Analysis of the HLA-DR gene frequencies in Japanese cases of juveniles rheumatoid arthritis and rheumatoid arthritis by oligonucleotide DNA typing

Association of rheumatoid arthritis and its severity with human leukocytic antigen-DRB1 alleles in Kurdish region in North of Iraq

BACKGROUND

Rheumatoid arthritis is a complex multifactorial chronic disease, the importance of human leukocytic antigen (HLA) as a major genetic risk factor for rheumatoid arthritis was studied worldwide. The objective of this study is to identify the association of HLA-DRB1 subtypes with rheumatoid arthritis and its severity in Kurdish region.

METHODS

A case-control study recruited 65 rheumatoid arthritis patients and 100 healthy individuals as control group all over the Kurdistan region/Iraq. Both patient and control groups are genotyped using polymerase chain reaction with sequence specific primer. Anti-CCP antibodies were measured by ELISA test. Rheumatoid factor, C-reactive protein, and disease activity score 28 which measured by DAS-28 values were calculated. The DAS-28 was used to assess the clinical severity of the patients.

RESULTS

HLA-DRB1-0404 and HLA-DRB1-0405 frequencies showed a strong association with disease susceptibility (P < 0.001). The frequency of HLA-DRB1-0411 and HLA-DRB1-0413 were significantly higher in control group (P < 0.001). The frequency of rheumatoid factor and Anti-CCP were significantly higher among shared epitope-positive patients compared to shared epitope-negative patients (P < 0.001). Regarding the disease activity by DAS-28, rheumatoid arthritis patients didn't show significant difference between the shared epitope-positive and shared epitope-negative patients.

CONCLUSIONS

HLA-DR0404 and HLA-DR0405 alleles are related to RA, while HLA-DR1-0411 and HLA-DRB1-0413 protect against RA in the Kurdistan region in the North of Iraq.

Adverse Childhood Experiences Are Associated with Childhood-Onset Arthritis in a National Sample of US Youth: An Analysis of the 2016 National Survey of Children's Health

OBJECTIVES

To determine whether there is an association between adverse childhood experiences (ACEs) and childhood-onset arthritis, comparing youth with arthritis to both healthy youth and youth with other acquired chronic physical diseases (OCPD); and to examine whether ACEs are associated with disease-related characteristics among children with arthritis.

STUDY DESIGN

In a cross-sectional analysis of data from the 2016 National Survey of Children's Health we examined whether ACEs were associated with having arthritis vs either being healthy or having a nonrheumatologic OCPD. ACE scores were categorized as 0, 1, 2-3, ≥4 ACEs. Multinomial logistic regression models examined associations between ACEs and health status while adjusting for age, sex, race/ethnicity, and poverty status. Among children with arthritis, associations between ACEs and disease-related characteristics were assessed by Pearson χ² analyses.

RESULTS

Compared with children with no ACEs, children with 1, 2-3, and ≥4 ACEs had an increased odds of having arthritis vs being healthy (adjusted OR for ≥4 ACEs, 9.4; 95% CI, 4.0-22.1) and vs OCPD (adjusted OR for ≥4 ACEs, 3.7; 95% CI-1.7, 8.1). Among children with arthritis, ACEs were associated with worse physical impairment.

CONCLUSIONS

Children with higher numbers of ACEs are more likely to have arthritis, when arthritis status is compared either with being healthy or with having OCPD. Further studies are needed to determine the direction of the association between ACEs and childhood arthritis, its impact on disease course, and potential intervention targets that might mitigate these effects.

