Shared epitope classification methods according to Gregersen and de Vries allow adequate characterization of patients with rheumatoid arthritis in a Colombian population

Introduction: The most important genetic association in rheumatoid arthritis (RA) is presented with some alleles from the HLA-DRB1 gene that encode the shared epitope (SE). Objectives: To apply the SE classification methods of Gregersen, de Vries, Raychaudhuri, Mattey, and Tezenas du Montcel in a group of Colombian patients with RA and determine the most common HLA-DRB1 alleles in the population. Methods: RA diagnosis, genetic study of the HLA-DRB1 region using Luminex technology in 50 RA and 50 healthy subjects. For the classification analysis, Fisher's exact test and chi-squared test were applied. Tables were created to count the RA-related alleles. We used odds ratio to determine the risk between the presence of the shared epitope (SE) and anti-cyclic citrullinated peptides (Anti-CCP). Results: Gregersen and de Vries methods were suitable for the characterization of RA in this population (p = .006). The most prevalent HLA-DRB1 alleles in the RA group were 14:02,04:04, 08:02,04:05, and 10:01. High frequencies of the 07:01, 03:01,13:02,01:02, and 12:01 HLA-DRB1 alleles were found in the healthy population. HLA-DRB1 alleles with similar distribution in both populations were 04:07, 15:01, 11:01, 16:02, and 01:01. A high frequency of SE + was observed in Anti-CCP + individuals (63.15%); however, this was not statistically significant [OR2.4 (.63-9.01); p = .19]. Conclusion: The SE classification methods of Gregersen and de Vries were adequate in characterizing RA in a Colombian population group. An equivalence of 100% was verified between the susceptibility alleles defined by de Vries and the alleles assigned as SE according to Gregersen.

Introducción: La asociación genética más importante en artritis reumatoide (AR) se presenta con algunos alelos del gen HLA DRB1 que codifican el epítope compartido (EC). Objetivos: Aplicar los métodos de clasificación de EC de Gregersen et al., de Vries et al., Raychaudhuri et al., Mattey et al., y Tezenas du Montcel et al., en un grupo de pacientes colombianos con AR, y determinar los alelos HLA DRB1 más frecuentes en esta población. Métodos: Diagnóstico para AR, estudio genético de la región HLA DRB1 por tecnología Luminex® de 50 sujetos AR y 50 sanos. Para análisis comparativos de clasificaciones EC, se aplicaron las pruebas test exacto de Fisher y Chi-cuadrado y se realizaron tablas de conteos para los alelos relacionados con AR. Se estimó la razón de odds para determinar el riesgo entre la presencia de EC y los anticuerpos antipéptidos cíclicos citrulinados (anti-PCC). Resultados: Los métodos de Gregersen et al. y de Vries et al. fueron adecuados para la caracterización de AR en esta población (p = 0,006). Los alelos HLA DRB1 más prevalentes en el grupo AR fueron 14:02, 04:04, 08:02, 04:05 y 10:01. Se encontraron altas frecuencias de los alelos HLA DRB1 07:01, 03:01,13:02, 01:02 y 12:01 en población sana. Alelos HLA DRB1 con distribución similar en ambas poblaciones fueron: 04:07, 15:01, 11:01, 16:02 y 01:01. Se observó alta frecuencia de individuos EC+ en el grupo AR anti-PCC+ (63,15%); no obstante, sin asociación estadística (OR: 2,4 [0,63-9,01]; p = 0,19). Conclusión: Los métodos de clasificación para EC de Gregersen et al. y de Vries et al. fueron adecuados caracterizando AR en un grupo de población colombiana. Se corroboró equivalencia del 100% entre los alelos de susceptibilidad definidos por de Vries y los alelos asignados como EC según Gregersen et al.

Biomarcadores genéticos de los sistemas MHC/HLA-DRB1* y PTPN22 asociados a enfermedad reumática: artritis idiopática juvenil y artritis reumatoide de instalación temprana. Un enfoque analítico en un estudio piloto / Genetics Biomarckers off the MHC/HLA-DRB1* and PTPN 22 Systems Associated to Rheumatics diseases: idiopatic juvenile arthritis and rheumatoid of early installation. A descriptive approach in a pilot study

