Table 1 Deriving the PNH risk-factor score

Observed LDH category

LDH < 1.5×ULN

2

LDH 1.5–< 3×ULN

4

LDH ≥ 3xULN

6

Observed pRBC stratum

0 unit pRBC

NA

1–14 units pRBC

NA

> 14 units pRBC

NA

Immuno-suppressant treatment

No

1

Yes

2

Aplastic anemia

No

1

Yes

2

Myelodysplastic syndrome

No

1

Yes

2

Bone marrow disorder

No

1

Yes

2

Summary score creation

Sum all assigned values

Sum assigned values for observed LDH, Immuno-suppressant treatment, aplastic anemia, myelodysplastic syndrome, and bone marrow disorder

Create PNH risk-factor group

Lower

6–8

Higher

9–12