Quantification of IGF-1 Receptor Is Useful in the Differential Diagnosis of Essential Thrombocytosis from Reactive Thrombocytosis

Abstract

To make a definite diagnosis of essential thrombocytosis (ET) from reactive thrombocytosis (RT), the most reliable criteria are the presence of driver mutations, namely JAK2, CALR, or MPL gene mutations. In the absence of these driver mutations, so-called triple-negative ET, the differential diagnosis could be difficult; bone marrow biopsy could be helpful, but in some cases it may be difficult, to do gene sequence analysis to find other clonal marker gene mutations than the driver mutations, only very few were found. We studied IGF-1R quantification by flow cytometry in mononuclear cells (MNC) from peripheral blood, a substitute for performing endogenous erythroid colony formation (EEC), in 33 patients with ET (untreated or off treatment with hydroxyurea), 28 patients with RT, and 16 normal volunteer controls. We found IGF-1R levels significantly elevated in ET patients compared to RT patients or controls. A cutoff value of 253 was chosen from the logistic regression to predict each patient's group, a value ≥253 meant that a patient belonged to the ET group (sensitivity of 68.6% and specificity 96.4.%). Therefore, we suggest adding quantification of IGF-1R in blood MNC by flow cytometry is useful in differentiating ET from RT , we suggest this maybe added to the minor criteria for diagnosing ET. Funding Statement: JCW received grants from Celgen Corp. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Declaration of Interests: The author declares no conflicting interests with the commercial funder relating to using products, consultancy, patents, product development, or market products. The other authors declare no competing financial interests. Ethics Approval Statement: Peripheral blood was obtained from patients with written informed consent, the protocol for which was approved by the IRB of Brookdale University Hospital.