Autoantibody status is not associated with change in lung function or survival in patients with idiopathic pulmonary fibrosis.

INTRODUCTION: A proportion of patients with idiopathic pulmonary fibrosis (IPF) have autoantibodies directed against intracellular targets. This study aimed to determine the relationship between serologic status, lung function decline and survival. METHODS: IPF patients assessed for antinuclear antibody (ANA) and related antigen-specific serology detected by addressable laser bead immunoassay (ALBIA) were included. Demographics, serial pulmonary function tests and survival were compared between patients with and without autoantibodies. Linear mixed models were used to estimate changes in forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DLCO) over time. Cox-proportional hazards models were used to compare survival, adjusted for a composite score including age, sex and baseline lung function. RESULTS: Of 61 included patients, the mean baseline age was 70 years (SD = 9), 77% were male, and 87% were Caucasian. Either ANA or antigen-specific serology by ALBIA was positive in 25 (41%) during follow-up. ANA was detected in 23 (38%), and specific autoantibodies by ALBIA in 6 (10%). There was no difference in age, sex, race, smoking status, anti-fibrotic use or baseline FVC or DLCO in patients with and without autoantibodies. There was no association between autoantibody status and survival (HR = 1.18, 95% CI 0.61, 2.29), rate of decline in FVC or DLCO (difference in FVC = 4.2 mL/year, p = 0.82; difference in DLCO = 4.6*10-4 mL/min/mmHg/year, p = 0.20). CONCLUSION: These data suggest that autoantibodies are common in IPF and that patients with a subset of autoantibodies, but without features of autoimmunity, demonstrate similar disease behaviour to those without autoantibodies.

Repeated sputum inductions induce a transient neutrophilic and eosinophilic response.

INTRODUCTION: Sputum induction is a tool to monitor airway inflammation, yet it may induce by itself a neutrophilic response when repeated within 24 to 48 h. This limits its repeated use in clinical trials. OBJECTIVE: We aimed to investigate the induction and resolution of inflammation generated by repeated sputum inductions. SUBJECTS AND DESIGN: Sixteen healthy intermittent smokers participated in a study on the short-term effects of smoking. The nonsmoking arm consisted of seven successive sputum inductions with increasing time intervals (3, 6, 12, 24, 48, and 96 h). Inflammatory cellular characteristics and different soluble mediators were investigated. MEASUREMENTS AND RESULTS: The median percentage of sputum neutrophils increased significantly from baseline to 6 h (58.9% [range, 31.8 to 94.2%] to 83.2% [range, 26.7 to 98.3%], respectively). Surprisingly, the percentage of eosinophils also increased significantly from baseline to 6, 12, 24, and 48 h, as follows: 0.3% (range, 0.0 to 1.2%) to 1.7% (range, 0.0 to 15.5%), 2.2% (range, 0.5 to 12.5%), 1.2% (range, 0.0 to 4.8%), and 0.8% (range, 0.0 to 2.8%), respectively. Interleukin-8 increased significantly from baseline to 24 h (1,553 pg/mL [range, 462 to 8,192 pg/mL] to 2,178 pg/mL [range, 666 to 128,544 pg/mL]). CONCLUSIONS: Repeated sputum inductions should preferably be avoided within 48 h. It induces not only a short-lived neutrophilic response but also a prolonged eosinophilic inflammatory response in healthy subjects, possibly by local changes in osmolarity, and subsequent epithelial and/or mast cell activation.

Pulmonary diffusion capacity in patients with systemic lupus erythematosus.

OBJECTIVE: The aim of this study was to clarify the characteristics of pulmonary function tests (PFT), especially carbon monoxide diffusion capacity (DLCO), and their correlation with clinical features and immunological findings in patients with systemic lupus erythematosus (SLE). METHODOLOGY: Vital capacity (VC) and DLCO were analysed retrospectively in 110 sequential Japanese SLE patients with active disease between 1985 and 1999. In 38 patients, serial measurements of PFT were also assessed during high-dose corticosteroid therapy. RESULTS: DLCO was reduced in 52 patients (47%) and a restrictive impairment of PFT was observed in nine patients (8%). The prevalence of pulmonary fibrosis was 13%. Reduced DLCO was frequently observed, even in patients with neither pulmonary fibrosis nor a restrictive pattern. No correlation between immunological data and reduced DLCO was found, except for the presence of anti-RNP. Patients with Raynaud's phenomenon showed a higher prevalence of DLCO impairment than those without this phenomenon. Although immunological parameters improved significantly after the corticosteroid therapy, no significant change in the level of DLCO was observed. CONCLUSIONS: Impairment of DLCO was frequently observed in patients with SLE who had no clinical respiratory abnormalities. DLCO impairments were correlated with Raynaud's phenomenon clinically, and the presence of anti-RNP immunologically. No significant correlation was found between impairment of DLCO and disease activity of SLE.