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International Prognostic Scoring System

Revised International Prognostic Scoring System (IPSS-R)

The IPSS is a system used to assess risk and predict clinical outcomes in MDS. A revised version of the IPSS classification now includes 5 (instead of 3) cytogenetic prognostic factors1:

  • BM blast cell percentage, which falls into 1 of 4 categories:
    • ≤2%
    • >2%-<5%
    • 5%-10%
    • >10%
  • Cytogenetic pattern (karyotype), which is categorized into 1 of 5 definitions:
    • Very good: –Y, del(11q)
    • Good: normal, del(5q), del(12p), del(20q), double including del(5q)
    • Intermediate: del(7q), +8, +19, i(17q), any other single or double independent clones
    • Poor: –7, inv(3)/t(3q)/del(3q), double including –7/del(7q); complex: 3 abnormalities
    • Very poor: Complex: >3 abnormalities
  • Hemoglobin, with 3 cutoff points:
    • ≥10 g/dL
    • 8-<10 g/dL
    • <8 g/dL
  • Platelets, with 3 cutoff points:
    • ≥100 x 109/L
    • 50-<100 x 109/L
    • <50 x 109/L
  • ANC, with 2 cutoff points:
    • ≥0.8 x 109/L
    • <0.8 x 109/L
  • Based on these and other prognostic factors, the IPSS-R stratifies patients into risk categories by score:

  • Very low (≤1.5)
  • Low (>1.5-3)
  • Intermediate (>3-4.5)
  • High (>4.5-6)
  • Very high (>6)
FactorValueIPSS-R score
Blasts in
bone marrow
≤2% 0
Cell DNA changes (cytogenetics) Very good 0
Very poor4
Hemoglobin ≥10 g/dL 0
8-<10 g/dL1
<8 g/dL1.5
Platelets ≥100 x 109/L 0
50-<100 x 109/L0.5
<50 x 109/L1
ANC ≥0.8 x 109/L 0
<0.8 x 109/L0.5

Origins of the IPSS

Between 1982 and 1997, at least 6 risk classification systems were proposed to evaluate the potential clinical outcomes for patients with MDS. Each of these systems used differing clinical variables to classify risk, including bone marrow (BM) morphological classification, BM myeloblast percentage, BM biopsy features, specific cytopenias, age, lactate dehydrogenase level, and BM cytogenetic pattern.2

An International MDS Risk Analysis Workshop was convened to evaluate these systems and develop a consensus prognostic risk-based analysis system with greater discriminating power.3

Workshop participants performed a global analysis on the combined cytogenic, morphological, and clinical data from 816 patients with primary MDS in 7 previously reported studies that had generated prognostic systems. Critical variables were reevaluated using this data, and these analyses formed the basis of the IPSS.2,3

To access the IPSS calculator, please click here.


EXJADE reduces LIC and serum ferritin in transfused patients with lower-risk myelodyspastic syndrome.

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