Erythrokinetic Studies in Myelofibrosis: Their Significance for Prognosis

Abstract

Eighty-three patients with myelofibrosis have been studied by erythrokinetics and have been followed up until death or for at least 12 months. Because of a large plasma volume the venous haematocrit gives only a poor idea of the red blood cell volume. The red cell survival was reduced in the majority of cases but significant haemolysis was rare. The amount of haemolysis of autologous and isologous red cells was similar, suggesting an extra-corpuscular origin for the haemolysis. Plasma iron turnover was always increased, sometimes markedly, but red cell iron incorporation was reduced in 70% of cases, indicating ineffective erythropoiesis. Surface counting showed an absence on diminution of sacral iron fixation and a rapid and marked splenic uptake in more than 90% of the cases; uptake of iron by the liver occurred in half the cases, usually not very high; iron release from the spleen was absent or reduced in 67% of the cases. The degree of ineffective erythropoiesis as measured by radio-iron incorporation and release by the spleen, the amount of haemolysis, and the red cell volume were strongly correlated with prognosis. These factors enabled a more precise prediction to be made of the clinical outcome in the 2 years following the study, than the clinical data alone. A prospective study might show whether erythrokinetic studies are also useful in determining the choice of treatment.

Life expectancy and prognostic factors in the classic BCR/ABL-negative myeloproliferative disorders

“…13,14,27,30,36 A correlation has been observed between decreased erythropoiesis at isotopic studies and shorter survival. 7,37 Bone marrow histologic findings did not have prognostic relevance in most studies. 12,38,39 A pattern of red cell aplasia in a cellular bone marrow has been associated with a more unfavourable outcome.…”

Polycythemia vera: myths, mechanisms, and management

“…An additional difficulty in this regard, as discussed above, is the definition of myelofibrosis; a dry tap or increased reticulin is not sufficient for this purpose. 158,179 Finally, implicit in this contention is the notion that myelofibrosis is deleterious in polycythemia vera, when in fact it is perfectly compatible with normal bone marrow function, 134,155,181,183 is a reversible process, 168,175,[184][185][186] and has not been shown to impact adversely on survival. 150,174,177 Indeed, failure to recognize polycythemia vera presenting as myelofibrosis is potentially more deleterious than the development of myelofibrosis during the course of the disease.…”

“…Within the limitations of these data, it appears that increased marrow reticulin is part of the natural history of the disease, presumably reflecting in part the increase in marrow cellularity 158,179 and possibly disease duration. 180 However, an increase in marrow reticulin, or even osteosclerosis, is certainly not synonymous with a "spent" phase 75,134,135,155,158,[181][182][183] and can be modified to a certain extent by therapy, 75 particularly with busulfan. 182,184 Spontaneous regression of myelofibrosis has also been observed, 168,175,182,185,186 although the patchy nature of the process makes this observation as difficult to substantiate as the contention that myelofibrosis is a progressive and destructive process.…”

Spontaneous Remission of Agnogenic Myeloid Metaplasia in a Splenectomized Patient: A Case Report with Erythrokinetic Studies

“…Increased plasma iron turnover and reduced red cell iron utilization were interpreted as indicating ineffective erythropoiesis [7,8]. Red cell survival was reduced, and hemolysis was moderate (3.21%/day).…”

“…Knee Pubis Xiphoid Chin Head Umbilicus ropoiesis with subsequent red cell sequestration in the spleen and loss of normal sacral and vertebral bone marrow erythropoiesis with expansion of erythroid marrow activity in the tibia [7,8].…”