Can circulating CD34⁺ cell count be used for the prognosis of myelofibrosis?

Abstract

We read with great interest the findings of the Iurlo et al. 1 prospective cohort study, where the number of circulating CD34 + cells increased briefly and then returned to the pretreatment level during ruxolitinib treatment. Furthermore, the authors found a positive correlation between the change in the number of circulating CD34 + cells and the degree of splenomegaly during the first 6 months of treatment.A relative circulating CD34 + cell count of 0.015 × 10 9 /L is the most frequently used criterion to discriminate between myelofibrosis (MF) and other myeloproliferative neoplasms. However, whether and how the circulating CD34 + cell count can be used in the treatment and prognosis of MF remain unclear, requiring further supporting data. The following points may provide some clarity.

Reply to: Can circulating CD34+ cells count be used for the prognosis of myelofibrosis? Probably yes, at least in patients treated with ruxolitinib

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We have read with great interest the letter of Zhang et al 1 in response to our recent prospective cohort study evaluating CD34+ cells count in patients with primary or secondary myelofibrosis (PMF/SMF) during ruxolitinib treatment. 2 Our main focus was to examine any association between circulating CD34+ cells count and spleen response; consequently, we did not draw any definitive conclusion on their potential impact on MF prognosis as it required further supporting data.However, we have attempted to address the important points raised by Zhang et al

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