Safety and efficacy of tocilizumab, an anti-IL-6-receptor monoclonal antibody, in patients with polyarticular-course juvenile idiopathic arthritis

We evaluated the safety and efficacy of tocilizumab in polyarticular-course juvenile idiopathic arthritis (pJIA) with polyarticular or oligoarticular onset. Patients received 8 mg/kg tocilizumab every 4 weeks in the open-label studies: initial study (to week 12) and then an extension study (at least 48 weeks). Nineteen patients intractable to conventional methotrexate therapy were enrolled. Seventeen patients had polyarticular-onset pJIA; two had oligoarticular-onset pJIA. Mean age was 11.6 years; mean disease duration 5.3 years. American College of Rheumatology Pediatric (ACR Pedi) 30, 50, 70, and 90 response rates, respectively, were 94.7%, 94.7%, 57.9%, and 10.5% at week 12, and 100%, 94.1%, 88.2%, and 64.7% at week 48. Mean disease activity score (DAS28) remained below the remission level (2.6) from week 24. Administration was discontinued in two patients during the extension study because the ACR Pedi 50 response was judged insufficient (one patient) and antitocilizumab antibodies developed (one patient). Adverse events were generally mild, and the four serious adverse events resolved spontaneously or with treatment. In conclusion, tocilizumab showed early and sustained efficacy and tolerability for treating intractable pJIA, which suggests that it is a promising new treatment for this disease.

Juvenile idiopathic arthritis profile in Turkish children

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of disorders. Publications from different countries point to differences in the disease manifestation of JIA among different populations. The aim of the present paper was to evaluate the clinical and laboratory features of JIA in Turkish children.

METHODS

A total of 196 JIA patients who fulfilled International League of Associations for Rheumatology (ILAR) diagnostic criteria were included in this retrospective study. The data collected were age, gender, age at disease onset and at diagnosis, and follow-up duration. Antinuclear antibody (ANA), rheumatoid factor (RF), and human leukocyte antigen B-27 were evaluated for each patient.

RESULTS

There were 102 boys and 94 girls with a mean duration of disease of 4.1 years. The mean age at the first visit was 8.8 years, and the mean age at onset of disease was 6.8 years (range, 8 months-15 years). Polyarticular JIA was the most frequent onset type (37.2%). Other subtypes included oligoarthritis (34.2%), systemic arthritis (15.3%), psoriatic arthritis (1%), enthesitis-related arthritis (9.7%), and other arthritis (2.2%). ANA was positive in 28 patients (14.2%). Chronic uveitis occurred in two patients with oligoarthritis; and two patients with enthesitis-related arthritis had acute uveitis. Three patients (1.4%) developed amyloidosis.

CONCLUSION

Compared to reports from Western countries, remarkably different features of JIA were found in Turkish children, which included higher frequency of polyarticular JIA, higher prevalence among boys, lower rate of ANA positivity and uveitis. Further studies are required to understand how genetic and environmental differences affect JIA expression.

HLA-DRB1 genotyping in patients with juvenile idiopathic arthritis in Taiwan

The object of this study was to investigate whether there is an association between HLA-DRB1 alleles and the development of juvenile idiopathic arthritis (JIA) in Taiwan. HLA-DRB1 alleles were studied in 60 patients with JIA and 200 healthy controls using polymerase chain reaction (PCR)/sequence-specific oligonucleotide probes (SSO). The frequency of HLA-DRB1*0405 in patients with JIA was found to be significantly higher than that in healthy controls [odds ratio (OR) 2.64, 95% confidence interval (CI) 1.01-6.91]. The DRB1*0405 allele was significantly associated with the development of both polyarthritis (OR 4.30, 95% CI 1.34-13.80) and oligoarthritis (OR 3.27, 95% CI 1.01-10.58). The frequency of HLA-DRB1*1502 was higher in Taiwanese JIA patients with systemic arthritis than in controls (OR 18.09, 95% CI 2.25-145.73). We conclude that, in Taiwan, HLA-DRB1*0405 is associated with the development of polyarthritis and oligoarthritis in children, and HLA-DRB1*1502 is associated with the development of systemic arthritis.

