Clinical spectrum and evolution of monoclonal gammopathy-associated neuropathy: an observational study

A rare presentation of acute-onset chronic inflammatory demyelinating polyneuropathy with the detection of anti-GM3 and anti-sulfatides antibodies: a case report

Objectives

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated neuropathy defined by clinical progression for more than 2 months. 16-20% of CIDP patients may present with rapidly progressive weakness that resembles GBS, known as acute-onset CIDP (A-CIDP). However, it is challenging to distinguish from GBS-TRF because of their similar clinical symptom and features. In this case review, we report a patient with A-CIDP with the detection of anti-GM3 and anti-sulfatides antibodies, which rarely have been in A-CIDP and may account for her progressive and recurrent symptoms.

Methods

We analyzed existing medical literature and described a clinical case of A-CIDP with antibodies positive.

Results

We reported a 56-year-old female presented with bilateral lower extremity weakness and distal numbness. She experienced similar symptoms four times and responded well to the IVIg therapy. Lumbar puncture demonstrated albumin-cytologic dissociation and EDX examination revealed multiple peripheral nerve damage. After ruling out other demyelination diseases, a diagnosis of A-CIDP was made.

Discussion

The antiganglioside and anti-sulfatide antibodies are involved in CIDP pathogenesis and can help to distinguish A-CIDP and other variants. To prevent secondary damage, it is important to monitor relapse and remission symptoms along the treatment line. A rare case of A-CIDP is discussed concerning the detection of anti-GM3 and anti-sulfatides antibodies, thus making a retrospective comparison of antibodies in some literature to understand A-CIDP better.

Thymic plasmacytoma presenting as polyneuropathy and revealing multiple myeloma: a case report

Background

Multiple myeloma (MM) is the most frequent malignant plasma cell disorder with proliferation of neoplastic plasma cells in the bone marrow or other tissue, most commonly in the upper aerodigestive tract. The invasion of the thymus is exceptional. Neurological complications are usual, but represent exceptionally the revealing symptom.

Case presentation

We report a case of polyneuropathy revealing a thymic plasmacytoma as a mediastinal invasion of MM in a 48-year-old woman. She was admitted after developing progressive ascending distal paresthesias and weakness in lower limbs. Examination showed symmetrical distal sensorimotor impairment with axillary and inguinal adenopathies. Electroneuromyography revealed a sensorimotor length-dependent neuropathy. Serum protein electrophoresis showed monoclonal protein peak in β-γ globulin region. Immunoelectrophoresis showed IgA lambda monoclonal gammapathy. Myelogram and bone marrow biopsy revealed plasmocytosis of 5%. Chest computed tomography showed a histologically confirmed thymic plasmacytoma associated with a lytic lesion of the 5th rib leading to the diagnosis of MM.

Conclusions

The association between a thymic plasmacytoma and peripheral neuropathy is rare and a workup for MM is necessary to guide therapeutic management.

Monoclonal gammopathies of clinical significance (MGCS): In pursuit of optimal treatment

Monoclonal gammopathy of clinical significance (MGCS) represents a new clinical entity referring to a myriad of pathological conditions associated with the monoclonal gammopathy of undetermined significance (MGUS). The establishment of MGCS expands our current understanding of the pathophysiology of a range of diseases, in which the M protein is often found. Aside from the kidney, the three main organ systems most affected by monoclonal gammopathy include the peripheral nervous system, skin, and eye. The optimal management of these MGUS-related conditions is not known yet due to the paucity of clinical data, the rarity of some syndromes, and limited awareness among healthcare professionals. Currently, two main treatment approaches exist. The first one resembles the now-established therapeutic strategy for monoclonal gammopathy of renal significance (MGRS), in which chemotherapy with anti-myeloma agents is used to target clonal lesion that is thought to be the culprit of the complex clinical presentation. The second approach includes various systemic immunomodulatory or immunosuppressive options, including intravenous immunoglobulins, corticosteroids, or biological agents. Although some conditions of the MGCS spectrum can be effectively managed with therapies aiming at the etiology or pathogenesis of the disease, evidence regarding other pathologies is severely limited to individual patient data from case reports or series. Future research should pursue filling the gap in knowledge and finding the optimal treatment for this novel clinical category.

Neuropathy associated with IgA monoclonal Gammopathy. A harbinger of AL amyloidosis

Peripheral neuropathy is seen in 15% of patients with IgA monoclonal gammopathy. Treatment and prognosis of dysproteinemic neuropathy is usually guided by the underlying plasma cell disorders, which could be either benign or malignant. The true incidence of hematologic malignancy in patients with neuropathy associated with IgA monoclonal gammopathy is not known. However, patients with IgA M-protein are generally at increased risk for malignant transformation. Since neuropathy may be the first and only organ involvement, neurologists are key contributors in identifying each patient's plasma cell dyscrasia. We report two patients who presented with severe progressive polyneuropathy, had a detectable low-level IgA lambda paraproteinemia dismissed as incidental. Both were diagnosed later with a combination of malignant plasma cell dyscrasia and AL amyloidosis resulting in multiorgan failure and death. Both patients demonstrated red flags for malignant progression including abnormal serum free light chain, rapidly progressive debilitating neuropathy refractory to immunotherapy, prominent autonomic dysfunction, and weight loss. In summary, patients with IgA monoclonal gammopathy presenting with polyneuropathy can be at risk for malignant transformation. Failure to investigate for hematologic malignancy and AL amyloidosis may cause significant delays in treatment and result in fatal outcomes.

