Pure erythrocytosis: Reappraisal of a study of 51 cases

Abstract

Fifty-one cases of pure, primary erythrocytosis were identified and followed at Hôpital Saint-Louis, Paris, and compared with 350 cases of polycythemia vera (PV) observed during the same period. At the initial evaluation, these cases did not differ from PV cases with respect to age, sex ratio, degree of red cell volume increase, and clinical symptoms. They did differ by the absence of splenomegaly, granulocytosis and thrombocytosis. At a late stage of evolution only a few cases developed classical criteria of PV. From this group of apparently homogeneous cases, two subgroups evolved. Sixty percent of the cases were highly responsive to myelosuppression with 32P. The median duration of the first remission was greater than five years, the mean yearly dose of 32P was very low, and there was a low incidence of complications. The other group (40% of cases) was relatively resistant to myelosuppressive agents. The development of better methods of investigate this disorder might help in discriminating these two groups from both an etiological and pathophysiological viewpoint. The thromboembolic risk of these diseases suggests that myelosuppressive therapy should be utilized in older patients with higher risk of vascular accidents, reserving phlebotomy for younger patients and those who are shown to be resistant to 32P therapy.

Prodromal myeloproliferative neoplasms: The 2008 WHO classification

“…Although it is certainly difficult to tackle the very beginning of PV, it is tempting to assume that in the series of patients previously described to present idiopathic (pure, benign) erythrocytosis or an occult/smouldering PV, a considerable number may be consistent with initial disease manifestations [63][64][65][66][67], but particularly those with positive JAK2V617F mutation status and high allele burden [3,10,15,28,29,[68][69][70]. As shown by an elaborate epidemiological study in 88 patients with an confirmed high hematocrit level (women >0.48, men >0.51) after an observation time of 5 years progression into manifest PV [5,7] occurred in three patients [71].…”

Differential polycythemia: A comparative study between spurious polycythemia and pure erythrocytosis.

“…PE was diagnosed according to all the criteria of Najean et al (1981), except for TRCV. All patients with PE had TRCVs that were greater than 25% above their mean predicted normal values (Pearson et al 1978).…”

The 2006 → 2008 European Clinical, Molecular and Patholobiogical (2008 ECMP) Classification and the 2007 WHO Revised Criteria for Myeloproliferative Neoplasms

“…The PVSG and WHO classifications excluded ECP defined Idiopathic Erythrocythemia (IE) by definition [31,32]. IE is featured by increased hemoglobin, haematocrit, erythrocytes and increased red cell mass but normal leukocytes, thrombocytes and spleen size on palpation [31,32]. Minor B criteria did appear in untreated IE patients during follow up and was associated with a high incidence of major or lethal cerebrovascular thrombotic disease 31.…”

“…Minor B criteria did appear in untreated IE patients during follow up and was associated with a high incidence of major or lethal cerebrovascular thrombotic disease 31. This category of IE or the earliest erythrocythemic stage of PV comprises about 10 to 20% of the PV cases at time of presentation [31,32]. In the 1970s tools available to separate the Idiopathic Erythrocytoses into myeloproliferative PV (IE) versus primary or secondary erythrocytosis by including pretreatment bone marrow biopsy [33][34][35] and EEC 36,37 were overlooked by the PVSG.…”

“…5 RCM in PV patients corresponded to hematocrit values between 0.48 and 0.76 in all, platelet count above 400 x10 9 /L in two-third and palpable spleen in two-third of about 400 PV patients in the PVSG-01 study [13]. The PVSG and WHO classifications excluded ECP defined Idiopathic Erythrocythemia (IE) by definition [31,32]. IE is featured by increased hemoglobin, haematocrit, erythrocytes and increased red cell mass but normal leukocytes, thrombocytes and spleen size on palpation [31,32].…”