients of European ancestry, there was a significant association of the SE with the presence of the anti-CCP antibody: 86 (48.9%) of 176 patients with anti-CCP antibody-positive RA had at least 1 SE allele, compared with 36 (32.7%) of 110 patients with anti-CCP antibody-negative RA (P = 0.01, by chi-square test).

CONCLUSION

HLA-DRB1 alleles containing the SE are strongly associated with susceptibility to RA in African Americans. The absolute contribution is less than that reported in RA among populations of European ancestry, in which approximately 50-70% of patients have at least 1 SE allele. As in Europeans with RA, the SE association was strongest in the subset of African American patients with anti-CCP antibodies. The finding of a higher degree of European ancestry among African Americans with SE alleles suggests that a genetic risk factor for RA was introduced into the African American population through admixture, thus making these individuals more susceptible to subsequent environmental or unknown factors that trigger the disease.

Analysis of SAA1 gene polymorphisms in the Greek population: rheumatoid arthritis and FMF patients relative to normal controls. Homogeneous distribution and low incidence of AA amyloidosis

OBJECTIVE

To address whether or not the rarity of amyloidosis in Greek patients with rheumatoid arthritis (RA) is related to specific alleles of single nucleotide polymorphisms (SNPs) in the 5'-flanking region and the exon 3 of the SSA1 gene.

METHODS

The genotypes of the -13T/C SNP in the 5'-flanking region of the SAA1 gene and the two SNPs within exon 3 of SAA1 (2995C/T and 3010C/T polymorphisms) were determined in 88 Greek patients with RA, 14 patients with familial Mediterranean fever (FMF) and 110 healthy controls. Linkage disequilibrium and haplotype frequencies involving -13T/C, 2995C/T and 3010C/T in these populations were tested and estimated, respectively.

RESULTS

The genotypic distribution and allelic frequencies were similar in all groups tested. SNPs 2995 and 3010 were in linkage disequilibrium for all study populations (p < 0.05), whereas SNP -13 was not in linkage disequilibrium with either 2995 or 3010 (p > or = 0.05). Two major haplotypes presented in all patients with RA and FMF and controls: -13C; 2995T; 3010C (-13C; alpha) and -13C; 2995C; 3010T (-13C; beta). The -13T allele was linked with the gamma haplotype in Greek patients with RA and controls. The frequency of the -13T allele was found to be very rare in all groups tested.

CONCLUSIONS

In conclusion, the rarity of the putative amyloidogenic -13T allele in Greek populations may be related to low prevalence of AA amyloidosis development in Greek RA patients.

Diagnostic value of anti-cyclic citrullinated peptide antibodies in Greek patients with rheumatoid arthritis

BACKGROUND

Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been of diagnostic value in Northern European Caucasian patients with rheumatoid arthritis (RA). In these populations, anti-CCP antibodies are associated with the HLA-DRB1 shared epitope. We assessed the diagnostic value of anti-CCP antibodies in Greek patients with RA where the HLA shared epitope was reported in a minority of patients.

METHODS

Using an enzyme-linked immunosorbent assay (ELISA) (CCP2) kit, we tested anti-CCP antibodies in serum samples from 155 Greek patients with RA, 178 patients with other rheumatic diseases, and 100 blood donors. We also determined rheumatoid factor (RF) and compared it to anti-CCP antibodies for area under the curve (AUC), sensitivity, specificity and likelihood ratios.

RESULTS

Sensitivity of anti-CCP2 antibodies and RF for RA was 63.2% and 59.1%, and specificity was 95.0% and 91.2%, respectively. When considered simultaneously, the AUC for anti-CCP antibodies was 0.90 with 95% CI of 0.87 to 0.93 and the AUC for RF was 0.71 with 95% CI of 0.64 to 0.77. The presence of both antibodies increased specificity to 98.2%. Anti-CCP antibodies were positive in 34.9% of RF-negative RA patients. Anti-CCP antibodies showed a correlation with the radiographic joint damage. Anti-CCP-positive RA patients had increased the swollen joint count and serum CRP concentration compared to anti-CCP-negative RA patients (Mann-Whitney U test, p = 0.01, and p < 0.001, respectively). However, no correlation was found between anti-CCP antibodies and DAS28 score (r = 0.13, p = 0.12).

CONCLUSION

In Greek patients with RA, anti-CCP2 antibodies exhibit a better diagnostic value than RF and a correlation with radiological joint damage and therefore are useful in everyday rheumatology practice.

The association of HLA-DRB1 alleles with rheumatoid arthritis in the Chinese Shantou population: a follow-up study