HLA-DRB1 alleles and HLA-DRB1 shared epitopes are markers for juvenile rheumatoid arthritis subgroups in Colombian mestizos

We studied the association of human leukocyte antigen (HLA)-DRB1 and HLA-DQB1 alleles and HLA haplotypes with juvenile rheumatoid arthritis (JRA) in 65 patients and 65 controls from Colombia. The JRA subsets were distinguished on the basis of criteria established by the American College of Rheumatology. Two alleles were associated with protection, HLA-DRB1*1501 (p = 0.002) and HLA-DRB1*1402 (p = 0.01). HLA-DRB1*1602 (p = 0.0000002) was associated with susceptibility for systemic JRA and HLA-DRB1*1104 (p = 0.0002) for pauciarticular JRA. Amino acid sequences at residues 70-74 of DRB1 chain shared by HLA-DRB1 alleles (shared epitomes) were also informative. The polyarticular JRA subset revealed association with (70)QRRAA(74), which includes HLA-DRB1*04, 01, and (70)DRRAA(74), which includes DRB1*1601, 1602, 1101, and 1104. Two new findings of interest were the association of the haplotypes DRB1*1104, DQB1*0301(p = 0.0002) with pauciarticular JRA and DRB1*1602, DQB1*0301 (p = 0.0000002) association with systemic JRA. The DRB1 alleles of these two haplotypes share the epitope (70)DRRAA(74)and were associated with both the pauciarticular and the systemic subset of JRA. Our results suggest that studies of disease susceptibility in populations of admixed genetic background should take into account the contribution of different ethnic groups or nationalities in the recruitment of controls and patients studied in order to rule out genetic stratification.

HLA class II and TNF genes in African Americans from the Southeastern United States: regional differences in allele frequencies

Knowledge of population major histocompatibility complex gene frequencies is important for construction of organ donor pools and for studies of disease association. Human leukocyte antigen DRB1 (HLA-DRB1), HLA-DQB1, and TNFalpha -308 (G-A) promoter genetic typing was performed in 112 healthy, unrelated African Americans (AAs) from the southeastern United States. Allele frequencies were compared with published frequency data from other AA populations. Our AA population had the highest frequency of HLA- DRB1*09 (6.7%) reported in any AA population. The frequency of the TNF alpha -308A polymorphism was also high (14.4%), when compared with published frequencies in AAs. Significant regional differences in the distribution of most HLA-DRB1 and HLA-DQB1 alleles were observed in all AA populations examined. The AA HLA-DRB1 and -DQB1 frequencies also differed from published Caucasian frequencies. This is the first report describing the distribution of TNF alpha promoter alleles in the Southeastern United States. The high DRB1*09 and TNF alpha -308A allele frequencies of our population most resemble the frequencies of these alleles in certain West African populations. These varying major histocompatibility complex gene frequencies may reflect different regional population structures among AAs in the United States, which may be due to differences in ancestral origins, migration, and racial admixture.

Reshaping the shared epitope hypothesis: HLA-associated risk for rheumatoid arthritis is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule

OBJECTIVE

To further analyze the association of HLA-DRB1 alleles with disease susceptibility in recent-onset rheumatoid arthritis (RA).

METHODS

One hundred sixty-seven Caucasian RA patients and 166 healthy controls were typed for HLA-DRB1.

RESULTS

The association of susceptibility to RA with the group of alleles encoding the shared epitope susceptibility sequences (SESSs) was confirmed in recent-onset RA. Among non-SESS alleles, DRB1*07, *1201, *1301, and *1501 showed significant protective effects. Even after correction for the influence of SESS alleles, significant independent protective effects of DRB1 alleles were observed. Protective alleles shared a third hypervariable region motif. Independent homozygosity effects were observed both for susceptibility and for protective alleles.

CONCLUSION

Nonsusceptibility alleles differ significantly with regard to RA risk. Protective alleles show clear homology at positions 67-74, often encoding isoleucine at position 67 or aspartic acid at position 70. Susceptibility and protective alleles both show homozygosity effects. Based on these results and on data reported in the literature, in order to incorporate the finding of differential risks among nonsusceptibility alleles, we propose to reshape the shared epitope hypothesis as follows: HLA-associated risk for RA is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule.

