Initial Laboratory and Clinical Evaluation for Newly Diagnosed HIV-Positive Patients
All newly diagnosed HIV-positive patients require immediate baseline testing including CD4 count, HIV viral load, tuberculosis screening (TST or IGRA), renal function assessment with urinalysis and calculated creatinine clearance, and hepatitis B/C serology 1.
Essential Baseline Laboratory Tests
Immunologic and Virologic Assessment
- CD4 T-cell count: Establishes disease stage and determines urgency of ART initiation and prophylaxis needs 2
- HIV-1 RNA viral load: Provides baseline for monitoring treatment response and confirms active infection 3
Tuberculosis Screening (Critical Priority)
- Perform TST or IGRA on all patients without prior TB history or positive screening 1
- A positive result (TST induration >5 mm in HIV patients) requires chest radiography to exclude active TB before treating latent infection
- Repeat testing is mandatory if initial test is negative but CD4 count subsequently rises to >200 cells/µL on ART, as immune reconstitution may unmask previously undetectable infection 1
- Treat latent TB infection after excluding active disease in all close contacts of infectious TB cases, regardless of test results 1
Renal Function Assessment
- Baseline urinalysis and calculated creatinine clearance/eGFR are mandatory, particularly for Black patients and those with advanced disease 1
- Up to 30% of HIV-infected patients have abnormal kidney function at baseline 1
- Screen for proteinuria (≥1+ on dipstick) annually, especially in high-risk groups: Black patients, CD4 <200 cells/µL, viral load >4000 copies/mL, or those with diabetes, hypertension, or HCV coinfection 1
- This testing must occur before initiating nephrotoxic agents like tenofovir or indinavir 1
Additional Essential Tests
- Hepatitis B and C serology: Coinfection significantly impacts treatment choices and prognosis
- Complete blood count: Establishes baseline and identifies cytopenias that may indicate bone marrow involvement, particularly in advanced disease 4
- Comprehensive metabolic panel: Assesses liver and kidney function baseline
- Fasting lipid panel and glucose: Establishes cardiovascular risk baseline before ART initiation 5
Clinical Staging and Assessment
Disease Staging
- Use WHO clinical staging system (Stages I-IV) based on presence/absence of HIV-related signs and symptoms 2
- Clinical staging guides treatment urgency and prophylaxis decisions 6
Key Clinical Evaluations
- Identify opportunistic infections: Active screening for tuberculosis, cryptococcosis, and other AIDS-defining conditions based on CD4 count 5
- Sexual health screening: Test for all sexually transmitted infections including syphilis, gonorrhea, and chlamydia 5
- Cancer screening: Initiate age-appropriate screening, with particular attention to anal and cervical cancer in high-risk populations 5, 7
Important Caveats
Medication Interactions
Be aware that certain medications (cobicistat, dolutegravir, trimethoprim) can elevate serum creatinine by affecting tubular secretion without true renal dysfunction 1. This is a common pitfall that can lead to unnecessary medication adjustments.
Timing Considerations
Do not delay ART initiation while waiting for all test results unless active TB or other opportunistic infections requiring specific treatment sequencing are suspected 5. The priority is rapid viral suppression.
Anergy Testing
Do not perform routine cutaneous anergy testing—it lacks standardization and has poor predictive value 1.