We investigated the distribution of HLA-DRB1 alleles in a sample of the Chinese Shantou population, and explored the relationship between HLA-DRB1 alleles and the susceptibility and clinical features of rheumatoid arthritis (RA). We studied 117 consecutive patients with RA and control groups, including 38 cases of systemic lupus erythematosus and 100 healthy individuals. HLA-DRB1 genotyping was performed using PCR with sequence-specific primers. HLA-DRB1*04 subtypes were detected using spot hybridization of PCR products with sequence-specific oligonucleotide probes. We compared the frequency of HLA-DRB1 alleles in healthy control patients with that in patients with RA. Patients with RA were evaluated for sex, age at disease onset, disease duration, extra-articular involvement, presence of autoantibodies, global functional status, and radiographic damage. The frequency of HLA-DRB1*04 was found to be significantly higher in RA patients than in healthy individuals (49.6% vs 18.0%, odds ratio = 4.478, P < 0.001). HLA-DRB1*0405 was the most prominently associated subtype in RA patients (62.1% vs 27.8%, odds ratio = 4.255, P = 0.011). Compared with the HLA-DRB1*04-negative RA group, the mean duration of RA in the HLA-DRB1*04-positive RA group was longer, and the mean age at disease onset was lower. A 2-9 year follow-up study was performed, and the risk factors associated with the radiographic progression of RA were determined. Logistic regression analysis revealed that only HLA-DRB1*04 alleles were significantly associated with the radiographic progression of RA (B = 2.652, P = 0.018, Exp(B) = 14.182). Our observations indicated that the HLA-DRB1*04 alleles, especially the subtype HLA-DRB1*0405, were significantly associated with RA susceptibility in the Chinese Shantou population. The HLA-DRB1*04 alleles may be associated with the severity of RA.

Incidence and Prevalence of Rheumatoid Arthritis, Based on the 1987 American College of Rheumatology Criteria: A Systematic Review

OBJECTIVES

To conduct a systematic review of incidence and prevalence studies of rheumatoid arthritis (RA), based on the 1987 revised American College of Rheumatology (ACR) criteria, to compare their methodologies and summarize their results, and to investigate the possible geographic variations and changes over time in the frequency of the disease.

METHODS

We conducted a Medline search between January 1988 and December 2005. Studies reporting the incidence and prevalence of RA in adult populations (16 to 20 years and over), based on 1987 ACR criteria, were eligible for inclusion. From each study included, we extracted the country, year of publication, type of study (retrospective, prospective, or cross-sectional), and incidence or prevalence rates. The study areas were grouped into (a) North American countries; (b) north European countries; (c) south European countries; and (d) developing countries. We examined the geographical differences of prevalence and incidence rates using the Mann-Whitney and the Kruskall-Wallis tests.

RESULTS

A total of 28 studies were identified meeting the inclusion criteria. Nine were incidence studies, 17 were prevalence studies, and 2 estimated both prevalence and incidence rates. Incidence studies were not available from developing countries. There is a significant difference of prevalence estimates between northern European and American countries and developing countries. South European countries have lower median incidence rates than North American and north European countries. As concerning the time trends of RA occurrence, only 3 incidence studies provided secular data from the same study area, based on ACR criteria, using the same methods of case ascertainment. Two of these studies indicate a decreasing incidence of RA in Finland and United States of America.

CONCLUSIONS

The occurrence of RA varies among countries and areas of the world. A decreasing trend has been observed in countries characterized by high rates of RA incidence and prevalence. However, the relatively small number of studies for most areas of the world and the lack of incidence studies for the developing countries limits the understanding of worldwide RA epidemiology.

HLA-DRB1 association in Saudi rheumatoid arthritis patients

Association between HLA-DRB1 alleles and rheumatoid arthritis (RA) has been known for more than three decades. However, the strength of these links varies between ethnic groups. This study examines the frequency of HLA-DRB1 alleles amongst Saudi RA patients. The DRB1 region of major histocompatibility complex was screened by polymerase chain reaction/sequence specific primers (PCR/SSP) in a total of 140 subjects including 70 RA patients and 70 matched healthy controls. HLA-DRB1 *04 was found to be the most frequent allele associated with RA followed by DRB1 *08 and DRB1 *10. On the other hand, the frequency of DRB1*06 was found to be decreased in RA patients as compared to controls. Molecular sub typing of the most prevalent allele DRB1 *04 revealed a statistically significant association between RA and DRB1 *0405. We conclude that an improved understanding about the influence of HLA on RA might help in predicting the susceptibility or protection against disease.

Psychological distress and personality traits in early rheumatoid arthritis: a preliminary survey

OBJECTIVES

To investigate psychiatric manifestations, personality traits, and ego mechanisms of defense involved in early rheumatoid arthritis (RA).

METHODS

Twenty-two unselected early RA outpatients with disease duration less than 1 year participated in the study. The majority of participants were females (72.7%), married (81.8%), aged 51.0+/-14.6 years. Thirty-four subjects matched for age, sex and educational level served as "healthy" controls. General Heath Questionnaire, Symptom Distress Checklist, Defense Style Questionnaire and Hostility and Direction of Hostility Questionnaire were used; disease activity was estimated by disease activity for 28-joint indices score.

RESULTS

Seven patients (31.8%) presented psychological distress scores indicative of possible psychiatric caseness, expressing obsessive-compulsive symptoms and depression, as compared to six (17.6%) of controls. Social dysfunction distress and somatization were prominent psychiatric manifestations in early RA group. Early RA patients tend to adopt a less adaptive defense style than controls. Although disease activity was not correlated to psychological distress, a significant association between disease activity and patients' defensive style was observed: as the disease is exacerbated, there was a shift from "non-adaptive" to "immature image distorting or borderline" defense style, suggesting a rather fragile underlying personality structure.

CONCLUSION

Psychological distress is a relatively common experience in early RA. Social dysfunction, along with the less adaptive defense style, which under the stress of the disease exacerbation turns to "borderline", underlines the importance of a careful assessment and consultation in early RA patients in order to face the distress shortly after diagnosis and highlights potential risk factors for future adaptation to exacerbations of the disease.

