Investigation and management of IgM and Waldenström-associated peripheral neuropathies: recommendations from the IWWM-8 consensus panel

Recent insights into haematology and peripheral nerve disease

PURPOSE OF REVIEW

The association between clonal haematological disorders and peripheral nerve disease is recognized. Paraproteinaemic phenomena are the most common mechanism, but direct neural lymphomatous infiltration is seen and can be challenging to diagnose. Traditional and novel anticancer therapies have neuropathic side effects.

RECENT FINDINGS

Novel studies using sensitive techniques are refining the incidence of peripheral neuropathy in patients with a monoclonal gammopathy, and the pathogenesis of IgM Peripheral neuropathy (PN) and POEMS syndrome. Recent series give insight into the characteristics and diagnostic challenges of patients with neurolymphomatosis and amyloid light chain amyloidosis. There is an increasing repertoire of effective anticancer drugs in haematological oncology, but chemotherapy-related neuropathy remains a common side effect.

SUMMARY

This review of the current literature focuses on recent updates and developments for the paraproteinaemic neuropathies, and the evaluation, diagnosis and treatment of peripheral nerve disease due to high-grade and low-grade lymphomas and lymphoproliferative disorders.

Neurosurgical Intervention for Nerve and Muscle Biopsies

(1) Background: Neurologic and musculoskeletal diseases represent a considerable portion of the underlying etiologies responsible for the widely prevalent symptoms of pain, weakness, numbness, and paresthesia. Because of the subjective and often nonspecific nature of these symptoms, different diagnostic modalities have been explored and utilized. (2) Methods: Literature review. (3) Results: Nerve and muscle biopsy remains the gold standard for diagnosing many of the responsible neurological and musculoskeletal conditions. However, the need for invasive tissue sampling is diminishing as more investigations explore alternative diagnostic modalities. Because of this, it is important to explore the current role of neurosurgical intervention for nerve and muscle biopsies and its current relevance in the diagnostic landscape of neurological and musculoskeletal disorders. With consideration of the role of nerve and muscle biopsy, it is also important to explore innovations and emerging techniques for conducting these procedures. This review explores the indications and emerging techniques for neurological intervention for nerve and muscle biopsies. (4) Conclusions: The role of neurosurgical intervention for nerve and muscle biopsy remains relevant in diagnosing many neurological and musculoskeletal disorders. Biopsy is especially relevant as a supportive point of evidence for diagnosis in atypical cases. Additionally, emerging techniques have been explored to guide diagnostics and biopsy, conduct less invasive biopsies, and reduce risks of worsening neurologic function and other symptoms secondary to biopsy.

How to manage waldenström's macroglobulinemia in 2024

Clinical management of Waldenström's Macroglobulinemia has seen major progress in the recent years, triggered by our improved understanding of the biology of the disease and the development of new therapies. Based on this there are multiple treatment options available for patients with WM ranging from classical immunochemotherapy to targeted approaches blocking key enzymes involved in lymphoma growth. This review summarizes our current knowledge about diagnostics and treatment of this rare but recurrent lymphoma subtype, which often presents a major clinical challenge in daily clinical life.

Ultrasensitive assay technology and fluid biomarkers for the evaluation of peripheral nerve disease

The field of biomarker discovery is rapidly expanding. The introduction of ultrasensitive immunoassays and the growing precision of genetic technologies are poised to revolutionise the assessment and monitoring of many diseases. Given the difficulties in imaging and tissue diagnosis, there is mounting interest in serum and cerebrospinal fluid biomarkers of peripheral neuropathy. Realised and potential fluid biomarkers of peripheral nerve disease include neuronal biomarkers of axonal degeneration, glial biomarkers for peripheral demyelinating disorders, immunopathogenic biomarkers (such as the presence and titre of antibodies or the levels of cytokines) and genetic biomarkers. Several are already starting to inform clinical practice, whereas others remain under evaluation as potential indicators of disease activity and treatment response. As more biomarkers become available for clinical use, it has become increasingly difficult for clinicians and researchers to keep up-to-date with the most recent discovery and interpretation. In this review, we aim to inform practising neurologists, neuroscientists and other clinicians about recent advances in fluid biomarker technology, with a focus on single molecule arrays (Simoa), chemiluminescent enzyme immunoassays (CLEIA), electrochemiluminescence (ECL), proximity extension assays (PEA), and microfluidic technology. We discuss established and emerging fluid biomarkers of peripheral neuropathy, their clinical applications, limitations and potential future developments.

