Monitoring of soluble HLA class I size variants after liver transplantation

• Published in: Human immunology 1999-05, Vol.60 (5), p.424-429
• Main Authors: Rebmann, Vera, Päßler, Monika, Erhard, Jochen, Lange, Reinhard, Eigler, Friedrich Wilhelm, Grosse-Wilde, Hans
• Format: Article
• Language: English
• Subjects: acute allograft rejection; Acute Disease; Biomarkers - blood; Blotting, Western; Cholangitis - immunology; cholangitis/cholestasis; Cholestasis - immunology; Densitometry; Enzyme-Linked Immunosorbent Assay; Graft Rejection - immunology; Histocompatibility Antigens Class I - blood; Histocompatibility Antigens Class I - chemistry; Humans; liver transplantation; Liver Transplantation - immunology; Molecular Weight; sHLA class I size variants; sHLA-I release
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/S0198-8859(99)00011-7

To monitor soluble HLA class I (sHLA-I) and their size variants after liver transplantation (LTX) plasma samples from 22 LTX patients were studied by sHLA-I ELISA, SDS-PAGE, and densitometry. Samples collected were classified into three groups: Group 1 comprised samples taken during episodes without complications, group 2 during episodes of cholangitis/cholestasis (CC), and group 3 during episodes of acute rejection (AR). Compared to group 1 (0.27 ± 0.03 SEM μg/ml) mean sHLA-I increments in groups 2 and 3 were with 0.53 ± 0.05 SEM μg/ml and 0.47 ± 0.04 SEM μg/ml increased ( p < 0.001). The same samples were studied by SDS-PAGE and the 43, 39, and 35 kD sHLA-I variants were quantified densitometrically. In samples of group 1 ratios of 43 vs. 39 kD bands revealed a mean of 2.1 ± 0.3, whereas in group 2 and 3 these were only 0.8 ± 0.1 SEM and 0.9 ± 0.1 SEM, respectively, ( p < 0.001). For the relation between 43 and 35 kD variants a reduced ratio of 1.1 ± 0.2 SEM was confined to group 3 samples ( p < 0.001), as groups 1 and 2 had ratios of 13.4 ± 2.3 SEM and 8.4 ± 2.9 SEM, respectively. This indicates that elevated sHLA-I levels during CC or AR are mainly caused by increases of 39 and/or 35 kD sized molecules. Therefore, our study demonstrates, that after LTX the contribution of sHLA-I size variants to total sHLA-I amounts changes drastically during immune activation pointing to different mechanisms of sHLA-I release.