This head-to-head clinical evaluation compared two National Medical Products Administration (NMPA)-approved Chinese HIV-1 viral load assays (Livzon and SymBio) with the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 Test v2.0 reference method using plasma from 279 HIV-infected individuals. The Roche assay detected HIV-1 RNA in 92.47% (258/279) of samples; both Livzon and SymBio detected 94.62% (264/279). Positive agreement with the reference assay was 98.06% (95% CI: 95.54–99.17%) and overall agreement was 94.27% (95% CI: 90.89–96.44%). Correlation coefficients were high (Livzon r = 0.989, SymBio r = 0.988). Bland–Altman mean biases versus Roche were +0.18 log10 copies/mL for Livzon and −0.09 log10 copies/mL for SymBio. Domestic assays were reported as >30% less expensive and 20–50% faster in batch turnaround time compared with the reference.
Viral load (VL) testing is central to antiretroviral therapy (ART) monitoring, treatment decisions, and public-health surveillance. The World Health Organization recommends VL testing to identify ART failure and to guide clinical management. Rising test volumes and costs in low- and middle-income countries have created demand for cost-effective alternatives. Historically, China relied heavily on imported VL platforms and reagents; domestically produced assays that meet international performance standards could expand access and reduce costs. This study aimed to verify the real-world clinical performance and utility of two such domestic assays against an established global standard.
Sample size was determined per CLSI EP09-A3 guidance to ensure coverage across the measuring interval. The study enrolled 279 participants between May 2023 and November 2023. Inclusion criteria encompassed newly diagnosed, short-term treated (≤3 months), and patients with incomplete viral suppression (detectable VL or ≥20 copies/mL) after treatment. Ten mL of EDTA whole blood was collected from each participant; plasma separation was completed within 6 hours and aliquots stored at −80°C. The study received ethics approval from the Medical Ethics Committee of the Zhejiang Provincial Center for Disease Control and Prevention (Approval No. 2022-048-01) and followed the Declaration of Helsinki.
Both evaluated systems (Livzon and SymBio) are NMPA-certified quantitative HIV-1 RNA assays with limits of detection established using the WHO 4th International Standard. The Livzon assay (NMPA approval No. 20193400849) uses single-dose lyophilized reagents targeting pol and LTR genes, requires 0.65 mL plasma, and reports a linear range of 17.5 to 5.8 × 10^7 copies/mL with an LoD of 17.5 copies/mL (manufacturer-stated conversion: 1 copy = 1.71 IU). The study executed all three assays in parallel using aliquots from the same thawed plasma, initiating tests within one hour of each other to limit pre-analytical variability. The Livzon workflow incorporated an automated Microlab® STARlet liquid handler for RNA extraction per the manufacturer’s instructions.
Aliquots were homogenized and thawed immediately before testing; all assays were performed according to manufacturers’ instructions. The investigators ran Livzon, SymBio, and Roche assays in parallel to minimize temporal and handling variation. The study intentionally verified clinical performance under routine diagnostic conditions rather than repeating foundational analytical validation previously required for regulatory approval.
The Roche TaqMan reference assay detected HIV-1 RNA in 258 of 279 samples (92.47%). Both Livzon and SymBio detected HIV-1 RNA in 264 of 279 samples (94.62%). The reported positive agreement with the reference assay was 98.06% (95% CI: 95.54–99.17%), and overall agreement across assays was 94.27% (95% CI: 90.89–96.44%). These metrics indicate high concordance between the domestic assays and the reference in a real-world clinical sample set.
Linear regression and correlation analyses demonstrated strong quantitative concordance. Livzon showed a Pearson correlation coefficient of r = 0.989 versus Roche with a Bland–Altman mean bias of +0.18 log10 copies/mL. SymBio showed r = 0.988 with a mean bias of −0.09 log10 copies/mL versus Roche. Across the assessed viral load range, Pearson coefficients for comparisons exceeded 0.985. Reported biases versus Roche spanned −0.17 to +0.24 log10 copies/mL depending on subgroup analyses reported in the article.
The study evaluated performance across diverse HIV-1 subtypes present in the sample cohort; Pearson correlations remained >0.985 across subtypes and biases were within the range noted above. Direct comparison between Livzon and SymBio yielded r = 0.988 and a mean difference (Livzon − SymBio) of 0.27 log10 copies/mL, indicating strong agreement between the two domestic assays.
The investigators reported that both domestic assays were priced at more than 30% lower cost than the Roche reference assay. Batch turnaround time (TAT) for the domestic assays was reduced by 20–50% relative to the reference, according to the data presented. These operational advantages were highlighted as potential enablers for expanded VL testing in resource-limited settings.
In this real-world verification using 279 clinical plasma samples, the two Chinese-manufactured assays (Livzon and SymBio) demonstrated high concordance, strong quantitative correlation, and small biases relative to the Roche COBAS TaqMan reference. The lower cost and shorter batch TAT reported suggest these assays could help bridge HIV-1 monitoring gaps in resource-limited settings by enabling broader and more frequent viral load testing while meeting required performance standards.
The study was approved by the Zhejiang Provincial CDC Medical Ethics Committee (2022-048-01). Participant informed consent did not permit public deposition of individual VL and subtype data; thus the dataset is not publicly available. Data access requests must be directed to the Medical Ethics Committee contact provided by the authors. The work was supported by a Major infectious disease prevention and control project in 2023 (1-23C021-06). The authors declared no competing interests.