Waldenström Macroglobulinemia-Associated Peripheral Neuropathy in the Brachial Plexus With Bing-Neel Syndrome Diagnosed Through Repeated Cerebrospinal Tests

In Waldenström macroglobulinemia (WM), confirming the presence of Bing-Neel syndrome (BNS) is important because drugs that penetrate the central nervous system (CNS) must be selected. We report the case of a 75-year-old man for whom tirabrutinib, a second-generation Bruton's tyrosine kinase inhibitor (BTKi), was useful in treating WM-associated peripheral neuropathy (PN) with BNS. Numbness and muscle weakness in the fingers occurred three years after the initial treatment of WM. WM-associated PN due to demyelinating disease was diagnosed based on the results of a nerve conduction study and magnetic resonance imaging showing bilateral symmetric swelling of the brachial plexus. The cerebrospinal fluid (CSF) cytology results were initially negative; however, the CSF test was repeated because of extremely high protein levels (984 mg/dL) and slightly elevated leukocyte counts (14/µL). The second test revealed abnormal lymphoplasmacytic cells (189/µL), indicating BNS. Rituximab and high-dose methotrexate-containing chemotherapy were administered. Despite the subsequent negative CSF cytology results, his neurological symptoms persisted but subsided soon after the initiation of tirabrutinib. The therapeutic effects of tirabrutinib persisted for 25 months. This case suggested that a careful search for concurrent BNS is important when lesions are close to the CNS or when atypical CSF findings are obtained in patients with WM-associated PN, especially when BTKi options are available.

Clinical and clonal characteristics of monoclonal immunoglobulin M-associated type I cryoglobulinaemia

Monoclonal immunoglobulin M-associated type I cryoglobulinaemia is poorly characterised. We screened 534 patients with monoclonal IgM disorders over a 9-year period and identified 134 patients with IgM type I cryoglobulins. Of these, 76% had Waldenström macroglobulinaemia (WM), 5% had other non-Hodgkin lymphoma (NHL) and 19% had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinically relevant IgM-associated disorders (including cold agglutinin disease [CAD], anti-MAG antibodies, amyloidosis and Schnitzler syndrome) coexisted in 31%, more frequently in MGUS versus WM/NHL (72% vs. 22%/29%, p < 0.001). The majority of those with cryoglobulins and coexistent CAD/syndrome had the molecular characteristics of a CAD clone (wild-type MYD88 in 80%). A half of all patients had active manifestations at cryoglobulin detection: vasomotor (22%), cutaneous (16%), peripheral neuropathy (22%) and hyperviscosity (9%). 16/134 required treatment for cryoglobulin-related symptoms alone at a median of 38 days (range: 6-239) from cryoglobulin detection. At a median follow-up of 3 years (range: 0-10), 3-year cryoglobulinaemia-treatment-free survival was 77% (95% CI: 68%-84%). Age was the only predictor of overall survival. Predictors of cryoglobulinaemia-related treatment/death were hyperviscosity (HR: 73.01; 95% CI: 15.62-341.36, p < 0.0001) and cutaneous involvement (HR: 2.95; 95% CI: 1.13-7.71, p = 0.028). Type I IgM cryoglobulinaemia is more prevalent than previously described in IgM gammopathy and should be actively sought.

Investigation and Management of Immunoglobulin M- and Waldenström-Associated Peripheral Neuropathies

The immunoglobulin M (IgM)-associated peripheral neuropathies (PN) are a heterogeneous group of disorders representing most paraproteinemic neuropathy cases. They are associated with IgM monoclonal gammopathy of undetermined significance (MGUS) or Waldenström macroglobulinemia. Establishing a causal link between a paraprotein and neuropathy can be challenging but is necessary to adopt an appropriate therapeutic approach. The most common type of IgM-PN is Antimyelin-Associated-Glycoprotein neuropathy, but half of the cases are of other causes. Progressive functional impairment is an indication for treatment, even when the underlying disorder is IgM MGUS, involving either rituximab monotherapy or combination chemotherapy to achieve clinical stabilization.

Hematologic Disorders and the Nervous System

OBJECTIVE

This article discusses the epidemiology, diagnosis, treatment, and prevention of neurologic complications of red blood cell, platelet, and plasma cell disorders.

LATEST DEVELOPMENTS

Cerebrovascular complications can occur in patients with blood cell and platelet disorders. Treatment strategies to prevent stroke are available for patients with sickle cell disease, polycythemia vera, and essential thrombocythemia. A diagnosis of thrombotic thrombocytopenic purpura should be considered in patients with neurologic symptoms, hemolytic anemia, thrombocytopenia, mild renal insufficiency, and fever. Plasma cell disorders can be associated with peripheral neuropathy, and classification of the monoclonal protein type and neuropathy aid in diagnosis. Patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes) syndrome can present with arterial and venous neurologic events.

ESSENTIAL POINTS

This article discusses the neurologic complications of blood cell disorders and the most recent advances in prevention and treatment.

Monoclonal gammopathy of increasing significance: time to screen?

