The epidemiology and the pathogenesis of inflammatory bowel disease

• Published in: European journal of radiology 2000-09, Vol.35 (3), p.154-167
• Main Authors: Karlinger, Kinga, Györke, Tamás, Makö, Ernő, Mester, Ádám, Tarján, Zsolt
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Bacteria; Bacterial; Behavioral research; Colitis, Ulcerative - epidemiology; Colitis, Ulcerative - etiology; Colitis, Ulcerative - genetics; Colitis, Ulcerative - immunology; Crohn Disease - epidemiology; Crohn Disease - etiology; Crohn Disease - genetics; Crohn Disease - immunology; Diet; Diseases; Environmental; Environmental engineering; Epidemiology; Ethnic; Extra-intestinal; Female; Genetic; Genetic engineering; Humans; IBD; Immunological; Immunology; Incidence; Male; Middle Aged; Pathogenesis; Prevalence; Racial; Risk Factors; Smoking - adverse effects; Social aspects; Viral; Viruses
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/S0720-048X(00)00238-2

The etiology of inflammatory bowel disease (IBD) is still unknown. However, a satisfactory solution cannot be far away. IBD actually encompasses two diseases, i.e. Crohn’s disease (CD) and ulcerous colitis (UC). These diseases resemble each other so closely that they cannot be distinguished even pathologically, but differ from each other sufficiently to regard them as independent entities. Epidemiological observations may be helpful in identifying the true causative factors of this evasive disease. Geographically, the prevalence of the disease has a slope from North to South and, to a lesser degree, from West to East. The Western–Eastern discrepancy can be attributed to a difference in Western life styles. The incidence of the disease has been increasing world-wide of late, but its spread has been slowing down in highly affected countries. Racial and ethnic relations in different populations and immigration studies offer interesting data which can reflect genetic, inherited, environmental and behavioural factors. The disease seems to have a characteristic racial–ethnic distribution: the Jewish population is highly susceptible everywhere, but its prevalence in that population nears that of the domestic society in which they live. In Hungary, the Roma (Gypsies) have a considerably lower prevalence than the average population. This can be attributed to a genetic or environmental influence. According to age, the onset of the disease occurs more often in the second or the third decade of life, but there also is another peak in the 60s. Regarding sexual distribution, there is a slight preponderance of colitis ulcerosa in men and of Crohn’s disease in women. It may correspond to the stronger auto-immune affection in the process of Crohn’s disease. Environmental factors and behavioural influences also are investigated. Diet, the role of the early ages, smoking habits and the influence of hormonal status and drugs are viewed as useful contributing factors in the manifestation of the disease. Genetic studies show that one-fourth of IBD patients have an affected family member. HLAB27 histocombatibility also plays an important, but not determining role in the development of the disease. Genetic factors seem to have a stronger influence in Crohn’s disease than ulcerative colitis. The existence of multiple sclerosis–IBD families may reflect the common genetic background or the similar microbial effect as well. A great number of bacterial and viral factors has been suspe