Effects of an immunostimulating agent on acute exacerbations and hospitalizations in patients with chronic obstructive pulmonary disease. The PARI-IS Study Steering Committee and Research Group. Prevention of Acute Respiratory Infection by an Immunostimulant

Am J Respir Crit Care Med. 1997 Dec;156(6):1719-24. doi: 10.1164/ajrccm.156.6.9612096.


The PARI-IS Study is a double-blind placebo-controlled randomized clinical trial to study the effect of an immunostimulating agent to prevent acute respiratory exacerbation in patients with COPD. Three hundred eighty-one ambulatory patients (190 placebo and 191 immunostimulant) were followed at home for 6 mo by experienced research nurses. The risk of having at least one episode of acute exacerbation (primary outcome) was similar in the two groups (p = 0.872). In contrast, the total number of days of hospitalization for a respiratory problem was 55% less in the group treated with OM-85 BV (287 d) than in the group treated with placebo (642 d). Patients treated with OM-85 BV spent an average of 1.5 d in hospital compared with 3.4 d for patients treated with placebo (p = 0.037). The risk of being hospitalized for a respiratory problem was 30% lower in the treated group (16.2%) than in the placebo group (23.2%); p = 0.089. Eight deaths were observed: two in patients treated with OM-85 BV and six in patients treated with placebo (p = 0.153). During the course of the study dyspnea improved slightly in patients treated with OM-85 BV, whereas it deteriorated slightly in patients receiving placebo (p = 0.028). These results suggest that this immunostimulating agent may be beneficial for patients with COPD by reducing the likelihood of severe respiratory events leading to hospitalization.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adjuvants, Immunologic / therapeutic use*
  • Aged
  • Bacteria*
  • Cell Extracts*
  • Double-Blind Method
  • Female
  • Hospitalization
  • Humans
  • Lung Diseases, Obstructive / complications
  • Lung Diseases, Obstructive / immunology
  • Lung Diseases, Obstructive / therapy*
  • Male
  • Middle Aged
  • Premedication
  • Respiratory Tract Infections / complications
  • Respiratory Tract Infections / prevention & control


  • Adjuvants, Immunologic
  • Broncho-Vaxom
  • Cell Extracts