Monoclonal gammopathy (MG) is a frequently detected clonal B-cell or plasma-cell disorder. Importantly, every multiple myeloma (MM) case is preceded by MG. Although clinical algorithms now allow earlier treatment of patients with biomarkers of malignancy before MM-induced tissue damage (CRAB) occurs, most patients are still diagnosed late. It is important to revisit how MG should be managed in clinical practice and whether screening is required. As the prevalence of MG and other medical co-morbidities both rise with increasing age, the degree of contribution of MG to disease states other than malignant progression is often unclear. This can lead to monitoring lapses and under recognition of the organ dysfunction that can occur with monoclonal gammopathy of clinical significance (MGCS). Therefore, models of progression to MM and/or MGCS require further refinement. While MG is currently detected incidentally, a case for screening has been made with ongoing studies in this area. Screening has the potential benefit of earlier detection and prevention of both MGCS and delayed MM presentations, but important drawbacks include the psychosocial impact on individuals and resource burden on healthcare services. MG terminology should transition alongside our increasing understanding of the condition and genomic characterization that have already begun to revise the MG nomenclature. The biology of MG has been poorly understood and is often inferred from the biology of MM, which is unhelpful. We review the literature and case for MG screening in this paper. In particular, we highlight areas that require focus to establish screening for MG.

First-Line Treatment of Waldenström’s Macroglobulinaemia: Considerations Based on the Dutch National Guideline

Waldenström macroglobulinemia (WM) is a rare B-cell Non-Hodgkin Lymphoma. There are only few prospective randomized clinical trials to guide treatment recommendations and there is no international consensus on a preferred first line treatment approach. In the recently revised Dutch guideline for WM, we describe recommendations for practice based as much as possible on the known data. Here, we summarize the considerations for first-line treatment based on these Dutch guidelines. Available evidence is summarized, including efficacy and toxicity data. Combinations of Rituximab with chemotherapy, proteasome inhibition or BTK-inhibition are all valid first line treatment options. The Dutch WM working group considers Dexamethasone/Rituximab/Cylofosfamide (DRC) a suitable first-line treatment for many WM patients, given the efficacy, the relatively mild toxicity profile and the extensive experience with this regimen. However, the long-term toxicities of DRC are unclear and need further clarification. Other regimens such as R-bendamustine, R-Bortezomib-dexamethason are also effective options, however with specific toxicities. BTK-inhibitors are not a preferred option in first line for most patients in the Dutch WM guidelines because of the need for longterm treatment and toxicities. Based on patient preferences research, future clinical trials should focus on effective fixed-duration regimens with non-cytotoxic therapies that have a favorable toxicity profile. Further development of (combinations with) BCL-2 inhibititors, novel proteasome inhibitors and BTK-inhibition could be interesting. In addition T-cell-directed treatments including bispecific antibodies as a monotherapy or combined with other novel agents deserve further study in WM.

Polyneuropathy Associated with IgM Monoclonal Gammopathy; Advances in Genetics and Treatment, Focusing on Anti-MAG Antibodies

With increasing age, the chances of developing either MGUS or polyneuropathy increase as well. In some cases, there is a causative relationship between the IgM M-protein and polyneuropathy. In approximately half of these cases, IgM targets the myelin-associated glycoprotein (MAG). This results in chronic polyneuropathy with slowly progressive, predominantly sensory neurological deficits and distally demyelinating features in nerve conduction studies. Despite the disease being chronic and developing slowly, it can cause considerable impairment. We reviewed English medical publications between 1980 and May 2022 on IgM gammopathy-associated polyneuropathy, with special attention to studies addressing the pathophysiology or treatment of anti-MAG polyneuropathy. Treatment options have been limited to a temporizing effect of intravenous immunoglobulins in some patients and a more sustained effect of rituximab but in only 30 to 55 percent of patients. An increase in our knowledge concerning genetic mutations, particularly the MYD88L265P mutation, led to the development of novel targeted treatment options such as BTK inhibitors. Similarly, due to the increasing knowledge of the pathophysiology of anti-MAG polyneuropathy, new treatment options are emerging. Since anti-MAG polyneuropathy is a rare disease with diverse symptomatology, large trials with good outcome measures are a challenge.

Pragmatic guide to peripheral nerve disease and the role of clinical biomarkers

In clinical neurology practice, there are few sensitive, specific and responsive serological biomarkers reflecting pathological processes affecting the peripheral nervous system. Instead, we rely on surrogate multimodality biomarkers for diagnosis and management. Correct use and interpretation of the available tests is essential to ensure that appropriate treatments are used and adjusted in a timely fashion. The incorrect application or interpretation of biomarkers can result in misdiagnosis and delays in appropriate treatment. Here, we discuss the uses and limitations of such biomarkers and discuss possible future developments.

