QUANTITATIVE POLYMERASE CHAIN-REACTION FOR HUMAN-HERPESVIRUS DIAGNOSIS AND MEASUREMENT OF EPSTEIN-BARR-VIRUS BURDEN IN POSTTRANSPLANT LYMPHOPROLIFERATIVE DISORDER

Human herpesviruses can cause acute diseases such as chicken pox or mo nonucleosis, but also may reactivate during immunosuppression and resu lt in severe or life-threatening illnesses such as shingles or lymphop roliferative disorders. We report the development and validation of a quantitative PCR method to measure viral burden for all eight human he rpesviruses (HSV1, HSV2, VZV, EBV, CMV, HHV6, HHV7, and KSHV) in patie nts' samples. The method uses an internal standard that is coamplified with the viral target, allowing quantification of viral genomes in ab solute terms (e.g., viral targets/mL of blood) and ruling out false-ne gative results. We demonstrate that transplant patients with lymphopro liferative disorder carry an EBV viral burden 3 logs higher than nontr ansplant patients. EBV titers in transplant patients without a lymphop roliferative disorder are between these values. This quantitative PCR method may aid in differentiating clinically significant vs latent vir al burden in immunosuppressed patients.