Joint disease in children of Asiatic origin

Joint disorders in Asian children are varied due to the diversity of the Asian population and show some ethnic trends. The ethnic diversity, socio-economic and geographic factors in Asia have limited the availability of data from some of the ethnic groups, many of whom live in remote and relatively underdeveloped areas, are not subjected to epidemiological surveillance and have little awareness of these diseases and their consequences. Geographic and socio-economic factors also play a significant role in some of the joint diseases peculiar to Asian children. In general, the current available data suggests that there are no large differences in the epidemiology and clinical features between the Western and Asian children. This article reviews the available literature on joint diseases in Asian children.

Identification of a genetic risk factor for systemic juvenile rheumatoid arthritis in the 5'-flanking region of the TNFalpha gene and HLA genes

OBJECTIVE

To study polymorphisms in the 5'-flanking promoter/enhancer region of the tumor necrosis factor alpha (TNFalpha) gene and in the coding regions of HLA class I and class II genes, in order to better understand the genetic background of juvenile rheumatoid arthritis (JRA).

METHODS

One hundred eleven Japanese JRA patients (50 with systemic disease, 29 with pauciarticular disease, and 32 with polyarticular disease) and 575 healthy Japanese subjects were examined for the allele frequencies of the TNFalpha, HLA-A, and HLA class II (DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, and DPB1) genes, by DNA typing using the polymerase chain reaction-sequence-specific oligonucleotide probe method.

RESULTS

The frequencies of the polymorphic allele at positions -1,031 (T to C substitution, termed -1,031C), -863 (C to A, termed -863A), and -857 (C to T, termed -857T) of the TNFalpha gene in patients with systemic JRA, but not in those with polyarticular or pauciarticular JRA, were significantly higher than in the healthy controls. The allele frequencies of DRB1*0405 and DQB1*0401 in systemic JRA, but not in the other JRA types, were significantly higher than in controls. Linkage analysis showed that the presence of both the TNFalpha -857T allele and DRB1*0405 yielded a significantly increased odds ratio (3.84), while the presence of only 1 of them did not yield a high odds ratio (0.87 and 1.58).

CONCLUSION

The -1,031C/-863A allele and the -857T allele of the TNFalpha gene, both of which are related to high production of tumor necrosis factor alpha, are associated with systemic JRA. The -857T allele may enhance the effect of the DRB1*0405/DQB1*0401 haplotype in predisposing to development of systemic JRA.

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 class II genes in Latvian patients with juvenile rheumatoid arthritis

PCR-based HLA genotyping was used to analyze the association of HLA-DR and -DQ genes in 127 juvenile rheumatoid arthritis patients and 111 population-based controls from Latvia. The results show DQA1*03 to be positively associated in overall patients and DRB1*01-DQA1*0101-DQB1*0501 to be negatively associated with JRA in overall patients and in polyarthritis patients compared to controls. These data indicate the immunogenetic heterogeneity in the JRA patients, in the disease subgroups and in different ethnic groups. Rheumatoid factor (RF) was assayed in patients (n = 119) and controls (n = 98). RF was present in patients (7/119, 6%) compared to controls (5/98, 5%). None of the DQA1, DQB1 alleles, DQ and DR-DQ haplotypes was associated in seropositive patients compared to seropositive controls. DR1-DQ5 (DQA1*0101-B*0501) was decreased in seronegative patients (11/111, 10%) compared to seronegative controls (24/105, 23%), but the difference was not significant after correction of the p value.