Immunoglobulin M Monoclonal Gammopathies of Clinical Significance

Immunoglobulin M monoclonal gammopathy of undetermined significance (MGUS) comprises 15-20% of all cases of MGUS. IgM MGUS is distinct from other forms of MGUS in that the typical primary progression events include Waldenstrom macroglobulinaemia and light chain amyloidosis. Owing to its large pentameric structure, IgM molecules have high intrinsic viscosity and precipitate more readily than other immunoglobulin subtypes. They are also more commonly associated with autoimmune phenomena, resulting in unique clinical manifestations. Organ damage attributable to the paraprotein, not fulfilling criteria for a lymphoid or plasma cell malignancy has recently been termed monoclonal gammopathy of clinical significance (MGCS) and encompasses an important family of disorders for which diagnostic and treatment algorithms are evolving. IgM related MGCS include unique entities such as cold haemagglutinin disease, IgM related neuropathies, renal manifestations and Schnitzler's syndrome. The diagnostic approach to, and management of these disorders differs significantly from other categories of MGCS. We describe a practical approach to the evaluation of these patients and our approach to their treatment. We will also elaborate on the key unmet needs in IgM MGCS and highlight potential areas for future research.

SOHO State of the Art Updates and Next Questions: Waldenström Macroglobulinemia - 2021 Update on Management and Future Directions

Waldenstrom macroglobulinemia (WM) is a low-grade B-cell lymphoproliferative disorder. It is defined by having ≥ 10% bone marrow infiltration with lymphoplasmacytic cells and/or an immunoglobulin M (IgM) monoclonal gammopathy of ≥3g/dL. Risk factors include a personal history of IgM MGUS, and a family history of WM or a related disorder. Race, sex, and chronic antigen stimulation also appear to influence risk. Between 93 to 97% of patients with WM have a somatic mutation of the MYD88 gene. Of these, approximately 30% also have a mutation of CXCR4. The presence of a MYD88 mutation is associated with higher 10-year overall survival (90% vs. 73%; P < .001), while CXCR4 mutation status does not appear to have a similar effect. Based on consensus guidelines, WM patients with a disease-related hemoglobin level of less than 10g/dL, a platelet count of less than 100×10 9/L, bulky adenopathy or organomegaly, symptomatic hyperviscosity, severe neuropathy, amyloidosis, cryoglobulinemia, cold agglutinin disease, or evidence of disease transformation, should be considered for immediate therapy. Patients not meeting these criteria may be observed, with monitoring at 3 to 6 month intervals. When treatment is warranted, combinations of rituximab with alkylating agents and proteasome inhibitors are often effective, as are Bruton's tyrosine kinase (BTK) inhibitors and BCL-2 inhibitors. Selection among available regimens should take patients' gene mutation profile, disease-related features, and co-morbid conditions into account. Promising novel therapies in development include non-covalent BTK inhibitors, CXCR4 antagonists, BCL 2 inhibitors, bi-specific antibodies, radioimmunoconjugates, and CD19- and CD20-Targeted Chimeric Antigen Receptor T cells.

When a Monoclonal Gammopathy Is Not Multiple Myeloma

Our knowledge of monoclonal gammopathies is continuously evolving. Once accepted as a possible precursor condition to multiple myeloma, monoclonal gammopathies as an entity are now associated with many renal, neurologic, and dermatologic disorders of clinical significance. This change has created a challenge for patients and clinicians, as a monoclonal gammopathy may be a harbinger not of multiple myeloma but of other lymphoproliferative disorders such as light-chain amyloidosis and Waldenström macroglobulinemia. Early recognition of monoclonal gammopathies along with a careful workup are essential in determining the next steps in the care of a given patient. Recognition has become all the more important as we understand how to triage the 4% to 9% of patients with monoclonal gammopathies depending on age, with the goal of limiting overdiagnosis and misdiagnosis. In this review, we focus on treatment strategies for patients with monoclonal gammopathies that are not multiple myeloma, including smoldering multiple myeloma, light-chain amyloidosis, and Waldenström macroglobulinemia.

Diagnosis and management of Waldenström macroglobulinaemia-A British Society for Haematology guideline

SCOPE

The objective of this guideline is to provide healthcare professionals with clear guidance on the management of patients with Waldenström macroglobulinaemia. In individual patients, circumstances may dictate an alternative approach.

METHODOLOGY

This guideline was compiled according to the British Society for Haematology (BSH) process at http://www.b-s-h.org.uk/guidelines/proposing-and-writing-a-new-bsh-guideline/. Recommendations are based on a review of the literature using Medline, Pubmed, Embase, Central, Web of Science searches from beginning of 2013 (since the publication of the previous guidelines) up to November 2021. The following search terms were used: Waldenström('s) macroglobulin(a)emia OR lymphoplasmacytic lymphoma, IgM(-related) neuropathy OR cold h(a)emagglutinin disease OR cold agglutinin disease OR cryoglobulin(a)emia AND (for group a only) cytogenetic OR molecular OR mutation OR MYD88 OR CXCR4, management OR treatment OR transfusion OR supportive care OR plasma exchange OR plasmapheresis OR chemotherapy OR bendamustine OR bortezomib OR ibrutinib OR fludarabine OR dexamethasone OR cyclophosphamide OR rituximab OR everolimus, bone marrow transplantation OR stem cell transplantation. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) nomenclature was used to evaluate levels of evidence and to assess the strength of recommendations. The GRADE criteria can be found at http://www.gradeworkinggroup.org. Review of the manuscript was performed by the British Society for Haematology (BSH) Guidelines Committee Haemato-Oncology Task Force, the BSH Guidelines Committee and the Haemato-Oncology sounding board of BSH. It was also on the members section of the BSH website for comment. It has also been reviewed by UK Charity WMUK; these organisations do not necessarily approve or endorse the contents.

