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No Detectable HIV RNA in Thirteen Individuals Months after Stopping Antiretroviral Therapy R. SHERER*1, B. DUTTA2, R. ANDERSON3, J. LAUDETTE-ABOULHAB4, A. KAMARULZAMAN5, R. D’AMICO6, N. PATON4, M. S. ABDULLAH7, R. POLLARD8, T. COOLEY9, M. FLAVIN2, and Z.-Q. XU2.
1CORE Ctr., Cook County Hosp., Chicago, IL; 2Sarawak MediChem Pharmaceuticals, Lemont, IL; 3Anderson Clin. Res., Pittsburgh, PA; 4CDC, Tan Tock Seng Hosp., Singapore; 5Univ. Hosp., Kuala Lumpur, Malaysia; 6Beth Israel Med. Ctr., New York, NY; 7Univ. of Malaya, Kuala Lumpur, Malaysia; 8Univ. of Texas Med. Branch at Galveston; and 9Boston Univ. Med. Ctr., MA Background: We identified 13 HIV infected individuals since 1996 with viral loads (pVL) below 500 copies/ml a minimum of 90 days after stopping antiretroviral therapy (median 2.5 years; range 3 months-5.6 years). We attempted to identify viral, host or treatment-specific factors that could account for these observations.
Methods: Western Blot, pVL (Amplicor) and CD4 counts were determined by standard methods. RT-PCR was used to amplify HIV gag, pol and env products from plasma for sequence analyses of viral clade and primer complementarity to pVL primers. DNA PCR from peripheral blood cells was used to amplify patient CCR-5 promoter and deletion profiles, SDF-1 genotype, and proviral DNA.
Results: Prescribed antiviral regimens of these individuals were unremarkable, and would not be expected to result in viral eradication. Patients received mono- or dual-nucleoside therapy for between 1-54 months (median 3 months). Only 2 patients were treated with intermittent therapy, and 2 during primary infection. All patients remain HIV infected by serological criteria after stopping therapy. PCR products from HIV gag, pol or env were obtained from the plasma or cells of 12 of 13 individuals. Pre-therapy viral loads (available for 7 of 13 patients) were very low (min <500, max 9000 copies/ml). 3/10 patients were heterozygous for the CCR-5 deletion, and 2/12 patients had Clade A HIV. Other human chemokine receptor genotypes and viral clades were not unusual.
Conclusion: Isolated cases of individuals with low or undetectable HIV RNA upon stopping therapy do not be evidence of an exceptional therapeutic effect, particularly if treated during primary infection before a viral "set-point" has been achieved.
Key Words: HIV, therapy, viral load
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