Increased levels of surfactant protein A and D in bronchoalveolar lavage fluids in patients with bronchial asthma

Abstract

Surfactant proteins (SP)-A and SP-D are collagen-like glycoproteins belonging to the "collectin" class of C-type lectins, which are primarily synthesized in type II cells. Recent studies reported the possibility of local production of SP-A and SP-D in the airways, but the amounts of surfactant proteins in patients with bronchial asthma have not been studied.The composition of surfactant proteins in mild, stable asthmatics in the first lavage as bronchial lavage (BL) and the second and third lavages consecutively as alveolar lavages (AL) were therefore, analysed separately. The co-relationships in the BL between the amounts of surfactant proteins and those of fucose, which is one of the markers of submucosal secretion were also analysed.Increased amounts of SP-A in BL and AL of in asthmatics were found as compared with those in controls. A high concentration of SP-D in the AL asthma patients was also found. The levels of SP-A correlated with those of fucose in patients with bronchial asthma (r=0.849, p<0.01).The observations in the present study suggested that surfactant protein A may be secreted from the airways with allergic inflammation in a different manner from the alveoli. The increased levels of surfactant proteins A and D may play a protective role in an allergic inflammation in the pathogenesis of bronchial asthma. Eur Respir J 2000; 16: 831±835.

Innate immune activation in neutrophilic asthma and bronchiectasis

“…SP-A levels are also increased in bronchial lavage fluid from subjects with asthma. 45 Further investigation is required to determine whether the integrity of SP-A from the airways of subjects with asthma is maintained.…”

Major House Dust Mite Allergens Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1 Degrade and Inactivate Lung Surfactant Proteins A and D

“…SP-A and SP-D levels increase severalfold in allergic asthma (11)(12)(13), and furthermore, the kinetics of the increase in SP-D levels after allergen challenge have been reported to coincide with the resolution of inflammation (14). Mouse models of house dust mite (Dermatophagoides pteronyssinus (Der p)) allergy have clearly demonstrated a protective role for SP-D during secondary allergen exposure.…”

Significance of surfactant proteins in the diagnosis of therapeutic diseases

“…Выявлено, что исходные уровни SP-D значительно повышены в сыворотке кро-ви у больных аллергической БА [52,53]. Показано, что уровни SP-D в БАЛЖ пациентов с БА в несколько раз выше, чем у паци-ентов без нее [51,54].…”