BACKGROUND
Currently, the conformity assessment procedure in the form of clinical trials of medical devices for in vitro diagnostics intended for immunohistochemistry is not sufficiently standardized. In this regard, the relevance of studies aimed at development of optimal methodological approaches to testing such devices in medical organizations is beyond doubt.
AIM
To improve the methodology for conducting clinical trials of an instrument for immunohistochemical staining included in the set of medical devices for in vitro diagnostics that are intended for identification of both well-known and new markers of malignant neoplasms when staining human tissues in automatic and manual mode (using the immunostainer manufactured by «Shenzhen Dartmon Biotechnology Co., Ltd.» (China) as an example).
MATERIALS AND METHODS
The analytical systems under test (AST) included several products manufactured by Shenzhen Dartmon Biotechnology Co., Ltd.: «Dartmon AS Automatic Immunostainer with accessories, in variants», «Set of auxiliary cleaning and washing buffer solutions for conducting immunohistochemical studies for in vitro diagnostics for automated use on Dartmon AS series Automatic Immunostainer, 4 pcs./pack», «Set of reagents for detecting target cells (antigens) in conducting immunohistochemical studies for in vitro diagnostics (Immunochromogenic Reagent), in variants», as well as one of the primary antibodies or a panel of primary antibodies (PAT-Dartmon). Primary antibodies manufactured by «Cell Marque Corporation» (PAT-CM) were also tried in AST. The following medical devices were used for comparison (as parts of the analytical comparison systems (ACS)): «Immunohistochemical and Immunocytological Staining Instrument (versions: 360, 480S, 720) Autostainer with accessories»; «Ventana BenchMark Ultra Automatic Immunostainer, with accessories». Formalin-fixed, paraffin-embedded (FFPE) tumor tissues from different organs were used to make micropreparations.
RESULTS
Repeatability and reproducibility of automatic staining on the two tested instruments were 100% when examining serial sections from positive and negative FFPE samples using PAT-Dartmon to Vimentin (the latter were included in the composition of the immunostainer). When assessing clinical performance of the instrument using PAT-CM, the results of staining by AST in all cases coincided with those obtained by ACS. Clinical efficiency of AST was confirmed in joint trials of the instrument with PAT-Dartmon.
CONCLUSION
The functional characteristics that need to be verified at the stage of clinical trials of an instrument for automatic immunohistochemical staining within the state registration procedure were studied. Methodological approaches to assessing clinical performance of the immunostainer and clinical efficiency of AST which includes this instrument are proposed. The possibility of using the term «clinical performance» when assessing conformity of instruments for in vitro diagnostics in clinical trials is discussed.
