Reference Values

Negative (reported as positive, equivocal, or negative)

Rheumatoid factor may cause false-positive results. Concomitant high CMV IgG antibody can cause false-negative results. Positive results may not be valid in patients who have received blood in the past several months. A negative CMV IgM result does not preclude recent CMV infection if specimen was drawn very early in disease. Increases in antibody level may indicate recent antigenic stimulation without being confirmatory of recent primary infection or reactivation of pre-existing latent process with viral excretion. Results must be used in conjunction with clinical symptoms and history.