Detection of surfactant proteins A and D (SP-A and SP-D) in the serum of patients with pulmonary diseases is thought to reflect an injury of the alveolar epithelial barrier and as such serve as a biomarker for these diseases.However, the data for SP-B are limited.
The pulmonary surfactant-associated protein (SFTPA1, SP-A) gene has been studied as a candidate gene for lung disease resistance in humans and livestock.
Future areas for clinical research include disease specific SP-A expression pattern and their functional consequences, the differential roles of SP-A1 and SP-A2 in human lung diseases, and therapeutical approaches to correct altered SP-A levels.
Allelic variations of the SP-A and SP-B genes have been shown to be important genetic determinants in individual susceptibility to RDS, which is a good general model for a multifactorial pulmonary disease resulting from complex interactions between several environmental and genetic factors.
The heterozygosity indices and polymorphism information content values ranged between 0.50--0.62 indicating that SP-A gene locus is polymorphic enough for studies associating the locus with pulmonary diseases.