BRONCHOALVEOLAR AND SYSTEMIC CYTOKINE PROFILES IN PATIENTS WITH ARDS,SEVERE PNEUMONIA AND CARDIOGENIC PULMONARY-EDEMA

The aim of this study was to investigate whether bronchoalveolar lavag e (BAL) and serum levels of proinflammatory cytokines discriminate bet ween different entities of patients with acute respiratory failure. BA L and circulating concentrations of interleukin-6 (IL-6), interleukin- 8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) were measured in 74 mechanically-ventilated patients and 17 healthy controls, Patients were classified as cardiogenic pulmonary oedema (CPO), acute respirat ory distress syndrome (ARDS), primary severe pneumonia (PN) and a comb ined group (PN+ARDS). In all patients with ARDS and/or PN, markedly el evated BAL levels of IL-6 and IL-8 were detected, which were significa ntly greater than levels in CPO and healthy tumour necrosis factor-a c ontrols, Absolute quantities and time-course of these cytokines did no t differentiate between the absence and presence of lung infection, or different categories of PN, Similarly, circulating IL-6 levels were c omparably elevated in patients with ARDS and/or PN, whereas circulatin g IL-8 concentrations were inconsistently increased, TNF-alpha was rar ely detected in BAL samples, but increased serum concentrations were m easured in ARDS and/or PN patients. Bronchoalveolar lavage levels of i nterleukin-6 and interleukin-8, but not tumour necrosis factor-alpha, and serum concentrations of interleukin-6 are consistently elevated in acute respiratory distress syndrome and/or severe pneumonia, discrimi nating these entities from cardiogenic pulmonary oedema. Alveolar and systemic cytokine profiles do not differentiate between acute respirat ory distress syndrome in the absence of lung infection and states of s evere primacy or secondary pneumonia, which evidently present with com parable local and systemic inflammatory sequelae.