This says that these people are 'human models' of
pyruvate kinase deficiency. 
They are all iron loading THEN they 'catch' it.
IE: leukemia being treated with iron chelators.
Polycythemia is an iron loading disease treated by 
phlebotomy.
Iron before the protein kinase deficiency ..
Acquired pyruvate kinase deficiency with hemolysis in preleukemia
Authors: V Helmstädter, H Arnold, K G Blume, N Uhl, W Hunstein
Impact factor: 1.35, Cited half life: 7.8, Immediacy index: 0.17
Journal: Acta Haematologica
Acquired erythrocyte pyruvate kinase deficiency may appear as a 
symptom secondary to various hematologic disorders, e.g. acute 
leukemia, sideroblastic anemia, polycythemia vera. 
The case of a 68-year-old patient with PK deficiency (1.75 U/g Hb) 
and severe hemolytic anemia is presented, who 1 year later showed 
acute myeloid leukemia. 
It is considered that a dialysable inhibiting factor may play a 
pathogenetic role in this enzyme change since enzyme activity was 
raised by dialysis. 
A survey of the literature is presented.
Acta haematologica. 01/02/1977; 57(6):339-43.
ISSN: 0001-5792