Use of the organic solvent, tri(n-butyl)phosphate (TNBP), and detergents for the inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation obtained with TNBP plus Tween 80 was superior to that observed with ethyl ether plus Tween 80, a condition previously shown to inactivate greater than or equal to 10(6.9) CID50 of hepatitis B and greater than or equal to 10(4) CID50 of Hutchinson strain non-A, non-B hepatitis. The AHF recovery after TNBP/Tween treatment was greater than or equal to 90 percent. Following the reaction, TNBP could be removed from the protein by gel exclusion chromatography on Sephadex G25; however, because of its large micelle size, Tween 80 could not be removed from protein by this method. Attempts to remove Tween 80 by differential precipitation of protein were only partially successful. An alternate detergent, sodium cholate, when combined with TNBP, resulted in almost as efficient virus inactivation and an 80 percent recovery of AHF. Because sodium cholate forms small micelles, it could be removed by Sephadex G25 chromatography. Electrophoretic examination of TNBP/cholate-treated AHF concentrates revealed few, if any, changes in protein mobility, except for plasma lipoprotein(s).

Solvent/Detergent (SD) is an extraordinarily effective means for eliminating enveloped viruses from plasma and plasma products. The safety margin suggested by the rapid and complete kill of enveloped viruses observed in the laboratory has been confirmed repeatedly by groups worldwide and by thirteen years of routine clinical use encompassing an estimated 35 million doses of a wide variety of products. Throughout this time, there has not been a single documented case of enveloped virus transmission by an SD-treated product. This record of safety spawned the development of SD-treated plasma as a substitute for fresh frozen plasma (FFP) and has encouraged the adoption of SD for the treatment of non-blood products such as monoclonal antibodies and those derived from recombinant DNA procedures. This review summarizes the use of SD treatment, including its use in combination with other viral elimination procedures, and also summarizes Vitex's initial experience in the manufacture of SD-Plasma, recently licensed by the U.S. FDA.

The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure to lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated.

A new reversed passive hemagglutination test for HBsAg, termed Raphadex B, has been developed using immunochemically purified chimpanzee anti-HBs bound to stabilized human erythrocytes. The test has been found to have equivalent sensitivity to the Ausria 125 I radioimmunoassay, and detected a similar number of HBsAg-containing specimens in screening of volunteer blood donors. This method offers an economical approach to third generation methodology for hepatitis B screening of blood donors.

Hepatitis B antigen-associated particles, isolated from sera of antigen carriers, were submitted to affinity chromatography on columns of insolubilized antibodies to normal human plasma. The (7) suggest the presence of DNA in the core of the 42-nm particles. The molecular masses of the polypeptides identified in HBAg, which has a particle weight of approximately 7 X 10-18 g (8), add up to 320,000-490,000 daltons (9, 10), corresponding to 2550 to 3935 amino acids as calculated from the amino-acid composition (8). The lower and upper numbers correspond to the d and y subtypes of HBAg, respectively. Thus the total length of cistrons coding for these polypeptides should correspond to 7,650 to 11,805 nucleotides. The (500 and 0.5 mg/ml, respectively, 25,000, 30 min at 370) and diethylether + Tween 80 (500 and 0.5 mg/ml, respec-