Reactivation of viral replication in chronic hepatitis B virus infection
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11 REACTIVATION OF VIRAL REPLICATION IN CHRONIC HEPATITIS B VIRUS INFECTION K. Krogsgaard+, J.Aldershvile, P. Kryger, P. Andersson++, J.O. Nielsen, The Copenhagen Hepatltls Acuta Programme. +Department ot Medlclne, u1vlslons ot Hepatology and Infectious Diseases, Hvidovre Hospital and ++ The Gene Technology Group, Technical University of Copenhagen, Copenhagen, Denmark. The aim of this study was to examine the rate of reactivation of viral replication in chronic HBsAg carriers and in this context to evaluate the significance of serum HBV DNA. Fifty five out of 107 consecutive HBsAg carriers were available for this study being negative for both HBeAg and HBV DNA at study entry or during follow-up. Eight (15%) were male homosexuals, 31 (56%) were drug addicts, 16 patients did not belong to any major risk group. Serological HBV and HDV markers were assayed by RIA. Anti-HIV was assayed by ELISA and confirmed by Western blot. HBV DNA was detected by spot hybridization. Median follow-up time without detectable HBV replication was 24 months (range, 1 month to 12 years). Reacti- vation defined as reappearance of at least one marker of active viral replication was noted in II (20%) patients and the annual rate of reactivation was 8%. Reactivation was in 3 patients ascribed to immunosuppression caused by HIV infection (two) and malignant disease (one). Reactivation was also noted in 3 HDV infected patients in whom the primary loss of HBeAg and HBV DNA was preceded by HDV infection. In 5 patients reactivation occurred spon- taneously. Reactivation was in 4 patients revealed by reappearance of both HBeAg and HBV DNA. In the majority, 6 patients, reactivation was solely detected by reappearance of HBV DNA. Reactivation of viral replication occurs frequently among HBsAg carriers and is often solely detected by reappearance of HBV DNA. Further, it is suggested that reactivation may be responsible for the disparity between HBeAg and HBV DNA noted in some HBsAg carriers. 72 REDUCED PLATELET AGGREGATION IN RESPONSE TO THROMBIN IN CIRRHOTIC PATIENTS IS RELATED TO ALTERED POLYPHOSPHOINOSITIDE METABOLISM. G. Laffi, F. Cominelli, G. La Villa, M. Ruggiero*, S. Fedi§, M. Pinzani & P. Gentilini. Istituti di Clinica Medica II e Patologia Generale*, Dipartimento di Fisiopatologia Clinica, University of Florence, Italy. Platelet (P) aggregation is often reduced in cirrhotics (C). It is still unclear if such defect is related to intrinsic P defect or to abnormalities of plasma factors. In order to focus our investigation on P function only, we used washed P, prelabelled with 14C-Arachidonic acid. P aggregation triggered by thrombin (T) and the underlying molecular mechanism was assessed in 6 C with advanced disease (Child C) in comparison to 6 healthy controls. T induces sequential activation of phospholipase C (with production of inositol phosphate, diacylglycerol and phosphatidic acid - PA) and phospholipase A2, which leads to the formation of arachidonic acid (AA). Aliquots of washed, labelled P were stimulated by T (0.02 UI/I) while stirring at 37°C in a dual channel aggregometer, in order to measure aggregation. 2 minutes later, the reaction was stopped by adding chlorophorm,methanol (100:200 v/v). The formation of 14C-PA and 14CAA was measured after isolation of these compounds by thin-layer chromatography. T induced P aggregation was significantly reduced in C (12.7 ± 1.7 vs. 66.7 ± 3.8, %, p L 0.001). Activation of phospholipase C, as measured by 14C-PA formation, was also greatly impaired in C (201 + 56.5 vs. 368 + 132.5) as well as the liberation of 14C-AA by phospholipase A2 (269.7 ~ 137.2 vs. 856.5 ± 134.6, p L 0.05). We conclude that: I) platelets from cirrhotic patients have an intrinsec aggregating defect in response to thrombin; 2) this defect can be related to a deficiency in the molecular mechanism of transmembrane signalling responsible for platelet activation. $38
Transcript of Reactivation of viral replication in chronic hepatitis B virus infection
11 REACTIVATION OF VIRAL REPLICATION IN CHRONIC HEPATITIS B VIRUS INFECTION
K. Krogsgaard+, J .A ldershv i le , P. Kryger, P. Andersson++, J.O. Nielsen, The Copenhagen Hepat l t ls Acuta Programme. +Department ot Medlclne, u1vlslons ot Hepatology and Infect ious Diseases, Hvidovre Hospital and ++ The Gene Technology Group, Technical Univers i ty of Copenhagen, Copenhagen, Denmark.
