UP-REGULATED EPITHELIAL EXPRESSION OF HLA-DR AND SECRETORY COMPONENT IN SALIVARY-GLANDS - REFLECTION OF MUCOSAL IMMUNOSTIMULATION IN SUDDEN-INFANT-DEATH-SYNDROME

Human parotid glands from 55 forensic autopsy subjects, 1-12 mo of age , were examined by immunohistochemistry without knowledge about the ca use of death. Various combinations of monoclonal or polyclonal antibod y reagents of the following specificities were applied in two-color im munofluorescence analyses: HLA class I or II (DR, DP, or DQ); pan-T ce ll (CD3); leukocyte common antigen (CD45); and secretory component (po ly-Ig receptor). Sudden infant death syndrome victims (n = 17) were sh own to have significantly increased numbers of CD45(+) stromal leukocy tes and intensified epithelial expression of HLA-DR and secretory comp onent as well as increased endothelial expression of both HLA class I and II (DR, DP, and DQ) determinants compared with controls (n = 31) w ho had died from noninfectious causes. Seven overtly infectious subjec ts (bronchopneumonia) showed still more up-regulated expression. This result suggested that enhanced stimulation of the local immune system exists in sudden infant death syndrome, with release of certain cytoki nes that are known to up-regulate epithelial expression of HLA-DR and secretory component.