Parvovirus B19 DNA in plasma pools and plasma derivatives

Background and Objectives Human parvovirus B19 (B19) has been transmitted b y various plasma-derived medicinal products. The aim of this study was to d etermine the frequency and the level of B19 DNA contamination in plasma poo ls destined for fractionation and in a broad range of plasma derivatives. I n addition, removal of B19 DNA by the manufacturing process was investigate d in cases where corresponding samples from plasma pool and product were av ailable. Materials and Methods Plasma pool samples and blood products were tested fo r B19 DNA by nested polymerase chain reaction (PCR), and the viral DNA cont ent was determined by TaqMan (TM) quantitative PCR. Results Two-hundred and twenty two of 372 plasma pools for fractionation co ntained B19 DNA at concentrations of 10(2)-10(8) genome equivalents/ml (geq /ml). While approximate to 65% of the DNA-positive plasma pools were only m oderately contaminated (< 10(5) geq/ml), 35% contained > 10(6) geq/ml. High frequencies of contamination were detected in Factor VIII (79 of 91), prot hrombin complex concentrates (38 of 43) and Factor IX (41 of 62), where the concentration of B19 DNA ranged between 10(2) and 10(7) geq/ml. A lower le vel of B19 DNA contamination was found in antithrombin III (five of 26 samp les), in anti-D immunoglobulins (three of 37 samples) and in albumin (four of 51 samples), with levels ranging between 10(2) and 10(3) geq/ml. Further more, investigation of plasma pools for solvent/detergent plasma (S/D plasm a), from two manufacturers, revealed B19 DNA in 15 of 66 batches at concent rations of 10(2)-10(8) geq/ml. Similar concentrations were detected in the corresponding final S/D plasma products. Anti-B19 immunoglobulin G (IgG) wa s found in plasma pools and S/D plasma at concentrations of approximate to 40 IU/ml. Conclusion Although positive PCR results do not necessarily reflect infecti vity, these data show that B19 is a common contaminant in plasma pools and in plasma-derived medicinal products. Considering the resistance of animal parvoviruses to inactivation by heat and chemical agents, and the absence o f specific information for B19, the risk of B19 transmission by plasma prod ucts should be considered. Physicians should be aware of this problem when treating patients of B19-related risk groups. The plasma fractionation indu stry should continue their efforts to avoid B19 contamination of plasma der ivatives and develop methods which are effective in removing/inactivating p arvovirus B19.