Use of BTK inhibitors with special focus on ibrutinib in Waldenström macroglobulinemia: an expert panel opinion statement

The pivotal role that ibrutinib plays in the management of Waldenström macroglobulinemia (WM) is undisputed but there are ongoing questions regarding its positioning in the therapeutic algorithm of WM as well as in some peculiar clinical situations. A panel of experts from Italy was convened to provide real world recommendations on the use of BTK inhibitors in lymphoproliferative diseases in general, and in patients with WM in particular. This position paper represents the panel's collective analysis, evaluation, and opinions and is made up of a series of questions frequently asked by practicing clinicians and answers based on currently available evidence. This article is protected by copyright. All rights reserved.

Treatment of Patients with Monoclonal Gammopathy of Clinical Significance

Simple Summary

Monoclonal gammopathy of clinical significance (MGCS) is a recently recognized clinical-pathological entity. Symptoms are caused by the presence of a monoclonal protein leading to high comorbidity. The affected organs vary according to the target antigen However, as most of the knowledge relies on case reports or short series; there is a lack of consensus regarding treatment approach. Here, we discuss MGCS other than renal (skin, ocular, neurologic, and bleeding disorders). We provide insights into the pathophysiology, diagnosis, treatment, and follow-up based on clinical cases. Finally, we discuss future directions in this field, such as potential novel therapeutic targets and prognosis of patients with MGCS.

Abstract

Monoclonal gammopathy of undetermined significance (MGUS) is defined as the presence of a monoclonal protein (M-protein) produced by a small amount of plasma cells. The majority of patients remain asymptomatic; however, a fraction of them develop clinical manifestations related to the monoclonal gammopathy despite not fulfilling criteria of multiple myeloma or other lymphoproliferative disorder. These patients constitute an emerging clinical issue coined as monoclonal gammopathy of clinical significance (MGCS). The mechanisms involved are poorly understood, and literature is scarce regarding management. The clinical spectrum involves symptoms related to renal, neurologic, skin, ocular, or bleeding manifestations, requiring a multidisciplinary approach. Treatment strategies rely on the basis of symptomatic disease and the M-protein isotype. In this review, we focus on MGCS other than renal, as the latter was earliest recognized and better known. We review the literature and discuss management from diagnosis to treatment based on illustrative cases from daily practice.

Waldenström's Macroglobulinemia: An Exploration into the Pathology and Diagnosis of a Complex B-Cell Malignancy

After 77 years since the initial description, Waldenström macroglobulinemia (WM) remains as a bone marrow neoplastic disorder with lymphoplasmacytic differentiation oversecreting a monoclonal immunoglobulin M (IgM). However, many biological and genetic aspects of this entity have been unraveled and it is now easy to correctly diagnose patients with this illness. The diagnosis requires the presence of a monoclonal IgM component and bone marrow lymphoid infiltration must be demonstrated. In addition, other small B-cell lymphoid neoplasms with plasma cell differentiation must be discarded. Although the clinical picture is highly heterogeneous, the diagnosis is much easier today compared to the past, since now we can demonstrate the presence of somatic mutations, especially the L265P mutation in the MYD88 gene, highly characteristic of WM (>90% of the patients), followed by the WHIM-like mutations in the CXCR4 gene (~35%). The identification of these mutations is very important, because they can modulate the response to new treatments with Bruton's tyrosine kinase (BTK) inhibitors. Thus, the conventional prognostic factors that predict the outcome of these patients (anemia, thrombopenia, high M component, high B2M, and advanced age), must be complemented with the genetic evaluation of the patient, that can help us in the prediction of the risk of transformation from asymptomatic to symptomatic forms (Del6q) and/or from indolent forms of the disease to aggressive lymphomas (CD79b mutations).

Nerve biopsy: Current indications and decision tools

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Paraproteinaemic neuropathy: MGUS and beyond

Paraproteinaemic neuropathies comprise a heterogeneous group of neuro-haematological conditions with some distinct neurological, haematological and systemic phenotypes. The spectrum of disease varies from mild to severe, indolent to rapidly progressive and from small fibre sensory involvement to dramatic sensorimotor deficits. The haematological association may be overlooked, resulting in delayed treatment, disability, impaired quality of life and increased mortality. However, the presence of an irrelevant benign paraprotein can sometimes lead to inappropriate treatment. In this review, we outline our practical approach to paraproteinaemic disorders, discuss the utility and limitations of diagnostic tests and the distinctive clinical phenotypes and touch on the complex multidisciplinary management approaches.

