Clinical spectrum of Castleman disease-associated neuropathy

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.

Paraneoplastic neuropathies and peripheral nerve hyperexcitability disorders

Peripheral neuropathy is a common referral for patients to the neurologic clinics. Paraneoplastic neuropathies account for a small but high morbidity and mortality subgroup. Symptoms include weakness, sensory loss, sweating irregularity, blood pressure instability, severe constipation, and neuropathic pain. Neuropathy is the first presenting symptom of malignancy among many patients. The molecular and cellular oncogenic immune targets reside within cell bodies, axons, cytoplasms, or surface membranes of neural tissues. A more favorable immune treatment outcome occurs in those where the targets reside on the cell surface. Patients with antibodies binding cell surface antigens commonly have neural hyperexcitability with pain, cramps, fasciculations, and hyperhidrotic attacks (CASPR2, LGI1, and others). The antigenic targets are also commonly expressed in the central nervous system, with presenting symptoms being myelopathy, encephalopathy, and seizures with neuropathy, often masked. Pain and autonomic components typically relate to small nerve fiber involvement (nociceptive, adrenergic, enteric, and sudomotor), sometimes without nerve fiber loss but rather hyperexcitability. The specific antibodies discovered help direct cancer investigations. Among the primary axonal paraneoplastic neuropathies, pathognomonic clinical features do not exist, and testing for multiple antibodies simultaneously provides the best sensitivity in testing (AGNA1-SOX1; amphiphysin; ANNA-1-HU; ANNA-3-DACH1; CASPR2; CRMP5; LGI1; PCA2-MAP1B, and others). Performing confirmatory antibody testing using adjunct methods improves specificity. Antibody-mediated demyelinating paraneoplastic neuropathies are limited to MAG-IgM (IgM-MGUS, Waldenström's, and myeloma), with the others associated with cytokine elevations (VEGF, IL6) caused by osteosclerotic myeloma, plasmacytoma (POEMS), and rarely angiofollicular lymphoma (Castleman's). Paraneoplastic disorders have clinical overlap with other idiopathic antibody disorders, including IgG4 demyelinating nodopathies (NF155 and Contactin-1). This review summarizes the paraneoplastic neuropathies, including those with peripheral nerve hyperexcitability.

Unmet Clinical Needs in the Management of Idiopathic Multicentric Castleman Disease: A Consensus-based Position Paper From an ad hoc Expert Panel

Castleman disease describes a group of heterogeneous clinicopathological disorders now included in the tumor-like lesions with B-cell predominance of the World Health Organization classification. Managing idiopathic multicentric Castleman disease (iMCD) is challenging, because few systematic studies or comparative randomized clinical trials have been conducted. International, consensus evidence-based guidelines for iMCD were published in 2018, but gaps in the therapeutic options for difficult-to-treat patients, who do not respond to siltuximab and other conventional therapies, still exist. This article presents the results of group discussion among an ad hoc constituted Panel of Italian experts to identify and address unmet clinical needs (UCNs) in managing iMCD. Recommendations on the appropriateness of clinical decisions and proposals for new research concerning the identified UCNs were issued through formalized multiple-step procedures after a comprehensive analysis of the scientific literature. The following key UCNs were addressed: strengthening the diagnostic certainty in iMCD patients before planning first-line therapy; management of siltuximab therapy; choice and management of immune-modulating, or chemotherapy agents in patients resistant/intolerant to siltuximab therapy. While most of the conclusions reached by the Panel are consistent with the existing guidelines, some alternative therapeutic options were stressed, and the discussion contributed to bringing forth the issues that need further investigation. Hopefully, this comprehensive overview will improve the practice of iMCD and inform the design and implementation of new studies in the field.

From Biology to Treatment of Monoclonal Gammopathies of Neurological Significance

Monoclonal gammopathy and peripheral neuropathy are common diseases of elderly patients, and almost 10% of patients with neuropathy of unknown cause have paraprotein. However, growing evidence suggests that several hematological malignancies synthesize and release monoclonal proteins that damage the peripheral nervous system through different mechanisms. The spectrum of the disease varies from mild to rapidly progressive symptoms, sometimes affecting not only sensory nerve fibers, but also motor and autonomic fibers. Therefore, a multidisciplinary approach, mainly between hematologists and neurologists, is recommended in order to establish the correct diagnosis of monoclonal gammopathy of neurological significance and to tailor therapy based on specific genetic mutations. In this review, we summarize the spectrum of monoclonal gammopathies of neurological significance, their distinctive clinical and neurophysiological phenotypes, the most relevant pathophysiological events and new therapeutic approaches.

