Association of the HLA-DRB1*0701 allele with perinuclear anti-neutrophil cytoplasmatic antibodies in Mexican patients with severe ulcerative colitis.
OBJECTIVE
To determine the association between the HLA-DRB1 alleles and perinuclear anti-neutrophil cytoplasmatic antibodies (p-ANCA) positive in Mexican patients with ulcerative colitis (UC).


METHODS
Ninety Mexican mestizo patients (45 females) with UC, confirmed by biopsy, were studied. High resolution HLA typing was performed by PCR-SSO reverse dot blot and PCR-SSP. Molecular typing techniques were applied to define HLA-DRB1 alleles. Enzyme-linked immunosorbent assay and immunofluorescence techniques were used to detect p-ANCA.


RESULTS
Forty-eight (53%) UC patients were positive for p-ANCA by ELISA and IF. We found that p-ANCA-positive UC patients had a significantly increased frequency of HLA-DR7 compared with p-ANCA-negative controls (22% vs 5.1%; pC=0.02, OR=5.2, CI 95%: 1.06-37.82). Disease activity was scored as severe in 20 patients, moderate in 8, mild in 14 and no activity in the remaining 38 patients according to the Truelove and Witts criteria. Subgroup analysis showed a significantly increased frequency of the HLA-DRB1*07 allele in 15 of 20 UC patients with severe activity of UC and p-ANCA positivity [100% vs 0%; pC=0.0000001; OR=35]. No significant differences were found between p-ANCA positive patients, HLA-DR alleles and other clinical features such as extraintestinal manifestations, proctocolectomy and extension.


CONCLUSIONS
The HLA-DRB1*07 is associated with p-ANCA positive UC Mexican patients.
Department of Gastroenterology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Col. Seccion XVI. CP 14000 Tlalpan. México, D F, Mexico.
Jesus K
JK
Yamamoto-Furusho
Luis
L
Uscanga-Domínguez
Alondra
A
Lopez-Martinez
Julio
J
Granados
D000328:Adult; D000483:Alleles; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D003093:Colitis, Ulcerative / Q000208:ethnology* / Q000276:immunology*; D005260:Female; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008800:Mexico; D012720:Severity of Illness Index
D019268:Antibodies, Antineutrophil Cytoplasmic; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C456920:HLA-DRB1*07 antigen