· Thrombotic risks for patients with MF are numerous and have been incorporated into several ‘prognostic scoring systems’. Current MF prognostic scoring systems are:
o Mutation-enhanced International Prognostic Scoring System developed for transplant-age patients ≤70 years of age (MIPSS70) and the MPISS70+ which includes additional cytogenetic information.
· World Health Organisation (WHO includes six clinical risk variables and two genetic variables:
o Haemoglobin <10 g/dL
o White blood cells >25´109/L
o Platelets <100´109/L
o Circulating abnormal cells ≥2%
o Bone marrow fibrosis grade ≥2
o Clinical symptoms
o Five high-risk mutations:
– ASXL1 (Additional Sex Combs Like-1)
– SRSF2 (Serine and Arginine Rich Splicing Factor 2)
– EZH2 (Enhancer of zeste homolog 2)
– IDH1 (Isocitrate dehydrogenase 1)
– IDH2 (Isocitrate dehydrogenase 2)
o One favourable mutation (CALR type 1/like).
o MIPSS70 risk factors were used to compose three risk categories:
– Low
– Intermediate
– High
· MIPSS70+ includes the same list of mutations but only three clinical risk factors which are:
o Haemoglobin <10 g/dL
o Circulating abnormal cells ≥2%
o Clinical symptoms
o MIPSS70+ includes a two-tiered cytogenetic risk variable (unfavourable v favourable).
o MIPSS70+ risk factors are combined to create 4 risk categories for patients with MF:
– Low
– Intermediate
– High
– Very high· Recent research into the genetics of MF has resulted in the development of MIPSS70+ version 2.0 that addresses the fact that MIPSS70+ does not include the additional prognostic distinction between very-high-risk
