Characterization of microsomal target antigens of autoantibodies in chronic delta virus (HDV) infection

CHARACTERIZATION OF MICROSOMALTARGETANTIGENS OF AUTOANTIBODIESIN CHRONIC DELTA VIRUS (HDV) INFECTION G.Gerken, M.Manns,A.Kyriatsoulis,mH.P. Dienes, G.Hess, K.-H. Meyer zum BUschenfelde I. Medizinische Klinik and mPathologisches I n s t i t u t der Johannes Gutenberg Universit~t Mainz, Langenbeckstr. l, 65-Mainz, FRG In about 15% chronic Delta hepatitis is associated with autoantibodies against microsomes of livers and kidneys (LKM) (Clin.exp. Immunol.1983,54:232). In this study HDV-associated microsomal antigens were analysed with regard to their biochemical properties and compared to the target antigen of LKM-autoantibodies in autoimmune chronic active hepatitis (AI-CAH) (J.Clin. Lab.Anal.1987,1:344). Sera from patients with chronic Delta hepatitis (17), chronic hepatitis B (lO), LKM-positive AI-CAH (5) and normalhumanserum controls were included. Indirect immunofluorescence (IF) and immunoperoxidase (IP) technique were performed on rat and human cryostat sections of livers and kidneys. LKM-typical r e a c t i v i t y was found in LKM-AI-CAH (5/5) using IF and IP and in chronic Delta hepatitis (5/17) using IP on rat and human sections. For immunoblotting microsomal f r a c t ions of rat and human livers were separated by one and two dimensional SDS-gelelectrophoresis, blotted onto nitrocellulose, incubated with human sera (l:lO0) and immunostained with peroxidase-coupled IgG (1:300) (Clin.exp. Immunol.1987,70:53). Sera from chronic Delta hepatitis (5/17) reacted with proteins at around 40 kD and pl 7,5-8,5. LKM-AI-CAH sera showed typical bands at 50 kD and pl 7,5-8,5. In conclusion, immunohistologically, HDV-associated microsomal antibodies could be detected by immunoperoxidase rather than by immunofluorescence technique. By immunoblotting non-species specific HDV-associated microsomal target antigens could be clearly d i f f e r e n t iated from those in LKM-positive autoimmune hepatitis. However, immunopathological significance of Delta-associated LKM-antibodies remains to be evaluated.

UNIVERSAL BIOREACTOR FOR STUDIES OF LIVER CELL FUNCTION UNDER DIFFERENT CULTURE C O N D I T I O N S J.Gerlach, H.H.Schauwecker. Universit&tsklinikum Rudolf Virchow/Charlottenburg, Chirurgische Klinik, Spandauer Damm 130, Freie Universit&t, 1000 Berlin 19, West Germany.

To perform investigations on metabolic functions of hepatocytes, their interactions with different cell types, the cell metabolism in dependence of the structure of the membranes where they are attached and in dependence of medium/blood flw concepts, special culture devices are needed for cultivating the cells. This devices have been developed, consisting of : 1. independent chambers, separated by exchangeable flat membranes. 2. pressure resistant frames and 3. four in/outlets. A modified perfusion unit, including heat exchanger, bubble oxygenator and roller pumps, has been adapted for perfusion of the reactors with medium/blood. Cell cultivation is possible in suspension, attached on flat membranes, attached on hollow fiber membranes or attached on microcarriers. Hepatocytes have been cultivated under different culture conditions in this newly developed bioreactor under steady state and flow conditions. By measurements of amonia metabolism to urea, the design has been proven. $134