A Prospective Study on the Incidence and Risk Factors Related to Infection in Patients With Inflammatory Bowel Disease
Condition: Inflammatory Bowel Diseases
MeSH terms: Infections; Intestinal Diseases; Inflammatory Bowel Diseases
Study type: Observational [Patient Registry]

Summary: 
      The purpose of this study is to determine the incidence and risk factors related to Infection
      in patients with Inflammatory Bowel Disease (IBD)
    

Detailed description: 
      IBD could lead to an increased risk of infections, particularly related to immunosuppressive
      therapy. The true effect of having IBD in the development of infections has not been studied
      in depth since the cohort studies are scarce and the results of studies with different
      approaches are contradictory.

      The limited time period of former studies may not be enough to assess infectious
      complications that may occur in a long term period.

      Moreover, certain polymorphisms demonstrated to confer a higher risk of opportunistic
      infections under immunosuppressive conditions, for instance HIV, patients with cystic
      fibrosis and Candida' infections. For this reason, it seems reasonable to think that genetic
      factors might play a role in the risk of opportunistic infections in IBD.

      The hypothesis of this study is that patients with IBD have an increased risk of infection by
      immunosuppressive treatment.

      TYPE OF STUDY Prospective cohort study that evaluates the effect of immunosuppression and
      other clinical factors in the onset of infection in IBD

      STUDY DESIGN PATIENTS & METHODS This study is aimed to all incidental patients diagnosed with
      Crohn's disease and ulcerative colitis included in the ENEIDA database.

      METHODS An infection would be considered as relevant when: 1) requires hospital admission, 2)
      leads to death or endangers the patient's life (ICU admission, presence of hemodynamic
      instability, sepsis, tracheal intubation, vasoactive drug requirement), 3) must be treated
      with specific antibiotics (antibacterials, antivirals, antifungals) 4) affects recurrently
      (herpes virus, papilloma virus, etc). 5) requires change/withdrawal of immunosuppressive or
      biological treatment.

      The appearance of relevant infection will be prospectively evaluated, performing a
      subanalysis at 3 and 5 years using ENEIDA platform. ENEIDA is a database from a Spanish
      national study in IBD on genetic and environmental determinants run under GETECCU (Grupo
      Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa) supervision. This database
      basically comprises: demographic characteristics, type of IBD, immunosuppressant treatment,
      biological treatment or surgery)

      At the time of inclusion the following variables should be available (and are mandatory):
      demographic characteristics, type of IBD, date of diagnosis, phenotypic characteristics of
      the disease, history of serious infections, information on received treatments particularly
      the exposure to immunosuppressants, biological treatment or surgery and whether an infection
      has occurred as a complication of the three treatment groups. It should also be collected the
      following serologic details: hepatitis type B virus C, HIV, tuberculosis (TB), varicella
      zoster status.

      At the time of registration a blood sample (10cc) will be drawn and sent to a biobank to
      analyze the DNA for genetic research.

      STUDY ANALYSIS Sample calculation

      The main objective of this study is to determine the percentage of infections in IBD and the
      related risk factors for the development of infections in patients with IBD. Given that the
      reported prevalence of infection varies between 6 and 10%the formula for estimating endless
      samples, establishing:

        -  Security level of the confidence interval at 95%

        -  Expected value for the worst case scenario of 6% (prevalence of infection)

        -  Precision of 1.5%

        -  The minimum sample number is set to 963, and assuming a loss rate of 20%

      With these assumptions, the total number of patients to be included is 1204 patients.

      The statistical analysis will be in three steps: (1) independent clinical factors analysis,
      (2) genetic factors infection-related analysis and (3) clinical and genetic factors
      infection- related analysis.

      Baseline and follow up data will be compared among patients who develop infection and those
      who do not. Quantitative variables will be contrast by T-student and Mann-Whitney test.
      Qualitative variable will be contrast by X2 or Fisher test. Logistic regression will be
      conducted to analyze independent associations between variables and Kaplan-Meier test to
      calculate survival curves.

      An analysis of Cox proportional hazards will be conducted to assess the effect of exposure to
      independent predictors of the risk of significant infection or mortality.

      Finally the intensity of the significant associations will be measured by calculating the OR,
      HR and confidence interval of 95%.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Incident cases of IBD registered on ENEIDA data base
      
Biospecimen description: 
      blood sample of 10 cc
    
Keywords: IBD; Infection