Rare Association Between Idiopathic Multicentric Castleman Disease, Nephrotic Syndrome and Polyneuropathy in an Immunocompetent Patient

Multicentric Castleman disease (MCD) represents a group of poorly understood lymphoproliferative disorders related to proinflammatory hypercytokinaemia. In immunocompetent patients the aetiology is still unknown, hence the designation of idiopathic MCD (iMCD). To successfully diagnose iMCD, diagnostic criteria must be fulfilled and a large array of alternative diagnoses excluded. Peripheral neuropathy and nephropathy are relatively common findings in cases associated with POEMS syndrome, but very rarely reported in iMCD. We present the case of a 64-year-old man with iMCD (HIV- and HHV-8-negative) with nephrotic syndrome and severe motor polyneuropathy. Alternative diagnoses were excluded. The patient was treated with intravenous glucocorticoid followed by rituximab. Complete clinical and laboratory remission was achieved and maintained at the 2-year follow-up.

LEARNING POINTS

iMCD is a lymphoproliferative disease in immunocompetent patients with no known cause.To diagnose iMCD major and minor criteria must be fulfilled, and alternative diagnoses must be excluded.Nephrotic syndrome and motor polyneuropathy are rare in iMCD and all alternative diagnoses must be excluded before relating all of these.

Weathering the COVID-19 storm: Lessons from hematologic cytokine syndromes

A subset of patients with severe COVID-19 develop profound inflammation and multi-organ dysfunction consistent with a "Cytokine Storm Syndrome" (CSS). In this review we compare the clinical features, diagnosis, and pathogenesis of COVID-CSS with other hematological CSS, namely secondary hemophagocytic lymphohistiocytosis (sHLH), idiopathic multicentric Castleman disease (iMCD), and CAR-T cell therapy associated Cytokine Release Syndrome (CRS). Novel therapeutics targeting cytokines or inhibiting cell signaling pathways have now become the mainstay of treatment in these CSS. We review the evidence for cytokine blockade and attenuation in these known CSS as well as the emerging literature and clinical trials pertaining to COVID-CSS. Established markers of inflammation as well as cytokine levels are compared and contrasted between these four entities in order to establish a foundation for future diagnostic criteria of COVID-CSS.

Overview of Castleman disease

Castleman disease (CD) describes a group of at least 4 disorders that share a spectrum of characteristic histopathological features but have a wide range of etiologies, presentations, treatments, and outcomes. CD includes unicentric CD (UCD) and multicentric CD (MCD), the latter of which is divided into idiopathic MCD (iMCD), human herpes virus-8 (HHV8)-associated MCD (HHV8-MCD), and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD (POEMS-MCD). iMCD can be further subclassified into iMCD-thrombocytopenia, ascites, reticulin fibrosis, renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS). Advances in diagnosis, classification, pathogenesis, and therapy are substantial since the original description of UCD by Benjamin Castleman in 1954. The advent of effective retroviral therapy and use of rituximab in HHV8-MCD have improved outcomes in HHV8-MCD. Anti-interleukin-6-directed therapies are highly effective in many iMCD patients, but additional therapies are required for refractory cases. Much of the recent progress has been coordinated by the Castleman Disease Collaborative Network (CDCN), and further progress will be made by continued engagement of physicians, scientists, and patients. Progress can also be facilitated by encouraging patients to self-enroll in the CDCN's ACCELERATE natural history registry (#NCT02817997; www.CDCN.org/ACCELERATE).

POEMS syndrome: A multisystem clonal disorder

Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome is a rare condition defined by monoclonal plasma cell disorder, peripheral neuropathy, and other systemic symptoms. The pathophysiology of POEMS syndrome is unknown, but the overproduction of vascular endothelial growth factor (VEGF) appears to be an important contributory element. The diagnosis of POEMS syndrome requires the presence of both mandatory criteria (ie, polyneuropathy and a monoclonal plasma cell disorder), at least one major criterion (ie, osteosclerotic bone lesions, Castleman disease, or elevated serum or plasma levels of vascular endothelial growth factor), and at least one of the six minor criteria. POEMS syndrome lacks a standard treatment, but patients with limited sclerotic bone lesions are typically treated with radiation therapy. In contrast, those with widespread lesions receive chemotherapy and hematopoietic stem cell transplantation.

From pathogenesis to personalized treatments of neuropathies in hematological malignancies

The peripheral nervous system may be involved at any stage in the course of several hematological diseases, the most common being monoclonal gammopathies (of undetermined significance or malignant) or lymphomas. The underlying pathogenic mechanisms are different and therapies aim at targeting the dangerous either B-cell or plasma cell clones. Recently, high-throughput technologies, and next-generation sequencing have increased our knowledge of hematological diseases pathogenesis by the identification of somatic mutation affecting pivotal signaling pathways. Accordingly, new target therapies are used that may also be borrowed for treatment of neuropathies in hematological diseases.

