Dried Blood Spot Samples for Seroepidemiology of Infections with Human Papillomaviruses, Helicobacter pylori, Hepatitis C Virus, and JC Virus

Abstract

To establish antibody analysis from dried blood spots (DBS) on filter paper for seroepidemiologic infection and cancer association studies, we analyzed data from a population-based study in Mongolia. Using multiplex serology, we analyzed 985 paired DBS and serum samples from the same donors for antibodies to 12 different proteins from four groups of infectious agents: human papillomaviruses (HPV), Helicobacter pylori (H. pylori), hepatitis C virus (HCV), and JC polyomavirus (JCV). Quantitative antibody reactivities in serum and DBS showed good correlation, with median correlation coefficients (Pearson R(2)) of 0.88 (range, 0.80-0.90) for high-titer (i.e., H. pylori, HCV, JCV) and 0.79 (range, 0.72-0.85) for low-titer antibodies (i.e., HPV). For high-titer antibodies, serum and DBS data were comparable (median slope of linear trend line, 1.14; range, 1.09-1.21), whereas for low-titer antibodies, DBS reactivities were lower than in serum (median slope, 0.54; range, 0.50-0.80). By extrapolating seropositivity cutoff points previously defined for serum to DBS, we found high agreement (>89% for all antigens) of dichotomized DBS and serum results and median kappa values for high- and low-titer antibodies of 0.86 and 0.78 (range, 0.78-0.92 and 0.55-0.86), respectively. Epidemiologic associations with known risk factors for HPV antibodies were as strong for DBS as for serum. DBS provide a reliable alternative to serum or plasma for detection of antibodies against various pathogens by multiplex serology. DBS do not require blood centrifugation and allow storage and shipment at ambient temperature, thus facilitating field work for seroepidemiologic studies especially in environments with limited technical infrastructure.