HLA class II gene frequencies in Crohn's disease: a population based analysis in Germany

• Published in: Gut 1996-04, Vol.38 (4), p.538-542
• Main Authors: Reinshagen, M, Loeliger, C, Kuehnl, P, Weiss, U, Manfras, B J, Adler, G, Boehm, B O
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Alleles; Base Sequence; Biological and medical sciences; Case-Control Studies; Child; Crohn Disease - blood; Crohn Disease - epidemiology; Crohn Disease - genetics; Female; Gastroenterology. Liver. Pancreas. Abdomen; Gene Frequency; Genes, MHC Class II; Germany - epidemiology; HLA-DQ Antigens - genetics; HLA-DR Antigens - genetics; Humans; Male; Medical sciences; Middle Aged; Molecular Sequence Data; Other diseases. Semiology; Polymerase Chain Reaction; Risk Factors; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus
• ISSN: 0017-5749; 1468-3288; 1458-3288
• DOI: 10.1136/gut.38.4.538

BACKGROUND--Ulcerative colitis is the only known inflammatory bowel disease associated with particular HLA alleles. Whereas the association with the HLA-DRB1*15 allele has been described in several independent studies for ulcerative colitis, no contribution of HLA alleles to susceptibility in Crohn's disease has yet been shown. AIM--This study was designed to study the strength of association of HLA class II alleles as risk markers for Crohn's disease in a homogenous population in Germany. PATIENTS--A total of 4251 randomly selected control subjects, and 162 unrelated subjects with Crohn's disease were studied. Subjects were studied for their HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles. METHOD--HLA DNA typing was performed after locus specific amplification with the polymerase chain reaction and reverse dot blot hybridisation. RESULTS--The HLA-DRB1*07 was the only HLA class II allele found to be significantly associated with Crohn's disease (relative risk (RR) = 1.9, 95% CI: 1.66 to 2.14; p = 0.0001). This association remained significant after correction for the number of DRB1 alleles compared. In patients with disease onset before 35 years the RR for the disease in HLA-DRB1*07 positive subjects was found to be higher (RR = 3.1, 95% CI: 2.44 to 3.76). The HLA-DRB1*03 was significantly decreased in frequency in Crohn's disease (RR = 0.5, 95% CI: 0.39 to 0.61; p = 0.0028). CONCLUSION--The HLA-DRB1*07 allele provides risk for the disease especially in patients with younger ages of onset. These data also provide indirect evidence for an immunogenetically based heterogeneity of the disease.