Pulmonary infection in Wegener’s granulomatosis and Idiopathic pulmonary fibrosis

Alex G Richter ¹, Robert A Stockley ², Lorraine Harper ¹ and David R Thickett ^1*

¹ Birmingham University, United Kingdom
² Queen Elizabeth Hospital, United Kingdom

^* To whom correspondence should be addressed. E-mail: d.thickett{at}bham.ac.uk.

Accepted 12 March 2009

Abstract

Rationale: Wegener’s Granulomatosis (WG) has previously been associated with increased nasal carriage of Staphylococcus aureus, but no studies have investigated the occurrence of pathogen growth in the lower airways.

Objectives: To culture bronchoalveolar lavage fluid (BALF) from WG, idiopathic pulmonary fibrosis (IPF) patients and normal controls.

Methods: 33 patients with WG, 22 with IPF and 8 normal controls underwent bronchoscopy and bronchoalveolar lavage. Quantitative culture established bacterial levels in the lower airways. Culture experiments were designed to investigate whether bronchoalveolar lavage fluid (BALF) is a supportive environment for S. aureus growth. BALF cytokines were measured by ELISA.

Results: Pathogens were commonly grown from both WG and IPF patients BALF. S. aureus was particularly associated with WG patients both in relapse and in remission. BAL levels of IL-1ra were statistically significant elevated in those patients who grew a pathogen from lavage fluid. BALF from WG and IPF patients stimulated S. aureus growth compared to normal lavage fluid.

Conclusions: Pathogens are more commonly isolated from WG BALF than from IPF or normal controls and with a different culture profile. IL-1ra was associated with pathogen growth in WG and IPF. WG BALF is a trophic environment for S. aureus growth. Pulmonologists treating patients with acute or relapsing WG should consider bronchoscopic microbiological sampling and consider antibiotics with anti-staphylococcal activity.