Clinical,serological and genetic predictors of inflammatory bowel disease course

Patients with extensive or complicated Crohn's disease(CD) at diagnosis should be treated straightaway with immunosuppressive therapy according to the most recent guidelines.In patients with localized and uncomplicated CD at diagnosis,early use of immunosuppressive therapy is debated for preventing disease progression and limiting the disabling clinical impact.In this context,there is a need for predictors of benign or unfavourable subsequent clinical course,in order to avoid over-treating with risky drugs those patients who would have experienced spontaneous mid-term asymptomatic disease without progression towards irreversible intestinal lesions.At diagnosis,an age below 40 years,the presence of perianal lesions and the need for treating the first flare with steroids have been consistently associated with an unfavourable subsequent 5-year or 10-year clinical course.The positive predictive value of unfavourable course in patients with 2 or 3 predictors ranges between 0.75 and 0.95 in population-based and referral centre cohorts.Consequently,the use of these predictors can be integrated into the elements that influence individual decisions.In the CD postoperative context,keeping smoking and history of prior resection are the stron-gest predictors of disease symptomatic recurrence.However,these clinical predictors alone are not as reliable as severity of early postoperative endoscopic recurrence in clinical practice.In ulcerative colitis(UC),extensive colitis at diagnosis is associated with unfavourable clinical course in the first 5 to 10 years of the disease,and also with long-term colectomy and colorectal inflammation-associated colorectal cancer.In patients with extensive UC at diagnosis,a rapid step-up strategy aiming to achieve sustained deep remission should therefore be considered.At the moment,no reliable serological or genetic predictor of inflammatory bowel disease clinical course has been identified.

Crucial steps in the natural history of inflammatory bowel disease

Inflammatory bowel diseases(IBD),including ulcerative colitis(UC) and Crohn's disease(CD),are chronic,progressive and disabling disorders.Over the last few decades,new therapeutic approaches have been introduced which have led not only to a reduction in the mortality rate but also offered the possibility of a favorable modification in the natural history of IBD.The identification of clinical,genetic and serological prognostic factors has permitted a better stratification of the disease,thus allowing the opportunity to indicate the most appropriate therapy.Early treatment with immunosuppressive drugs and biologics has offered the opportunity to change,at least in the short term,the course of the disease by reducing,in a subset of patients with IBD,hospitalization and the need for surgery.In this review,the crucial steps in the natural history of both UC and CD will be discussed,as well as the factors that may change their clinical course.The methodological requirements for high quality studies on the course and prognosis of IBD,the true impact of environmental and dietary factors on the clinical course of IBD,the clinical,serological and genetic predictors of the IBD course(in particular,which of these are rel-evant and appropriate for use in clinical practice),the impact of the various forms of medical treatment on the IBD complication rate,the role of surgery for IBD in the biologic era,the true magnitude of risk of colorectal cancer associated with IBD,as well as the mortality rate related to IBD will be stressed;all topics that are extensively discussed in separate reviews included in this issue of World Journal of Gastroenterology.