Alveolar fibroblasts in acute lung injury: biological behaviour and clinical relevance.

Although fibroblasts are key cells in the lung repair/fibrosis process, their characteristics are poorly studied in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The aims of our study were to: 1) determine the biological behaviour of alveolar fibroblasts during ALI; and 2) to evaluate the clinical relevance of positive alveolar fibroblast culture from patients with ALI/ARDS. Cells were cultured from bronchoalveolar lavage (BAL) obtained from 68 critically ill, ventilated patients: ALI n = 17; ARDS n = 31; and ventilated controls n = 20. Patients were followed for 28 days and clinical data was recorded. We studied proliferation, migration and collagen-1 synthesis capacities of fibroblasts. Cells expressing fibroblast markers were cultured from BAL obtained in six (35%) ALI patients and six (19%) ARDS patients, but never from ventilated controls. Alveolar fibroblasts exhibited a persistent activated phenotype with enhanced migratory and collagen-1 production capacities, with hyporesponsiveness to prostaglandin E(2) compared to normal lung fibroblasts (p< or =0.04). Positive fibroblast culture was associated with both an increased collagen-1 concentration and monocyte/macrophage percentage in BAL fluid (p< or =0.01), and with a reduced duration of mechanical ventilation (p<0.001). We conclude that activated alveolar fibroblasts can be cultured either in ALI or ARDS and that their presence might reflect the initiation of the organising phase of ALI.

Plasma free amino acid profiles and nutrition proteins in chronic renal failure; effect of dialysis treatment.

A well preserved nutritional status is beneficial in chronically uremic patients for slowing the pace of deterioration of renal function, and delaying the need for dialysis therapy. The purpose of this study was to assess the nutritional profile of 10 patients in a steady state of advanced CRF, and of 15 patients with terminal renal failure immediately prior to their first hemodialysis session (J0), and 7, 14, 45, 60, days post start of dialysis. Patients were 18 to 65 years old with total plasma proteins ≥ 60g/1. Plasma concentrations of amino acids, nutrition proteins, apolipoproteins A1, and B were evaluated. Non inflammatory reaction was evaluated by determination of alpha-1-acid glycoprotein, and C reactive protein. The data (mean ± 1 SD) were compared with mean values of 15 healthy individuals.