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HIV Dx and Work up and Follow up

  • Laboratory Work up / Monitoring during treatment: 
    • Entry into care / ART Modification/ Initiation: HIV Serology, CD4 count, Viral Load, Resistance Testing, , CMP, CBC/diff, Lipid Panel, Pregnancy Test,  T, A1C, UA, Ur-Pr, Ur-Cr, HLA- B*5701 Testing if considering ABC, Tropism Testing if considering CCR5 antagonists,
    • F/U 2-8 wks After ART Initiation or Modification: Viral Load, CMP, CBC/diff (if on ZDV), Lipid Panel (if affects lipid profile)
    • Every 3-6 months:  CD4 count (esp first 2 yrs), Viral Load, CMP, CBC/diff, A1C (if previously abnormal), UA (if on TDF), Lipid Panel (if previously abnormal), 
    • Treatment Failure: CD4 count, Viral Load, Resistance Testing, Tropism Testing if considering CCR5 antagonist
  • Baseline Screening for infection 
    • Tuberculin skin test or IGRA, anti-Toxoplasma IgG (Provide prophylaxis is CD4 < 100), NG/CH NAT, Trepanoma Pallidium (IgG, VDRL or RPR) 
    • Total HAV antibody, Anti-HBc, Anti-HBs, HBsAg,  Anti-HC IgG,  
    • Anti-VZV IgG (if no prior history of Zoster or Varicella)
    • CrAg (consider if CD4 < 100)

HIV-Dx

  • Case 1
    • HIV-1/2 antigen/antibody combination immunoassay is reactive. 
    • Result on a subsequent HIV-1/HIV-2 antibody differentiation immunoassay is negative or indeterminate, as is result on an HIV-1 nucleic acid amplification test (see below Box 1 of  updated recommendations CDC 2014)
    • What should be done next. 
      • Ans: No further testing as the initial test was likely false positive (No need of western blot or repeat testing in 6 weeks)
  • WB for HIV confirmation
    • No longer recommended as it has high rate of false negative in the early stage of infection 
Diagnostic Tests - Basics 






Note:
  • Saliva Assay:
    • Detects HIV antibody. Hence, this is more like 3rd generation test. 


  • Case 2
    • HIV-1/2 antigen/antibody combination immunoassay is reactive. 
    • Result on a subsequent HIV-1/HIV-2 antibody differentiation immunoassay is negative or indeterminate
      • This differentiation assay detects only the antibody. Hence, if this differentiation assay is negative, then it means the test detected p24 antigen or false positive. 
    • HIV-1 nucleic acid amplification test is positive with viral load of 30000. 
    • Does this confirm diagnosis. 
      • Yes, for HIV-1. This is ACUTE HIV infection. 
    • Next step in management? 
Additional References 

HIV / AIDS: duration, last CD4 Counts, on ART or not, who is treating this, if not why is patient not taking medication
  • Identifying, Diagnosis, and Mnt of Acute and Recent HIV Infection: 
    • Signs and Sympfever, lymphadenopathy, skin rash, myalgia/arthralgia, headache, diarrhea, oral ulcers, leucopenia, thrombocytopenia, transaminase elevation 
    • DDx:  infectious mononucleosis syndromes (EBV and non-EBV i.e CMV), influenza, viral hepatitis, streptococcal infection, or syphilis. 
    • Resistance testing: Genosure PRIme (Resistance for NRTI, NNRTI, INI, PI are included)
Table 11 , Pg 17 of ART Guidelines

HIV-Work Up

  • Laboratory Work up / Monitoring during treatment: 
    • Entry into care / ART Modification/ Initiation: HIV Serology, CD4 count, Viral Load, Resistance Testing, HBV Serology, HCV Serology, CMP, CBC/diff, Lipid Panel, Pregnancy Test, A1C, UA, Ur-Pr, Ur-Cr, HLA- B*5701 Testing if considering ABC, Tropism Testing if considering CCR5 antagonists,
    • F/U 2-8 wks After ART Initiation or Modification: Viral Load, CMP, CBC/diff (if on ZDV), Lipid Panel (if affects lipid profile)
    • Every 3-6 months:  CD4 count (esp first 2 yrs), Viral Load, CMP, CBC/diff, A1C (if previously abnormal), UA (if on TDF), Lipid Panel (if previously abnormal), 
    • Treatment Failure: CD4 count, Viral Load, Resistance Testing, Tropism Testing if considering CCR5 antagonist
Table 3 (Page 3,4,5 of ART Guidelines
  • Indications of Viral Load and CD4 Count Monitoring: 
Table 4 , Page 6 of ART Guidelines
  • Recommendations for using Drug Resistance Assays: Table 5 (Page 7,8 oART Guidelines

HIV testing and management of newly diagnosed HIV BMJ 2014
Guidelines for Prevention and Rx of Opportunistic Infections in HIV-Infected patients CDC 2009 MMWR
HIV-Dx


HIV and Immunization
  • Pneumonoccous: 
    • Irrespective of CD4 and Viral load, all patient needs13-valent pneumococcal conjugate vaccine (PCV13) 
    • This should also be followed by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) at least 8 weeks later
    • This is called a “prime-boost” strategy that is used to improve the antibody response to immunization
  • Hep B if not already immunized 
  • HPV (11-26 females)
HIV-Follow up
  • Resistance testing done while the patient is not receiving therapy may be unreliable without the selective pressure of the medications to maintain the presence of mutations in the predominant virus population. HENCE, do not discontinue therapy will testing for HIV resistance
HIV-Resistance Tests
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