The following techniques are not available as diagnostic tests but have been used in research settings to evaluate the presence or absence of dense granules in blood platelets.

Measuring Platelet Serotonin (5-HT)

The dense granules of platelets contain a number of chemicals including serotonin.  Due to the absence of dense granules in HPS platelets the level of serotonin found is typically extremely low.  This property has been used as an indirect measure of the presence \ absence of dense granules.

Platelet Serotonin reference ranges:

ELISA – Enzyme Linked Immunoabsorbent Assay

Given the near absence of Serotonin it can be used as a marker for HPS. Commercially available ELISA kits can be used on a research basis to measure the level of serotonin present in PRP.   None, however, are currently licensed \ approved as a diagnostic test for HPS.

Flow Cytometry

Ceroid lipofucin – a simple marker

Ceroid Lipofucin is a yellow autofluorescent, amorphous lipid-protein complex.  It is typically found in the  urinary sediment and parenchymal and cheek cells of patients who have HPS.


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Research based tests for Hermansky-Pudlak Syndrome