Low risk of viral infection after administration of vapor-heated factor VIII concentrate. International Investigator Group

A multicenter prospective study was carried out to evaluate whether a vapor-heated factor VIII concentrate transmitted blood-borne viral infections over a surveillance period of 15 months. Thirty-five patients with hemophilia and von Willebrand disease who had never received any blood components were treated. Twenty-eight were analyzed and found not to have non-A, non-B hepatitis. Sera from 20 of these 28 patients were also tested for the antibody to the hepatitis C virus. None had sero-converted during the follow-up period. None of the patients analyzed developed markers of the hepatitis B virus (n = 17) or the human immunodeficiency virus (n = 31). This vapor-heated factor VIII concentrate carries a low risk of transmitting hepatitis and human immunodeficiency virus infection.     

Plasma levels of nucleosomes and nucleosome–autoantibody complexes in murine lupus: Effects of disease progression and lipopolysaccharide administration

Objective

To evaluate the effect of disease progression and lipopolysaccharide (LPS) administration on the presence of nucleosomes, antinucleosome reactivity, and nucleosome–Ig complexes in the circulation of MRL and control mice.

Methods

Plasma samples from lupus‐prone (MRL/lpr and MRL/+) and control (CBA, Swiss, and BALB/c) mice were tested in enzyme‐linked immunosorbent assays for the presence of nucleosomes, antinucleosome antibodies, and nucleosome–Ig complexes. Nucleosome kinetics, apoptosis induction, and phagocytosis of apoptotic cells were also analyzed in MRL/lpr, MRL/+, and CBA control mice after a single injection of LPS or phosphate buffered saline.

Results

Nucleosomes were found in the circulation of MRL/lpr and MRL/+ mice from week 4 onward. Nucleosomes were also detected in young control mice, but with increasing age, the nucleosomes disappeared. Antinucleosome antibodies, nucleosome–Ig complexes, and albuminuria were found only in the MRL/lpr mice. LPS administration led to a significant increase in circulating nucleosomes (3–8‐fold) in all strains tested. In only the MRL/lpr mice was this increase followed by a significant decrease in antinucleosome titers and an increase in nucleosome–Ig complexes. The number of apoptotic cells in the thymus after LPS was significantly higher in the MRL/lpr mice than in the MRL/+ and CBA control mice. LPS caused a profound reduction (50–70%) of the phagocytosis of apoptotic cells by peritoneal macrophages, which was comparable for all strains.

Conclusion

In MRL lupus‐prone mice, nucleosomes are persistently present in the circulation, whereas in control mice, nucleosomes are present only at a young age. The formation of antinucleosome antibodies and nucleosome–Ig complexes is a characteristic feature of MRL/lpr mice. LPS administration increases systemic nucleosome release due to an enhancement of apoptosis and a decrease in the clearance of apoptotic cells.