Validation of methodologies for quantifying isolated human islets: an Islet Cell Resources study

Clin Transplant. 2010 Mar-Apr;24(2):236-42. doi: 10.1111/j.1399-0012.2009.01052.x. Epub 2009 Aug 30.


Background: Quantification of islet mass is a crucial criterion for defining the quality of the islet product ensuring a potent islet transplant when used as a therapeutic intervention for select patients with type I diabetes.

Methods: This multi-center study involved all eight member institutions of the National Institutes of Health-supported Islet Cell Resources Consortium. The study was designed to validate the standard counting procedure for quantifying isolated, dithizone-stained human islets as a reliable methodology by ascertaining the accuracy, repeatability (intra-observer variability), and intermediate precision (inter-observer variability). The secondary aim of the study was to evaluate a new software-assisted digital image analysis method as a supplement for islet quantification.

Results: The study demonstrated the accuracy, repeatability and intermediate precision of the standard counting procedure for isolated human islets. This study also demonstrated that software-assisted digital image analysis as a supplemental method for islet quantification was more accurate and consistent than the standard manual counting method.

Conclusions: Standard counting procedures for enumerating isolated stained human islets is a valid methodology, but computer-assisted digital image analysis assessment of islet mass has the added benefit of providing a permanent record of the isolated islet product being evaluated that improves quality assurance operations of current good manufacturing practice.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Validation Study

MeSH terms

  • Cell Separation / methods
  • Cell Size
  • Delphi Technique
  • Flow Cytometry
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Islets of Langerhans / cytology*
  • Islets of Langerhans Transplantation* / methods
  • Reproducibility of Results