Association of HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies in Han and Uyghur patients with ulcerative colitis in China.
Objective: We aimed to study the association between HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies (ANCA) among Uyghur and Han patients with ulcerative colitis (UC) in China.
Methods: Altogether 160 UC patients and 466 healthy controls of Uyghur and Han groups residing in the Xinjiang Uyghur Autonomous Region of China were included. HLA-DRB1 variants were identified from genomic DNA using polymerase chain reaction and gene sequencing. Serum ANCA were determined by indirect immunofluorescence assay.
Results: Among the Uyghur populations, the HLA-DRB1*08 gene frequency was lower in the UC patients than in the control group (P = 0.012, OR 0.12, 95% CI 0.02-0.91); however, that of HLA-DRB1*13 was much higher in the UC patients than in the controls (P = 0.001, OR 4.32, 95% CI 1.92-9.74). In Han patients with UC, there was no significant difference in HLA-DRB1 frequency between UC patients and healthy controls. The positive rate of ANCA in Uyghur patients with UC was significantly higher than in Han UC patients (P = 0.026), and ANCA positivity was associated with an increased frequency of HLA-DRB1*13 in Uyghur UC patients, but no such difference was observed in the Han patients.
Conclusions: Genetic polymorphisms of the HLA-DRB1*08 and *13 may contribute to the clinical heterogeneity of UC between Uyghur and Han UC patients in China. In Uyghur UC patients, HLA-DRB1*13 may be correlated with ANCA positivity.