Immunohistochemical staining for megakaryocyte c-mpl may complement morphologic distinction between polycythemia vera and secondary erythrocytosis.
Recent studies have shown decreased megakaryocyte expression of the thrombopoietin receptor (c-mpl) in patients with polycythemia vera (PV) but not in those with reactive erythrocytosis. We examined the diagnostic utility of this observation in 22 patients with PV, 7 patients with secondary erythrocytosis (SE), and 10 normal controls. Commercial antibodies against c-mpl were used with standard immunoperoxidase methods. Megakaryocyte c-mpl staining intensity was uniformly moderate-to-strong in the healthy controls and in all the patients with SE. In contrast, staining intensity in 9 patients with PV (41%) was uniformly weak. Furthermore, in 12 of the remaining 13 patients with PV, the c-mpl staining pattern in each case was heterogeneous and was associated with weak staining intensity in more than 20% of the megakaryocyte population. These preliminary data suggest that c-mpl immunostains may complement bone marrow histopathology in distinguishing PV from nonclonal causes of erythrocytosis. (Blood. 2000;96:771-772)
Tefferi
A
A
Division of Hematology and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN 55095, USA.
Yoon
S Y
SY
Li
C Y
CY
D001853:Bone Marrow / Q000737:chemistry / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D008533:Megakaryocytes / Q000737:chemistry*; D009363:Neoplasm Proteins; D011086:Polycythemia; D011087:Polycythemia Vera / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D018121:Receptors, Cytokine; D053628:Receptors, Thrombopoietin
D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D018121:Receptors, Cytokine; D053628:Receptors, Thrombopoietin; C082218:MPL protein, human