Electrophysiologic features of POEMS syndrome compared with MGUS-related neuropathy

INTRODUCTION

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome and monoclonal gammopathy of undetermined significance (MGUS) are paraproteinemic disorders that can cause demyelinating polyneuropathy. Herein we assessed the findings of nerve conduction studies (NCS) in patients with POEMS syndrome and MGUS-related neuropathy to determine whether the NCS characteristics can help differentiate between these conditions.

METHODS

We enrolled 24 POEMS and 37 MGUS-related neuropathy patients. NCS parameters, including compound muscle action potential (CMAP), motor conduction velocity (MCV), and terminal latency index (TLI), were evaluated.

RESULTS

Compared with MGUS-related neuropathy patients, POEMS syndrome patients demonstrated a greater reduction in both the upper and lower limb CMAPs and a greater reduction in the median and ulnar MCVs. The TLIs were significantly higher in POEMS patients.

DISCUSSION

NCS can help distinguish POEMS syndrome from MGUS-related neuropathy. Reduced CMAPs, slow MCVs, and high TLIs are indicative of POEMS syndrome rather than MGUS-related neuropathy. Muscle Nerve 56: E73-E77, 2017.

Monoclonal Gammopathy-Associated Peripheral Neuropathy: Diagnosis and Management

Monoclonal gammopathies comprise a spectrum of clonal plasma cell disorders that include monoclonal gammopathy of undetermined significance, multiple myeloma, and Waldenström macroglobulinemia. In this review, we outline the epidemiology, etiology, classification, diagnosis, and treatment of monoclonal gammopathy-associated peripheral neuropathy. Monoclonal gammopathy of undetermined significance is relatively common in the general population, with a prevalence of 3% to 4% among individuals older than age 50 years. Therefore, the presence of M protein in a patient with neuropathy does not automatically indicate a causal relationship. Monoclonal gammopathy-associated peripheral neuropathy is often a difficult diagnosis with limited treatment options. Studies addressing the optimal approach to diagnosis and management of this entity are limited. In addition to a review of the literature, we present a diagnostic approach to patients with monoclonal gammopathy-associated peripheral neuropathy and discuss available data and options for treatment.

Analyzing Relationship Between Monoclonal Gammopathy of Undetermined Significance (MGUS) with Different Types of Neuropathy: An Observational Study

To analyze multiple variables, including immunoglobulin subtypes in patients with monoclonal gammopathy of undetermined significance (MGUS) and different types of neuropathy. This was a retrospective, single center study done in a tertiary care hospital in the United States. The data was collected for years 2001-2011. Inclusion criteria were the presence of MGUS and neuropathy. Exclusion criteria were the presence of other factors such as diabetes, vitamin B12 deficiency, alcoholism etc. which can cause neuropathy. Patients with IgM MGUS were compared with patients having Non-IgM MGUS. A total of 281 patients were analyzed in this study. The average age at the time of diagnosis of MGUS and neuropathy was 68 years. The most common type of neuropathy was sensorimotor peripheral neuropathy (46 %). The most common location of neuropathy was the lower extremities (68 %). Among our patients, 52 % had their neuropathy symptoms for 1-5 years before presenting to the clinic. When IgM MGUS was compared with Non-IgM MGUS, a statistically significant difference was found in terms of race (White vs. Others, OR 4.43, 95 % CI 2.13, 9.19, p < 0.001) and survival status (OR 1.98, 95 % CI 1.01, 3.90, p = 0.046). Patients with MGUS are prone to develop different types of neuropathies. Caucasians are more likely to have IgM MGUS as compared to other races. IgM MGUS is generally related to worse outcomes as compared to Non-IgM MGUS. Medical therapies, including gabapentin and pregabalin are effective treatments and the response rate can be as high as 80-90 % with these medications.

Comparison of monoclonal gammopathy of undetermined significance-associated neuropathy and chronic inflammatory demyelinating polyneuropathy patients

OBJECTIVES

There are varying reports on whether monoclonal gammopathy of undetermined significance-associated neuropathy (MGUSN) patients are distinguishable from those with chronic inflammatory demyelinating polyneuropathy (CIDP) and whether specific MGUSN subclasses are associated with specific clinical phenotypes.

METHODS

We performed a retrospective chart review of MGUSN (n = 56) and CIDP (n = 67) patients. Data extracted included: demographics, neurological examination, and nerve conduction studies (NCS) at baseline and last visit. Clinical status was rated as 0 = worse, 1 = unchanged, 2 = stabilized after a declining course, or 3 = improved. The electrophysiology data were rated as 0 = worse, 1 = stable, or 2 = improved. Statistical analyses were performed using JMP (version 9.0.2 for Macintosh, from SAS).

RESULTS

Seventy percent were males, aged 68.1 ± 12.6 years with neuropathy for 9.8 ± 6.8 years and follow-up of 4.0 ± 3.2 years. CIDP patients had more severe neuropathy, and were more likely to receive treatment and to respond. The clinical neuropathy status remained unchanged in 52.8 % of the MGUSN and 24.2 % of the CIDP patients, and stabilized in 7.6 % of MGUSN and 30.3 % of CIDP patients. IgM-MGUSN patients did not differ from other immunoglobulin subclasses in response to treatment. The clinical severity and the number of abnormal NCS parameters were greater in the demyelinating MGUSN in comparison to the axonal group.

CONCLUSION

MGUSN patients have less severe neuropathy than CIDP patients, but among the MGUSN patients the severity is greater in the demyelinating and the IgM groups. MGUSN patients may do well without treatment and exposure to potential adverse effects.