Familial ITP is very rare so if a FH exists, think about hereditary platelet disorders. Get historical plt counts and bleeding challenge history.
Investigations:
– FBC, film, coagulation, fibrinogen, von Willebrand screen, malaria screen, haematinics initially.
– Platelet function testing – PFA 100 – uses whole blood. 2 cartridges with differing agonists. Read out is the time for aperture closure.
– Light transmission aggregation testing – uses platelet rich and poor plasma. Individual agonists used in each cuvette (BSH guidance advises on profile to use). When the platelets aggregate, more light transmits through. Compare to control. Published normal reference ranges don’t exist.
– Secretion assays.
– Flow cytometry for glycoprotein expression to confirm Glanzmanns and Bernard Soulier
– Genetics – haemostatic gene panel on NHS available later in the year.
Conditions covered include storage pool disorders (alpha and dense), glycoprotein deficit disorders, MYH9 syndrome, TAR, Wiskott Aldrich.
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