THE CLINICAL UTILITY OF VIRAL QUANTITATION USING MOLECULAR METHODS

Background: The quantitation of viral nucleic acids in biological flui ds has become increasingly desirable over the past several years. To t his end, a number of quantitative molecular procedures have been devel oped. Objectives: The objective was to review the current literature o n the molecular techniques used in the quantitation of viral nucleic a cids and to assess the appropriateness of these methods for clinical u se. Results: Assays involving both target and signal amplification are now available for the accurate and precise quantitation of viral burd en in infected patients. These methods include quantitative polymerase chain reaction (PCR), branched chain signal amplification (bDNA), nuc leic acid sequence-based amplification (NASBA) and the SHARP signal an d hybrid capture systems. Our understanding of the natural history and pathogenesis of viruses such as the human immunodeficiency virus (HIV ), hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus ( CMV) and Epstein-Barr virus (EBV) may be greatly facilitated by accura te determinations of viral and infected cell burden. Quantitation of v iral load in infected individuals may also be useful to assess disease progression, monitor the efficacy of therapy and to predict treatment failure and the emergence of drug-resistant viruses. Conclusion: Prec ise, accurate and reproducible quantitation of viral load is now feasi ble. Molecular assays for viral quantitation should have a considerabl e impact on medical research and clinical care. (C) 1998 Elsevier Scie nce B.V, All rights reserved.