Screening of Blood Donors for Human Parvovirus B19 and Characterization of the Results

Abstract

Background and Objectives: Human parvovirus B19 (B19 virus) can be transmitted through blood transfusion and plasma–derived products. In a previous report, we utilized the simple hemagglutination method based on the interaction between the B19 virus and P antigen on human erythrocytes in order to screen the blood donors. We called this method receptor–mediated hemagglutination (RHA) [Lancet 1995;346:1237–1238]. In this paper, we report on a large–scale screening of the B19 virus by RHA and discuss the results. Materials and Methods: Donor sera from September 1995 to March 1997 and seroconversion panels were enrolled. Donor sera were examined by RHA for large–scale screening. The positive sera in the first screening were then further investigated by the RHA inhibition test, countercurrent immunoelectrophoresis (CIE), an enzyme–linked immunosorbent assay, and polymerase chain reaction (PCR). We also evaluated the infectivity and neutralizing activity of various kinds of sera by the erythroid colony forming unit (CFU–e) assay. To examine the detection limits of the B19 virus by RHA, B19–viremic sera were purified by sucrose gradient ultracentrifugation. Results: Among 257,710 sera specimens, 293 sera (0.11%) gave a positive reaction in the first screening using RHA. Out of these 293 sera specimens, 31 were positive for PCR, of which 28 were also RHA inhibition–positive, and 25 of the 28 CIE–positive. In the CFU–e injury assay, all the RHA inhibition (+) sera showed a decrease in the number of erythroid colonies. The RHA inhibition (–) PCR (+) B19 antibody (+) sera did not affect the erythroid colony formation and protected CFU–e from injury by the B19 virus. By measuring the amount of purified B19 protein and its RHA titer, the detection limit of the B19 virus by RHA was calculated to the 0.37±0.03 ng/ml. Conclusion: These results suggest that the RHA(+) RHA inhibition (+) sera were infectious in vitro. The combination of RHA and the RHA inhibition test is considered to be useful for the large–scale screening of infectious B19 virus in blood donors with high specificity.

Distribution of parvovirus B19 DNA in blood compartments and persistence of virus in blood donors

“…We speculate that the explanation for these results is loose binding of spiked B19V to RBCs, either through weak binding to the P blood group receptor site or through nonspecific binding. These findings are not inconsistent with development of B19 antigen agglutination assays employed in donor screening in Japan, given that those assays employ optimized conditions to maximize binding and they require more than 10 10 B19 particles/mL of plasma for positive results 28,29 …”

Symptomatic parvovirus B19 infection caused by blood component transfusion

“…In 1998, JRC implemented a receptor‐mediated hemagglutination (RHA) assay as a screening test for B19V and used it for all donated blood until 2007. The theoretical basis of the RHA assay system was described elsewhere 19,20 ; briefly, it is a B19V antigen detection method in which the indicator RBCs agglutinate via B19V particle binding to globosides on the RBC membrane at a critical pH (pH 5.6 ± 0.1). The sensitivity of RHA is approximately 10 10 IU/mL, and by this method, 300 to 400 B19V‐positive donors with very high titer viremia have been identified every year 21 .…”

Implementation of a 20‐nm pore‐size filter in the plasma‐derived Factor VIII manufacturing process

“…In Japan, as safety measures, blood donated voluntarily is screened by serological tests for blood‐borne infectious agents, such as hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus types 1 and 2 (HIV‐1, HIV‐2) and human T‐cell lymphotropic virus type 1 (HTLV‐1); furthermore, nucleic acid amplification testing (NAT) for HBV, HCV and HIV‐1 was implemented by the Japanese Red Cross in 1999 [1,2]. The screening of donated blood by a receptor‐mediated haemagglutination assay (RHA) for human parvovirus B19 (B19) was implemented, in 1998, by the Japanese Red Cross [3–5]. In addition to the screening tests, the production process of the coagulation factor VIII (FVIII) product, CROSS EIGHT M®, produced by the Japanese Red Cross Plasma Fractionation Center, contains four virus‐clearance steps.…”