In general, there are three stages leading from iron deficiency to anemia: 1  First, there is an insufficient supply of iron, which causes iron stores in the bone marrow to be depleted. This stage generally has no symptoms. 2  Second, iron deficiencies develop and begin to affect hemoglobin production.
Surfactant immune function is primarily attributed to two proteins: SP-A and SP-D. These proteins can bind to sugars on the surface of pathogens and thereby opsonize them for uptake by phagocytes. It also regulates inflammatory responses and interacts with the adaptive immune response.
SP-A is a 34â36 kDa protein that facilitates the surface tension-lowering properties of surfactant phospholipids in the alveolus, regulates surfactant phospholipid synthesis, secretion, and recycling, and counteracts the inhibitory effects of plasma proteins released during lung injury on surfactant function (2) â .urfactant protein A has been shown to regulate the homeostasis of surfactant phospholipids, facilitate the lowering of surface tension in the alveolus, and prevent the inhibition of surfactant function by plasma proteins.