Morphometry and Stereology in Immunopathology

In some immunopathology studies, subtle changes in particle density or quantity may be present that are below the ability of detection by routine histopathology. In those cases, quantitative analysis may be required to further categorize the change. Quantitative analysis can be performed in either a 2-dimenstional (histomorphometry) or 3-dimensional (stereology) fashion, and the type of data produced differ depending on the technique used. Morphometric analysis results in data expressed as densities or ratios, whereas stereological analysis results in absolute estimates. Both techniques have their place in immunopathology evaluation; however, the differences between them need to be understood and appreciated. This chapter outlines the principals and techniques involved in both histomorphometry and stereology and the type of data that are produced. Practical examples for using these techniques in immunopathology are also discussed.