Mononeuritis multiplex in a patient with macroglobulinaemia

Neuropathy and monoclonal gammopathy

The association of neuropathy with monoclonal gammopathy has been known for several years, even if the clinical and pathogenetic relevance of this association is not completely defined. This is not a marginal problem since monoclonal gammopathy is present in 1-3% of the population above 50 years in whom it is often asymptomatic, and in at least 8% of patients is associated with a symptomatic neuropathy, representing one of the leading causes of neuropathy in aged people. Monoclonal gammopathy may result from malignant lymphoproliferative diseases including multiple myeloma or solitary plasmocytoma, Waldenström's macroglobulinemia (WM), other IgM-secreting lymphoma or chronic lymphocytic leukemia, and primary systemic amyloidosis (AL). In most instances it is not associated with any of these disorders and is defined monoclonal gammopathy of undetermined significance (MGUS) for its possible, though infrequent, evolution into malignant forms. Several data support the pathogenetic role of the monoclonal gammopathy in the neuropathy particularly when of IgM isotype where IgM reactivity to several neural antigens has been reported. Increased levels of VEGF have been implicated in POEMS syndrome. However, there are as yet no defined therapies for these neuropathies, as their efficacy has not been confirmed in randomized trials.

Bing-Neel Syndrome revisited

Since the 1936 seminal description of neurologic difficulties in patients with hyperglobulinemia, the "Bing-Neel Syndrome" has been applied to a range of neurologic symptoms. To clarify the central nervous system (CNS) manifestations of Waldenström macroglobulinemia (WM), we performed a literature search (years 1936 to 2008) of reports of "Bing-Neel Syndrome" or "WM affecting the CNS" (WM-CNS). We excluded cases of hyperviscosity, malignant transformation, vasculitis, and purely ophthalmologic manifestations. After analysis of symptoms, cerebrospinal fluid (CSF), imaging, and histopathology, we separate WM-CNS into (1) lymphoplasmacytoid cells infiltrating the CNS, and (2) a non-cellular form, in which other mechanisms, such as IgM deposition, might produce the neurologic symptoms.

Case of mononeuritis multiplex onset with rituximab therapy for Waldenström's macroglobulinemia

Waldenström's macroglobulinemia (WM) is a lymphoplasmacytic disorder with associated monoclonal gammopathy. A wide variety of neuropathies can be associated with WM, but most commonly it is a mild length-dependent sensory neuropathy of unclear etiology. Rituximab is a monoclonal antibody which suppresses mature B-cell populations. It has increasingly been used in wide applications including WM, especially in those cases with severe neuropathy. The highlighted case provides an example of rituximab treatment complication in a WM patient with mild sensory neuropathy that evolved to multiple mononeuropathies with features of systemic vasculitis and unusual conversion of type I to type II cryoglobulinemia.

Mononeuritis multiplex in Waldenström's macroglobulinemia

We describe a patient with mononeuritis multiplex who had cranial nerve involvement in association with Waldenström's macroglobulinemia. Sural nerve biopsy showed abundant endoneurial granulofibrillary deposits related to microangiopathic changes. These changes were distributed in a multifocal pattern among the fascicles. Immunohistochemistry demonstrated the IgM nature of the deposit located in the endoneurial interstitium.

Reactivity of sera and isolated monoclonal IgM from patients with Waldenström's macroglobulinaemia with peripheral nerve myelin

Sera of 23 patients with Waldenström's macroglobulinaemia and six monoclonal IgM paraproteins, which had been isolated from these sera, were examined for reactivity against peripheral nerve tissue. Of these 23 patients, 12 had clinical signs of peripheral polyneuropathy (PN). Using an indirect immunofluorescence method, all sera and monoclonal IgM preparations reacted with peripheral nerve structures, displaying a distinct granular fluorescence pattern with anti-IgM sera. The Waldenström sera reacted mainly with structures at the border of the myelin sheath, as well as between myelin and axon, and occasionally with the axon itself. There was no difference between sera of patients with PN and those without. Negative results were obtained in a complement fixation assay. Of the 23 sera, 15 reacted in an antibody-dependent lymphocyte-mediated cytotoxicity reaction (ADLC) with peripheral nerve myelin, and to a much lesser extent with myelin basic protein from CNS. Five of the six isolated monoclonal IgM preparations also gave positive ADLC reactions. These results constitute additional evidence for an immunological mechanism in the pathogenesis of PN in Waldenström's macroglobulinaemia.

Monoclonal gammopathy with neurological signs and symptoms. A clinical, neurophysiological and muscle biopsy study

Clinical, neurophysiological and muscle biopsy findings in ten patients with monoclonal gammopathy are reported. Three patients had polyneuropathy, one had hemiparkinsonism, one migraine and radicular symptoms and one paresthesiae and radicular symptoms. Amyloidosis was not found in muscle biopsy specimens. All but one patient with neurological findings also had positive immunofluorescence staining for tissue-bound immunoglobulins in muscle biopsy specimens. The tissue-bound immunoglobulins usually belonged to the same class as the M-component. None of the biopsies of patients without neurological findings were positive.