Myeloproliferative Neoplasms with Monocytosis

Area of Science:

• Hematology
• Oncology
• Stem Cell Neoplasms

Background:

• Myeloproliferative neoplasms (MPN) encompass polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF).
• These conditions stem from shared driver mutations (JAK2/CALR/MPL) activating JAK/STAT pathways, leading to shortened survival and leukemia risk.
• Current risk stratification uses mutation-enhanced scoring systems (e.g., MIPSS70-plus v2.0).

Purpose of the Study:

• To review the clinical and pathological features of MPN associated with monocytosis.
• To elucidate the prognostic significance of monocytosis in MPN.

Main Methods:

• Review of recent studies on MPN with monocytosis.
• Analysis of clinical and genetic parameters in PV and PMF patients with elevated monocyte counts.

Main Results:

• Monocytosis (absolute monocyte count ≥ 1 × 10^9/L) occurs in 21% of PV and 17% of PMF patients.
• MPN patients with monocytosis are older, have leukocytosis, and specific genetic/cytogenetic abnormalities (e.g., +8, SRSF2 in PV; ASXL1 in PMF).
• Monocytosis is linked to unfavorable outcomes, including inferior survival in both PV and PMF.

Conclusions:

• Monocytosis in MPN is associated with a distinct clinical and genetic profile.
• The presence of monocytosis may signify more aggressive disease biology in MPN.
• Monocytosis serves as a prognostic marker for inferior survival in PV and PMF.