Prevalence of HLA-B27 in Moroccan healthy subjects and patients with ankylosing spondylitis and mapping construction of several factors influencing AS diagnosis by using multiple correspondence analysis.

The aim of the present study was to determine the prevalence of human leukocyte antigen HLA-B27 in Moroccan healthy controls and in patients with ankylosing spondylitis (AS), and to analyze the correlation between HLA-B27 and AS in Moroccan patients. The prevalence of HLA-B27 was determined by evaluating the number of HLA-B27-positive samples in 128 healthy subjects and in 53 patients diagnosed with AS according to the ESSG and AMOR criteria. HLA-B27 was determined by the polymerase chain reaction using sequence-specific primers. Multivariate analysis of our data (HLA-B27, age, sex, and family history) for AS and healthy controls was performed by multiple correspondence analysis (MCA). The frequency of HLA-B27 was significantly greater in AS patients (45.3 %) than in healthy controls (4.7 %) [p < 0.0001, OR 16.8, and CI 95 % (5.83-51.03)]. In addition, HLA-B27 was more common in male patients than in female ones (p < 0.05). 100 % of the AS patients reported a family history of AS, whereas only 20 % of the healthy controls reported a family history of AS. The graphical interpretation of MCA showed a significant relation between the presence of HLA-B27 and AS. This study strengthens the link between HLA-B27 and AS and represents a very valuable informative diagnostic tool, especially in regard to male patients who have a family history of AS.