71.有關pp65 antigenemia assay 的敘述，下列何者錯誤？
(A)檢體可為周邊血（peripheral blood）
(B)為immunofluorescence assay
(C)無法分離人類巨細胞病毒（human cytomegalovirus, CMV）
(D)可測得CMV抗體的效價（titer）

Pre-emptive treatment strategies, however, require a rapid diagnostic test with high sensitivity that accurately predicts CMV disease (high positive predictive values [PPVs]). Several CMV diagnostic techniques, including shell vial culture to detect viremia, the antigenemia assay, and methods to detect DNAemia, such as the polymerase chain reaction (PCR) and hybrid-capture RNA-DNA assays, enable quantification of viral replication (9). Among these techniques, the pp65 antigenemia assay remains the most common method for monitoring transplant recipients for evidence of CMV disease (8). The CMV antigenemia assay quantifies the level of replicating virus by assessing the expression of the pp65 antigen in polymorphonuclear leukocytes (PMN). However, the exact number of antigen-expressing cells that should be treated as a positive test result is not uniform, with breakpoints for positive test results ranging from one cell per 200,000 PMN to 50 cells per 200,000 PMN at different centres