Morphologic quantification of blood platelets by image analysis

For morphologic and functional investigations on the physiology and pathology of human blood platelets, their adhesion plays an important role. This feature is normally assessed concerning qualitative aspects, but there is a lack of quantitative investigations.

We developed a model to quantify in vitro manipulations on thrombocytes by measuring their adhesion areas automatically. This was achieved by combining the VIDAS 2.5 image analysis system with reflection contrast microscopy (RCM). The evaluation was performed independent of the position of the grey value histogram by analyzing each digitized image corresponding to its individual mean grey value.

The applicability and validity were verified from the example of a pharmacologic experiment administering the platelet stimulant oxidized low density lipoprotein (ox-LDL) to thrombocyte suspensions and confirming it by aggregometry. We assessed the temporal increase in adhesion area and mean total adhesion area of activated platelets, comparing unstimulated to stimulated ones. Ox-LDL accelerated the adhesion process and increased the adhesion area.

The combination of RCM with consecutive image analysis provides useful parameters for in vitro examination on vital human platelets. Large amounts of data can be accumulated in a short time for an evaluation of influences of and on blood platelets.