CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
- Centers for Disease Control and Prevention (CDC). HIV prevalence estimates—United States, 2006. MMWR Morb Mortal Wkly Rep. 2008;57(39):1073–1076.
- Criteria for laboratory testing and diagnosis of human immunodeficiency virus infection; approved guideline. Document M-53A. Clinical and Laboratory Standards Institute; 2011.
- Ginocchio CC, Carman WF, Arens MQ. Update on HIV diagnostic testing algorithms. Editor’s introduction. J Clin Virol. 2011;52(suppl 1):S1.
- de Wolf F, Spijkerman I, Schellekens PT, et al. AIDS prognosis based on HIV-1 RNA, CD4+ T-cell count and function: markers with reciprocal predictive value over time after seroconversion. AIDS. 1997;11(15):1799–1806.
- Thompson MA, Aberg JA, Hoy JF, et al. Antiretroviral treatment of adult HIV infection: 2012 recommendations of the International Antiviral Society—USA panel. JAMA. 2012;308(4):387–402.
- Panel on Antiretroviral Therapy and Medical Management of HIV-Infected Children. Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection. Available at http://aidsinfo.nih.gov/contentfiles/lvguide lines/pediatricguidelines.pdf. Accessed March 10, 2013:1–268.
- Deeks SG, Walker BD. Human immunodeficiency virus controllers: mechanisms of durable virus control in the absence of antiretroviral therapy. Immunity. 2007;27(3):406–416.
- Cobb BR, Vaks JE, Do T, Vilchez RA. Evolution in the sensitivity of quantitative HIV-1 viral load tests. J Clin Virol. 2011;52(suppl 1):S77–S82.
- Korn K, Weissbrich B, Henke-Gendo C, et al. Single-point mutations causing more than 100-fold underestimation of human immunodeficiency virus type 1 (HIV-1) load with the Cobas TaqMan HIV-1 real-time PCR assay. J Clin Microbiol. 2009;47(4):1238–1240.
- Drexler JF, de Souza Luna LK, Pedroso C, et al. Rates of and reasons for failure of commercial human immunodeficiency virus type 1 viral load assays in Brazil. J Clin Microbiol. 2007;45(6):2061–2063.
- Colson P, Solas C, Moreau J, Motte A, Henry M, Tamalet C. Impaired quantification of plasma HIV-1 RNA with a commercialized real-time PCR assay in a couple of HIV-1-infected individuals. J Clin Virol. 2007;39(3):226–229.
- Damond F, Roquebert B, Bénard A, et al. Human immunodeficiency virus type 1 (HIV-1) plasma load discrepancies between the Roche Cobas Amplicor HIV-1 Monitor version 1.5 and the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 assays. J Clin Microbiol. 2007;45(10):3436–3438.
Test Yourself
Here are three questions taken from the case report. Answers are online now at www.amp.org/casereviews and will be published in CAP TODAY next month.
- Some individuals with HIV infection by repeated serologic testing have extremely low (<50 copies/mL) or unquantifiable HIV RNA-1 viral loads. Reasons for this discrepancy may include all of the following except:
a) The patient may be an “elite controller,” having a rare (less than one percent) phenotype that has the same viral control as patients taking ART.
b) The patient has a new HIV-1 infection and a low viral load is expected at time of seroconversion.
c) The patient has a HIV-1 primer site mutation. Testing by an alternative assay may lead to a detectable viral load.
d) The patient may have an HIV-2 infection.
- A newly diagnosed HIV-1 patient is referred to the clinical laboratory for HIV-1 viral load testing as part of his therapeutic monitoring. What viral load corresponds to suppression of viremia and successful ART therapy?
a) 50–200 copies/mL
b) <500 copies/mL
c) <50 copies/mL
d) <1,000 copies/mL
- Nucleic acid testing for HIV-1 is useful in which of the following clinical situations?
a) Monitoring response to ART
b) Diagnosing a patient in the serological window period
c) Identifying an elite controller
d) All of the above
Dr. Azzato is a clinical pathology resident, Dr. Edelstein is a professor of pathology and laboratory medicine and director of the clinical microbiology laboratory, and Dr. Watt is an assistant professor of clinical pathology and laboratory medicine and associate director of the molecular pathology laboratory—all in the Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia.