Evaluation of Platelet Tests for Measurement of Cell Integrity

Abstract

SummaryVarious tests were evaluated for their capacity to differentiate between platelet suspensions with different degrees of cell damage. Those suspensions were prepared by simultaneous isolation of platelets from the same platelet-rich plasma (PRP) using the following procedures:1. centrifugation at 4°C with EDTA2. gel filtration in Tangen’s buffer3. gel filtration in Ca2+-free Tyrode’s solution4. gel filtration in Ca2+-free Tyrode followed by dehydration against polyethylene glycol 20,000 and5. albumin density gradient centrifugation.In these suspensions and in the original PRP the following parameters were studied: 1. morphology; 2. aggregability upon ADP addition; 3. platelet factor 3 availability; 4. uptake of 14C-serotonin and 3H-adenine; 5. metabolism of 3H-adenine and adenylate energy charge; 6. endogenous total ATP, ADP and serotonin and 7. lactate dehydrogenase (LDH) activity.Quantitation of pseudopod formation in the light or electron microscope and log dose response studies for ADP-induced aggregation proved to be the most sensitive and reproducible of the tests studied. Additional information could be obtained from measurement of the 3H-label in the ATP and hypoxanthine-inosine fractions and calculation of the adenylate energy charge. Determination of platelet factor 3 availability or uptake studies of 14C-serotonin and 3H-adenine were less suitable for discriminating between cell suspensions. Data for total ATP and serotonin concentrations and LDH activity differed between the cell suspensions but instead of detecting various degrees of cell damage they reflected alterations in platelet population caused by the isolation procedures.

Altered red cell and platelet adhesion in hemolytic diseases: Hereditary spherocytosis, paroxysmal nocturnal hemoglobinuria and sickle cell disease

“…A contribution of other additional factors to elevated LDH levels in PNH should not be overlooked. For example, other non-hemolytic clonal diseases, such as myelodysplatic syndromes, present elevated LDH, which appears to be an important prognostic marker [28], and LDH is a known marker of tissue and cell injury [29]. Whilst hemolysis is common to HS, PNH and SCD, we found cell adhesive functions to vary between diseases.…”

Alterations in 32P-labelled intermediates during flux activation of human platelet glycolysis

“…Measurement of the specific radioactivity of the various spots confirmed that the 32p measurement was a true reflection of the quantities of the various fractions [10]. Spectrophotometric analysis of Fru-2,6-P 2 was carried out according to the method of van Schaftingen et al [13] in alkaline extracts of gel-filtered platelets as well as in extracts of concentrated platelet suspensions obtained by repeated centrifugation-resuspension in EDTA-containing Ringer solution [14].…”

Shape and Functional Properties of Human Platelets Washed with Acid Citrate

“…The platelets washed with acid citrate exhibit hardly any pseudopods. Besides their functional integrity, the platelets washed with acid citrate thus exhibit ultrastructural features (1,13,28,31) which also indicate maintenance in morphology.…”

“…Quantification of pseudopod formation proved to be one of the most sensitive tests of platelet integrity (1). The platelets washed with acid citrate exhibit hardly any pseudopods.…”