DETECTION IMPROVEMENT OF CYTOMEGALOVIRUS ANTIGEN IN HUMAN PERIPHERAL-BLOOD USING MONOCLONAL-ANTIBODIES AND AUTOMATED READING OF CELL PREPARATIONS

One of the major drawbacks in cytomegalovirus (CMV)-antigenaemia detec tion for diagnosis of active CMV infection is the low number of CMV-an tigen positive cells present in peripheral blood. It is therefore nece ssary to screen large numbers of peripheral blood granulocytes to find only a few antigen-positive cells. We have optimized this detection b y testing several monoclonal antibodies (mAb) to CMV-antigens (mAbs C1 O/C11, C12, BM222, E13 and SL20). In total 550 blood samples from 40 p atients were investigated. More blood samples were found positive with mAb C12 than with the other mAbs. Also the average number of positive cells per slide was highest for mAb C12. Furthermore, duplicate slide s were examined automatically using an image analysis system (LEYTAS) and compared to visual detection (cytospin slides). The detection sens itivity of both screening methods was compared for mAb C12. In total 3 60 slides were analysed, from positive as well as negative blood sampl es. The sensitivity of the automated screening was 93% and for the vis ual evaluation of the cytospin slides 73%. In conclusion, mAb C12 was the most suitable of the mAbs tested for detection of antigenaemia, an d automatic detection of CMV antigenaemia with image analysis of slide s is a sensitive method due to the large numbers of cells that can be screened.