Production and Performance Evaluation of External Quality Assessment Materials for Human Epididymis Protein 4 Assay / 임상검사와정도관리

ABSTRACT

BACKGROUND: External quality assessment (EQA) is important for standardizing cancer biomarker assays, thereby, ensuring accurate and precise results. Although the human epididymis-specific protein 4 (HE4) assay has been increasingly used to detect and monitor ovarian malignancy in Korea, a nation-wide EQA program for HE4 has not been appropriately established. To conduct an EQA program, a large amount of quality control (QC) materials are required. This study aimed to produce HE4 QC materials for an EQA program and evaluate their homogeneity and stability. METHODS: QC materials for three different concentrations of HE4 were produced from the collected remnant sera of 275 patients for whom the HE4 assays were performed. These materials were evaluated for homogeneity between vials and stability during storage. The frozen QC materials were distributed to 13 representative organizations for a provisional EQA. RESULTS: The total coefficient of variation of the HE4 QC materials of three concentrations was 0.75%–1.24%, and no significant differences were noted between vials; therefore, the samples were considered to be homogenous. With respect to stability, the HE4 QC materials were found to be stable till 30 days when frozen and for 24 hours when refrigerated. The results of the provisional HE4 EQA were reviewed and the survey results were reported to each participant. CONCLUSIONS: The HE4 QC materials produced from remnant specimens were found to be homogenous between vials and stable in a frozen condition until 30 days. The findings of this study may be practically applied for establishing a future HE4 EQA program.