Different behavior of erythrovirus B19 and torquetenovirus in response to a single step of albumin purification.
BACKGROUND
The safety of human serum albumin (HSA) is of special interest with respect to virus transmission because of the wide use of this blood product as a therapeutic agent and also, added to other products, as an excipient or a stabilizer. Conflicting data are reported concerning HSA contamination by small, naked viruses such as the erythrovirus B19 (B19V) and the anellovirus torquetenovirus (TTV). This study has been performed to assess the effect of the HSA purification procedures on the viral contamination.


METHODS
Known concentrations of B19V and TTV virus were spiked in raw Fraction V, the starting material from fractionated human plasma for HSA purification, which was subsequently submitted to the depth filtration procedure. After spiking, B19V and TTV genome copies were determined by real-time quantitative polymerase chain reaction assays in the mixture at the end of Fraction V dissolution, to determine the virus concentration achieved, in the HSA solution after the filtration step, in the filtered postwashing fluid, and in the supernatant of resuspended Celite.


RESULTS
B19V was completely adsorbed by the Celite used as a filter aid in the depth filtration process and was thus undetectable in the resulting HSA-containing fraction. In contrast, in 2 out of 3 experiments, TTV was detected in all samples.


CONCLUSIONS
The different behavior of the two viruses might be a reflection of their different surface charge.
Azzi
Alberta
A
Department of Public Health, University of Florence, Florence, Italy. alberta.azzi@unifi.it
Maggi
Fabrizio
F
Zakrzewska
Krystyna
K
Menconi
Maria Carla
MC
Di Pietro
Niccolò
N
Salotti
Vittorio
V
Farina
Claudio
C
Andreoli
Elisabetta
E
Fiorentino
Bruno
B
Angelini
Cristina
C
Corcioli
Fabiana
F
Bendinelli
Mauro
M
D000327:Adsorption; D001781:Blood Component Removal / Q000379:methods / Q000592:standards; D017848:Blood-Borne Pathogens / Q000302:isolation & purification; D004279:DNA, Viral / Q000032:analysis; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005374:Filtration / Q000379:methods; D006801:Humans; D016732:Parvovirus B19, Human / Q000302:isolation & purification*; D010949:Plasma / Q000821:virology*; D016133:Polymerase Chain Reaction; D012709:Serum Albumin / Q000302:isolation & purification*; D022783:Torque teno virus / Q000302:isolation & purification*
D004279:DNA, Viral; D012709:Serum Albumin