The overall survival of POEMS patients who have been treated for their disease is relatively good for a disease occurring in patients with an average age of 50 years; one estimate of median overall survival is 14 years. POEMS patients evaluated to be in low and intermediate risk groups had ≥>85% survival at 10 years; those in the high risk group had a 40% survival over this time period. Cryoglobulinemia
Cryoglobulins are proteins, principally immunoglobulins, that circulate in the blood, precipitate at temperatures <37 °C (98.6 °F), and re-solubilize upon restoring physiological blood temperatures. They are made and secreted into the blood as a result of underlying pathological conditions viz., inflammation, infection, or malignancies. Rarely, cryoglobulinemia (i.e. essential cryoglobulinemia) occurs in patients without these or other identifiable conditions. Non-essential cryoglobulonemia is classified into three types. Type 1 cryoglobulinemia (10-25% of cases) involves a circulating myeloma protein, typically IgM or IgG but in rare case reports IgA. The condition is associated with Waldenström macroglobulinemia or multiple myeloma in ~40% of type I cases, the MGUS or smoldering predecessors to these diseases in ~44% of type I cases, and other B cell lymphoproliferative disorders in ~16% of type I cases. Type II cryglobulinemia (50-60% of cases) involves circulating IgM myeloma protein with rheumatoid factor activity and therefore bound to polyclonal IgG and protein components of the blood complement system; hepatitis C virus and, far more rarely, hepatitis B virus or human immunodeficiency virus infections are the major causes of this cryoglobulinemia.
However, more sensitive methods of detecting urinary and serum light chain myeloma proteins using enzyme-linked immunosorbent assays indicate that >60% of cases initially diagnosed as non-secretory multiple myeloma had abnormal levels of either a clonal κ or λ light chain in their urine or serum and therefore were better diagnosed as having light chain multiple myeloma. Based on the latter definition, non-secretory multiple myeloma represents ~1% of all multiple myeloma cases with formerly diagnosed non-secretory myelomas considered to be cases primarily of light chain multiple myeloma but on occasion "false non-secretors", i.e. cases in which there is evidence of myeloma protein secretion such as renal myeloma protein deposits.A Mayo Clinic study of 124 patients initially diagnosed as having non-secretory multiple myeloma were later found to be composed of 65% free light chain secretors and 35% true non-secretors. As a group, these patients response to therapy, time to disease recurrence, and overall survival were similar to typical myeloma patients. However, in a subset of patients diagnosed after 2001 and therefore treated with more effective therapy that included autologous stem-cell transplantation, prognosis was significantly better in non-secretory multiple myeloma patients (median survival 8.3 years) compared to typical myeloma patients (median survival 5.4 years). In addition, non-secretory patients exhibited a better prognosis than light chain-secretory patients.