Increased susceptibility to rheumatoid arthritis in Koreans heterozygous for HLA-DRB1*0405 and *0901

OBJECTIVE

To investigate the association of susceptibility and protective HLA-DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in an Asian population.

METHODS

All RA patients (n = 574) and control subjects (n = 392) were Korean. HLA-DRB1 typing and further subtyping of all alleles was performed by polymerase chain reaction, sequence-specific oligonucleotide probe hybridization, and direct DNA sequencing analysis. We used a relative predispositional effects (RPEs) method and a false discovery rate correction method for multiple comparisons.

RESULTS

The DRB1*0405 and *0901 alleles showed the most significant associations with RA (P = 7.83 x 10(-24), odds ratio [OR] 4.40 [95% confidence interval (95% CI) 3.24-5.99], and P = 3.76 x 10(-9), OR 2.47 [95% CI 1.82-3.36], respectively). The RPEs test showed that the DRB1*0401 and *0410 alleles conferred susceptibility and that the DRB1*0701, *0802, *1301, *1302, *1403, and *1405 alleles showed significant protective effects. Susceptibility and protective alleles both showed a pattern consistent with additive genetic effects, and each influenced RA independently of the other. The compound heterozygote DRB1*0405/*0901 was associated with the highest risk of RA (corrected P = 1.81 x 10(-11), OR 58.2 [95% CI 7.95-425.70]). The mean age at disease onset was approximately 4 years earlier or was 3 years earlier, respectively, in patients with at least 1 copy of the DRB1*0405 or the DRB1*0901 allele. Radiographic changes (stages II-IV) were more frequent in patients with at least 1 copy of DRB1*0405 (P = 0.032, 92.6% versus 84.3%, OR 2.33 [95% CI 1.24-4.39]).

CONCLUSION

The DRB1*0405/*0901 heterozygote has the strongest association with RA, suggesting that this heterozygote enhances the susceptibility to RA in Koreans.

HLA-DRB1 genes and disease severity in rheumatoid arthritis in Turkey

OBJECTIVE

Association with human leukocyte antigen (HLA)-DRB alleles, implicated in the aetiopathogenesis of rheumatoid arthritis (RA), is found to be different in various ethnic groups. This study aimed to investigate DRB1 alleles in RA patients in Turkey, and to examine the effect of these alleles on disease severity.

METHODS

We performed PCR-based DRBI genotyping of 104 RA patients recruited from clinical settings and 110 healthy controls. HLA DRB1 alleles frequencies in RA patients and healthy controls were determined. Phenotype frequencies of patients and controls were compared. Disease severity was assessed by radiological erosion, presence of extra-articular involvement, and functional index.

RESULTS

Significant differences were in the frequencies of DRB1*04 (46.2% versus 20.9%, p < 0.001), DRB1*0401 (10.6% versus 0%, p < 0.001), DRB1*0405 (8.7% versus 0%, p = 0.001), DRB1* 0404 (15.4% versus 3.6%, p < 0.01), DRB1*01 (21.2% versus 10.9%, p < 0.05) and DRB1*0101 (16.3% versus 5.5%, p = 0.01) between RA patients and controls. HLA-DRB1 alleles did not show any association with seropositivity, extra-articular involvement, radiological erosion, or functional index.

CONCLUSION

Our results suggest that the HLA-DRB1 alleles, particularly HLA-DRB1*04 and subtypes, were associated with RA.

Associations of HLA microsatellites with rheumatoid arthritis in Singaporean Chinese

Rheumatoid arthritis in Singaporean Chinese has previously been shown to be associated with the DRB1*0405, DRB1*1001 haplotypes and to the DRB1*0901 haplotype when the former two were removed. The present paper focused on eight HLA associated microsatellite markers (TNFa, TNFd, D6S273, TAP1CA, DQCAR, DQCARII, D6S2222, D6S2223) and their allelic associations with Chinese RA. 60 RA patients and 75 healthy controls were studied. It appeared that DQCARII*194/DRB1*0405/TNFa*117 was part of the extended haplotype predisposed to RA, whereas DRB1*0901/D6S273*128 contributed to susceptibility to RA to a lesser degree in Singaporean Chinese. Additionally, a negative association with DQCAR*186/DRB1*0301/D6S273*122/TNFd*124 was observed. No association with disease development was observed in this study.

Ethnic variation in the clinical manifestations of rheumatoid arthritis: role of HLA-DRB1 alleles

OBJECTIVE

To assess the extent of ethnic variation in the clinical expression of rheumatoid arthritis (RA) and the role of HLA-DRB1 alleles in this variation.

METHODS

We assessed consecutive RA patients for joint findings, subcutaneous nodules, laboratory and radiographic findings, and treatment. We typed HLA-DRB1 alleles to identify those that contain the shared epitope (SE). We adjusted ethnic comparisons for age and sex, and tested for ethnic heterogeneity in the effect of the SE.

