Alveolar epithelial lining fluid cellularity, protein and endothelin-1 in children with congenital heart disease

Abstract

This study applied bronchoalveolar lavage (BAL) to children with congenital heart disease (CHD) prior to elective cardiac catheterization (n=48), to determine the influence of pulmonary blood flow and viral infection on the alveolar epithelial lining fluid (ELF) concentration of leucocytes, protein and endothelin-1 (ET-1).Lower respiratory tract (LRT) viral infection was defined as either a positive immunofluorescence for virus, or a virus cultured from the bronchoalveolar lavage fluid (BALF). Haemodynamic status was determined at cardiac catheterization. Normative data for BALF, but not ELF parameters, were obtained from 26 asymptomatic, noninfected normal children undergoing elective surgery.In the absence of LRT infection, the BALF macrophage, lymphocyte and neutrophil differential in CHD was not significantly different from the normal controls. In CHD, both increased pulmonary-to-systemic flow ratio (Q'p/Q's) and increased pulmonary artery-to-left ventricular pressure ratio PAP/LVP were associated with a decrease in ELF protein (r s = -0.59; p<0.0001; and r s = -0.50; p<0.0001 respectively). A respiratory virus was isolated from the BALF in 8 (17%) of CHD children. Virus isolation was associated with an increased ELF total protein (p<0.05 vs no infection), a decreased alveolar macrophage differential count (p<0.01), and an increased neutrophil differential count (p<0.05). ET-1 was detected in the BALF of 83% of the noninfected CHD children compared to only 23% of the controls (p<0.001). ELF ET-1 concentrations did not correlate with haemodynamic status in CHD, but were up to 100 times higher than paired plasma levels.We conclude that, in congenital heart disease, both lower respiratory tract viral infection and increased pulmonary blood flow and/or pulmonary vascular pressure influence the alveolar milieu. High alveolar epithelial lining fluid concentrations of endothelin-1 occur in congenital heart disease, but the stimulus for pulmonary endothelin-1 production is unclear.

Structure-Based Prediction of Anti-infective Drug Concentrations in the Human Lung Epithelial Lining Fluid

“…For the ELF concentrations we assumed that protein binding plays a negligible role since protein concentrations in the ELF are much lower than in plasma (23). an assumption also made by other investigators (7).…”

Interpretation of Antibiotic Concentration Ratios Measured in Epithelial Lining Fluid

“…Total protein concentrations in ELF measured in children with congestive heart disease were reported as 3.9 mg/ml and 8.0 mg/ml depending on the children's infection status; these values were only 6 and 12% of plasma concentration of protein (55 to 85 mg/ml) (47). The low concentration of protein in ELF in this study might be the result of dilution by increased volume of alveolar fluid or diminished protein production within the alveolar space due to congestive heart disease.…”

Alveolar macrophage immaturity in infants and young children

“…BAL was performed before surgery by a single operator using a nonbronchoscopic BAL technique [7]. Immediately after intubation, and with the child's head turned to the left, a straight 60 cm end hole suction catheter (Vygon S.A., E Â couen, France) was inserted into the endotracheal tube (ET) through a right-angle swivel bronchoscope connector (Mallinckrodt Medical Pty.…”

“…AM and other alveolar leukocytes were collected prior to surgery by a nonbronchoscopic bronchoalveolar lavage (BAL) technique as previously described [7].…”