title: Effect of radiotherapy on the levels of secretory immunoglobulin A against indigenous and virulent streptococci.
abstract: It is well known that the frequency of upper respiratory infection is clinically increased after radiotherapy of the head and neck region. This study found higher antibacterial secretory immunoglobulin A (S-IgA) activity against three indigenous streptococci (Streptococcus mitis, S. salivarius, and S. sanguis I) and S. pneumoniae in patients who had undergone radiation therapy of the head and neck region than in control subjects. This showed no relation to the extent of the radiation field. Compared with before radiotherapy, the S-IgA titer against S. pneumoniae and its ratio to the activities against the indigenous streptococci were significantly higher in patients with fully irradiated major salivary glands. These results indicated that the radiotherapy promoted the antigen-specific S-IgA production of virulent streptococci in most patients with head and neck cancer, even more than 6 months after radiotherapy. The resulting altered balance in the S-IgA system of normal indigenous streptococci may also impair the ability to maintain the stable bacterial interference between normal indigenous and virulent streptococci in the oropharyngeal cavity.
authors.affiliation: Department of Otolaryngology, School of Medicine, Sapporo Medical University, Hokkaido, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Himi
authors.forename: Y
authors.initials: Y
authors.lastname: Kukuminato
authors.forename: H
authors.initials: H
authors.lastname: Kita
authors.forename: I
authors.initials: I
authors.lastname: Yoshioka
authors.forename: A
authors.initials: A
authors.lastname: Kataura
mesh_terms: D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology; D003037:Cobalt Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D000939:Epitopes / Q000528:radiation effects; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000276:immunology / Q000528:radiation effects*; D008875:Middle Aged; D009960:Oropharynx / Q000276:immunology / Q000382:microbiology; D011008:Pneumococcal Infections / Q000276:immunology; D011832:Radiation Injuries / Q000209:etiology; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012141:Respiratory Tract Infections / Q000209:etiology; D012463:Saliva / Q000276:immunology / Q000382:microbiology*; D012469:Salivary Glands / Q000276:immunology / Q000528:radiation effects; D012636:Secretory Rate / Q000528:radiation effects; D013280:Stomatitis / Q000209:etiology; D013290:Streptococcal Infections / Q000276:immunology; D013291:Streptococcus / Q000276:immunology* / Q000472:pathogenicity; D013296:Streptococcus pneumoniae / Q000276:immunology / Q000472:pathogenicity; D013298:Streptococcus sanguis / Q000276:immunology / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D003037:Cobalt Radioisotopes; D000939:Epitopes; D007071:Immunoglobulin A, Secretory; D019275:Radiopharmaceuticals