Anais do Congresso Paranaense de Microbiologia
IV Congress of Microbiology in Paraná

Viral hepatitis B (HBV) and C (HCV) are infections that can evolve silently for decades without diagnosis and treatment, leading to serious hepatic impairments.
Viral load quantification (VL) tests are fundamental for infection and treatment monitoring, as they allow quantifying the number of copies of viral genomes in plasma samples of the patient. Because these are quantitative tests, it is essential to use strategies to ensure the reliability of the results.
Commercial kits are accompanied by positive, negative and internal controls, which are used as validation criteria of the assay. However, they are not able to detect small analytical variations.
Although current legislation requires, the use of internal quality control (CIQ) is not commercially available for HBV and HCV VL. Thus, in order to control factors that may negatively impact the reproducibility of the assay (variation between batches, stability of reagents, inaccuracy of the analysis process), LACEN/PR implemented the use of a locally produced CIQ.
The production took place from a fresh plasma bag provided by HEMEPAR. The bag was contaminated with plasma pool of patients with high VL, in order to produce final concentration with log between 4.0 and 5.0. Aliquots of 1 mL were performed, and these were kept at -80 ºC.
The CIQs produced were processed in 10 consecutive routines, together with the samples, in M2000sp and M2000rt equipment (extraction and amplification) and by the Abbott Real Time HBV and Abbott Real Time HCV systems. The mean and standard deviation of the VL log were used in the construction of a Levey Jennings chart, which was used as a standard for the application of the Multiple Rules criteria recommended by Westgard.
CIQ aliquots were included in the 52 VL-HBV routines and 22 VL-HCV routines processed in 2020. As variables, 2 equipment, 3 operators and different lots of calibrators, controls, extraction kits and amplification were used.
In the first 10 evaluations, a VL-HBV log of 4.60 ± 0.21. Over the 52 routines evaluated, the mean observed was 4.62 ± 0.08, with a coefficient of variation of 2.0%. For HCV, a VL log of 4.43 ± 0.13 was observed in the first 10 evaluations, and 4.40 ± 0.08 for the 22 subsequent routines.
Abbott methodology proved to be very stable and the produced CIQ showed good stability during the analyzed period, being an economical and effective alternative for situations where it is not possible to acquire commercial CIQ.