Abstract
Inherited platelet function disorders (IPFDs) manifest with mucocutaneous bleeding
and are frequently difficult to diagnose due to their heterogeneity, the complexity
of the platelet activation pathways and a lack of standardization of the platelet
function laboratory assays and of their use for this purpose. A rational diagnostic
approach to IPFDs should follow an algorithm where clinical examination and a stepwise
laboratory evaluation play a crucial role. A streamlined panel of laboratory tests,
with consecutive steps of increasing level of complexity, allows the phenotypic characterization
of most IPFDs. A first-line diagnosis of a significant fraction of the IPFD may be
made also at nonspecialized centers by using relatively simple tests, including platelet
count, peripheral blood smear, light transmission aggregometry, measurement of platelet
granule content and release, and the expression of glycoproteins by flow cytometry.
Some of the most complex, second- and third-step tests may be performed only in highly
specialized laboratories. Genotyping, including the widespread application of next-generation
sequencing, has enabled discovery in the last few years of several novel genes associated
with platelet disorders and this method may eventually become a first-line diagnostic
approach; however, a preliminary clinical and laboratory phenotypic characterization
nowadays still remains crucial for diagnosis of IPFDs.
Keywords
bleeding - diagnostic algorithm - genetic testing - inherited platelet function disorders
- laboratory investigation