HCV RNA Testing of Plasma Samples from Cornea Donors: Suitability of Plasma Samples Stored at 4 °C for up to 8 Days.

BACKGROUND: The HCV RNA testing of potential cornea donors frequently relies on blood samples stored pre mortem. The recommended storage time of maximum 72 h frequently excludes a significant fraction of donors.

METHODS: The influence of storage time of EDTA plasma samples at 4 °C on the viral load measured with the Roche HCV Quantitative Test vs. 2.0 was evaluated for 43 samples from HCV-positive individuals.

RESULTS: The mean reduction of the viral load after 4 °C storage for 6-8 days was 0.46 log10 IU/ml (range +0.17 to -1.66 log10 IU/ml). After 1-3 days a mean loss of 0.19 log10 IU/ml (range +0.30 to -1.41 log10 IU/ml) and after 3-5 days of 0.32 log10 IU/ml (range +0.36 to -1.81 log10 IU/ml) was observed. In 23.3% of samples, a viral load reduction ≥ 1 log10 IU/ml (1.0-1.81 log10 IU/ml) was found after prolonged storage (5-8 days). In none of the samples did the HCV load fall below the detection limit.

CONCLUSION: Plasma storage for up to 8 days can quantitatively reduce the HCV RNA load, yet has no influence on the reliability of a qualitative HCV RNA detection by this ultrasensitive test to determine the HCV status of serologically negative cornea donors.