IDDF2018-ABS-0268 Familial aggregation of inflammatory bowel disease in india: prevalence, risks and impact on disease behaviour

Abstract

Background Positive family history is considered the strongest risk factor for the development of Inflammatory Bowel Disease (IBD). However, information about familial aggregation of IBD in Asia is limited. We aimed to analyse the prevalence and risk of familial IBD in an ethnically distinct Indian population and the differences in disease behaviour and severity between familial and sporadic cases. Methods Familial aggregation was assessed in a large well established and prospectively maintained IBD database of 3553 patients (UC 2053, CD1500). The prevalence and relative risk of IBD in first and second-degree relatives of the index cases were evaluated. The disease behaviour and severity were compared to sporadic cases. Results 4.13% of CD and 4.34% of UC patients had a family history of IBD. Positive family history was more common in the paediatric age group ( 18 years) (p=0.0002, OR-2.8, 95% CI 1.6–4.8) (figure 1). Patients with a family history were more likely to have an affected family member on the paternal side (67.4% UC and 70.9% CD). Concordance of disease type in affected relatives was significantly higher in UC (79.7%) compared to CD (37.1%). Pan-colitis was higher in familial UC (41.57%) than sporadic UC (27.65%). Fistulizing disease was more common in familial CD compared to sporadic CD (p=0.041, OR-2.044, 95% CI-1.030–4.056) (IDDF2018-ABS-0268 table 1). Conclusions The prevalence of family history of IBD in India is comparable to rest of Asia but lower than west. Overall familial IBD has a younger age of onset and is associated with a significantly higher incidence of pan-colitis in UC and fistulizing disease in CD compared to sporadic IBD. The results suggest that the presence of family history of IBD has important prognostic implications and could be a risk factor for severe disease.