USE OF LABORATORY ASSAYS TO PREDICT CYTOMEGALOVIRUS DISEASE IN RENAL-TRANSPLANT RECIPIENTS

Eight laboratory assays, viz,, the pp65 direct antigenemia test, a qua ntitative cytomegalovirus (CMV)-specific immunoglobulin G (IgG) assay (Biomerieux VIDAS), a CMV-specific IgM assay (Biomerieux VIDAS), the H ybrid Capture system (Murex), an in-house PCR with plasma (P-PCR) and leukocytes (L-PCR), and a commercial PCR (Roche AMPLICOR) with plasma (P-Ah IP) and leukocytes (L-AMP), were compared for their abilities to predict CMV disease before the onset of illness in a prospective stud y of 37 renal transplant recipients. By using an expanded criterion fo r active infection (two or more of the markers positive) and a clinica l definition of disease, 22 (59%) patients were identified as having a ctive CMV infection and 13 (35%) were identified as having CMV disease . Of the 13 CMV-seronegative recipients who received seropositive kidn eys (R- group), 8 had active infection and disease. All assays were 10 0% specific and 100% predictive of CMV disease in the R- group, The le ukocyte PCRs (L-PCR and L-AMP) were the most sensitive assays, had pos itive results an average of between 8 and 13 days before the onset of illness, and were the assays of choice, The performance of the assays was less satisfactory for the 24 patients who were CMV seropositive be fore transplantation (R+ group). A negative result was more useful for this group. Overall, P-AMP had the best results, and it could be the assay of choice for monitoring RS patients. The non-PCR-based methods generally had high specificities but often gave late positive results and were not sensitive enough for use as prediction tools for either g roup of patients.