Polymorphisms of HLA‐A, ‐B, ‐Cw and DRB1 antigens in Moroccan patients with ankylosing spondylitis and a comparison of clinical features with frequencies of HLA‐B*27

Abstract

Ankylosing spondylitis (AS) is very often associated with human leukocyte antigen (HLA), particularly HLA-B*27. However, the strength of this association and clinical features may vary in different ethnic groups. Our study aims to assess the distribution of HLA-A, -B, -Cw and DRB1 alleles in Moroccan patients with AS and to compare the clinical features of AS and the frequencies of HLA-B27 in patients from Morocco with other series. Seventy-five patients diagnosed with AS and assessed for clinical manifestations were selected and compared to 100 healthy controls. HLA class I and II antigens were typed by polymerase chain reaction sequence-specific oligonucleotide. HLA-B27 subtypes were studied by polymerase chain reaction amplification with sequence-specific primers. HLA-B27 was found in 64% of patients. It was positively associated with younger age at disease onset, family history, and uveitis while it had a negative association with late onset. Six B*27 subtypes were identified in the AS group. HLA-B*2705 and B*2702 were the most common observed subtypes. Among other HLA genes, a significant increase in the prevalence of HLA-Cw*02 and HLA-DRB*15 was found in AS patients. HLA-B27 is involved in the predisposition of AS in the Moroccan population. HLA-B*2705 and B*2702 were the predominant subtypes supporting previous reports in Caucasian spondyloarthropathies. Other HLA genes, HLA-Cw*02 and HLA-DRB1*15, seem to confer predisposing effect to the disease. However, the lower frequency of HLA-B27 compared to the literature in our study suggests the existence of different genetic and/or environmental factors in Morocco.

HLA class I and II alleles in susceptibility to ankylosing spondylitis

“…We could not confirm some other associations described in smaller AS or SpA cohorts elsewhere32–34 perhaps due to clinical heterogeneity. One small recent study of HLA-A, HLA-B, HLA-C and DRB1 alleles in 75 Moroccan patients with AS reported an allele frequency of HLA-B*27 of 32%, with associations also seen with B*57 , C*02 and DRB1*15 and negative associations with HLA-B*35 and B*49 32. The reasons for the discrepancies of these data and ours are hard to interpret given the small size of the cohort, which precluded examination of HLA-B*27 negatives.…”

A genomic study on distribution of human leukocyte antigen ( HLA ) -A and HLA-B alleles in Lak population of Iran

“…Alleles B*35 and B*51 high frequency was like Lak population, whereas B*15 is low frequent in Lak population. The allele frequency of B*27 – which is associated with Ankylosing spondylitis [45] – is low frequent in Lak population as other populations so. In Africans, alleles B*35 and B*53 were high frequent [46] as the Laks respectively are and are not so.…”

Role of HLA class I and II alleles in susceptibility to ankylosing spondylitis in Chinese Han

“…Reveille et al found that the frequency of HLA‐C*02 was increased in white AS patients 8 . In a study of Macedonian and Moroccan AS populations, HLA‐C*02 was found to be positively correlated with the occurrence of AS 30,31 . HLA‐C*12:02 has been confirmed to be closely related to late‐onset psoriasis in the Japanese population.…”