Flow Cytometric Analysis of Platelet Surface Glycoproteins in the Diagnosis of Bernard-Soulier Syndrome

Abstract

The use of flow cytometry in the diagnosis of Bernard-Soulier syndrome (BSS) in patients with giant platelets and thrombocytopenia was investigated as an adjunct to ristocetin-induced platelet aggregation (RIPA) studies because of problems experienced with aggregation studies, particularly at the time of presentation, in the pediatric age group. Eight patients suspected of having BSS were studied with respect to platelet expression of glycoprotein Ib alpha (CD42b) and glycoprotein IIIa (CD61) using an EPICS Profile II flow cytometer. Twelve patients with normal platelet morphology and platelet counts were used as normal controls. One patient with Alport's syndrome, four patients with immune thrombocytopenic purpura (ITP), and one patient with Glanzmann thrombasthenia were also studied. In all eight patients suspected of having BSS, deficiency of glycoprotein Ib alpha was demonstrated. Normal expression was demonstrated in 12 control patients, in one patient with giant platelets with Alport's syndrome, and in four patients with ITP. Absence of glycoprotein IIIa was demonstrated in Glanzmann thrombasthenia. In the pediatric age group one is able to demonstrate abnormalities of platelet membrane glycoprotien in patients with thrombocytopathias using flow cytometry. This method has the advantage of being rapid and can be performed on small volumes of blood suitable for pediatric practice.

The Level of Laboratory Testing Required for Diagnosis or Exclusion of a Platelet Function Disorder Using Platelet Aggregation and Secretion Assays

“…39 Flow cytometry is commonly used to diagnose deficiencies of platelet surface glycoproteins (e.g., Glanzmann thrombasthenia 121 or Bernard-Soulier syndrome). 122 Other assays have been developed to assess the platelet dense granules by measuring fluorescence emitted by mepacrine-labeled platelets. 103 Flow cytometry is also being used to evaluate platelet microparticle formation and the exposure of anionic phospholipids, 123,124 phenomena that are associated with platelet PCA.…”

Platelet preparation for function testing in the laboratory and clinic: Historical and practical aspects

“…Quantification of platelet membrane glycoproteins (GPs) is widely used in diagnosis and research laboratories . Commercial kits are now available to quantify the major platelet GPs, including αIIbβ3, the GPIb‐V‐IX complex, and α2β1.…”

“…widely used in diagnosis and research laboratories. 31,32 Commercial kits are now available to quantify the major platelet GPs, including αIIbβ3, the GPIb-V-IX complex, and α2β1. Other commercial kits can be used to quantify any platelet receptor (Platelet Calibrator, BioCytex, Marseille, France), for example, GPVI, provided a monoclonal antibody against the target protein is available.…”

How we treat the platelet glycoprotein defects; Glanzmann thrombasthenia and Bernard Soulier syndrome in children and adults

“…Flow cytometry has several advantages over LTA. FCA is less prone to pre‐analytical variables, can be performed at very low platelet counts and requires a smaller volume of sample, making it particularly appropriate for the investigation of neonates, infants and young children (Cohn et al , ). Finally, it is possible to identify the genetic abnormality by molecular genetics in both BSS and GT, thus making antenatal diagnosis possible for many affected families.…”