The aim of th is study was to examine the rate of react ivat ion of v i ra l rep l i ca t ion in chronic HBsAg carr iers and in th is context to evaluate the s ign i f icance of serum HBV DNA. F i f t y f i ve out of 107 consecutive HBsAg carr iers were avai lab le for th is study being negative for both HBeAg and HBV DNA at study entry or during fo l low-up. Eight (15%) were male homosexuals, 31 (56%) were drug addicts, 16 patients did not belong to any major r isk group. Serological HBV and HDV markers were assayed by RIA. Anti-HIV was assayed by ELISA and confirmed by Western b lo t . HBV DNA was detected by spot hybr id iza t ion . Median fol low-up time without detectable HBV rep l i ca t ion was 24 months (range, 1 month to 12 years). Reacti- vation defined as reappearance of at least one marker of act ive v i ra l rep l i ca t ion was noted in I I (20%) patients and the annual rate of react iva t ion was 8%. Reactivation was in 3 patients ascribed to immunosuppression caused by HIV in fec t ion (two) and malignant disease (one). Reactivation was also noted in 3 HDV infected patients in whom the primary loss of HBeAg and HBV DNA was preceded by HDV in fec t ion . In 5 pat ients react ivat ion occurred spon- taneously. Reactivation was in 4 pat ients revealed by reappearance of both HBeAg and HBV DNA. In the major i ty , 6 pat ients, react ivat ion was sole ly detected by reappearance of HBV DNA. Reactivation of v i ra l rep l i ca t ion occurs f requent ly among HBsAg carr iers and is often sole ly detected by reappearance of HBV DNA. Further, i t is suggested that react iva t ion may be responsible for the d ispar i t y between HBeAg and HBV DNA noted in some HBsAg car r iers .
72 REDUCED PLATELET AGGREGATION IN RESPONSE TO THROMBIN IN CIRRHOTIC PATIENTS IS RELATED TO ALTERED POLYPHOSPHOINOSITIDE METABOLISM.
G. La f f i , F. Cominell i , G. La V i l l a , M. Ruggiero*, S. Fedi§, M. Pinzani & P. Gen t i l i n i . I s t i t u t i di Cl in ica Medica I I e Patologia Generale*, Dipartimento di Fis iopatologia Cl in ica, Univers i ty of Florence, I t a l y .
P la te le t (P) aggregation is often reduced in c i r rho t i cs (C). I t is s t i l l unclear i f such defect is related to i n t r i n s i c P defect or to abnormalit ies of plasma factors. In order to focus our invest igat ion on P funct ion only, we used washed P, prelabel led with 14C-Arachidonic acid. P aggregation tr iggered by thrombin (T) and the underlying molecular mechanism was assessed in 6 C with advanced disease (Child C) in comparison to 6 healthy controls. T induces sequential ac t iva t ion of phospholipase C (with production of inos i to l phosphate, d iacy lg lycero l and phosphatidic acid - PA) and phospholipase A2, which leads to the formation of arachidonic acid (AA). Al iquots of washed, label led P were stimulated by T (0.02 UI / I ) while s t i r r i n g at 37°C in a dual channel aggregometer, in order to measure aggregation. 2 minutes la ter , the react ion was stopped by adding chlorophorm,methanol (100:200 v /v) . The formation of 14C-PA and 14CAA was measured af ter i so la t ion of these compounds by th in - layer chromatography. T induced P aggregation was s i g n i f i c a n t l y reduced in C (12.7 ± 1.7 vs. 66.7 ± 3.8, %, p L 0.001). Act ivat ion of phospholipase C, as measured by 14C-PA formation, was also great ly impaired in C (201 + 56.5 vs. 368 + 132.5) as well as the l ibera t ion of 14C-AA by phospholipase A2 (269.7 ~ 137.2 vs. 856.5 ± 134.6, p L 0.05). We conclude that : I) p la te le ts from c i r r ho t i c patients have an in t r insec aggregating defect in response to thrombin; 2) th is defect can be related to a def ic iency in the molecular mechanism of transmembrane s igna l l ing responsible for p la te le t ac t iva t ion .
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