Two Methods for Intraplatelet Serotonin Evaluation: Their Use in Thrombocytosis

Abstract

The content of platelet dense bodies is considered to be decreased in thrombocytosis associated myeloproliferative disorders and normal in reactive thrombocytosis. Intraplatelet serotonin i.e., 5-hydroxytryptamine (5HT), content is usually considered a particularly good marker. We report our experience of platelet 5HT levels evaluated by radioimmunoassay (RIA) and fluorimetric assays in patients with high platelet counts due to essential thrombocythemia (48 patients) or reactive thrombocytosis (34 patients). The diagnosis of essential thrombocythemia was made according to Polycythemia Vera Study Group criteria. A significant statistical difference was observed in serotonin platelet content between essential thrombocythemia and secondary thrombocytosis patients both with fluorimetric and RIA assays. On the contrary, no difference was evident between reactive thrombocytosis patients and normal control subjects. However, a significant difference was observed between 5HT in serum and platelet pellets when evaluated by RIA. Statistical analysis with the X² test showed that the sensitivity of the fluorimetric assay is slightly higher than that of the RIA assay; however, specificity is about the same with the two methods. It is possible that the two assays measure different molecules. At any rate, the fluorimetric assay seems to be better in evaluating the platelet content of 5HT at least in patients with high platelet counts. Key Words: Thrombocytosis—Serotonin.

Get full access to this article

View all access options for this article.

References

Bamhart MI Platelet responses in health and disease. Mol Cell Biochem 1978;22:113-37.

Vatassery GT , Sheridan MA , Krezowski AM Spectrophotofluorimetry of serotonin in blood platelets. Clin Chem 1981;27:328-30.

Sneddon JM Relationship between internal Na/K and the accumulation of 14-C-hydroxytryptamine by rat platelets. Br J Pharmacol 1971;43:834-44.

Drummond AH Interactions of blood platelets with biogenic amines: uptake, stimulation and receptor binding. In. Gordon JL , ed. Platelets in biology and pathology. Amsterdam : Elsevier, 1976:209-39.

Zucher S. , Mielke H. Classification of thrombocytosis based on platelet function test: hemorrhagic and thrombotic complications. J Lab Clin Med 1972 ;80:385-93.

Fabris F. , Randi ML , Casonato A. , Dal Bo Zanon R. , Bonvicini p , Girolami A. Clinical significance of beta-thromboglobulin in patient with high platelet count. Acta Hematol 1984;71:32-8.

Hindberg I. An improved specific and sensitive radioenzymatic method for determination of serotonin concentration in biological fluids (radioenzymatic serotonin method). Scand J Clin Lab Invest 1984;44:47-51.

Manz B. , Kosfeld H. Harbauer G. , Grill HJ , Pollow K. Radioimmunoassay of human serum serotonin. J Clin Chem Clin Biochem 1985;23:657-62.

Udenfriend S. , Weissbach H. , Clarck CT The estimation of 5-hydroxytryptamine (serotonin) in biological tissues. J Biol Chem 1955;215:337-44.

10.

Artigas F. , Sarrias MJ , Martinex E. , Gelpi E. Serotonin in body fluids: characterization of human plasmatic and cerebrospinal fluid pools by means of a new HPLC method. Life Sci 1985;37:441-7.

11.

Berlin NI Diagnosis and classification of polycythemias. Sem Hematol 1975;12:339-51.

12.

Murphy S. Thrombolyctosis and thrombocythennas. Clin Hematol 1993;12:89-106.

13.

Fabris F. , Randi ML , Sbrojavacca R. , Casonato A. , Girolami A. The possible value of platelet aggregation studies in patients with increased platelet number. Blut 1981;43:279-85.

14.

Caranobe C. , Sie P. , Nouvel C. , Laurent G. , Pris J. , Boneau B. Platelets and myeloproliferative disorders: serotonin uptake and storage. Scand J Hematol 1980;25:289-95.

15.

Hinori T. , Tokishi H. , Mikio T. , Yoshiyuki H. , Shigeru O. , Nobuhiko T. High performance liquid-chromatographic analysis for serotonin and tryptamine excreted in urine after oral loading with L-tryptophan. Clin Chem 1989;35:43-7.

16.

Anthony M. Serotonin, and cyclic nucleotides in migraine. Adv Neurol 1982;33:45-9.

17.

Emson PC , Martenson H. , Nabin A. Elevated concentrations of substance P and 5HT in plasma in patients with carcinoid tumors. Cancer 1984;54:705-18.

18.

Dreux C. , Launay JM , Gamen YJ ; Les tumeurs neuroendocriniennes. Ann Biot Clin 1987;45:495-507.

19.

Randi ML , Stocco F. , Tison T. , Fabris F. , Girolami A. Use of a radioimmunoassay for 5-hydroxytryptamine (5-HT) in thrombocytosis . Blood Coag Fibrinol 1991;2:205-8.