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Biomedical subjects

S Iwarson

Publications and source records attributed to S Iwarson.

170 records · Page 10Linked to original sources
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HLA class I antigens on the hepatocyte membrane during recovery from acute hepatitis B virus infection and during interferon therapy in chronic hepatitis B virus infection.

In a chimpanzee model of acute type B hepatitis, at the time of onset of hepatitis B virus replication and before the development of immunity to hepatitis B virus, interferon is present in the plasma. This is followed by an increase in the display of HLA class I, but not class II proteins, on the hepatocyte membrane. In chronic hepatitis B virus infection, there is a low density of HLA class I protein display on the infected hepatocyte. Administration of alpha-interferon enhances HLA display and in many cases is followed by a transaminase elevation, seroconversion of HBe antigen to antibody and disappearance of hepatitis B virus DNA from serum, changes implying clearance of infected hepatocytes. Successful response to interferon therapy may be predicted by a rapidly rising serum beta 2-microglobulin, a component of the HLA class I molecule, during the first 2 weeks of therapy, before the rise in transaminases.

Acute Disease↗
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Hepatitis B vaccination with short dose intervals--a possible alternative for post-exposure prophylaxis?

To achieve a more rapid antibody response following hepatitis B (HB) vaccination, vaccine injections were given to medical students at considerably shorter intervals than usually recommended. They received 10 micrograms of the Merck Sharp & Dohme recombinant HB vaccine at time 0, 2 and 6 weeks (27 vaccinees) or were vaccinated according to the recommended schedule for pre-exposure HB prophylaxis (0, 1 and 6 months) (26 vaccinees). The short interval regimen resulted in a significantly higher frequency of protective antibody levels (greater than or equal to 10 IU/l) two weeks after the second dose of vaccine (48% vs. 4%; p less than 0.001), and all short interval vaccinees had seroconverted within two months (i. e. two weeks after the third dose). The recommended interval regimen resulted in a slower development of antibodies but significantly higher peak antibody levels after the completed three doses (p less than 0.001). The results indicate that protective antibody levels against hepatitis B virus (HBV) can be achieved more rapidly in humans through vaccination with short intervals. This short interval vaccination regimen, which has proved effective for post-exposure prophylaxis in chimpanzees, should possibly also be considered for post-exposure prophylaxis in humans, for instance after accidental exposure to HBV-contaminated blood.

Adolescent↗
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Does Cohn-fractionated Rh immune globulin transmit viral hepatitis?

In light of recently raised doubts about the safety of Cohn fraction II globulins, a prospective study on the risk of transmission of viral hepatitis with a Cohn-fractionated Rh immune globulin (Rhesonativ, KabiVitrum AB, Stockholm, Sweden) was performed in 47 newly delivered mothers. The women were followed regularly for 6 months after the injection of the Rh immune globulin for biochemical, serological, and clinical signs of viral hepatitis. No clinical signs of acute hepatitis were noted during the study, nor were HBsAg or anti-HBc found in any patient. A slight and transient rise in alanine aminotransferase (ALT) levels was seen in three women, but these never reached 2.5 times the upper normal limit as is the currently used lower limit for a diagnosis of non-A, non-B hepatitis. One woman had positive tests for anti-HBs at 5 and 5.5 months, respectively, after the injection, but serum samples taken before and after this period were all anti-HBs negative. Nonspecific reactions in the method used probably explained this finding. This prospective study supports the contention that Rhesonativ, a Cohn-fractionated Rh immune globulin, does not transmit viral hepatitis.

Alanine Transaminase↗
PubMedDate not supplied

Chromatographic removal of hepatitis B virus from a factor IX concentrate. Experimental studies in chimpanzees.

Non-A, non-B hepatitis virus can be removed from a factor IX concentrate by a hydrophobic chromatographic step added to the ordinary fractionation process. The efficacy of this procedure for removal of hepatitis B virus (HBV) was evaluated in chimpanzees. A well-defined hepatitis B virus (HBV) inoculum was added to a factor IX preparation and this preparation was subjected to chromatography with octanohydrazide-Sepharose 4B at a high salt concentration and then injected intravenously into two chimpanzees. A control chimpanzee was inoculated with the part of the factor IX/HBV preparation that had not been chromatographed. The two chimpanzees that received the treated material remained free of any serologic or biochemical evidence of hepatitis B infection during a 12-month follow-up, whereas the control chimpanzee had hepatitis B. After a later HBV challenge, the two healthy animals also had hepatitis B. The hydrophobic binding procedure seems to be useful for the adsorption of viral agents in blood components.

Animals↗
PubMedDate not supplied

Hepatitis B immune serum globulin and standard gamma globulin in prevention of hepatitis B infection among hospital staff: a preliminary report.

In May 1973 a controlled double-blind clinical trail with prophylactic injects of hepatitis B immune serum globulin (antibody titer by passive hemagglutination 1:355,000) and standard gamma globulin (1:100) was started in Sahlgren's Hospital, Göteborg, Sweden. The annual attack rate of clinical hepatitis B in the three departments studied had been 5 to 8 per cent during recent years. A total of 118 members of the hospital staff were prophylactically treated while 125 staff members were unwilling to participate and received no prophylactic treatment. During the first 20 months of study nine cases of clinical hepatitis B with jaundice occurred within the untreated group (7.2 per cent) while three cases (2.5 per cent) were observed in prophylactically treated individuals. After decoding it was found that 60 individuals had received specific hepatitis B immune serum globulin while 58 had received standard gamma globulin. Two of the three clinical cases of hepatitis B occurred within the standard gamma globulin group. Both groups included two individuals with transient antigenemia only and the standard gamma globulin group also included four individuals with antibody seroconversion.

Antibody Formation↗