title: Association and frequency of HLA-A, B and HLA-DR genes in south Tunisian patients with spondyloarthritis (SpA).
abstract: The aim of this study is to investigate the association of HLA-A, B and HLA-DR gene expression and to assess an association of additional HLA antigens besides HLA-B27 in south Tunisian patients with spondyloarthritis (SpA). Eighty-five patients diagnosed with ankylosing spondylitis (AS, n=68) and reactive arthrithis (ReA, n=17) were selected and compared with 100 healthy controls (HC). HLA class I antigens were typed serologically using microlymphocytotoxicity technique. HLA-DRB1* alleles were studied by polymerase chain reaction amplification with sequence-specific primers. The significance of differences between patients and controls was tested by chi-square analysis. We found significantly increased frequencies of HLA-A3 (30.6%; pC=0.04; OR=2.95), HLA-B27 (62.35%; pC=4.10(-17), OR=53.55), and HLA-DRB1*15 (17.2%; pC=0.026; RR=2.58) alleles in SpA patients compared to HC. The most frequent and strongest association was observed for HLA-B27 in AS (pC=6.6 ×10(-16), OR=52.23). When AS and ReA patients were analysed separately, HLA-DRB1*15 and HLA-A3 were increased only in AS (pC=0.01, OR=2.99 and pC=0.03, OR=3.14, respectively). In ReA patients, HLA-DRB1*04 (p=0.033, pC=NS, OR=2.89) was found to be the most common allele. By analysing the HLA-B27-negative subgroup, HLA-A3 and HLA-DRB1*15 expression was found to be dependent on the presence of HLA-B27. HLA-B27 expression was higher in male (45/53; 85%) as compared to female (8/53; 15%) patients (p=0.03). Apart from HLA-B27, HLA-A3 and HLA-DRB1*15 are the MHC class I and II alleles found most frequent in Tunisian patients with AS, whereas HLA-DRB1*04 was found most frequent in ReA patients. HLA-B27 is more frequent in male than in female patients.
authors.affiliation: Service de laboratoire, EPS Hédi chaker, Sfax, Tunisia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Mahfoudh
authors.forename: Mariam
authors.initials: M
authors.lastname: Siala
authors.forename: Markus
authors.initials: M
authors.lastname: Rihl
authors.forename: Arwa
authors.initials: A
authors.lastname: Kammoun
authors.forename: Faten
authors.initials: F
authors.lastname: Frikha
authors.forename: Hela
authors.initials: H
authors.lastname: Fourati
authors.forename: Mohamed
authors.initials: M
authors.lastname: Younes
authors.forename: Radhouane
authors.initials: R
authors.lastname: Gdoura
authors.forename: Lilia
authors.initials: L
authors.lastname: Gaddour
authors.forename: Faiza
authors.initials: F
authors.lastname: Hakim
authors.forename: Zouheir
authors.initials: Z
authors.lastname: Bahloul
authors.forename: Sofien
authors.initials: S
authors.lastname: Baklouti
authors.forename: Naceur
authors.initials: N
authors.lastname: Bargaoui
authors.forename: Sleheddine
authors.initials: S
authors.lastname: Sellami
authors.forename: Adnene
authors.initials: A
authors.lastname: Hammami
authors.forename: Hafedh
authors.initials: H
authors.lastname: Makni
mesh_terms: D000328:Adult; D005260:Female; D015870:Gene Expression; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015234:HLA-A Antigens / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype; D000091402:Prohibitins; D013167:Spondylitis, Ankylosing / Q000208:ethnology / Q000235:genetics* / Q000503:physiopathology; D014416:Tunisia / Q000208:ethnology
chemical_list: D015234:HLA-A Antigens; D006684:HLA-DR Antigens; C000717331:PHB2 protein, human; D000091402:Prohibitins