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Objective: The most compelling real-world example of genetic testing for susceptibility to a workplace exposure involves those industries that process or fabricate beryllium. We examined ethical issues associated with testing for susceptibility to chronic beryllium disease., Methods: Using ethical and clinical criteria, we examined voluntary employer-sponsored testing programs in which individual results are reported directly to workers in a confidential manner., Results: Under reasonable assumptions, the longitudinal positive predictive value of the HLA-DPB1-Glu69 marker of susceptibility to beryllium disease is 12%. Interpretive challenges further limit the utility of the test and may inadvertently suggest a false sense of safety among workers. Concerns about confidential participation and pressures to be tested also must be addressed., Conclusions: Difficulties surrounding the interpretation of the HLA-DPB1-Glu69 marker, lack of assurance regarding the protection of worker confidentiality, and the potential lowering of social barriers to the implementation of mandatory worker screening combine to make testing beryllium workers inappropriate at this time.

Background: There is only limited knowledge of the development of the immune responses of the gut in very young infants after exposure to bacterial and food antigens at birth., Methods: In this study, 49 large intestinal biopsy specimens, which were judged to have normal morphology, were taken from 49 young infants. Eleven patients had Hirschsprung's disease (group 1) and 38 had miscellaneous conditions (group 2). The densities of T cells, their subsets expressing surface antigens CD8 and CD4, and T-cell receptors alpha/beta or gamma/beta were measured, as well as densities of mononuclear and epithelial cells expressing HLA-class II antigens., Results: T-cell densities in groups 1 and 2 were similar. Patients with Hirschsprung's disease had significantly more HLA-DR (p = 0.006) and HLA-DP-expressing cells (p = 0.003) in the lamina propria than did the patients in group 2. In group 1, HLA-DR- (r = 0.58; p = 0.46) and HLA-DP-expressing cells (r = 0.66; p = 0.03) showed a significant positive regression with age in the lamina propria, whereas in group 2, HLA-DR+ cells in the lamina propria showed marked (r = -0.9; p = 0.006) negative regression during the first 1.5 months of life. In contrast to results in previous reports, in the current results, HLA-D region antigens were present in the epithelium in a considerable proportion (up to one fourth) of specimens from the large intestine in both groups. CD3+ (r = -0.59; p = 0.006) and CD4+ (r = -0.64; p = 0.002) cells showed a strong negative regression with age in the lamina propria during the first 2.5 months; and thereafter, there was a weak, insignificant rise in the numbers of these cells. The distribution of CD4+, CD8+, and TCR alpha/beta or gamma/beta T cells of the epithelium of the young infants did not differ significantly from that in the epithelium of adults., Conclusions: These results show that several significant changes occur in the mucosal immune system during the first few weeks of life.

The expression of MHC class II antigens and ICAM-1 and the composition of lymphocyte infiltrates have been studied in frozen sections of transbronchial biopsies from lung transplant recipients. First, biopsies obtained from patients who showed acute rejection, OB, and normal features were compared. Second, we compared first-year biopsies from patients developing OB and patients with a good clinical outcome. HLA-DR was widely expressed on epithelia and vascular endothelium. Increased vascular HLA-DP expression was found in OB biopsies. In OB patients there was a significantly increased frequency of bronchial HLA-DP and vascular HLA-DQ expression. Expression of ICAM-1 by bronchial and bronchiolar basal cells, a phenomenon not reported previously in humans, was seen in a small number of biopsies. CD8 predominant lymphocytic infiltrates were present in all groups and were increased in OB biopsies and OB patients. Increased numbers of CD4-positive cells were found in rejection and OB when compared with normal biopsies. These findings support an immunological basis for the development of OB.

Endothelial adhesion molecules are directly involved in the localization and migration of leukocytes from the circulation into tissues at sites of inflammation. We have compared the expression of PECAM-1 (CD31), ELAM-1, ICAM-1 (CD54), and VCAM-1 in pretransplant (n = 20) and needle-core biopsies from renal transplants obtained during different clinical circumstances (n = 42). PECAM-1 was consistently expressed on all endothelium in both pretransplant and transplant biopsies. In contrast, there was variation in endothelial expression of ELAM-1 and in proximal tubular expression of ICAM-1 and VCAM-1 between pretransplant biopsies. After transplantation induced expression of endothelial ELAM-1 and VCAM-1 and tubular induction of ICAM-1 and VCAM-1 was detected. Induced adhesion molecule expression was frequently associated with focal leukocyte infiltration, and there was a significantly higher level of CD45 and CD25 positive cell infiltration in biopsies with induced adhesion molecule expression. The induction of adhesion molecule expression is evidence of endothelial activation in these transplant biopsies. Comparison of adhesion molecule expression and HLA-class II antigen expression revealed that induced tubular class II antigens may be detected in the absence of induced adhesion molecule expression.

The expression of class I and class II major histocompatibility complex (MHC) antigens in human liver grafts was analyzed in 88 liver biopsies from 22 patients. For the staining of MHC antigens, a panel of monoclonal antibodies directed against monomorphic determinants of class I and class II molecules and an indirect immunoperoxidase method were used. In the reference biopsies, class I antigens were expressed on all cell types but only weakly on hepatocytes; class II was only expressed on Kupffer cells, interstitial cells, and endothelia. After transplantation, this pattern of MHC expression was markedly modified. Increased class I expression on hepatocytes and HLA-DR expression on bile ducts occurred in the absence of clinical rejection. During acute rejection, class I was strongly expressed and HLA-DR weakly expressed on hepatocytes; on bile ducts, HLA-DR expression was further increased. Cytomegalovirus hepatitis caused class I and HLA-DR induction on hepatocytes; strong induction of HLA-DR on bile ducts was also found in cholangitis. These findings have a number of implications for the pathophysiology of rejection of the transplanted liver.