Summary
It is known that parvovirus B19 (B19) is transmitted to hemophiliacs by clotting factors
prepared from human plasma. However, it is not clear whether B19 is also transmitted
by the more recently used inactivated clotting factor preparations. Therefore, we
investigated 69 hemophiliacs, mostly children, receiving only virus-inactivated clotting
factors. 49 of them (71%) were B19 IgG-positive and 18 of the IgG-positive hemophiliacs
(37%) were also B19 IgM-positive. In contrast, out of 73 age-matched controls only
10 (14%) were IgG-positive, two of them being also IgM-positive. In hemophiliacs treated
before 1984 with noninactivated clotting factors, seroprevalence was very similar:
94/136 (69%) presented B19 IgG antibodies as compared to their age-matched controls
with 16/50 (32%). Out of the 94 IgG-positive patients 24 (26%) were IgM-positive,
whereas IgM antibodies were never found in 16 sera of 16 IgG-positive controls. In
4 out of 24 IgM positive hemophiliacs, B19 DNA was detected in the sera by using the
polymerase chain reaction. However, B19 DNA was also found in 3/69 anti-B19 IgM-negative,
HIV-infected hemophiliacs (all three patients in CDC stage IV). Since it seems unlikely
that the results only represent passive acquisition of B19 DNA from blood products
and induction of antibodies by immunization with inactivated antigen, the observations
rather suggest that infection with B19 is transmitted by clotting factors, including
those treated for virus inactivation.
