Table 1.

Risk stratification schemes for myelofibrosis involving clinical and genetic factors.

	IPSS	DIPSS-Plus	MIPSS70	MYSEC	GIPSS
Genetic factors	−	unfavorable karyotype (+8, −7/7q−, i(17q), inv(3), −5/5q−, 12p− or 11q23)	absence of CALR type 1 mutations presence of 1 or more HMR mutations (ASXL1, EZH2, SRSF2, IDH1/2)	absence of CALR mutations	absence of CALR type 1/like mutations presence of ASXL1, SRSF2, U2AF1Q157 mutations unfavorable karyotype
Clinical factors	age >65 hemoglobin <100 g/L WBC > 25 × 109/L circulating blasts ≥1% constitutional symptoms	age >65 hemoglobin <100 g/L WBC > 25 × 109/L circulating blasts ≥1% constitutional symptoms need for RBC transfusion platelets < 100 × 109/L	hemoglobin <100 g/L WBC > 25 × 109/L platelets < 100 × 109/L circulating blasts ≥2% fibrosis grade ≥2 constitutional symptoms	age at diagnosis hemoglobin <100 g/L platelets < 150 × 109/L circulating blasts ≥3% constitutional symptoms	−
Risk category (points)	low (0) intermediate-1 (1) intermediate-2 (2) high (3)	low (0) intermediate-1 (1) intermediate-2 (2–3) high (≥4)	low (0–1) intermediate (2–4) high (≥5)	low (0) intermediate-1 (1) intermediate-2 (2) high (≥3)	low (0) intermediate-1 (1) intermediate-2 (2) high (≥3)
Target patients	MF patients at diagnosis	MF patients at diagnosis and at any time point during clinical course	MF patients at evaluation for allogeneic HSCT	post-ET and post-PV myelofibrosis patients	PMF patients

IPSS: international prognostic scoring system, DIPSS: dynamic international prognostic system, MYSEC: myelofibrosis secondary to PV and ET-prognostic model, MIPPS70: mutation-enhanced international prognostic score system (validated up to 70 years of age), GIPSS: genetically inspired prognostic scoring system.