Hyperviscosity syndrome, seen in approximately 15% of patients with Waldenstrom macroglobulinemia, is the most serious and potentially fatal complication of macroglobulinemia.
Hyperviscosity syndrome commonly manifests as skin or mucosal bleeding, visual abnormalities, headache, vertigo, dizziness, nystagmus, deafness, ataxia and in severe cases confusion, dementia, stroke or coma. Pulmonary edema and congestive heart failure have also been reported. However, uncommonly, hyperviscosity syndrome may manifest with exertional chest pain and dyspnea without other symptoms. Tyically, symptoms improve with initiation of chemotherapy and reduction in plasma viscosity..
Elevated plasma viscosity along with characteristic symptoms can be diagnostic of hyperviscosity syndrome. Although it is usually seen with the plasma viscosity > 4 cP, the level at which patients become symptomatic is quite variable (“symptomatic threshold”). The presence of anemia or hypoxia may contribute to symptom manifestations at a marginally elevated plasma viscosity.
Laboratory evaluation of a suspected hyperviscosity syndrome should include serum protein electrophoresis and immunofixation, quantitative immunoglobulin levels and plasma viscosity measurements. Additionally, a complete blood count, kidney and liver function tests, lactate dehydrogenage and disease-specific evaluation are performed.
The immediate treatment relies on the physical removal of the IgM protein from the blood stream by plasmapheresis, while long-term management is aimed at the control of underlying disease.
Rituximab, an IgG(1)-kappa monoclonal antibody that targets the CD20 antigen on the surface of malignant and normal B lymphocytes, has been utilized in treatment as a single agent or in combination with chemotherapy.
Bendamustine hydrochloride, a novel alkylating agent, has shown efficacy in treatment of indolent non-Hodgkin lymphoma and can be administered in combination with rituximab with good outcomes.
Adapted from: World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online. Creative Commons License.