Time-resolved fluorescence (TRF) for total IgG and HPV16-specific antibody detection in first-void urine and serum: A comparative study

Abstract

Recent studies demonstrated that human papillomavirus (HPV) specific immunoglobulins (IgG) are present and detectable in non-invasively collected first-void urine (FVU) samples. As IgG levels in urine are low, we evaluated the potential of a highly sensitive HPV16-specific assay based on time-resolved fluorescence, DELFIA, and compared it with three immunoassays, GST-L1-MIA, M4ELISA, and M9ELISA. A total of 225 paired serum and FVU samples from two cohorts of healthy female volunteers were analyzed. Strong Spearman rank correlations between HPV16-specific IgG results measured with DELFIA, M4ELISA, GST-L1-MIA, and M9ELISA were found for both sample types (r_s > 0.80). Additionally, total human IgG results, determined in all samples using HTRF human IgG kit and BioPlex Pro™ Human Isotyping Assay, were compared. Moderate correlations between total human IgG concentrations in FVU samples were found for the two total IgG assays (r_s ≥ 0.42, p < 0.0001), while correlations for serum were non-significant. In conclusion, the HPV16-DELFIA assay is usable for detecting HPV16-specific antibodies in FVU and serum samples. As total human IgG remains an interesting parameter for the normalization of HPV-specific IgG in FVU, the accuracy of both assays needs to be validated further.