Objetivos: Identificar biomarcadores de susceptibilidad para AIJ poliarticular y AR de instalación temprana por estudio del polimorfismos de MHC/HLA-DRB1* y PTPN22. Materiales y métodos: Se realizó un estudio de casos y controles con una relación 1:2. Todos los sujetos de investigación y los controles provinieron de una corta anidada perteneciente a un proyecto institucional; 30 pacientes con AIJ y 30 con AR de instalación temprana. Como controles se estudiaron 60 individuos sanos. El ADN se obtuvo por salting out modificado. La tipificación de los alelos MHC/DRB1* se realizó por PCR-SSP y en el polimorfismo (C1858T) del sistema PTPN22 se utilizó PCR-RTq. Resultados: Para AIJ Poliarticular, el alelo DRB1*0404 se asoció con susceptibilidad (OR=10.82; p<0.05), en el grupo con AR de instalación temprana, DRB1*0101 se mostró como marcador de susceptibilidad (OR=4.04; p<0.05). Se destaca que el alelo HLA-DRB1*0701 aparece como marcador protector para ambas patologías (OR=0,15; p<0,05). El polimorfismo del SNP (C1858T) PTPN22 no se asoció con AIJ Poliarticular. En contraste, en AR de instalación temprana, el Alelo CC se asoció con protección p<0.05. En el mismo grupo, CT/TT se mostró como un marcador de susceptibilidad <0.05. El análisis de la secuencia aminoacídica 70QRRAA74 del epítope compartido se asoció con susceptibilidad para ambas entidades (p<0.05) y la secuencia 70DRRGQ74 con protección en ambos grupos de pacientes (p<0.05). Conclusión: Se destaca que en la asociación con la secuencia del epítope compartido, la ubicación del tipo de aminoácido y posición del mismo define probable asociación como marcador molecular de susceptibilidad en ambas entidades. Los polimorfismos compartidos sugieren un origen genético común para ambas entidades.

Objectives: To identify polymorphisms of MHCIHLA-DRB1* and PTPN22 systems as a genetic biomarker of susceptibility to JIA poliarticular and early installation RA. Material and methods; This was a pilot case control study with a relation of 1:2. Patients and control individuals involved in this study were selected from a nested cohort from an institutional previous RAIJIA project. The sample was represented by thirty patients with JIA and 30 diagnosed with early installation RA. Sixty unrelated healthy individuals were involved as a control DNA Isolation was obtained by a modified salting out technique. The oligotyping of the MHCIDRB1* alleles was performed by PCR-SSP and the typing of the PTPN22 polymorphism was done by RT-PCR. Results: The DRB1*0404 allele was associated with susceptibility to JIA(OR=10.82, P<0.05). In the early installation RA group the DRB1*0101 allele was showed as a marker of susceptibility to JIA patients (OR=4.04, P<0.05). It is noteworthy that the HLA-DRB1*0701 appears as a possible protective marker for both diseases (OR=015, p<0.05). The polymorphism of (C1858T)PTPN22 was not associated with poliarticular JIA. In contrast, in the early installation RA group of patients, the CC PTPN22 polymorphism was found to be as a protective marker (p<0.05). On the other hand, the amino acid sequence 70QRRAA74 of the share epitope was a marker for susceptibility to both entities (p<0.05) By contrast, the sequence 70DRRGQ74 of the same epitope was showed as a possible marker for protection on both entities (p<0.05.). Conclusion: The model that was used for searching association between the shared epitope -region 70-74 of the DRB1* alleles and these two entities showed the importance of the location and also the type of amino acid in those positions. The polymorphisms found as molecular markers of susceptibility for both entities suggested a common origin and could suggest its probable roll as a molecular marker of susceptibility.

Estudo da frequência dos alelos de HLA-DRB1 em pacientes brasileiros com artrite reumatoide / Study of the frequency of HLA-DRB1 alleles in Brazilian patients with rheumatoid arthritis

