Rapid Diagnosis of HCMV Diseases by pp65 Antigenemia Assay: Comparison of pp65 Antigenemia with Polymerase Chain Reaction

Kim, Uiseok; Lee, Bo Bin; Park, Wan Bum; Shin, Jong Wook; Oh, Myoung Don; Kim, Eui Chong; Choe, Kwangwon

Abstract

BACKGROUND
The present study was performed to evaluate clinical usefulness of pp65 antigenemia assay (pp65 Ag), plasma polymerase chain reaction (P-PCR) and peripheral blood mononuclear cell PCR (PBMC-PCR) in patients with cytomegalovirus (CMV) diseases. METHODS: Sixty samples from 41 patients admitted in Seoul National University Hospital from Sep, 2001 through Feb, 2002 were evaluated. Twenty-eight patients who had symptoms and signs of CMV disease and 13 patients who were asymptomatic were tested for CMV infection. Among 60 samples, 59 samples were tested for pp65 Ag by Clonab CMV kit (Biotest, Dreieich, Germany). Fifty-six samples were tested for P-PCR and PBMC-PCR, respectively. RESULTS: Fifteen (25%) out of 59 samples showed positive by pp65 Ag, 16 (29%) and 24 (43%) out of 56 samples showed positive by P-PCR and PBMC-PCR, respectively. The concordance rate of pp65 Ag and P-PCR in the same blood sample was 82%. CMV disease was diagnosed in 15 (37%) patients. The sensitivities of pp65 Ag, P-PCR and PBMC-PCR were 60, 53 and 80%, respectively, and in specificities were 96, 92, 88%, respectively. Of the 15 patients with CMV diseases, 4 patients who underwent allogenic bone marrow transplantation showed positive results by all the three assays, and the number of pp65 positive cells in these patients was high (3-30/4X10(5)). Eight out of the 15 patients with CMV diseases had CMV gastroenteritis. Four of them showed positive by pp65 Ag(the number of pp65 positive cells : 1-3/4X10(5)) and 2 patients showed positive by P-PCR. CONCLUSION: The senstivity of PBMC-PCR was high and the specificity was relatively low. It is quite likely PBMC-PCR was not able to distinguish CMV reactivation from latent infection. The sensitivity and specificity of pp65 Ag were similar to those of P-PCR. CMV pp65 positive cells could be quantitated by pp65 Ag.