Serum surfactant protein-A levels in patients with acute cardiogenic pulmonary edema and adult respiratory distress syndrome.

Abstract

Detection of alveolo-capillary damage has important implications for treatment modalities in ventilated patients. Although surfactant protein-A (SP-A) is normally only found in appreciable amounts in the lung, we describe significantly elevated concentrations in the sera of patients with acute cardiogenic pulmonary edema (median, 250 ng/ml; range, 180 to 364; n = 10) and in those with the adult respiratory distress syndrome (ARDS) (median, 378 ng/ml; range, 215 to 1,378; n = 15) relative to healthy control subjects (median, 175 ng/ml; range, 123 to 248; n = 15) and ventilated patients with no cardiorespiratory disease (median, 169 ng/ml; range, 126 to 253; n = 6) (p < 0.01, in all cases). Serum SP-A was inversely related to blood oxygenation and to static respiratory system compliance both at the time of the patient's entry into the study (p < 0.005, rs = -0.51, n = 31; p < 0.001, rs = 0.82, n = 17; respectively) and during the course of admission (p < 0.001, rs = -0.34, n = 168; p < 0.001, rs = -0.50, n = 111; respectively). In addition, we describe in detail three cases of ARDS where lung function either improved, remained static, or deteriorated. We conclude that serum SP-A is an acute indicator of lung function and alveolo-capillary membrane injury.

Serum biomarkers in idiopathic pulmonary fibrosis

“…Gene expression profiling of lung biopsies from patients with IPF showed upregulation of the SP-A1 gene [12]. Serum levels of SP-A and SP-D are increased in IPF, but also other pulmonary diseases, probably due to type II pneumocyte hyperplasia and/or epithelial barrier breakdown [36][37][38][39][40][41]. Surfactant proteins may play a role in IPF pathogenesis themselves.…”

Innate immune activation in neutrophilic asthma and bronchiectasis

“…27 SP-A concentration was determined by adapting a previously described method. 28 SP-A antigen and antibody were a gift from Dr Ian Doyle, Flinders University, South Australia, Australia. The mean recovery of SP-A (110 ng/ml) added to sputum supernatant processed using DTT dispersion was 84% (range 70-99%).…”

Surfactant Protein-A Concentration in Sera from Dogs with Pulmonary Parenchymal Diseases

“…Serum SP-A concentration increases in various lung diseases in humans [2,11,19,25,28]. Lung diseases are categorized as interstitial and bronchoalveolar on the basis of the site of occurrence.…”

“…SP-A concentration increases in the blood of humans with pulmonary diseases such as idiopathic pulmonary fibrosis [7,11], pulmonary alveolar proteinosis [11], acute respiratory distress syndrome [2], cardiogenic pulmonary edema [2], bacterial pneumonia [19] and primary lung adenocarcinoma [28]. Therefore, blood SP-A concentration is a useful biomarker for understanding the clinical features of pulmonary diseases and associated prognostic indices [7,19,[24][25][26].…”