RESULTS

We studied 777 RA patients, 498 of whom were women (64%), 432 were Hispanic (56%), 272 were non-Hispanic white (NHW; 35%), 53 were African American (AA; 7%), and 20 were Asian (3%). Compared with NHW, Hispanics had significantly more tender joints (17 versus 11), more swollen joints (8 versus 7), more frequent rheumatoid factor (RF) positivity (93% versus 84%), higher erythrocyte sedimentation rate (ESR; 45 versus 36 mm/hr), and a lower number of lifetime disease-modifying antirheumatic drugs (1.9 versus 2.5). AA were older at onset (46 versus 44 years), had less frequent subcutaneous nodules (18% versus 28%), and higher ESR (42 versus 36 mm/hour) than did NHW. Hispanics and AA were more likely than NHW to be null for the SE (odds ratio [OR] = 4.59 for AA; and OR = 1.61 for Hispanics), and less likely to have 2 SE-carrying alleles (OR = 0.59 for Hispanics and OR = 0.25 for AA). The number of SE copies was associated with subcutaneous nodules, ESR, RF, and radiographic changes. Ethnic heterogeneity in the effect of the SE was modest.

CONCLUSIONS

There is ethnic variation in the clinical expression of RA and in both the frequency and types of SE-carrying HLA-DRB1 alleles. Some ethnic variation in clinical findings is associated with differences in SE frequency. However, we found that the effect of the SE on the clinical features of RA varies little between ethnic groups.

Otolaryngologic manifestations of small vessel vasculitis

OBJECTIVE

The aim of the present study is to review the clinical manifestations associated with small vessel vasculitis (SVV) as they pertain to the head and neck region.

METHODS

A retrospective analysis was performed, including 34 individuals that filled the American College of Rheumatology criteria for the diagnosis of necrotizing vasculitis. Seven patients were classified as suffering from Wegener's granulomatosis (WG), 18 from microscopic polyangitis (MPA), and the remaining 19 were unclassified (unclassified small vessel vasculitis, USVV).

RESULTS

The percentage of ENT manifestations in the early clinical picture of WG patients was 86%, dropping to 44.5 and 22% for MPA and USVV patients, respectively. The overall percentage of ENT manifestations for SVV patients in their initial clinical profile was 47%.

CONCLUSION

The results of our investigation highlight the importance of an ENT clinical examination as a guide for diagnosis of an important percentage of SVV patients.

Shared epitopes and rheumatoid arthritis: disease associations in Greece and meta-analysis of Mediterranean European populations

OBJECTIVES

To assess the strength of the associations between HLA shared epitopes (SE) and rheumatoid arthritis (RA) susceptibility, articular disease severity, and extra-articular features in Mediterranean European populations.

METHODS

One hundred and seventy-four Greek RA patients and 103 controls were evaluated. Data were then included in a meta-analysis of 9 studies of Mediterranean European populations (959 RA patients and 1,405 controls).

RESULTS

In our study population, SE alleles were significantly more common in RA patients than in controls (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.4-4.3). Larsen radiologic score was predicted by SE and disease duration. SE did not increase the risk of any extra-articular manifestation. The meta-analysis showed a pooled OR of 3.7 (95% CI, 2.6-5.2) for susceptibility to RA conferred by SE (OR, 3.4 v 3.9 in Greek v non-Greek populations).

CONCLUSIONS

SE determine articular destruction without increasing the risk of extra-articular manifestations. The immunogenetic associations of RA susceptibility are consistent, but their strength may depend on the SE prevalence in different ethnic groups.

Heterogeneity between men and women in the influence of the HLA-DRB1 shared epitope on the clinical expression of rheumatoid arthritis

OBJECTIVE

To test the hypothesis that the influence of the HLA-DRB1 shared epitope (SE) on the clinical manifestations of rheumatoid arthritis (RA) differs between men and women.

METHODS

We assessed 777 consecutive RA patients for age at disease onset, articular manifestations, subcutaneous nodules, laboratory and radiographic findings, and treatment received. We typed HLA-DRB1 alleles by polymerase chain reaction-sequence-specific primer amplification and categorized the number of SE-containing alleles. We used regression models to adjust comparisons between the sexes for age and clustering by recruitment center, and included SE x sex interaction terms to look for heterogeneity between men and women in the effect of the SE.

RESULTS

Among the 777 RA patients, 548 (71%) were women. Men and women differed significantly in the adjusted frequency of SE positivity (women 71.4% versus men 78.4%; P < or = 0.001). The SE was associated with a younger age at symptom onset and RA diagnosis among men, but not among women. The SE likewise had a significant adverse effect on joint tenderness, swelling, and deformity among men only. The SE was associated with a higher erythrocyte sedimentation rate in women and more frequent positivity for rheumatoid factor among both men and women.

CONCLUSION

There is heterogeneity between men and women in the effect of the SE on RA susceptibility and clinical expression. Further research is needed to understand the mechanism of this heterogeneity.

Genetic studies, clinical heterogeneity, and disease outcome studies in rheumatoid arthritis

HLA haplotypes influence various clinical RA features considered to reflect severity in case-control and cohort studies. Of particular note is the fact that HLA generally influences the development of erosive and sometimes seropositive and nodular disease; in prospective studies, it noticeably affects joint surgical intervention. These are valuable clues indicating that HLA influences RA severity and chronicity. Nevertheless, HLA influences are generally weak enough so as to require large study subject numbers for detection. As a result, HLA genotyping has restricted usefulness for prediction of clinical severity in individual patients.

Tumor necrosis factor markers show sex-influenced association with rheumatoid arthritis

OBJECTIVE

The observation that not all shared-epitope genotypes confer the same risk suggests that a second HLA-region locus may confer risk. Tumor necrosis factor alpha (TNFgamma) is a possible candidate. We examined TNFalpha for sex influences on HLA-associated risk for rheumatoid arthritis (RA).

