Electron microscopic observation in case of platelet activation in a chronic haemodialysis subject

Abstract

During haemodialysis (HD), platelets (PLTs) are activated and release granule con-tents. As HD treatment occurs three times a week, it has been demonstrated that PLTs are exhausted due to the repetitive character of the treatment. To identify PLT depletion mor-phologically, PLT evaluation was performed by light microscopy and electron microscopy (EM) in a chronic HD subject and a healthy reference subject. Blood samples were taken before the start of HD treatment for measure-ment of PLT count, PLT volume and size parameters. Blood smears were screened by light microscopy for qualitative evaluation of PLT granule containing cytoplasm, as indicat-ed by its staining density. Morphological PLT parameters of surface area and size of dense bodies were assessed by EM. Data were compared with results of a group of 20 chronic HD subjects and a group of 20 healthy reference subjects. With respect to the percentage of PLTs with appropriate staining density (>75%), light microscopic evaluation showed that this value (9%) was within the range of a group of chronic HD subjects, but considerably below the reference range (70%). EM evaluation revealed an average PLT surface area and dense bodies area of respectively 42% and 31%, if the healthy reference subject was set on 100%. PLTs from a chronic HD subject are considerably smaller and substantially less granu-lar than PLTs from a healthy reference subject. These findings support the hypothesis of PLT depletion in chronic HD subjects due to fre-quent PLT activation and/or increased urea concentrations.