Comparison of a rapid cytomegalovirus pp65 antigenemia assay revealed by immunofluorescence to an in-house assay revealed by immunoperoxidase for diagnosis in solid organ transplant recipient patients

Abstract

Cytomegalovirus (CMV) antigenemia is still one of the two major assays available for diagnosis and monitoring of CMV infections. A commercial rapid test recently available in Brazil for quantification of human cytomegalovirus pp65 antigenemia revealed by immunofluorescence technique was compared with the original in-house method revealed by immunoperoxidase in patients receiving solid organ transplants. Of 80 blood samples tested for CMV antigenemia, 34 (42.5%) were positive: commercial assay detected 33 (97%) and in-house assay detected 20 (58.8%) samples. The numbers of positive cells in the two assays were different, with a median of 4.5 and 12 positive cells obtained by in-house and commercial kit, respectively. Discrepancies between assays occurred in 15 specimens from patients with low-grade antigenemia (median 6 positive cells). The assay-time was reduced in approximately 50% compared to in-house methodology. In conclusion, besides comparable results obtained for both assays, the commercial antigenemia assay provides more rapid and sensitive results. Keywords: cytomegalovirus, antigenemia assay, immmunoperoxidase, immunofluorescence