Electron Microscopic Observation in Case of Platelet Activation in a Chronic Haemodialysis Subject

Abstract

During haemodialysis (HD), platelets (PLTs) are activated and release granule contents. 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 morphologically, 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 measurement of PLT count, PLT volume and size parameters. Blood smears were screened by light microscopy for qualitative evaluation of PLT granule containing cytoplasm, as indicated 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 granular than PLTs from a healthy reference subject. These findings support the hypothesis of PLT depletion in chronic HD subjects due to frequent PLT activation and/or increased urea concentrations.

Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro

“…An impaired α-granule release has already been reported in uraemia [18]. This is further supported by the recent observations of Schoorl et al of an increase in platelets depleted from granules in patients undergoing chronic haemodialysis [19]. Nevertheless, we cannot exclude an impairment of release.…”

Haemodiafiltration elicits less platelet activation compared to haemodialysis

“…Further studies identified platelet trapping, particularly sequestration of the larger platelets in the circuit, and suggested that soluble markers like beta-thromboglobulin are suitable for detecting platelet degranulation [ 20 ]. Another methodological approach to investigate platelet activation was published by Schoorl and colleagues, who verified platelet degranulation by light and electron microscopy [ 21 ]. Nevertheless, in more recent reports the biocompatibility of the dialyzer membranes was monitored by the platelet count and it was concluded, that the more biocompatible newer membranes like the polysulfones do not result in marked thrombocytopenia [ 22 ].…”

The evaluation of platelet indices and markers of inflammation, coagulation and disease progression in treatment‐naïve, asymptomatic HIV‐infected individuals

“…The direct correlation of the MPV with viral load in our study was supported by the findings of Mena et al . interestingly, as a host defence mechanism; platelets are capable of directly interacting and engulfing HIV virions, which may result in platelet degranulation and a decrease in both MPV levels and HIV RNA in blood .…”