Antiretroviral Therapy for HIV-Infected Adults Follow Up

Monitoring

Follow-up – Patient Not Started on ART  

Patients not eligible for ART should have CD4 count measurement every 3-6 months to assess urgency of ART initiation and the need for prophylaxis for opportunistic infections. HBsAg should be performed to help identify people with HIV-HBV coinfection so appropriate ART can be given (eg TDF-containing ART). Patients should continue their regular visits for monitoring, prophylaxis, and other medical treatment. ART should also be discussed and be offered again to patients who initially declined treatment. The benefits of ART and the risks of delaying treatment should be discussed. Support or counseling is provided if there is lack of readiness, coping mechanisms or probably compliance difficulties are issues.    

Follow-up – Patient on ART  

It is recommended that symptom-directed lab monitoring for safety and toxicity be done for those on ART. CD4 T-cell count and plasma HIV RNA (viral load) are the 2 markers used routinely to evaluate immune function and level of viremia. The viral load is used to monitor therapy effectiveness after ART initiation. If resources are available, viral load is measured to confirm suspected treatment failure based on clinical and/or immunologic criteria. Treatment success is achieved when the results show a 10-fold decrease in HIV RNA copies/mL in the first month and suppression to <200 copies/mL by 6 months.  

Recommended Laboratory Parameters and Monitoring Schedule for Patients After Initiation of ART  

CD4 count monitoring is recommended every 3 months if CD4 count is <300 cells/mm³ during the first 2 years of ART then every 6 months after 2 years of consistently suppressed HIV RNA. A repeat CD4 count after 3 months from ART initiation will help determine the magnitude of immune reconstitution and is most important for patients who initiate ART with more advanced disease and require prophylaxis or treatment for opportunistic infections. CD4 count monitoring is done every 6 months in the first 2 years of ART if CD4 count is ≥300 cells/mm³. It is done every 12 months in clinically stable patients with consistently suppressed viral load after 2 years of ART if CD4 count is 300-500 cells/mm³ and optional for those with CD4 count of >500 cells/mm³ or >350 cells/mm³ on 2 occasions 1 year apart. However, for those patients who fail to maintain viral suppression while on ART, CD4 count monitoring is done every 3-6 months.  

HIV viral load monitoring is recommended 4-8 weeks post-ART initiation or modification to confirm adequate virologic response to ART, indicating appropriate regimen selection and adherence to therapy. Repeat viral load measurements are done at 4–8-week intervals until the level falls below the assay’s limit of detection. If the HIV RNA is detectable at 4-8 weeks, viral load is measured every 4-8 weeks until suppression to <50 copies/mL, then done every 3-6 months thereafter. For patients on a stable ART regimen, it is done every 3-6 months or as clinically indicated. For adherent patients with suppressed viral load and stable clinical and immunologic status for >1 year, monitoring may be extended to every 6 months. In virologically suppressed patients whose ART was modified because of drug toxicity or for regimen simplification, measurements should be performed within 4-8 weeks after changing the therapy to confirm effectiveness of the new regimen. In patients with virologic failure and require ARV regimen modification, viral load is measured before ART change and within 4-8 weeks after regimen modification to confirm adequate virologic response to the new regimen. Repeat viral load measurement is recommended every 4-8 weeks until the level falls below the assay’s limit of detection. Frequency of monitoring in patients with suboptimal response to ART will depend on the adherence and availability of other treatment options.  

Fasting lipid profile monitoring is considered 1-3 months after ART initiation or modification, then done every 12 months if profile is normal at baseline and with cardiovascular risk. Then, lipid profile monitoring is done every 5 years or if clinically indicated. CBC is recommended every 3-6 months when monitoring CD4 count then done every 12 months when CD4 count is no longer monitored. More frequent monitoring is recommended in patients receiving drugs which can cause cytopenias.  

Basic chemistry tests such as serum Na, K, bicarbonate, chloride, BUN, creatinine, glucose (preferably fasting), liver transaminases, creatinine-based GFR, and total bilirubin may also be done 4-8 weeks post-ART, then done every 6 months thereafter or if clinically indicated. For patients taking TDF and TAF, phosphorus is also included. Urinalysis may be done to monitor urine glucose and protein levels during treatment with TDF- or TAF-containing regimens. More frequent monitoring may be indicated for patients with evidence of a kidney disease (eg decreased GFR, proteinuria) or increased risk of renal insufficiency (eg diabetes mellitus [DM], hypertensive patients). In addition to viral load monitoring, other factors are also assessed such as adherence to the prescribed ART regimen, altered pharmacology, and drug interactions.  

Drug resistance testing is recommended for patients who fail to achieve viral suppression. This would aid in the choice of an alternative regimen. Drug resistance testing is recommended when modifying the regimen to assist in the selection of active drugs in patients with virologic failure and with HIV RNA levels of >200 copies/mL or in patients with suboptimal viral load reduction. It may also be considered in patients with confirmed HIV RNA levels of >200 copies/mL but <500 copies/mL. Reverse transcriptase and protease genotypic resistance testing is recommended in all patients with virologic failure while on INSTI-based therapy. Drug resistance testing in the setting of virologic failure is performed while still on ARV regimen for patients receiving non-long-acting ARV therapy or within 4 weeks after discontinuing ARV regimen. It is recommended to all patients who experienced virologic failure with injectable CAB-LA and RPV regimen or acquired HIV after receiving CAB-LA as pre-exposure prophylaxis regardless of the amount of time since drug discontinuation. Genotypic resistance testing is preferred to guide therapy in patients with suboptimal virologic response or virologic failure on first- or second-line therapy and in patients with known or without suspected complex resistance mutation patterns. Phenotypic drug resistance testing is recommended in addition to genotypic drug resistance testing in patients with known or suspected complex drug resistance mutation patterns. The previous and current drug resistance test results should be reviewed and taken into consideration when constructing a new regimen.