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Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents

Laboratory Testing

Laboratory Testing for Initial Assessment and Monitoring While on Antiretroviral Therapy

(Last updated: May 1, 2014; last reviewed: May 1, 2014)

A number of laboratory tests are important for initial evaluation of HIV-infected patients upon entry into care; during follow-up if antiretroviral therapy (ART) is not initiated; and before and after initiation or modification of therapy to assess the virologic and immunologic efficacy of ART and to monitor for laboratory abnormalities that may be associated with antiretroviral (ARV) drugs. Table 3 outlines the Panel’s recommendations on the frequency of testing. As noted in the table, some tests may be repeated more frequently if clinically indicated.

Two surrogate markers are used routinely to assess immune function and level of HIV viremia: CD4 T-cell count (CD4 count) and plasma HIV RNA (viral load), respectively. Resistance testing should be used to guide selection of an ARV regimen. A viral tropism assay should be performed before initiation of a CCR5 antagonist or at the time of virologic failure that occurs while a patient is receiving a CCR5 antagonist. HLA-B*5701 testing should be performed before initiation of abacavir (ABC). The rationale for and utility of these laboratory tests are discussed in the corresponding sections of the guidelines.

Table 3. Laboratory Monitoring Schedule for HIV-Infected Patients Before and After Initiation of Antiretroviral Therapy

Timepoint/Frequency of Testing
 Laboratory Test Entry into Care
Follow Up Before Initiation 
of ART
ART Initiation or Modif-icationb Follow-Up 2 to 8 Weeks After ART Initiation or Modif-ication  Every 3 to 6 Months  Every 6 Months
Every 12 Months
Clinically Indicated 
HIV Serology

If HIV diagnosis has not been confirmed
CD4 Count

Every 3-6 months


During first 2 years of ART or
if viremia develops while patient on ART or CD4 count <300 cells/mm

After 2 years on ART with consistently suppressed viral load:
CD4 Count 300–500 cells/mm
  • Every 12 months
Count >500 cells/mm3:

  • CD4 monitoring is optional

HIV Viral Load

Repeat testing is optional √  c

Resistance Testing


HLA-B*5701 Testing

If considering ABC
Tropism Testing    

If considering a CCR5 antagonist

If considering a CCR5 antagonist or for failure of CCR5 antagonist-based regimen

Hepatitis B Serologyf


May repeat if HBsAg (-) and HBsAb (-) at baseline
Hepatitis C Serology, with Confirmation of Positive Results

Basic Chemistryg,h

Every 6–12 months

ALT, AST, T. bilirubin

Every 6–12 months

CBC with Differential

Every 3–6 months

If on ZDV

Fasting Lipid Profile

If normal, annually

Consider 4–8 weeks after starting new ART regimen that affects lipids

If abnormal at last measure-ment

If normal at last measurement
Fasting Glucose or Hemoglobin A1C

If normal, annually


If abnormal at last measure-ment

If normal at last measurement


If on TDFi

Pregnancy Test

In women with child-bearing potential
This table pertains to laboratory tests done to select an ARV regimen and monitor for treatment responses or ART toxicities. Please refer to the HIV Primary Care guidelines for guidance on other laboratory tests generally recommended for primary health care maintenance of HIV patients.1 
ART may be modified because of treatment failure, adverse effects, or for regimen simplification.
If HIV RNA is detectable at 2 to 8 weeks, repeat every 4 to 8 weeks until viral load is suppressed to <200 copies/mL, and thereafter, every 3 to 6 months.
In patients on ART, viral load typically is measured every 3 to 4 months. However, for adherent patients with consistently suppressed viral load and stable immunologic status for more than 2 years, monitoring can be extended to 6 month intervals.
e In ART-naive patients, if resistance testing was performed at entry into care, repeat testing before initiation of ART is optional. The exception is pregnant women; repeat testing is recommended in this case. In virologically suppressed patients who are switching therapy because of toxicity or for convenience, viral amplification will not be possible; therefore, resistance testing should not be performed. Results from prior resistance testing can be helpful in constructing a new regimen.
f If HBsAg is positive at baseline or before initiation of ART, TDF plus either FTC or 3TC should be used as part of the ARV regimen to treat both HBV and HIV infections. If HBsAg, and HBsAb, and anti-HBc are negative at baseline, hepatitis B vaccine series should be administered. Refer to HIV Primary Care guidelines for more detailed recommendations.1
g Serum Na, K, HCO3, Cl, BUN, creatinine, glucose (preferably fasting). Some experts suggest monitoring the phosphorus levels of patients on TDF. Determination of renal function should include estimation of CrCl using the Cockcroft-Gault equation or estimation of glomerular filtration rate using the MDRD equation.
h For patients with renal disease, consult the Guidelines for the Management of Chronic Kidney Disease in HIV-Infected Patients: Recommendations of the HIV Medicine Association of the Infectious Diseases Society of America.2
i More frequent monitoring may be indicated for patients with evidence of kidney disease (e.g. proteinuria, decreased glomerular dysfunction) or increased risk of renal insufficiency (e.g., patients with diabetes, hypertension).

Key to Acronyms: 3TC = lamivudine, ABC = abacavir, ALT = alanine aminotransferase, ART = antiretroviral therapy, AST = aspartate aminotranserase, CBC = complete blood count, CrCl = creatinine clearance, EFV = efavirenz, FTC = emtricitabine, HBsAb = hepatitis B surface antibody, HBsAg = hepatitis B surface antigen, HBV = hepatitis B virus, MDRD = modification of diet in renal disease (equation), TDF = tenofovir, ZDV = zidovudine


  1. Aberg JA, Gallant JE, Ghanem KG, Emmanuel P, Zingman BS, Horberg MA. Primary care guidelines for the management of persons infected with HIV: 2013 update by the HIV medicine association of the Infectious Diseases Society of America. Clin Infect Dis. 2014;58(1):e1-34. Available at
  2. Gupta SK, Eustace JA, Winston JA, et al. Guidelines for the management of chronic kidney disease in HIV-infected patients: recommendations of the HIV Medicine Association of the Infectious Diseases Society of America. Clin Infect Dis. 2005;40(11):1559-1585. Available at

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