METHODS

DRB1 and TNF microsatellite typing of 297 Caucasian RA patients (132 men, 165 women) and 267 Caucasian controls was performed.

RESULTS

The TNFab microsatellite haplotype distribution differed among the male RA, female RA, and control groups (P < 0.01); the difference was largely an excess of TNFa2b1 haplotypes in the male RA group. However, this did not simply reflect an excess of shared-epitope haplotypes bearing TNFa2b1. In RA, not all shared-epitope-bearing haplotypes had the same TNFab. The *0401-bearing haplotypes commonly had TNFa6b5, TNFa2b1, TNFa10b4, and TNFa11b4, while the *0404-bearing haplotypes had TNFa11b4. In the female RA group, TNFa2b1 was most often on *0401-bearing haplotypes. In the male RA group, there was a surprise: TNFa2b1 was often on HLA haplotypes without shared-epitope DRB1 alleles. To estimate the relative strength of associated HLA markers, we performed logistic regression analyses stratified by sex and controlling for a potential confounder, age at disease onset. Among women, TNFa2b3 favored RA (odds ratio 1.932, P < 0.05) while TNFa6b5 was protective (odds ratio 0.522, P < 0.05). Among males, TNFa2b1 and TNFa11b4 conferred elevated odds ratios (2.58 and 1.681, respectively, P < 0.05). However, the odds ratios for TNFa2b1 in men and TNFa2b3 in women were generally well below those for RA-associated DRB1 markers (for example, DRB1*0401 3.553 in male RA patients and 6.991 in female RA patients).

CONCLUSION

Certain TNFab-bearing HLA haplotypes modify RA risk in a manner influenced by sex but independent of DRB1, particularly TNFa2b1 in men.

Dietary factors in relation to rheumatoid arthritis: a role for olive oil and cooked vegetables?

BACKGROUND

Although several studies showed that risk of rheumatoid arthritis (RA) is inversely associated with consumption of n-3 fatty acids, the one study showing that olive oil may have a protective role has not yet been confirmed.

OBJECTIVE

We examined the relation between dietary factors and risk of RA in persons from southern Greece.

DESIGN

We studied 145 RA patients and 188 control subjects who provided information on demographic and socioeconomic variables, prior medical and family history, and present disease status. Subjects responded to an interviewer-administered, validated, food-frequency questionnaire that assessed the consumption of >100 food items. We calculated chi-square statistics for linear trend and odds ratios (ORs) for the development of RA in relation to the consumption of olive oil, fish, vegetables, and a series of food groups classified in quartiles.

RESULTS

Risk of developing RA was inversely and significantly associated only with cooked vegetables (OR: 0.39) and olive oil (OR: 0.39) by univariate analysis. A significant trend was observed with increasing olive oil (chi-square: 4.28; P = 0.03) and cooked vegetable (chi-square: 10. 48; P = 0.001) consumption. Multiple logistic regression analysis models confirmed the independent and inverse association between olive oil or cooked vegetable consumption and risk of RA (OR: 0.38 and 0.24, respectively).

CONCLUSIONS

Consumption of both cooked vegetables and olive oil was inversely and independently associated with risk of RA in this population. Further research is needed to elucidate the underlying mechanisms of this finding, which may include the antioxidant properties or the high n-9 fatty acid content of the olive oil.

Role of cytokines in the pathogenesis of anemia of chronic disease in rheumatoid arthritis

The aim of our study was to evaluate the role of proinflammatory cytokines: tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6), as well as the possible contribution of interleukin-10 (IL-10) in anemia of chronic disease (ACD) of rheumatoid arthritis (RA) patients. We measured the serum levels of TNFalpha, IL-1beta, and IL-6 in 105 anemic and 127 nonanemic RA patients. We also investigated the effects of the above cytokines on the development of burst-forming units-erythroid (BFUe) and colony-forming units-erythroid (CFUe) in bone marrow cultures. Anemic patients had significantly higher serum levels of TNFalpha, IL-1beta, and IL-6 compared to nonanemics. Serum IL-10 levels were low and there was no significant difference in IL-10 concentrations between anemic and nonanemic patients. Proinflammatory cytokines inhibited proliferation of BFUe and CFUe. IL-10 did not decrease the erythroid colony growth. Proinflammatory cytokines may play a role in the pathogenesis of ACD in RA patients. Low levels of IL-10 possibly contribute to the development of ACD.

HLA-DRB1 alleles associated with susceptibility or resistance to rheumatoid arthritis, articular deformities, and disability in Mexican Americans

OBJECTIVE

To study the genetics (HLA-DRB1 allele associations) of rheumatoid arthritis (RA) susceptibility and severity among Mexican Americans, an important, but understudied, US population.

METHODS

HLA-DRB1 alleles were compared between 141 Mexican American patients with RA and 54 unrelated Mexican Americans without RA, and the association of these alleles with articular deformities and disability was examined. HLA-DRB1 alleles were typed using polymerase chain reaction-sequence-specific primer amplification and were classified according to the 1996 World Health Organization nomenclature.

RESULTS

Of the 141 patients, 105 (74%) had at least 1 copy of the shared epitope (SE) sequence, compared with 29 (54%) of the 54 controls (P = 0.007). A significant gene-dose effect was observed, with 31 patients (22%) being homozygous for the SE compared with 1 (2%) of the controls (P = 0.004). In terms of disease severity, only 3% of RA patients who were "null" for the SE were outliers in the rate of development of articular deformities, compared with 10% of heterozygotes and 27% of homozygotes (P = 0.002). Patients who were DRB1*08 positive had significantly fewer deformities per year of disease and a slower rate of development of disability than did patients with other DRB1 alleles.

