Optimizing treatment for patients with persistent low-level viremia is complicated because most genotyping tests are validated for viral loads >1000 copies per milliliter. In this study, genotypes of 92 treatment-experienced patients with persistent low-level viremia were determined using an in-house assay. Based on the resistance profiles obtained from genotyping and patient pharmacologic history, patients were either maintained on their antiviral regimen (n = 51) or received an optimized regimen (n = 41). In the group receiving optimized treatment, undetectable viral loads were achieved in 73.2% at 6 months and at 90.2% at 1 year, indicating that treatment guided by genotyping of patients with low-level viremia is effective in achieving viral suppression.
*Unit of Infectious Diseases, Microbiology and Preventive Medicine, Instituto de Biomedicina de Sevilla (IBIS)/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain
†Microbiology Service, Hospital Universitario Virgen Macarena de Sevilla, Spain.
Supported by the Consejería de Economía, Innovación y Ciencia P06-CTS-01915, Junta de Andalucía; and the Red de Investigación en SIDA (ISCIII RD06/0006), Ministerio de Ciencia e Innovación. M.J.M is supported by the Programme Juan de la Cierva of the Ministerio de Ciencia e Innovación of Spain. P.P.R. was funded by Instituto de Salud Carlos III, Programa Miguel Servet CP05/00226.
The authors J.M.M., L.F.L.C., P.V. and P.P.R. are listed as inventors on a patent registered by the Andalusian Foundation for Health Research of Seville with the Spanish Office of Patents and Trademarks covering the method described in this study. M.J.M. and J.M.M. contributed equally to this work.
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Correspondence to: Pilar Pérez-Romero, PhD, Unit of Infectious Diseases, Microbiology and Preventive Medicine. Instituto de Biomedicina de Sevilla (IBiS). University Hospital Virgen del Rocío/CSIC/University of Sevilla. Avda Manuel Siurot s/n, 41013 Sevilla, Spain (e-mail: firstname.lastname@example.org or email@example.com).
Received April 7, 2011
Accepted September 6, 2011