Characterization of Markers of the Progression of Human Parvovirus B19 Infection in Virus DNA-Positive Plasma Samples

Abstract

Background: Accurate characterization of the infection stage in parvovirus B19(B19V)-positive plasma donations would help establish the donation deferral period to contribute to a safe fractionation pool of plasma. Methods: Viral DNA load of 74 B19V DNA-positive plasma samples from whole blood donations was determined by titration using nucleic acid testing. Markers of cellular (neopterin) and humoral (B19V-specific IgM and IgG) immune response were determined by ELISA in 32 B19V DNA-positive samples and in 13 B19V DNA-negative samples. The infection progression profile was estimated according to B19V DNA load and the presence of immune response markers. Results: B19V DNA load in the 74 samples was 10⁶-10¹³ IU/ml. The distribution of 14 out of 32 selected B19V DNA-positive samples plus 2 B19V DNA-negative samples with no immune response marker followed along an upward curve according to B19V DNA load. After the peak, the distribution of 18 immune marker-positive samples followed along a downward curve according to their B19V DNA load and was grouped as follows: neopterin (n = 4), neopterin+ IgM (n = 8), neopterin + IgM + IgG (n = 3), IgM + IgG (n = 2), IgM (n = 1). There were 11 B19V DNA-negative IgG-positive samples. Conclusion: This study of B19V-DNA load and levels of neopterin, IgM, and IgG allows for reliable characterization and distribution into the different stages of B19V infection.