Managing complications secondary to Waldenström's macroglobulinemia

Introduction: Waldenström's macroglobulinemia (WM) is a rare lymphoma characterized by the accumulation of IgM-secreting lymphoplasmacytic cells in the bone marrow and other organs. Clinical sequelae relate to direct tissue infiltration by malignant cells but also to the physicochemical and immunological properties of the monoclonal IgM, resulting in a variety of disease-related complications.Areas covered: This narrative review, following a thorough Pubmed search of pertinent published literature, discusses complications secondary to WM, related to direct tumor infiltration, monoclonal IgM circulation, and deposition, as well as other less common ones. The description and pathophysiology of these complications were described together with their specific management strategies and in the context of available treatment options for WM (anti-CD20 monoclonal antibody-based combinations, proteasome inhibitors, BTK inhibitors, and other emerging ones).Expert opinion: The availability of many novel, active and less toxic regimens for the treatment of WM allows the management of the disease with strategies that depend on clinical presentation and disease-related complications, age, toxicity considerations, and presence of comorbidities.

The evaluation and management of monoclonal gammopathy of renal significance and monoclonal gammopathy of neurological significance

Despite the benign nature of monoclonal gammopathy of undetermined significance (MGUS), mounting data are associating MGUS with the development of organ dysfunction, specifically monoclonal gammopathy of renal significance (MGRS) and monoclonal gammopathy of neurological significance (MGNS), which could be associated with substantial morbidity. Emerging evidence suggests that patients with MGRS and MGNS could benefit from treatments used for myeloma, Waldenström macroglobulinemia, or chronic lymphocytic leukemia, depending on the underlying pathology. However, the treatment of MGRS and MGNS is not standardized, and potentially effective therapies might not be reimbursed because these conditions do not formally meet the criteria for malignant processes. The present review aims at establishing standards for the evaluation and management of MGRS and MGNS, which can facilitate the diagnosis of and provide therapeutic options for treating practitioners and patients affected by these conditions. The careful design and execution of clinical trials for patients with MGRS and MGNS are positively encouraged.

CANOMAD: a neurological monoclonal gammopathy of clinical significance that benefits from B-cell-targeted therapies

CANOMAD (chronic ataxic neuropathy, ophthalmoplegia, immunoglobulin M [IgM] paraprotein, cold agglutinins, and disialosyl antibodies) is a rare syndrome characterized by chronic neuropathy with sensory ataxia, ocular, and/or bulbar motor weakness in the presence of a monoclonal IgM reacting against gangliosides containing disialosyl epitopes. Data regarding associated hematologic malignancies and effective therapies in CANOMAD are scarce. We conducted a French multicenter retrospective study that included 45 patients with serum IgM antibodies reacting against disialosyl epitopes in the context of evocating neurologic symptoms. The main clinical features were sensitive symptoms (ataxia, paresthesia, hypoesthesia; n = 45, 100%), motor weakness (n = 18, 40%), ophthalmoplegia (n = 20, 45%), and bulbar symptoms (n = 6, 13%). Forty-five percent of the cohort had moderate to severe disability (modified Rankin score, 3-5). Cold agglutinins were identified in 15 (34%) patients. Electrophysiologic studies showed a demyelinating or axonal pattern in, respectively, 60% and 27% of cases. All patients had serum monoclonal IgM gammopathy (median, 2.6 g/L; range, 0.1-40 g/L). Overt hematologic malignancies were diagnosed in 16 patients (36%), with the most frequent being Waldenström macroglobulinemia (n = 9, 20%). Forty-one patients (91%) required treatment of CANOMAD. Intravenous immunoglobulins (IVIg) and rituximab-based regimens were the most effective therapies with, respectively, 53% and 52% of partial or better clinical responses. Corticosteroids and immunosuppressive drugs were largely ineffective. Although more studies are warranted to better define the optimal therapeutic sequence, IVIg should be proposed as the standard of care for first-line treatment and rituximab-based regimens for second-line treatment. These compiled data argue for CANOMAD to be included in neurologic monoclonal gammopathy of clinical significance.

The use of IVIg in the treatment of inflammatory polyneuropathies and myasthenia gravis at The Walton Centre

BACKGROUND

Immunoglobulin is a blood product used in a variety of medical disorders, usually delivered intravenously (IVIg). Neurology patients, particularly those with inflammatory polyneuropathy, utilise a lot of IVIg. There is a national shortage of immunoglobulin and, thus, pressing need to ensure minimum effective dosing as well as rigorous outcome assessments to assess benefit at treatment start and subsequently, as placebo effects can be strong.

