Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


HLA Class II Associations Differ in Indian (Asian) Patients Suffering from RA: Regional Population (Urban and Rural) Surveys Using COPCORD Bhigwan Model.

Venugopalan2,  Anuradha, Chopra3,  Arvind, Bharadwaj1,  Renu

BJ Medical College, Pune, India
Center for Rheumatic Diseases, Pune, India
Center for Rheumatic Diseases

The prevalence of RA and its association with HLA Class II alleles has varied considerably in different ethnic groups and populations. The data from Indian (Asian) studies, largely hospital based, is limited and supports association with HLA DRB1*04. We reported a striking prevalence (0.55%) of RA (ACR) in Bhigwan rural community but association with HLA DRB1*04 alleles was negligible (Chopra. Arthritis Rheum 2000:7(Suppl)S71). Later, we completed 8150 population survey (house-house) in neighboring urban Pune using a similar COPCORD (Community oriented program for control of Rheumatic Diseases) Bhigwan model and found an unusually low prevalence (0.3%) of RA (Chopra. J Rheumatol 2009; 36:614). Seropositive RF (nephlometry, cut off 40 IU/ml) and anti-CCP (second generation ELISA, cut off 5 RU/ml) was 45% and 59% in Bhigwan: corresponding 57% and 89% in Pune. There were several other differences found in the results from the surveys. We decided to determine HLA associations of RA in Pune and Bhigwan population based cohorts which included post survey incident cases. After ethic committee approval, consenting patients were bled. 101 rural and 54 urban subjects, ethnically matched and unrelated, were selected as healthy controls. HLA Class II typing for DRB1 (34), DQ (A1=10, B1=21) and DP (A1=5, B1=21) region alleles was performed by Polymerase Chain Reaction using sequence specific primers: number of alleles tested shown in parenthesis.

Results:

Table 1 shows significant OR of alleles and shared epitope (SE) genotype; 95% confidence interval (CI) is shown in parenthesis.

 RURAL Bhigwan (n=55)URBAN Pune (n=37)
Allele  
DRB1*10013.92 (1.57, 9.78)*1.19 (0.41, 3.47)
DQA1*01033.72 (2.09, 6.62)*3.07 (1.33, 7.07)*
DQB1*03034.15 (1.89, 9.10)*1.04 (0.27, 3.95)
DPB1*02012.29 (1.03, 5.07)*0.80 (0.24, 2.61)
DPB1*04010.68 (0.34, 1.33)3.55 (1.56, 8.08)*
SE Genotype  
SE+/x1.96 (0.86, 4.44)1.10 (0.87, 5.25)
QKRAA/x5.91 (0.24, 147.71)4.74 (0.25, 115.14)
QRRAA/x0.10 (0.01, 1.85)1.58 (0.51, 14.94)
RRRAA/x3.20 (1.14, 8.97)*0.74 (0.49, 3.79)
SE+/SE+1.96 (0.12, 32.0)8.13 (0.39, 152.97)
*P<0.05

DRB1*04 and *01 were conspicuous by their absence/low frequency. Though not significant, HLA-DQA1*0101 and HLA-DQB1*0601 was more frequent in seropositive (RF) RA patients. None of the alleles tested showed significant association with anti-CCP antibody or articular deformities. None of the haplotype chosen showed significant association with RA or its selected features.

Conclusions:

This COPCORD study demonstrated HLA Class II including SE associations of RA in an ethnically distinct Indian (Asian) community. To an extent, our small RA sample size is offset by the community study design and population sampling frame. Our results differ from several Caucasian and other ethnic studies and support the complex gene-environment interactions in the etiology of RA.

To cite this abstract, please use the following information:
Venugopalan, Anuradha, Chopra, Arvind, Bharadwaj, Renu; HLA Class II Associations Differ in Indian (Asian) Patients Suffering from RA: Regional Population (Urban and Rural) Surveys Using COPCORD Bhigwan Model. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :66
DOI: 10.1002/art.27835

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