Antiretroviral Lab Monitoring
ANTIRETROVIRAL LAB MONITORING
Laboratory Monitoring Schedule for Patients Before and After Initiation of Antiretroviral Therapy
Baseline Initiation or modifica- tiona Follow-up 2−8 weeks after initiation or modification Every 3−6 months Every 6 months Every 12 months Treatment failure Clinically indicated Delayed initiatione
HIV serology If diagnosis has not been confirmed
CD4 count During first 2yrs of ART or if viremia develops while patient on ART or CD4 count <300 cells/mm³ After 2yrs on ART with consistently suppressed viral load: if CD4 count 300−500 cells/mm³, monitor every 12 months. CD4 count >500 cells/mm³, monitoring is optional Every 3−6mos
HIV viral load b c c Repeat testing is optional
Resistance testing d d d d d
HLA-B*5701 testing If consi- dering ABC
Tropism testing If consi- dering CCR5 antagonist If consi- dering CCR5 antagonist or CCR5 antagonist-based regimen failed
Hepatitis B serology (HBsAb, HBsAg, HBcAb, total)i,j,k May repeat if nonimmune and no chronic HBV infectionj May repeat if nonimmune and no chronic HBV infectionj Including prior to starting HCV DAA
Hepatitis C screening (HCV antibody or, if indicated, HCV RNA)l Repeat HCV screening for at-risk patientsm
Basic chemistryf,g Every 6−12mos
ALT, AST, T. bilirubin Every 6−12mos
CBC with differentialp When monitoring CD4 count, perform CBC count and CD4 concurrently When no longer monitoring CD4 count Every 3−6mos
Random or fasting lipid profilen If normal at baseline, annually
Random or fasting glucoseq If normal at baseline, annually
Urinalysisg,h If on TDFf
Pregnancy testo
NOTES

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.

a  If ART initiation occurs soon after HIV diagnosis, repeat baseline testing is not necessary.

b  If HIV RNA is detectable at 2−8 weeks, repeat every 4−8 weeks until suppression to <200 copies/mL, then every 3−6 months.

c  Viral load typically is measured every 3−4 months in patients on ART. Consider more frequent monitoring in patients with adherence difficulties. However, for adherent patients with consistently suppressed viral load and stable immunologic status for ≥2yrs, may extend monitoring to 6-month intervals.

d  Standard genotypic drug-resistance testing in ART-naive patients should focus on mutations in the reverse transcriptase and protease genes. Also test for mutations to integrase strand transfer inhibitors if resistance is a concern. In ART-naive patients, if resistance testing was performed at entry into care, repeat testing before initiation of ART is optional. For virologically suppressed patients who are switching therapy for toxicity or convenience, viral amplification will not be possible and therefore resistance testing should not be performed. Results from prior resistance testing can be used to help in the construction of a new regimen.

e  ART is indicated for all patients with HIV and should be started as soon as possible. If ART initiation is delayed, patients should be retained in care, with periodic monitoring as noted above.

f  Serum Na, K, HCO3, Cl, BUN, creatinine, glucose (preferably fasting), and creatinine-based estimated GFR. Monitor serum phosphorus in patients with CKD who are on TDF-based regimens.

g  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. More frequent monitoring may be indicated for patients with evidence of kidney disease (eg, proteinuria, decreased glomerular dysfunction) or increased risk of renal insufficiency (eg, patients with diabetes, hypertension).

h  Assess urine glucose and protein before initiating TAF- or TDF-based regimens, and monitor during treatment.

i   If patient has HBV infection (as determined by a positive HBsAG or HBV DNA test), TDF or TAF plus either FTC or 3TC should be used as part of the ARV regimen to treat both HBV and HIV infections.

j  If HBsAg, HBsAb, and HBcAb are negative, HBV vaccine series should be given.

k  Most patients with isolated HBcAb have resolved HBV infection with loss of HBsAb. Consider performing an HBV viral load for confirmation. If HBV viral load is positive, patient may be acutely infected (and will usually display other signs of acute hepatitis) or chronically infected. If negative, patient should be vaccinated.

l   The HCV antibody test may not be adequate for screening in recent HCV infection (within the past 6mos), or advanced immunodeficiency (CD4 <100cells/mm3). HCV RNA screening is indicated in patients who have been successfully treated for HCV or who spontaneously cleared prior infection. HCV antibody-negative patients with elevated ALT may need HCV RNA testing.

m  At-risk patients for HCV infection include injection drug users, persons with a history of incarceration, men with HIV who have unprotected sex with men, and persons with percutaneous/parenteral exposure to blood in unregulated settings.

n  Obtain fasting lipids if random lipids are abnormal. Consult the 2018 Guideline on the Management of Blood Cholesterol for patients with dyslipidemia.

o  This applies to patients of childbearing potential.

p  CBC with differential should be done when a CD4 count is performed. When no longer monitoring CD4 count, monitor CBC with differential once a year. More frequent monitoring may be needed for patients who are on medications that potentially cause cytopenia (e.g., ZDV, TMP-SMX).

q  Obtain fasting glucose if random glucose is abnormal. HbA1C is no longer recommended for diabetes diagnosis in HIV patients on ART.


ACRONYMS: 3TC = lamivudine, ABC = abacavir, ALT = alanine aminotransferase, ART = antiretroviral therapy, AST = aspartate aminotranserase, CBC = complete blood count, CKD = chronic kidney disease, CrCl = creatinine clearance, DAA = direct-acting antiviral, EFV = efavirenz, FTC = emtricitabine, GFR = glomerular filtration rate, HBsAb = hepatitis B surface antibody, HBsAg = hepatitis B surface antigen, HBV = hepatitis B virus, HCV = hepatitis C virus, TAF = tenofovir alafenamide, TDF = tenofovir disoproxil fumarate, TMP-SMX = trimethoprim-sulfamethoxazole, ZDV = zidovudine

REFERENCES

Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV. Department of Health and Human Services. Available at https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/AdultandAdolescentGL.pdf. Accessed January 5, 2022 [Table 3].

(Rev. 1/2022)