METHODS

Serial audit of IVIg use at The Walton Centre against national guidelines was carried out through analysis of clinical notes of day unit patients. Review of the national immunoglobulin database and of neurology outpatient notes to benchmark our practice and provide some comparison with the wider nation was also performed.

RESULTS

Serial audit led to improved adherence to guidelines, and analysis of practice identified wide variation in IVIg use.

CONCLUSION

Local audit and benchmarking of practice can be used to promote quality and consistency of IVIg use across the NHS.

How I treat Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is an uncommon lymphoma characterized by the infiltration of the bone marrow by clonal lymphoplasmacytic cells that produce monoclonal immunoglobulin M (IgM). The disease may have an asymptomatic phase, or patients may present with symptoms and complications resulting from marrow or other tissue infiltration, or from physicochemical or immunological properties of the monoclonal IgM. Diagnosis of WM has been clearly defined, and genetic testing for somatic mutation of MYD88L265P is a useful tool for differential diagnosis from other conditions. Specific criteria that define symptomatic disease that needs treatment offer clinical guidance. The treatment of WM has evolved rapidly, with treatment options that include anti-CD20 monoclonal antibody-based combinations and BTK inhibitors. The choice of therapy is based on the need for rapid disease control, presence of specific disease complications, and patient's age. With the use of BTK inhibitors, the use of continuous therapy has been introduced as another option over fixed-duration chemoimmunotherapy. In this review, we focus on different clinical scenarios and discuss treatment options, based on the available data.

A matched case-control study comparing features, treatment and outcomes between patients with non-IgM lymphoplasmacytic lymphoma and Waldenström macroglobulinemia

Cases of non-IgM lymphoplasmacytic lymphoma (LPL) are rare. We performed a case-control study comparing features and outcomes of 31 non-IgM LPL cases and 93 Waldenström macroglobulinemia (WM) controls matched by age, sex, and year of diagnosis. Odds of MYD88 mutations were lower (odds ratio (OR) 0.22, p = .05), and median time to treatment was shorter in cases than in controls (4 vs. 32 months; p < .001). Odds of extramedullary disease were higher (OR 4.20, p = .01), while odds of neuropathy (OR 0.22, p = .25), and hyperviscosity (OR 0.26, p = .26) were lower in cases than in controls. Odds of using chemoimmunotherapy were higher (OR 2.62, p = .11) while odds of using proteasome inhibitors (OR 0.35, p = .15) and BTK inhibitors (OR 0.17, p = .21) were lower in cases than in controls. There were no differences in response and overall survival (OS) between cases and controls. Despite clinicopathological differences, response, and survival outcomes are similar between non-IgM LPL cases and WM controls.

A practical guide to laboratory investigations at diagnosis and follow up in Waldenström macroglobulinaemia: recommendations from the Medical and Scientific Advisory Group, Myeloma Australia, the Pathology Sub-committee of the Lymphoma and Related Diseases Registry and the Australasian Association of Clinical Biochemists Monoclonal Gammopathy Working Group

Waldenström macroglobulinaemia (WM) is an indolent non-Hodgkin lymphoma which usually presents with symptoms related to infiltration of bone marrow or other tissues like lymph nodes, liver or spleen and has certain unusual clinical manifestations, e.g., renal and central nervous system (CNS) involvement. It also has an array of laboratory features including hypersecretion of IgM, cryoglobulinaemia, increased plasma viscosity and identification of mutated MYD88^L265P in more than 90% of cases. In this review, we aim to provide a guide to the laboratory investigations recommended for WM at initial diagnosis and at follow-up. A discussion on the nuances of diagnosis and differential diagnoses is followed by bone marrow (BM) assessment, measurement of paraprotein and other ancillary investigations. Recommendations are provided on laboratory work-up at diagnosis, in the asymptomatic follow-up phase, and during and post-treatment. Finally, we briefly discuss the implications of laboratory diagnosis in regard to recruitment and monitoring on clinical trials.

How we manage Bing-Neel syndrome

Bing-Neel syndrome (BNS) is an uncommon presentation of Waldenström macroglobulinaemia (WM), seen during the course of the disease in about 1% of patients. BNS occurs when WM cells gain access to the central nervous system (CNS) causing neurological deficits. The diagnosis of BNS is suggested by the presence of radiological abnormalities, such as leptomeningeal enhancement on magnetic resonance imaging and confirmed by the presence of clonal lymphoplasmacytic cells and MYD88 L265P in the cerebrospinal fluid. The treatment of BNS requires agents with good penetration into the CNS, such as fludarabine, methotrexate and cytarabine. The novel Bruton Tyrosine Kinase inhibitor ibrutinib has shown CNS-penetrating properties, and recent data suggest a therapeutic role in BNS. In this review, we will discuss the clinical and pathological features, diagnostic criteria, treatment options and outcomes of patients with BNS.

