title: HLA-B27 subtypes in enthesitis-related arthritis category of juvenile idiopathic arthritis and ankylosing spondylitis in northern India.
abstract: OBJECTIVE
  Enthesitis-related arthritis (ERA) is the most common form of juvenile idiopathic arthritis (JIA) in the Asian and Indian populations. The presence of HLA-B27 has a strong association with JIA-ERA similar to that with adult ankylosing spondylitis (AS). The HLA-B27gene is highly polymorphic. Susceptibility to AS varies between different HLA-B27 subtypes; data on the relationship of susceptibility to JIA-ERA with HLA-B27 types are scant. In this study, we determined HLA-B27 subtypes in patients with JIA-ERA and AS to find out whether there is any difference in the HLA-B27 subtypes prevalent in these two diseases.
  
  
  METHODS
  Genomic DNA from 135 patients with JIA-ERA and 121 with AS was tested for the presence of HLA-B27. In patients testing positive, HLA-B27subtyping was done by sequencing a genomic region that contained second and third exons and the intervening intron of this gene; this method permitted identification of common HLA-B27 subtypes (HLA-B*27:01 to HLA-B*27:09).
  
  
  RESULTS
  One hundred and seven (79%) patients with JIA-ERA and 102 (84%) patients with AS tested positive for HLA-B27. In both groups, HLA-B*27:05 and HLA-B*27:04 were the common subtypes; some patients had HLA-B*27:07(7.4%) and HLA-B*27:18. Patients with JIA-ERA had a higher frequency of HLA-B*27:05 than those with AS (70% vs. 57%, p=0.047), and a lower frequency of HLA-B*27:04 (21% vs. 36%, p=0.018).
  
  
  CONCLUSIONS
  HLA-B*27:05 and HLA-B*27:04 were the most common HLA-27 subtypes in both JIA-ERA and AS. However, HLA-B*27:05 was more frequent and HLA-B*27:04 was less frequent in JIA-ERA. It is possible that HLA-B*27:05 being the ancestral HLA-27 subtype leads to expression of disease early in life.
authors: Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, and Department of Biosciences, Integral University, Lucknow, India.
authors: R
authors: R
authors: Srivastava
authors: Biomedical Informatic Centre, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors: S
authors: S
authors: Agnihotry
authors: Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors: R
authors: R
authors: Aggarwal
authors: Department of Biosciences, Integral University, Lucknow, India.
authors: P
authors: P
authors: Bajpai
authors: Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India. amita@sgpgi.ac.in.
authors: A
authors: A
authors: Aggarwal
mesh_terms: D000293:Adolescent; D000328:Adult; D001171:Arthritis, Juvenile / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D013167:Spondylitis, Ankylosing / Q000453:epidemiology / Q000235:genetics*
chemical_list: D015796:HLA-B27 Antigen