Diagnostic value of serum erythropoietin level in patients with absolute erythrocytosis.
OBJECTIVE
The diagnosis of polycythemia vera (PV) is based on clinical and biological criteria defined by either the Polycythemia Vera Study Group (PVSG) or the World Health Organization (WHO). Both the PVSG and WHO PV criteria have proved helpful and are extensively used, yet diagnostic strategies and scheduling of biological investigations vary. We assessed the value of measuring serum erythropoietin (Epo) as a first intention diagnostic test in patients with absolute erythrocytosis (AE).


METHODS
Serum and bone marrow (BM) samples of 241 patients with a suspicion of erythrocytosis were collected in 8 hospital centers. One hundred and ninety had an absolute erythrocytosis (116 had PV, 66 had secondary erythrocytosis and 4 had idiopathic erythrocytosis). Serum Epo was assayed (ELISA) in 186. Statistical analysis (ROC curves) was used to define serum Epo thresholds that were specific for PV and secondary erythrocytosis and to analyze the diagnostic value of a low or high serum Epo level.


RESULTS
A large majority of PV patients (87% or 101/116) had a serum Epo level below the normal range in healthy patients (3.3 IU/L), giving this value a specificity of 97% with a 97.8% positive predictive value for the diagnosis of PV. Statistical analysis (ROC curves) defined two thresholds allowing a specific and direct diagnosis of 65.6% (65/99) of untreated PV (Epo < 1.4 IU/L) and 19.7% (13/66) of those with secondary erythrocytosis (Epo > 13.7 IU/L).


CONCLUSIONS
Based on these data, we propose that measurement of serum Epo level, a simple, reliable and inexpensive test, should be considered as a first intention diagnostic test for patients with absolute erythrocytosis.
Laboratories of Hematology of Centre Hospitalier Universitaire, Grenoble, France. pmossuz@chu-grenoble.fr <pmossuz@chu-grenoble.fr>
Pascal
P
Mossuz
François
F
Girodon
Magali
M
Donnard
Véronique
V
Latger-Cannard
Irène
I
Dobo
Nathalie
N
Boiret
Jean Claude
JC
Lecron
Christine
C
Binquet
Claire
C
Barro
Sylvie
S
Hermouet
Vincent
V
Praloran
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001853:Bone Marrow / Q000737:chemistry; D003094:Collagen; D003114:Colony-Forming Units Assay; D003470:Culture Media / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D015672:Erythroid Precursor Cells / Q000473:pathology; D004921:Erythropoietin / Q000032:analysis / Q000097:blood* / Q000172:deficiency; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011086:Polycythemia / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D011087:Polycythemia Vera / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
D015415:Biomarkers; D003470:Culture Media; D016207:Cytokines; D004921:Erythropoietin; D003094:Collagen