An update on the diagnosis and management of the polyneuropathy of POEMS syndrome

POEMS syndrome is a rare, chronic, disabling paraneoplastic disorder characterized by peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma cells disorder and skin changes. Diagnosis relies on the fulfillment of a set of clinical criteria of which polyneuropathy and a monoclonal plasma cell dyscrasia are early and essential features. Treatment may be either local or systemic and is aimed at the monoclonal plasma cell disorder. Our knowledge of the pathogenesis underlying the POEMS syndrome has advanced greatly over the past years, favoring an important progression in the recognition and management of this disorder. Here, we discuss the recent literature that has advanced our knowledge of the pathogenesis and clinical management of the polyneuropathy in POEMS syndrome.

Initial Evaluation of the Patient with Waldenström Macroglobulinemia

The initial evaluation of the patient with Waldenström macroglobulinemia can be challenging. Not only is it a rare disease, but the clinical features can vary greatly from patient to patient. In this article, we aim at providing concise and practical recommendations for the initial evaluation of patients with Waldenström macroglobulinemia, specifically regarding history taking, physical examination, laboratory testing, bone marrow aspiration, and biopsy evaluation and imaging studies. We then review the most common special clinical situations seen in patients with Waldenström macroglobulinemia, especially anemia, hyperviscosity, cryoglobulinemia, peripheral neuropathy, extramedullary disease, Bing-Neel syndrome, and amyloidosis.

Waldenström macroglobulinemia treatment algorithm 2018

Waldenström macroglobulinemia is often an indolent disorder, and many patients are candidates for observation with careful monitoring. For symptomatic patients, one must distinguish between those patients whose symptoms are related to immunologic manifestations associated with the IgM monoclonal protein and those that have symptoms related to progressive marrow and nodal infiltration with lymphoplasmacytic lymphoma. In Waldenström macroglobulinemia, the driver for therapy in the majority of patients is progressive anemia, secondary to bone marrow replacement by lymphoplasmacytic lymphoma. Recent introduction of MYD88 mutational analysis has been very useful for diagnostic purposes but is unclear what effect it might have on the prognosis or response rate to therapy. An algorithm is provided on the management of asymptomatic individuals and the sequence used for chemotherapeutic intervention of symptomatic patients.

Waldenstrom's Macroglobulinemia: An Update

Waldenstrom Macroglobulinemia is a rare lymphoproliferative disorder with distinctive clinical features. Diagnostic and prognostic characterisation in WM significantly changed with the discovery of two molecular markers: MYD88 and CXCR4. Mutational status of these latter influences both clinical presentation and prognosis and demonstrated therapeutic implications. Treatment choice in Waldenstrom disease is strictly guided by patients age and characteristics, specific goals of therapy, the necessity for rapid disease control, the risk of treatment-related neuropathy, disease features, the risk of immunosuppression or secondary malignancies and potential for future autologous stem cell transplantation. The therapeutic landscape has expanded during the last years and the approval of ibrutinib, the first drug approved for Waldenstrom Macroglobulinemia, represents a significant step forward for a better management of the disease.

Waldenstrom's Macroglobulinemia: An Update

Waldenstrom Macroglobulinemia is a rare lymphoproliferative disorder with distinctive clinical features. Diagnostic and prognostic characterisation in WM significantly changed with the discovery of two molecular markers: MYD88 and CXCR4. Mutational status of these latter influences both clinical presentation and prognosis and demonstrated therapeutic implications. Treatment choice in Waldenstrom disease is strictly guided by patients age and characteristics, specific goals of therapy, the necessity for rapid disease control, the risk of treatment-related neuropathy, disease features, the risk of immunosuppression or secondary malignancies and potential for future autologous stem cell transplantation. The therapeutic landscape has expanded during the last years and the approval of ibrutinib, the first drug approved for Waldenstrom Macroglobulinemia, represents a significant step forward for a better management of the disease.

Advances in the understanding of IgM monoclonal gammopathy of undetermined significance

Among monoclonal gammopathies of undetermined significance (MGUSs), the immunoglobulin M (IgM) MGUS subtype stands as a unique entity and plays a pivotal role as a pre-malignant condition for multiple B-cell non-Hodgkin lymphomas, most notably Waldenström macroglobulinemia (WM). A relationship between IgM MGUS and WM has been proposed for decades. However, insight regarding the pathobiology of these two conditions improved significantly in recent years, strengthening the hypothesis that WM and IgM MGUS are different stages of the same disease. Therefore, the understanding of IgM MGUS and that of WM are interconnected and advances in one will likely impact the other. Furthermore, IgM MGUS has been more commonly recognized as the underlying etiology of IgM-related disorders. In this review, we explore recent advances in the understanding of the pathobiology of IgM MGUS and WM and the treatment of common IgM-related disorders.