CONCLUSION

HLA-DRB1 alleles containing the SE are associated with susceptibility to RA in Mexican Americans, and may also be associated with a more rapid development of articular deformities and disability. HLA-DRB1*08 appears to have a protective influence on RA susceptibility and disease severity in Mexican Americans.

Rheumatoid arthritis in the elderly

Rheumatoid arthritis of late onset (LORA) referred as the subset of rheumatoid arthritis with age of onset over 60 years old, seems to differ from young onset disease (YORA) by a more equal sex distribution, a higher frequency of abrupt disease onset, more large joint complaints and less extraarticular features. Different immunogenetic associations are also reported between the two age groups. The percentages of rheumatoid factor (RF) and C-reactive protein (CRP) positivity differ in various surveys in both groups examined. Favorable prognostic factors could be considered the absence of rheumatoid factor activity and the presence of pitting edema of the hands. Greek patients with LORAS appear not to have differences in comparison to their younger counterparts. Disease modifying drugs and low doses of prednisone are the mainstream of therapy with need for further caution in the aged group.

Association of HLA shared epitope with joint damage progression in rheumatoid arthritis

A nine years prospective study was performed on 82 Spanish rheumatoid arthritis patients with a disease duration of less than two years at the study entry, in order to evaluate the role of HLA markers in the susceptibility and progression of rheumatoid arthritis. Radiological evaluation of disease severity was performed at the time of diagnosis and 9 years later. High resolution HLA-DR typing demonstrated that the presence of the shared epitope (SE) was more frequent among patients (61% vs. 31% in controls; p = 0.00003; OR = 3.48). Fourteen patients carried two SE+ HLA-DRB1 alleles (SE+/+); 36, one single allele (SE+/-) and 32 were SE negative (SE-/-). HLA-DR4 (particularly DRB1*0401 and DRB 1*0405) and HLA-DR10 were increased among patients. At study entry, the frequencies of locally severe (hands and feet) RA were more frequent among SE+/+ patients (79%) than among SE+/- (47%) and SE-/-(44%) patients (p = 0.05; RR = 1.80). After 9 years of disease these differences disappeared, whereas differences in the extent of the disease arise: 79%, 50% and 32% of SE+/+, SE+/- and SE-/- patients respectively showed large joints involvement (shoulders, elbows, hips and knees) (p = 0.01; RR = 2.44 for SE+/+ vs. SE-/-; and p = 0.04; RR = 1.81 for SE+ vs. SE-). These results suggest that the presence of the shared epitope is associated with the extent and progression of radiological joint damage in rheumatoid arthritis.

HLA-DR/DQ interaction in patients with erosive rheumatoid arthritis presenting articular and extraarticular disease manifestations

In the present study we have analysed the effect of HLA-DRB1 and -DQB1 alleles on disease progression and genetic predisposition among 201 RA patients. We clearly confirm the association of RA with HLA class II alleles sharing the (Q)R/KRAA amino acid (AA) cassette in the third hypervariable region (HVR3) of the DR beta-chain. The HVR3 (Q)R/KRAA motif was significantly overrepresented among RA patients (79% vs. 40%, P < 0.001), with one third of the patients homozygous (28% vs. 6.7%, P < 10(-9)) and the number of rheumatoid factor positive (RF+) patients was significantly increased among HVR3 (Q)R/KRAA homozygous in comparison to HVR3 (Q)R/KRAA negative individuals. Erosive disease defined by the Larsen Score and personal disability determined using the Health Assessment Questionnaire (HAQ) was significantly increased among patients positive for the HVR3 motif with the worst outcome among HVR3 (Q)R/KRAA homozygous patients. In contrast, there was no association of the shared HVR3 AA cassette and disease severity in the majority of patients presenting systemic (extraarticular) disease. Homozygosity for the shared HVR3 motif was only marginally increased among patients presenting 'severe' extraarticular disease in comparison to patients with articular disease (33% vs. 43%, P = ns). Similarly, patients with nodular disease were not more often homozygous for the HVR3 (Q)R/KRAA motif. Furthermore, we observed no HLA-DR independent association of DQB1 alleles among HVR3 (Q)R/KRAA positive patients and controls. Our analysis supports the predominant role of HLA-DR for genetic susceptibility to RA. In the clinical setting, however, HLA-DR typing may be limited to assess the individual risk of patients for disease progression.

A new categorization of HLA DR alleles on a functional basis

In this analysis, we introduce a new categorization of HLA DR alleles which are important members of HLA class II genes encoding cell surface glycoproteins that function to present antigenic peptides to T cells. We have grouped all HLA DR molecules into seven different functional categories on the basis of their ability to bind and present antigenic peptides to T cells and their association with susceptibility or resistance to disease. This novel categorization of DR alleles on the basis of function allows for the prediction of seven similar subregion structures (supertypes or supermotifs) within pocket 4 of HLA DR peptide binding groove as the molecular basis for grouping these alleles. The physicochemical characteristics of HLA DR supertype residues, charge in particular, may influence the selectivity for binding peptide, dominate promiscuous T-cell recognition of antigenic peptides, and affect HLA DR disease associations. To rationalize the functional categories of DR alleles, we have further combined the seven DR supertype patterns into three groups based on the charges of residues within the supertypes. Grouping HLA DR alleles into functional categories may assist in understanding the mechanistic basis of autoimmunity, resolving current paradoxes in HLA disease associations, and developing new immunotherapy strategies.

