Immunoglobulin G and Its Function in the Human Respiratory Tract

Cigarette Smoking and Lower Respiratory Tract Infection

“…A selective increase in immunoglobulin levels could be explained either by stimulation of local immunoglobulin production or by exudation of plasma immunoglobulin into alveolar spaces in response to inhaled cigarette smoke (Warr et al, 1977). The availability of opsonic antimicrobial antibodies is essential for optimal function of phagocytes to take up and contain bacteria (Reynolds, 1988). The antibody response to a variety of antigens, such as influenza virus infection and vaccination is depressed in cigarette smokers (Finklea et al, 1971).…”

Antibody-Mediated Immunity to Fungi in the Lungs

“…Rather, Ab responses in the distal lung are believed to reflect systemic responses. In fluid obtained by lavage of the distal airways of normal human lung, immunoglobulin accounts for approximately 14% of the total protein content, yet cells of B lymphocyte lineage represent less than 1% of all cells recovered from BAL (Merrill et al, 1985;Reynolds, 1988;Hance et al, 1988). IgA predominates in fluid obtained by distal airway lavage, accounting for about half of the total immunoglobulin.…”

“…IgG in the distal airway is derived largely from plasma (Reynolds, 1988). Proteins significantly larger than 150 kDa are excluded from passage into the alveolar space, but IgG can pass freely by transudation (Reynolds, 1987).…”

The pneumococcus: carriage, disease and conjugate vaccines

“…Mucosal immune responses play an important role in the ®rst line of defence against infections with S. pneumoniae [30]. Secretory IgA is thought to be the most important mucosal factor in protection against carriage.…”