Subclinical Pulmonary Involvement in Active IBD Responds to Biologic Therapy

Objective: Increased mortality from respiratory diseases was observed in epidemiological studies of patients with ulcerative colitis [UC] as a potentially underestimated extraintestinal manifestation. We therefore investigated the presence of pulmonary manifestations of inflammatory bowel disease (IBD] and the potential effect of tumour necrosis factor alpha [TNF-alpha] inhibitors on pulmonary function tests [PFT] in a prospective, longitudinal study. Methods: In all, 92 consecutive patients with IBD (49 Crohn's disease [CD], 43 UC) and 20 healthy controls were recruited. Fifty patients with IBD were in remission, and 42 had active disease with 22 of these being examined before and 6 weeks after initiating anti-TNF therapy. Pulmonary function tests [PFT] were evaluated using the Medical Research Council [MRC] dyspnoea index and a standardized body plethysmography. IBD activity was assessed using Harvey-Bradshaw index for CD and partial Mayo score for UC. Data are presented as meant standard error of the mean [SEM]. Results: Patients with active IBD showed significant reduction of PEE Forced expiration [Tiffeneau index] values (FEV1%] were significantly reduced in IBD patients with active disease [78.8 +/- 1.1] compared with remission [86.1 +/- 0.9; p = 0.0002] and with controls [87.3 +/- 1.3; p = 0.001]. Treatment with anti-TNF induced a significant relief in obstruction [p = 0.003 for FEV1% in comparison with baseline levels]. The level of pulmonary obstruction significantly correlated with clinical inflammation scores [HBI or Mayo]. Conclusions: Patients with active IBD present with significant obstructive abnormalities in their PFTs. Obstruction is related to inflammatory activity, with anti-TNF improving PFTs. Pulmonary obstruction and possibly chronic bronchopulmonary inflammation is an overlooked problem in active IBD that is probably obscured by intestinal symptoms.

Automated summary

A prospective study revealed significant obstructive abnormalities in pulmonary function tests (PFT) of patients with active inflammatory bowel disease (IBD), which are related to inflammatory activity and can be improved with anti-TNF therapy. Pulmonary obstruction and potentially chronic bronchopulmonary inflammation are overlooked issues in active IBD, possibly overshadowed by intestinal symptoms.