A novel immunocytochemical assay for the detection of serotonin in platelets.
A method for the rapid, inexpensive and easy detection of platelet serotonin (5-hydroxytryptamine, 5-HT) is not currently available. Consequently, many patients suffering from unresolved platelet-related bleeding disorders are not examined for a possible platelet 5-HT deficiency. The direct measurement of 5-HT concentration with high-performance liquid chromatography (HPLC) or serotonin enzyme-linked immunosorbent assay (ELISA) is costly and highly demanding. Indirect methods, which determine the content of ATP or calcium with lumi-aggregometry or electron microscopy, rely upon the assumption that the ATP or calcium concentration is equivalent to that of 5-HT. We have developed a fluorescence-based assay for 5-HT that can be performed within 2 h on fresh or frozen samples using a fluorescence microscope or a flow cytometer. The assay requires only 0.2 ml of platelet-rich plasma and might therefore be of particular interest for paediatric patients. Samples from control and patient donors were analysed for 5-HT with the new immunocytochemical assay in comparison with HPLC and/or 5-HT ELISA. Patients with Hermansky-Pudlak syndrome were readily identified. The new assay was also reliable in cases where the 5-HT content of dense granules was not correlated with the calcium or ATP content, such as in calcium deficiency or in the presence of selective serotonin reuptake inhibitors.
Maurer-Spurej
Elisabeth
E
Canadian Blood Services, University of British Columbia, Department of Pathology, Vancouver, BC, Canada. emaurer@interchange.ubc.ca
Dyker
Kate
K
Gahl
William A
WA
Devine
Dana V
DV
D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000737:chemistry* / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D022861:Hermanski-Pudlak Syndrome / Q000175:diagnosis*; D006801:Humans; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D012701:Serotonin / Q000097:blood*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology
D015415:Biomarkers; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors