Diagnostic, Monitoring and Resistance Laboratory Tests for HIV

Table of Contents

• Editor's Note
• I. Introduction
• II. Diagnostic Tests
• III. Monitoring Tests
• References
• Appendix A: Assay Procedures
• Appendix B: Enzyme-Linked Immunosorbent Assay
• Appendix C: Western Blot
• Appendix D: Immunofluorescence Assay (IFA)
• Appendix E: Amplicor HIV-1 Monitor Test Format
• Appendix F: Versant bDNA Signal Amplification Assay
• Appendix G: Nucleic Acid Amplification System

Editor's Note

Diagnostic HIV laboratory tests and interpretation algorithms evolve; individual laboratories have internal protocols for reporting tests with preliminary results. Indeterminate, inconclusive, non-diagnostic, and pending validation are among the terms used when preliminary results cannot be classified definitively. The clinician should contact the appropriate laboratory authority to determine the significance of the non-definitive results and the supplemental testing that would be indicated. This is of particular importance with tests from pregnant women, newborn children, and patients with suspected acute HIV infection or HIV-2. Clinicians should become familiar with the internal test-reporting policies of their institutions.

I. Introduction

Technologic advances in HIV laboratory testing continue to aid in screening, diagnosis, and patient management. Effective methods for detection of HIV-related laboratory markers are critical for both accurate HIV screening and for monitoring patients for disease progression and viral resistance to therapy. This chapter provides an overview of currently available HIV laboratory screening methods, viral load assays, and HIV resistance tests. Many new technologies that will further enhance testing methods are in various stages of development.

Patients presenting for testing within 36 hours of exposure to HIV should be assessed for post-exposure prophylaxis (see Post-Exposure Prophylaxis Guidelines). Expert advice may be obtained from the National Clinicians' Consultation Center PEP Line at 1-888-HIV-4911 (1-888-448-4911).