Epidemiology of chronic arthritis in childhood

This study was performed to review reports of the descriptive epidemiology of chronic arthritis in childhood and to analyze the factors that may explain differences in its reported frequency. Articles were retrieved by searching MEDLINE and EMBASE under the following index terms: juvenile rheumatoid arthritis (JRA), juvenile chronic arthritis (JCA), spondyloarthropathy, epidemiology, prevalence, and incidence. For reports published between 1977 to 1982, the Index Medicus was used. All original articles that provided prevalence or incidence rates, population size, or number of cases, were reviewed and entered into the analysis. Variables analyzed were disease prevalence and incidence. Modifier variables investigated were diagnostic criteria, source population, geographic origin of the report (Europe or North America), duration of the study, and race of the population studied. Diagnostic criteria had no effect on reported prevalence or incidence rates. Prevalence per 100,000 at risk obtained from population studies (132, 95% CI: 119, 145) was significantly higher than values derived from practitioner- (26, 95% CI: 23, 29) or clinic-based studies (12, 95% CI: 10, 15) (P = .02). North American clinic-based studies had higher prevalence values compared with European reports (32, 95% CI: 26, 38 versus 8, 95% CI: 5, 11, P = .009). None of the factors analyzed accounted for the variability in reported incidence rates. An effect of race was detected only in the distribution of patients among onset subsets. Thus, the percentage of patients with pauciarticular JRA was highest in series of North American and European caucasian patients (58, 95% CI: 56, 60) compared with series of East Indian (25, 95% CI: 20, 31), native North American Indian (26, 95% CI: 15, 37), or other races (31, 95% CI: 28, 35) (P = .001). In contrast, the percentage of patients with polyarticular JRA was lowest in the former (27, 95% CI: 25, 28) compared with the other racial groups (East Indian, 61, 95% CI: 55, 66; native North American Indian, 64, 95% CI: 53, 76; other races, 34, 95% CI: 30, 38) (P = .004). Although an effect of source population on reported prevalence was confirmed, the effect of geographic origin suggests that environmental or ethnic differences also may influence the prevalence of chronic arthritis in children. Differences in the percentages of patients with pauciarticular and polyarticular JRA may reflect racial differences in the prevalence of these conditions.

Predominance of HLA-DRB1*0405 in Korean patients with rheumatoid arthritis

OBJECTIVE

To identify the association of HLA-DR4 subtypes with rheumatoid arthritis (RA) in Koreans.

METHODS

Ninety five patients with RA and 118 normal control subjects were examined for HLA-DR antigens by serology. Subtypes of HLA-DR4 were determined by allele specific oligonucleotide typing.

RESULTS

The phenotype frequency of HLA-DR4 in RA patients was significantly greater than that in controls (60.0% versus 31.4%, odds ratio (OR) 3.28, 95% confidence interval (CI) 1.79 to 6.02 (p < 0.001)), but HLA-DR6 was decreased in RA patients (15.8% versus 32.2%, OR 0.39, 95% CI 0.19 to 0.81 (p < 0.001)). When DR4 was excluded from analysis of patients and controls, the allele frequency of DR1 was significantly increased in the patients compared with controls (11.3% versus 4.5%, OR 2.73, 95% CI 0.87 to 5.95 (p < 0.001)). Forty two of 57 DR4 positive patients (73.7%) possessed DRB1*0405, which was strongly associated with RA (44.2% of patients, versus 11.9% of controls: OR 5.88, 95% CI 2.81 to 12.47 (p < 0.001)). DRB1*0403 was not found in the patients, but was present in 8.5% of controls. Examining the third hyper-variable region at position 70-74 in the DRB1*04 chain by oligotyping, we found that 52 of 57 DR4 positive patients (91.2%) carried one of the conserved amino acid sequences QRRAA or QKRAA, known to be the epitope conferring predisposition to RA.

CONCLUSION

This study confirms that RA is strongly associated with DR4, especially with DRB1*0405, and that the presence of the inferred QRRAA sequence may be important in susceptibility to RA in Koreans.

Immunopathogenesis of juvenile rheumatoid arthritis: role of T cells and MHC

Juvenile rheumatoid arthritis (JRA) is defined as chronic arthritis of unknown etiology appearing in patients less than 16 years of age. The disease is heterogeneous and is classified as pauciarticular, polyarticular, or systemic-onset disease. A few lines of evidence suggest that T cells are involved in the pathogenesis of the disease. T cells infiltrating the synovial membrane bear markers of activation and produce cytokines. The association of particular subtypes of JRA with certain HLA class II alleles provides strong evidence in favor of T cell involvement through an HLA-peptide-T cell receptor complex. Limited data from a few patients with JRA on T cell receptor transcripts from synovial membrane or synovial fluid cells point towards oligoclonality. This further supports the concept that T cells infiltrating the synovial membrane or extravasating into synovial fluid in patients with JRA reflect antigen-driven T cell proliferation.