Basic sciences of the myeloproliferative diseases: pathogenic mechanisms of ET and PV

Nephrotic syndrome in a patient with IgM myeloma with associated neutrophilia

An unusual case having IgM monoclonal gammopathy with clinical and pathologic features of multiple myeloma (MM) in association with neutrophilia and nephrotic syndrome is reported. The patient showed lytic bone lesions, decreased IgG and IgA levels, Bence-Jones proteinuria, nephrotic proteinuria with edema, and histological plasma cell infiltration typical of MM. Moreover, mature neutrophilic leukocytosis, hepatomegaly, high leukocyte alkaline phosphatase score (LAP), absence of Philadelphia (Ph) chromosome and bcr gene rearrangement were also evidenced, all these features representing findings typical of the recently described plasma cell dyscrasia-associated neutrophilia. After the diagnosis, the patient was treated with melphalan and prednisone, with an excellent response to the treatment. Different from the 30 cases so far reported, this is the first case of plasma-cell dyscrasia with associated neutrophilia due to IgM-producing monoclonal gammopathy. At the same time, this is the first reported case of nephrotic syndrome secondary to IgM myeloma.

The polycythaemia rubra vera-1 gene is constitutively expressed by bone marrow cells and does not discriminate polycythaemia vera from reactive and other chronic myeloproliferative disorders

Little is known about the expression of the polycythaemia rubra vera-1 (PRV-1) gene in bone marrow cells. To determine the expression level of PRV-1 in the bone marrow, we analysed PRV-1 quantitatively in Polycythaemia vera, other chronic myeloproliferative disorders, and reactive states. We demonstrated that PRV-1 was constitutively expressed in both myeloproliferative and reactive states. We concluded that, rather than an upregulation of the PRV-1 gene in the clonal haematopoiesis of polycythaemia vera, a failure to downregulate PRV-1 in granulocytes emigrating from the bone marrow might be responsible for the increase of transcripts in peripheral cells.