The Influence of Second-Hand Cigarette Smoke Exposure during Childhood and Active Cigarette Smoking on Crohn's Disease Phenotype Defined by the Montreal Classification Scheme in a Western Cape Population, South Africa.

Tawanda Chivese,Tonya M Esterhuizen,Abigail Raffner Basson

doi:10.1371/journal.pone.0139597

Tawanda Chivese, Tonya M Esterhuizen + Show 1 more

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https://doi.org/10.1371/journal.pone.0139597

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Abstract

BackgroundSmoking may worsen the disease outcomes in patients with Crohn’s disease (CD), however the effect of exposure to second-hand cigarette smoke during childhood is unclear. In South Africa, no such literature exists. The aim of this study was to investigate whether disease phenotype, at time of diagnosis of CD, was associated with exposure to second-hand cigarette during childhood and active cigarette smoking habits.MethodsA cross sectional examination of all consecutive CD patients seen during the period September 2011-January 2013 at 2 large inflammatory bowel disease centers in the Western Cape, South Africa was performed. Data were collected via review of patient case notes, interviewer-administered questionnaire and clinical examination by the attending gastroenterologist. Disease phenotype (behavior and location) was evaluated at time of diagnosis, according to the Montreal Classification scheme. In addition, disease behavior was stratified as ‘complicated’ or ‘uncomplicated’, using predefined definitions. Passive cigarette smoke exposure was evaluated during 3 age intervals: 0–5, 6–10, and 11–18 years.ResultsOne hundred and ninety four CD patients were identified. Cigarette smoking during the 6 months prior to, or at time of diagnosis was significantly associated with ileo-colonic (L3) disease (RRR = 3.63; 95%CI, 1.32–9.98, p = 0.012) and ileal (L1) disease (RRR = 3.54; 95%CI, 1.06–11.83, p = 0.040) compared with colonic disease. In smokers, childhood passive cigarette smoke exposure during the 0–5 years age interval was significantly associated with ileo-colonic CD location (RRR = 21.3; 95%CI, 1.16–391.55, p = 0.040). No significant association between smoking habits and disease behavior at diagnosis, whether defined by the Montreal scheme, or stratified as ‘complicated’ vs ‘uncomplicated’, was observed.ConclusionSmoking habits were associated with ileo-colonic (L3) and ileal (L1) disease at time of diagnosis in a South African cohort.

Highlights

Crohn’s disease (CD), a subtype of inflammatory bowel disease (IBD), is a heterogeneous disorder, which results from a deregulated host immune response
A cross sectional examination of all consecutive CD patients seen during the period September 2011-January 2013 at 2 large inflammatory bowel disease centers in the Western Cape, South Africa was performed
Cigarette smoking during the 6 months prior to, or at time of diagnosis was significantly associated with ileo-colonic (L3) disease (RRR = 3.63; 95%CI, 1.32–9.98, p = 0.012) and ileal (L1) disease

Summary

Introduction

Crohn’s disease (CD), a subtype of inflammatory bowel disease (IBD), is a heterogeneous disorder, which results from a deregulated host immune response. While the mechanism(s) underlying the pathogenic role of smoking in CD remain unclear, a number of theories have been forwarded. These include; the up-regulation of susceptibility genes due to direct interaction with cigarette products; repeated irritation of intestinal mucosal T-cells by nicotine; and the consequent increased production of proinflammatory cytokines such as tumor necrosis factor alpha (TNFα), an important mediator in the inflammatory cascade [1,7]. Smoking may worsen the disease outcomes in patients with Crohn’s disease (CD), the effect of exposure to second-hand cigarette smoke during childhood is unclear. The aim of this study was to investigate whether disease phenotype, at time of diagnosis of CD, was associated with exposure to second-hand cigarette during childhood and active cigarette smoking habits

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