title: Immune function risk factors for acute lower respiratory tract infections.
abstract: The immune response of pneumonia patients and controls to Streptococcus pneumoniae was investigated by enzyme-linked immunosorbent assay (ELISA). Patients less than 6 months of age had significantly lower levels of anti-pneumococcal polysaccharide antibodies than their age-matched controls. Patients and controls 6-14 months of age had lower antibody levels than the children 0-5 months of age. Adult patients and controls did not differ in their antibody status. However, patients and Papua New Guinean controls had depressed cell-mediated immunity and low T-cell numbers. Low levels of antibodies to pneumococcal polysaccharides in children less than 6 months of age appear to be an important risk factor for acute lower respiratory tract infections but other factors may be important in older infants and adults.
authors.affiliation: Royal Perth Hospital, Australia.
authors.forename: C S
authors.initials: CS
authors.lastname: Witt
authors.forename: W
authors.initials: W
authors.lastname: Pomat
mesh_terms: D000208:Acute Disease; D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D006801:Humans; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000032:analysis*; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D010219:Papua New Guinea; D011014:Pneumonia / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012307:Risk Factors; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013601:T-Lymphocytes
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial