Performance Validation and Blood Donation Analysis in Nagqu, Tibet, One of the Highest Cities in the World.

Background: Due to the unique geographical and climatic conditions in Nagqu (Tibet), the blood station laboratory was only fully established and accredited by 2020. This study validated the performance of the laboratory's blood screening system and analyzed recent trends in blood donation and screening effectiveness.

Methods: Various serum samples were used to assess the performance of hepatitis B, hepatitis C, HIV, and syphilis tests, both serological and nucleic acid tests. Donation data were also collected and analyzed.

Results: Serological testing demonstrated excellent sensitivity, specificity, and reproducibility (all 100%), with detection limits for HBsAg, HCV Ab, HIV-1 Ab, HIV-1 p24, and TP Ab of 0.2 IU/mL, 0.013 NCU/mL, 0.25 NCU/mL, 1.25 U/mL, and 1.5 mIU/mL, respectively. Nucleic acid testing systems also achieved 100% reproducibility with precision below 5%. PROBIT analysis revealed the 95% detection limits for HBV DNA, HCV RNA, and HIV-1 RNA as 8.29, 97.14, and 40.52 IU/mL, respectively. The study also found a high rate of unqualified donations for local markers such as ALT, HBsAg, syphilis, and HBV DNA.

Conclusions: The validation confirmed the screening system's high sensitivity, specificity, and reproducibility, highlighting the importance of effective predonation checks to ensure a safe blood supply in high-altitude areas.