1	absence of hepatomegaly (enlarged liver), regular iron chelation before transplant, absence of fibrosis in pretransplant liver biopsy result
2	hepatomegaly, a history of irregular iron chelation before transplant, histological evidence of liver fibrosis, or various combinations of the above
3	all of the following: large liver, poor compliance with chelation therapy, liver damage
4	class 2 or 3, irregular iron chelation, with a range of clinical symptoms and other diagnoses