Abstract
E
Methods
Sixteen HIV-1-infected patients negative to antiretroviral therapy were enrolled in AIDS clinics of the Guilin Third People's Hospital. Ethical approval was obtained from the local research ethics committee. The patients gave the midstream of their first morning urine samples. The urine samples were processed within 6 h, placed in a refrigerator, and maintained at −20°C for 1 month (36 to 85 ml). Plasma and peripheral blood mononuclear cells were isolated from these blood samples and used for viral load measurement and CD4+ T cell counts. Peripheral CD4+ cells were counted using flow cytometry (BD FACSAria III, San Jose, CA). HIV-1 RNA in urine and blood was concurrently detected with a RealTime HIV-1 assay (Abbott Laboratories S.A., Guangzhou, China). The assay shown from Abbott Laboratories has a 5-log10 linear range and assay specificity of 100%. The lower detection limit of the assay is 50 copies/ml. The concentration of HIV-1 RNA in urine with higher than 50 copies/ml was considered as positive.
Results
Five patients were urine positive for HIV-1 RNA (Table 1). High concentration of HIV-1 RNA in fresh urine samples was found in three patients (871,000, 150,500, and 100,200 copies), whereas low concentration was detected in two patients (472.2 and 214.4 copies). Viral load was 224,477 ± 164,223 (mean ± SD) copies in fresh urine samples and 11,560 ± 6,695 copies in paired blood samples (p = .147). There was no statistically significant correlation of urine HIV-1 load with blood HIV-1 viral load or CD4+ cell count. Among the three patients who had high concentration of urine HIV-1 RNA, two died within 1 month of enrollment before initiation of antiretroviral treatment. In contrast, none of the 11 urine negative patients died within a period of 12-month clinical observation.
Comment
The results of this study confirm a prior report that the urinary system is one reservoir of viral-infected cells and the site of viral replication. 3 Since HIV RNA found in urine could be derived from infectious virus or from exosomes, future studies with tissue biopsies are needed to prove the presence of a HIV tissue reservoir, as described in prior reports. 3 –5 The presence of HIV-1 in urine and renal epithelial cells despite the absence of detectable plasma viremia highlights the importance of genitourinary system as a target for HIV-1. 4,6 Whether the presence of high HIV-1 RNA loads in urine reflects poor prognosis warrants longitudinally clinical investigations.
Footnotes
Acknowledgments
This study was supported by the National Natural Science Foundation of China (81471054 and 81560574) and Innovation Project of Guangxi Graduate Education (JGY2015128).
Author Disclosure Statement
No competing financial interests exist.