Monoclonal gammopathies are common in the general population and occur in 10% of patients with peripheral neuropathy. It is important for the clinician to be able to determine whether an association exists between the paraprotein and the neuropathy. The clinical phenotype of the neuropathy, as well as the type of monoclonal protein, provides clues for the diagnosis. Optimal management of paraproteinemic neuropathies requires appropriate evaluation of the monoclonal protein for an underlying hematologic disorder.
Clinical studies in paraproteinemic neuropathies have provided a better understanding of these disorders, but much is still unknown regarding the pathophysiologic mechanisms. Recent clinical trials in immunoglobulin M (IgM) neuropathy have shown that better outcome measures and treatment approaches are needed. Peripheral blood stem cell transplantation has shown promising improvements in the treatment of polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) syndrome and immunoglobulin light chain (AL) amyloidosis.
Recognizing the frequent association of neuropathy with monoclonal proteins and evaluating for a hematologic malignancy should enable physicians to find better treatments and ultimately improve neuropathy outcome.