Primary thrombocythaemia: a composite approach to diagnosis

Area of Science:

• Hematology
• Oncology
• Internal Medicine

Background:

• Current primary thrombocythaemia (PT) diagnosis relies on excluding other conditions.
• There is a need for positive diagnostic markers for PT.
• Distinguishing PT from reactive thrombocytosis (RT) can be challenging.

Purpose of the Study:

• To identify specific parameters that effectively discriminate between PT and RT.
• To explore potential positive diagnostic markers for PT.

Main Methods:

• Studied three patient groups: new untreated PT, treated PT, and RT.
• Assessed various parameters including ESR, fibrinogen, factor VIIIC, von Willebrand factor antigen (vWF:Ag), PDW, ATP:ADP ratio, serum erythropoietin (Epo), ristocetin cofactor (vWF:RiCoF), vWF multimeric structure, interleukin-6 (IL6), clinical ischaemia, and erythroid colony formation.
• Utilized a discriminant function (DF) based on erythroid colony assays.

Main Results:

• Acute phase reactants (ESR, fibrinogen, VIIIC, vWF:Ag) and IL6 were the strongest discriminators between PT and RT.
• PDW and serum Epo showed less discriminatory power.
• Reduced vWF:RiCoF and high molecular weight vWF multimers were associated with PT.
• Half of the PT patients, versus one RT patient, had a DF suggestive of myeloproliferative disorder.

Conclusions:

• A combination of tests, particularly acute phase reactants and vWF parameters, can support the diagnosis of PT.
• These markers offer a more positive approach to diagnosing PT in complex cases.
• Further use of these discriminatory tests may refine PT diagnosis.