HLA-DR gene frequencies in a Zaïrean population with particular reference to rheumatic diseases

Epidemiological studies have shown that rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus are uncommon in black Africans, and in this population the prevalence and the clinical features of these rheumatic diseases are variable. Environmental and genetic factors have been pointed out to explain this variability. In the present study, HLA-DR genes have been determined in a Zaïrean population in order to compare our results with those found elsewhere in other black populations of the same Bantu origin. Our results show that the frequency of HLA-DR1 is higher than in Nigerians, Zimbabweans and Xhosas, the decrease in Xhosas being statistically significant (p < 0.006). The HLA-DR3 frequency is higher in Zaïreans than in Nigerians but not significantly, while it is lower than in Xhosas (p < 0.003) and in Zimbabweans (not significant). The HLA-DR4 frequency is higher in Zaïreans than in Nigerians but it is lower than in Xhosas and Zimbabweans; the differences are not statistically significant. The HLA-DR8 frequency is lower in Zaïreans than in Nigerians while it is higher than in Xhosas (p < 0.002) and in Zimbabweans (not significant). These data suggest that genetic factors partly explain the clinical and epidemiological variability of rheumatic diseases in black Africans.

Predictive factors in rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic polyarticular disease affecting about 1% of the adult population of the world, produces significant joint destruction, physical impairment, work disability, and early mortality. Patients with RA may have a slowly or rapidly progressive disease or a self-limited one. To design a rational treatment program for all patients, the clinician must identify early on whether patients are destined to have a rapidly progressive disease. This article reviews socioeconomic, psychological, immunogenetic, and disease-related features that may help to identify such patients.

HLA-DRB1 alleles in Greek rheumatoid arthritis patients and their association with clinical characteristics

The association of certain HLA-DRB1 alleles in Green rheumatoid arthritis (RA) patients with several features of the disease, the gender of the patient and the age at onset was investigated. This case control study includes 86 Greek RA patients and 130 healthy controls unrelated to the patients. HLA typing was performed by polymerase chain reaction (PCR) and hybridization with sequence-specific oligonucleotide (SSO) probes. HLA-DR4 was significantly increased in RA patients. The alleles *0101, *0401, *0405 and *1001 were associated with a higher risk of RA. The *0408 allele was absent from our patients. Sixty-five per cent of RA patients carried the 'sharp epitope' (SE) compared with 31.5% of controls. The risk for RA in individuals carrying a single allele positive for SE was 2.85 times higher, and for those carrying two alleles positive for SE 8.57 times higher, than in SE-negative individuals. The risk was higher in those carrying the *0401 allele, followed by *0405 and *0101, while the genotype *0401/*0404 was absent. Alleles positive for SE comprise a predisposing factor for RA at an early age, particularly in men, and are associated with positive rheumatoid factor, nodules and erosions.

HLA markers and prediction of clinical course and outcome in rheumatoid arthritis

OBJECTIVE

To evaluate HLA markers as early prognostic factors for disease severity in rheumatoid arthritis (RA).

METHODS

HLA genotyping was carried out in a retrospective analysis of 66 RA patients and in a prospective study of 55 RA patients and 87 healthy controls using polymerase chain reaction-based methods for HLA-DRB1 specificities, DR4 alleles, and their linked DQB1 alleles, as well as HLA-B27. The clinical course of RA was assessed by clinical and radiologic scores. The impact of HLA markers was evaluated by epidemiologic means in addition to modeling using multiple logistic regression analysis.

RESULTS

Shared epitope-positive (HVR3+) DR4 alleles and the HVR3 amino acid cassette QKRAA were associated with RA in both longstanding (relative risk [RR] 3.34 and 3.19) and recent-onset (RR 2.1 and 2.37) RA. In longstanding RA, radiologic evidence of severe joint destruction (Larsen score > 1.62) was seen more often in HVR3 shared epitope-positive patients than in epitope-negative patients (odds ratio [OR] = 25.67, chi 2 = 13.59, P = 0.0003). Moreover, rank sum analysis of Larsen indices indicated significantly higher ranking for the presence of the RA-associated HVR3 cassettes (QKRAA, QRRAA) when expressed on a DR4 allele (P < 0.0001). In the prospective study, DR4-positive patients had a significantly increased risk (OR = 13.75, P = 0.00083) of developing bony erosions. In addition, HVR3 epitope-positive DR4-positive individuals had significantly higher Larsen indices than did epitope-negative patients (P = 0.0083). In particular, the presence of the HVR3 epitope on DR4 resulted in an increased a posteriori likelihood (0.91) of developing early erosive disease compared with an a priori risk of 0.62. Conversely, the likelihood decreased to a minimum of 0.35 when the HVR3 epitope was absent.

CONCLUSION

While the contribution of HLA typing to establishing the diagnosis of RA is limited, HLA-DR genotyping and DR4 subtype determination provide valuable markers for the prognosis of joint destruction in RA.

Polymorphism at the TNF loci in rheumatoid arthritis

The purpose of this work was to analyze the possible influence of TNF loci polymorphism on the susceptibility and/or the disease profile of rheumatoid arthritis (RA). Tumor necrosis factor (alpha and beta) genotypes were determined in 60 patients with RA and 102 healthy subjects by a method based on PCR-RFLP with amplification-created restriction sites. The results obtained in the present study showed that there is not a significant association of either TNF alpha promoter variation (at positions -308 and -238) or TNF beta polymorphism with susceptibility to RA. However, a significant difference in the mean age at disease onset was found between -238 TNF alpha genotypes. In addition, a difference in the presence of nodular disease was observed between -308 TNF alpha genotype. The results of this study suggests that the TNF alpha gene may play a role in the disease profile of rheumatoid arthritis.

HLA-DRB1 genes and disease severity in rheumatoid arthritis. The MIRA Trial Group. Minocycline in Rheumatoid Arthritis

OBJECTIVE

To examine the effect of alleles encoding the "shared"/"rheumatoid" epitope on rheumatoid arthritis (RA) disease severity in patients who participated in the minocycline in RA (MIRA) trial.

METHODS

Of 205 patients with a week-48 visit, blood was available for typing of HLA-DRB1 and HLA-DQB1 in 174 (85%) and successfully completed in 169 (82%). Baseline erosions were used to assess disease severity and new erosions at the last visit served as a proxy for progression.

RESULTS

At baseline, there was no association between the presence of erosive disease or rheumatoid factor status and the dose of rheumatoid epitope (homozygous, heterozygous, none) or the specific alleles identified. At the final visit, a gradient was observed for the 3 allelic subgroups (and their gene doses) in the occurrence of new erosions among the Caucasian placebo-treated, but not the minocycline-treated, patients. A treatment group/HLA-DR4 epitope interaction was demonstrated in multivariate analyses. Approximately two-thirds of African-American patients did not have the rheumatoid epitope.

CONCLUSION

HLA-DRB1 oligotyping may be useful in predicting the progression of disease in some Caucasian patients. Our study corroborates the infrequency of the epitope among African-American patients with RA.

The neuroendocrine immunology of rheumatoid arthritis

Rheumatoid arthritis patients have defective neuroendocrine-immune responses to the stress of inflammation, and currently available data shows that this contributes to the pathophysiology of the disease. The advances in neuroendocrine immunology have improved our understanding of the pathophysiological mechanisms involved in RA. These observations raise important therapeutic questions which are certainly worth further investigation as they may open up novel avenues for the management of the disease.

HLA-DR4 and HLA-DR10 motifs that carry susceptibility to rheumatoid arthritis bind 70-kD heat shock proteins

Most patients with rheumatoid arthritis express particular HLA-DR alleles. The DRbeta1 chains of these alleles share a highly homologous amino acid motif, in their third hypervariable (HV3) region, and this motif seems to help the development of rheumatoid arthritis via unknown mechanisms. In an attempt to identify a ligand of this motif, we screened bacterial proteins. HV3 peptides from HLA-DRB1 alleles containing a QKRAA or RRRAA motif bound the 70-kD heat shock protein (HSP) from Escherichia coli, dnaK. In lymphoblastoid cells homozygous for these same HLA-DRB1 alleles the constitutive 70-kD HSP, HSP73, that targets selected proteins to lysosomes coprecipitated with HLA-DR. Thus the QKRAA and RRRAA amino acid motifs of HLA-DR mediate binding of HLA-DR to HSP73. This property may influence the intracellular route, processing or peptide associations of the HLA-DRbeta1 chain in these two rheumatoid arthritis-associated alleles.

Clinical expression of rheumatoid arthritis in Chilean patients

In populations such as Northern Europeans in which the HLA-DR4 subtypes DW14 and Dw4 show strong association with rheumatoid arthritis (RA), these alleles and the double allelic dose of the shared epitope are considered severity markers. The clinical expression of RA varies in different populations, which may be determined by variation in the prevalence of these markers. In the present study we analyzed the expression of RA in 112 consecutive Chilean patients and its relation to the prevalence of genetic factors, prompted by our previous observation that DR4 is weakly associated to RA in this population. Mean age was 50 +/- 14 years; 90% were seropositive and 87% were female, with a disease duration of 10 +/- 8 years. Extra-articular manifestations were found in 38% of patients, rheumatoid nodules in 27%, vasculitis in 8%, and Sjogren's syndrome in 29%. Functional capacity (ACR, 1991) I or II: 82%.15% of patients stopped working. Hand radiographs scored according to Steinbrocker in 89 patients: I, 21%; II, 15%; III, 43%; IV, 21%. In this series, patients with less formal education seemed to have more benign arthritis. In 97 controls and in 65 (56%) RA patients the presence of DRB1 alleles corresponding to DR1 and DR4 serotypes, to DR4-Dw subtypes, and homozygocity, were determined by polymerase chain reaction followed by specific oligonucleotide hybridization. The shared epitope was present in 53% of RA patients and in 30% of controls (P = .0048, odds ratio [OR] = 2.64). A double allelic dose of the epitope was present in 15% of RA patients compared with 4% of controls (P = .026, OR = 4.23). In a subgroup of 31 erosive RA patients we did not find a significant association of disease severity with the shared epitope in a single or double allelic dose. None of the DR4 subtypes that associate with RA in other populations was found significantly more prevalent in our patients. The severity of RA in our study compared with published series was intermediate between British patients with severe RA and Greek patients with milder disease. This may be due to the high prevalence of Dwl3*0403 in our population.