Detection Of Cmv Disease And Infection

Antibodies: the development of IGM anti-CMV antibodies, a four fold or greater increase in IgG titers Culture:

A. Standard culture in a fibroblast monolayer

Results may require up to 6 wk

B. Shell vial cultures—the buffy coat is centrifuged onto fibroblasts increasing fibroblast infection. Viral infection is detected by applying a monoclonal antibody directed against the 72-Kd major immediate early protein of CMV. RBCs in the buffy coat may be toxic to the monolayer resulting in a false-negative test. Urine and BAL specimens may be positive without predicting disease. Results are available in 16 to 36 h.

Other:

A. Antigenemia—Granulocytes and monocytes are isolated and stained with a monoclonal antibody against a matrix, tegument protein pp65 (structural late protein). Culture is not required, granulocytes and monocytes from the buffy coat are stained, testing results are available in 4 to 6 h. It may be argued that the positivity may not be due to replicating virus in the WBCs but due to exogenous acquisition from infected endothelial cells. The number of antigen positive cells per unit number of WBC counted that determines the onset of symptomatic diseases depends upon the individual laboratory; however, usually over 10 positive cells per 105WBC precede the onset of symptoms by approximately 1 week.

B. Polymerase chain reaction—For the detection of CMV DNA in whole blood or serum. CMV DNA is amplified from whole blood or serum. The sensitivity and predictive value depend on the laboratory.

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