DETECTION OF CMV DNA IN BONE-MARROW TRANSPLANT RECIPIENTS - PLASMA VERSUS LEUKOCYTE POLYMERASE CHAIN-REACTION

Aims-To compare the nested polymerase chain reaction (PCR) assay for t he detection of cytomegalovirus (CMV) DNA in peripheral blood leucocyt es and plasma obtained from heparinised blood; to determine the effici ency of various DNA extraction methods to minimise inhibition of plasm a PCR and their effect on the sensitivity of plasma PCR; to determine the inhibitory effect of heparin, dextran, and EDTA on the CMV PCR ass ay. Methods-217 heparinised blood specimens from 58 bone marrow transp lant patients were processed and the sensitivities and specificities o f the PCR assays using peripheral blood leucocytes and plasma (with si mple, Instagene, and Geneclean extraction methods) were compared to th ose of conventional CMV culture. In a separate experiment, dilutions o f heparin, dextran, and EDTA were included in PCR assays. Results-The detection of CMV DNA using peripheral blood leucocytes for PCR assay w as significantly more sensitive (100%) than when using plasma (60%). I nstagene and Geneclean extraction removed inherent inhibition but did not improve the sensitivity of the plasma PCR reaction. Heparin had an inhibitory effect on PCR. Conclusions-PCR assay using peripheral bloo d leucocytes is better than plasma for guiding the prescription of gan ciclovir to bone marrow transplant patients. Heparin is inhibitory to the plasma PCR reaction.