Os alelos HLA-DRB1, que codificam uma sequência de aminoácidos (QKRAA/QRRAA/RRRAA) nas posições 70 a 74 da terceira região hipervariável da cadeia β1 do gene DRB1, denominada epítopo compartilhado (EC), estão associados a maior suscetibilidade e gravidade para artrite reumatoide (AR) em diversas populações. OBJETIVO: Determinar a frequência dos alelos HLA-DRB1 em pacientes brasileiros com AR, e sua associação a fator reumatoide (FR) e anticorpos antipeptídeos citrulinados (ACPA). MATERIAL E MÉTODOS: Foram incluídos 412 pacientes com AR e 215 controles. A tipificação HLA-DRB1 foi realizada pela reação em cadeia da polimerase (PCR) usando primers específicos e hibridização com oligonucleotídeos de sequência específica (SSOP). A pesquisa de ACPA foi determinada pela técnica de ELISA, e a do FR por nefelometria. Para análises estatísticas foram utilizados os testes do qui-quadrado e t de Student e a regressão logística. RESULTADOS: Alelos HLA-DRB1*04:01, *04:04 e *04:05 associaram-se à AR (P < 0,05)); a despeito do amplo intervalo de confiança, vale a pena ressaltar a associação observada entre o alelo DRB1*09:01 e a doença (P < 0,05). Alelos HLA-DRB1 EC+ foram observados em 62,8 por cento dos pacientes e em 31,1 por cento do grupo-controle (OR 3,62; P < 0,001) e estiveram associados a ACPA (OR 2,03; P < 0,001). Alelos DRB1-DERAA mostraram efeito protetor para AR (OR 0,42; P < 0,001). CONCLUSÃO: Em uma amostra de pacientes brasileiros com AR de etnia majoritariamente mestiça, alelos HLA-DRB1 EC+ estiveram associados à suscetibilidade à doença e à presença de ACPA.

The HLA-DRB1 alleles encoding an amino acid sequence (QKRAA/QRRAA/RRRAA) at position 70 74 of the third hypervariable region of the β1 chain of the HLA-DRB1 gene, called shared epitope (SE), are associated with increased susceptibility to and severity of rheumatoid arthritis (RA) in different populations. OBJECTIVE: To determine the frequency of HLA-DRB1 alleles in Brazilian patients with RA and their association with rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA). METHODS: Four hundred and twelve patients with RA (ACR 1987) and 215 controls were included. HLA-DRB1 typing was performed by use of polymerase chain reaction (PCR) with specific primers and hybridization with sequence-specific oligonucleotide probe (SSOP). ACPA was measured by use of the ELISA technique and RF by nephelometry. The statistical analysis comprised the chi-square and Student t tests and logistic regression. RESULTS: HLA-DRB1*04:01, *04:04, *04:05 alleles were associated with RA (P < 0.05); despite the wide confidence interval, it is worth noting the association between the DRB1*09:01 allele and RA (P < 0.05). HLA-DRB1 SE+ alleles were observed in 62.8 percent of the patients and in 31.1 percent of controls (OR 3.62; P < 0.001) and were associated with ACPA (OR 2.03; P < 0.001). DRB1-DERAA alleles showed a protective effect against RA (OR 0.42; P < 0.001). CONCLUSION: In a sample of Brazilian patients with RA, most of whom of mixed heritage, HLA-DRB1 SE+ alleles were associated with susceptibility to disease and presence of ACPA.

A majority of Brazilian patients with rheumatoid arthritis HLA-DRB1 alleles carry both the HLA-DRB1 shared epitope and anti-citrunillated peptide antibodies

The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6 percent, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7 percent, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated, the results of this study support the findings observed in most genetically homogeneous populations with RA; however, they are not mutually exclusive but rather complementary. The participation of DRB1-DERAA alleles in protection against RA was also observed (OR = 0.4; 95 percentCI = 0.23-0.68).

Clinical Significance of Autoantibodies to Glucose-6-phosphate Isomerase in Serum of Patients with Rheumatoid Arthritis / 대한류마티스학회지

OBJECTIVE: Anti-glucose-6-phosphate isomerase (GPI) antibody (Ab) is known to be arthritogenic in K/BxN mice. Anti-GPI Ab is present in some patients with rheumatoid arthritis (RA), but their clinical manifestations are not clearly elucidated. The purpose of this study was to evaluate whether GPI serves as a specific autoantigen in patients with RA and to investigate the relationship of anti-GPI Ab with clinical parameters of RA. METHODS: Sera were collected from 54 patients with RA, 15 patients with osteoarthritis (OA) and 28 healthy controls. The samples were tested by enzyme-linked immunosorbent assay (ELISA) using human recombinant GPI as antigen. Patients with RA were classified according to rheumatoid factor (RF) positivity, the presence of RA shared epitope (SE), the presence of extraarticular manifestations, and evidence of bony erosive changes. RESULTS: Serum levels of anti-GPI Ab were higher in patients with RA than controls (1599.46+/-1022.48 versus 344.82+/-223.16 AU, p<0.001), and the levels of patients with OA were also higher than controls (1161.47+/-917.44 versus 344.82+/-223.16 AU, p<0.01). In RA, there were no significant difference in anti-GPI Ab levels according to RF positivity, the presence of RA SE, the presence of extraarticular manifestations, and evidence of bony erosive changes. CONCLUSION: Our results suggest that anti-GPI Ab may not be RA specific Ab and not related to the severity of RA.

Rheumatoid arthritis shared epitope in RT1 of Wistar rats and its role in collagen-induced arthritis / 中华风湿病学杂志

0.05). The positive rate of the SE in rats experiencing longer arthritis duration (≥4 weeks) was significantly higher than that with shorter arthritis duration (

Association between rheumatoid arthritis and shared epitope of HLA-DRB1 gene in Shandong population / 中华风湿病学杂志

Objective To investigate the association between rheumatoid arthritis (RA) and the presence of the shared epitope (SE) of HLA DRB1 gene in Han nationality of Shandong population.Methods The method of DNA amplification with sequence specific primers (PCR SSP) was used to determine 17 alleles of HLA DRB101,04,10 genotypes in 132 RA patients and 130 healthy controls from the Han nationality population in Shandong.Results The frequencies of SE were significantly increased in RA patients compared with controls (50 0% vs 22 3%, P

Association between rheumatoid arthritis and shared epitope of HLA-DRB1 gene in Han nationality Neimenggu population / 中华风湿病学杂志

Objective To investigate the assoiation between rheumatoid arthritis(RA)and the pres- ence of the shared epitope(SE)of HLA-DRBI gene in Han nationality of Neimenggu population.Methods The method of DNA amplification with sequence-specific primers(PCR-SSP)was used to determine 17 alleles of HLA-DRB1*01,*04,*10 genotypes in 80 RA patients and 110 healthy controls from the Han nationality population in Neimenggu.Results The frequencies of SE were significantly increased in RA patiens com- pared with controls(48.8%:20%,P＜0.01).Epitope analysis revealed that the most predominant allele subtype of DR4(*0405)was usceptible sequence in Neimenggu patients with RA(28.8%:12%,P＜0.01).No statisticall significant difference of other subtypes of DR1,DR4 nd DR10 was noted including DRB1*0101(2.5%:0.9%), *0102(2.5%:0),*0103(1.25%:0.9%),*0104(2.5%:0),*0401(6.25:1.8%),*0402(3.75%:0.9%),*0403 (1.25%:1.8%),*0404(2.5%:1.8%),*0406(2.5%:2.7%),*0407(1.25%:0.9%),*0408(3.75 %:0.9%),*0409 (1.25%:0),*0410(2.5%:0.9%),*0411(0:0)and *1001(8.75%:4.5%)respectively.Logistic regression analy- sis showed that the disease of patients with SE homozgote was more severe than that of patients with heterozy- gote(P＜0.01).Conclusion The results suggest that there is an association between SE of HLA-DRBI gene and susceptibility and severity of RA,especially,HLA-DR4 subtypes are strongly associated with RA in Han nationality in Neimenggu population.

The Clinical Significance of Shared Epitope in Rheumatoid Arthritis / 대한류마티스학회지

OBJECTIVE: The application of DNA sequencing and molecular-based typing to detect HLA-DRB1 alleles showed that those associated with rheumatoid arthritis (RA)shared a consensus amino acid sequence (QKRAA or QRRAA)at positions 70-74 of the third hypervariable region of the HLA-DRB1 chain.This is defined as the so-called 'shared epitope'. Many studies reported that shared epitope was associated with RA susceptibility and disease severity.Also,DRB1*0401 and DRB1*0404 alleles confer genetic predisposition to RA in Caucasian.We studied the frequency of shared epitope,DRB1*04,DRB1*0401,and DRB1*0404 in Korean RA patients using monoclonal antibodies.We also tried to investigate the influence of these factors on susceptibility and severity in RA patients and to evaluate the method. METHODS: RA patients were 32 persons with classical or definite RA who attended the Hospital for Rheumatic Diseases,Hanyang University Hospital,Seoul,Korea.We separated lymphocytes from whole blood and used indirect immunofluorescence staining method using four monoclonal antibodies (Terra Nova,Canada). RESULTS: The frequency of DRB1*04 and shared epitope were 56%and 56%, respectively.That of DRB1*0401 and DRB1*0404 were positive in 19%and 9%of all patients,respectively.There were no association between share epitope and disease severity. CONCLUSION: The shared epitope is expressed with high frequency,as many as DR4 frequency in Korean RA patients.But the frequency of DRB1*0401 and DRB1*0404 is low different from Caucasian.The used method is simple and easy to screen shared epitope.