a Glomerular filtration rate of <40; and c) biopsy confirmed or suspicion of cast nephropathy, glomerulonephritis, of other morphological expressions of clonal immunoglobulin-induced kidney injury. Increased excretion of a urinary monoclonal light chain (typically >0.5 gram/day), which suggests the presence of a particularly severe form of kidney injury (myeloma cast nephropathy), supports but is not a requirement for the diagnosis of MGRS. The disorder can also be caused by a monoclonal immunoglobulin that acts as an autoantibody that activates the blood complement system to cause complement-related kidney injury. This form of MGRS is usually associated with other syndromes like glomerulopathy associated with a monoclonal immunoglobulin or C4 dense deposit disease associated with a monoclonal immunoglobulin. Diagnosis depends or identifying these other syndromes and the identification of complement components on kidney biopsy. Regardless of the exact pathophysiology causing monoclonal immunoglobulin-induced kidney injury, MGRS has a greater morbidity and mortality than other forms of MGUS. Since renal dysfunction usually improves with therapy directed at the underlying plasma cell dyscrasia, MGRS may warrant treatment even when other parameters of plasma cell dyscrasia severity (e.g. low levels of serum monoclonal immunoglobulin and bone marrow plasma cells) suggest the presence of minimal, non-malignant disease. Smoldering multiple myeloma stage
Smoldering multiple myeloma or SMM (also termed smoldering myeloma) is the next stage following MGUS in the spectrum of plasma cell dyscrasias. While still considered a pre-malignant condition, its chances of progressing to a malignant plasma cell dyscrasia are generally greater than that for MGUS.
In general, patients with plasma cell myeloma with concomitant chronic Lymphocytic Leukemia/monoclonal B-cell Lymphocytosis have been treated with the same regimens used for multiple myeloma patients unless significant complications related to the lymphocytic component of their disease (e.g. autoimmune hemolytic anemia) require treatments used in chronic lymphocytic leukemia. Some patients who lack appreciable symptoms have been followed with no specific treatment of their disease. Waldenström macroglobulinemia
According to the International Workshop on Waldenströms Macroglobulinemia, the disease is diagnosed in patients that have a serum IgM monoclonal protein and a bone marrow that contains ≥10% of its nucleated cells as lymphoplasmacytic cells. There is no requirement for symptomatic disease, a particular level of IgM protein, or presence of extramedullary (i.e. non-bone) lymphoplasmacytic cell infiltrates. The overall survival for this malignancy at 5 and 10 years among >5,000 patients is 62% and 39%, respectively, with newer treatment regimens anticipated to improve these survival rates in the future. Multiple myeloma
Multiple myeloma is diagnosed in patients that (except for non-secretory multiple myeloma patients) have a clonal IgG, IgA, IgD, or IgE myeloma protein in their serum and/or a clonal κ or λ light chain in their serum or urine plus either one of two sets of criteria.