Detection of human cytomegalovirus (HCMV) pp67-mRNA and pp65 antigenemia in relation to development of clinical HCMV disease in renal transplant recipients

Objective To evaluate the performance of the recently introduced method bas ed on detection of human cytomegalovirus (HCMV) pp67 mRNA in blood by the n ucleic acid sequence-based amplification (NucliSens). in comparison to semi quantitative detection of pp65 HCMV antigen in white blood cells, in relati on to development of clinical HCMV disease. Methods Thirty patients, recipients of renal transplants, were monitored pr ospectively for the presence of pp67 mRNA, the presence and level of pp65 a ntigenemia, IgG and IgM antibodies, and the development of clinical HCMV di sease. A total of 148 samples were examined during the observation period. Results Twenty-five samples were positive for pp67-mRNA and 45 samples cont ained at least one pp65 positive cell, with 68% agreement between the two a ssays. Both assays predicted correctly the development of clinical disease in five patients, giving a sensitivity of 100%. However, the specificity of the pp67-mRNA test was 72%, and of the pp65 antigenemia test from 20 to 64 %, depending on the level of antigenemia chosen for cut-off. pp67-RNA appea red somewhat earlier than pp65 antigenemia. and responded earlier to treatm ent. Sero-conversion and appearance of IgM antibodies were of very little c linical value. Conclusion Both the pp67-mRNA and the pp65 antigenemia assay predicted corr ectly the development of clinical HCMV disease in renal transplant recipien ts. However, the specificity of both tests with respect to development of H CMV disease, especially the pp65 antigen test was moderate. Significantly p ositive tests not necessarily prove the development of clinical disease. Te sting for pp67-mRNA may improve the diagnosis and management of HCMV diseas e in renal transplant patients.