Goldman, Joshua J.;
Vandris, Katherine;
Adriano, Fernando;
Bourla, Michael;
Silver, Richard T.
Normal Serum-Erythropoietin (S-epo) Level at Diagnosis of Polycythemia Vera (PV) Correlates with LowJAK2V617F Mutant Allele Burden and Indicates Mild Phenotype
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Medientyp:
E-Artikel
Titel:
Normal Serum-Erythropoietin (S-epo) Level at Diagnosis of Polycythemia Vera (PV) Correlates with LowJAK2V617F Mutant Allele Burden and Indicates Mild Phenotype
Beteiligte:
Goldman, Joshua J.;
Vandris, Katherine;
Adriano, Fernando;
Bourla, Michael;
Silver, Richard T.
Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>Abstract 4978</jats:p>
<jats:p>A low serum-erythropoietin (S-epo) level is a minor criterion of the World Health Organization (WHO) recommendations for diagnosing polycythemia vera (PV) even though previous studies indicate that a normal level does not always rule out PV. We wished to determine whether a normal S-epo level correlates with a low JAK2V617F mutant allele burden and a low phlebotomy (PHL) rate, since the relationship between S-epo level, JAK2V617F allele burden, and PHL rate heretofore has not been reported.</jats:p>
<jats:p>At diagnosis, we grouped the S-epo levels of 26 PV patients (pts) as follows: low (<5 U/l), normal (5-10 U/l), and high (>10 U/l). Of the 26 pts, 4 (15.4%) had normal S-epo levels, and 22 had low S-epo levels. The diagnosis of PV in pts with normal S-epo levels was made by quantitative JAK2V617F analysis and elevated Cr51 red cell mass (RCM). All pts had a bone marrow biopsy consistent with PV.</jats:p>
<jats:p>We determined the number of phlebotomies required to maintain normal hematocrit (hct) levels ('42% women, '45% men) as an assessment of disease severity during the period prior to myelosuppressive therapy. We then examined the number of phlebotomies per year (PHL/yr) in relation to S-epo level at diagnosis. Of the 26 pts, 14 were treated with PHL-only for a mean of 15 months (mos) prior to beginning other therapies including anagrelide, hydroxyurea, imatinib, and rIFNa-2b. The number of PHL/yr were grouped into 4 categories: 0 (none), 1 – 5 (low), 6 – 10 (moderate), and >10 (high). Of the 14 pts, 3 had a normal S-epo level at diagnosis, all of whom had a low PHL requirement, median 3/yr. The other 11 pts had low S-epo levels at diagnosis and a median PHL requirement of 6/yr (7 moderate and 4 low). Thus, while a low S-epo level at presentation was usually associated with moderate PHL requirement, a normal S-epo level at diagnosis was always associated with a subsequently low PHL requirement during the period of observation (mean 15 mos).</jats:p>
<jats:p>Of the 26 pts, 14 had quantitative JAK2 analyses done at diagnosis. The other 12 were diagnosed prior to 2002 and quantitative JAK2 determinations were not available. Of the 14 pts, 2 had a normal S-epo level and a low JAK2V617F mutant allele burden (1-25%). These 2 pts also had a low PHL requirement. Thus, these pts who had normal S-epo levels, had JAK2V617F allele burdens in the lowest quartile, and had low PHL rates. Of the remaining 12 pts, 5 had JAK2V617F allele burdens in the 2nd (25-50%) quartile, 5 in the 3rd (50-75%) quartile, and 1 each in the 1st and 4th quartiles.</jats:p>
<jats:p>We conclude (1) as previously reported, about 15% of pts with PV present with normal S-epo levels at diagnosis, suggesting a limitation of this WHO criterion, and (2) those pts with a low JAK2V617F allele burden and a normal S-epo level required fewer PHL/yr, all suggesting a more benign phenotype. This may provide a useful prognostic tool for patients with PV.</jats:p>
<jats:sec>
<jats:title>Disclosures</jats:title>
<jats:p>No relevant conflicts of interest to declare.</jats:p>
</jats:sec>