TT virus contaminates first-generation recombinant factor VIII concentrates

Area of Science:

• Virology
• Hematology
• Biotechnology

Background:

• Recombinant factor concentrates are crucial for hemophilia treatment.
• Viral safety of blood products is a primary concern.
• TT virus (TTV) is a common human parvovirus with unknown pathogenicity.

Purpose of the Study:

• To investigate the presence of TT virus (TTV) in recombinant factor VIII and factor IX concentrates and human-plasma-derived albumin.
• To determine if TTV infection develops in previously untreated hemophilia patients receiving these concentrates.
• To identify the potential source of TTV contamination in recombinant products.

Main Methods:

• Polymerase chain reaction (PCR) testing was used to detect TTV DNA.
• Recombinant factor concentrates (first- and second-generation), albumin lots, and patient blood samples were analyzed.
• Patient samples were collected prospectively before and during therapy.

Main Results:

• TTV was detected in 23.5% of recombinant product lots and 55.5% of albumin lots.
• Only first-generation factor VIII concentrates stabilized with human albumin tested positive for TTV.
• Second-generation (human protein-free) factor VIII concentrates were TTV-negative.
• TTV infection developed in 59% of patients receiving recombinant factor concentrates.
• TTV infection did not appear clinically significant in treated patients.

Conclusions:

• First-generation recombinant factor VIII concentrates may harbor TTV, with human albumin identified as a potential contamination source.
• Second-generation recombinant factor VIII concentrates are free of TTV contamination.
• TTV infection is common in hemophilia patients treated with recombinant factor concentrates but lacks apparent clinical significance.