Clinical characteristics, risk factors, and outcomes of POEMS syndrome

Objective

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin lesions) is a paraneoplastic disorder resulting in severe neurologic disability. Understanding the clinical, laboratory, neurophysiologic, and histopathologic features as well as treatment responses of POEMS will assist in more accurate and timely diagnosis, risk stratification, and effective management.

Methods

This was a retrospective longitudinal cohort study from 1998 to March 2019, with 7,184 person-months of follow-up time. Hospital databases were used to collate presenting features, investigations, therapies, and response.

Results

One hundred patients were included with a median follow-up time of 59 months (range, 1–252). Mean symptom onset to diagnosis was 15 months (range, 1–77), with 54% of patients initially misdiagnosed with chronic inflammatory demyelinating polyneuropathy. Median number of multisystem features at diagnosis was 7. Ninety-six (96%) presented with neuropathy, which was length-dependent in 93 (93%) and painful in 75 (75%). At diagnosis, 35% of patients were wheelchair or bedbound, with median Overall Neuropathy Limitation Score of 6, improving to 3 following treatment (p < 0.05). Five-year survival was 90% and 82% at 10 years, with 5- and 10-year progression-free survival of 65% and 53%. Nontreatment with autologous stem cell transplantation, nonhematologic response, and non–vascular endothelial growth factor response are significant risk factors in multivariate analysis to predict progression or death. Risk factors are incorporated to develop a risk score enabling stratification of high- and low-risk cases.

Conclusions

POEMS syndrome is a rare multisystem condition with delayed diagnosis and poor neurologic function at presentation. Therapy has favorable outcomes. Patients at high risk of death or progression can be identified, which may allow for more active monitoring and influence management.

Treatment response and prognosis of POEMS syndrome coexisting with Castleman disease

POEMS (polyneuropathy, organomegaly, endocrinopathy monoclonal gammopathy, and skin changes) syndrome is occasionally associated with Castleman disease (CD) and their prognosis is considered as poorer than that in POEMS alone patients. To elucidate recent prognosis of POEMS syndrome coexisting with CD, we reviewed clinical data of 102 patients with POEMS syndrome treated at our institution between 2000 and 2018 and compared clinical characteristics, response to treatment, and prognosis between POEMS patients with biopsy-proven CD (POEMS-CD) and those without it. Fourteen POEMS-CD patients and 56 POEMS alone patients were identified, and the remaining 32 patients with unbiopsied lymphadenopathy were excluded. POEMS-CD patients significantly showed earlier onset and less severe neuropathic symptoms. Most of the POEMS-CD patients were treated with thalidomide and dexamethasone (n = 10, 71%), and subsequently received autologous stem cell transplantation (n = 6, 43%). Response to thalidomide was better in patients with POEMS-CD than those with POEMS alone (90% vs 43% clinical response, [p = .012]; 80% vs 45% normalization of serum VEGF levels, [p = .079]). The 10-year overall survival (95% confidence interval) was 89% (50-98%) in POEMS-CD patients and 61% (42-77%) in those with POEMS alone. POEMS syndrome associated with CD constitutes a subgroup of POEMS syndromes characterized by earlier onset, mild polyneuropathy, and favorable response to treatment. Recognition of this subgroup is significant for determination of therapeutic strategy.

Characteristics of 1946 Cases of POEMS Syndrome in Chinese Subjects: A Literature-Based Study

POEMS syndrome is a rare paraneoplastic disorder characterized secondary to a rare plasma cell dyscrasia. Here, we aimed to analyze the clinical characteristics of large sample cases of POEMS in Chinese subjects through making a review of the Chinese literature. Four databases were electronically searched from inception until October 2016. Case reports and case series were identified. Six hundred studies with 1946 participants were identified. The first case was reported in 1986, and the number of reported cases peaked in 2009 and 2010. The top seven provinces on the number of reported cases were in the south-east area of China. The top three departments on the number of published papers and reported cases were ordinally department of Neurology, Hematology, and Endocrinology. The ratio of male to female was about 2.23. The range of age onset was from 10 to 81 years with the mean age of 46.39 (SD, 12.10 years). The initial symptoms of POEMS with peripheral neuropathy, edema and effusions, endocrinopathy, skin changes, and organomegaly accounted for 60.44, 15.72, 9.87, 8.05, and 2.13%, respectively, and subsequently acquired above symptoms as the prevalence was 99.49, 81.91, 75.56, 77.08, and 83.09%, respectively. The present study would help to understand the clinical presentations of POEMS syndrome in the Chinese population.

51-year old man with tingling, burning and progressive limb weakness

Peripheral neuropathy is a common reason for referral to neurology. Chronic acquired demyelinating neuropathies are an important and varied group with overlapping presentations, and may have an immune-mediated cause. Their correct diagnosis is important as they respond to different treatments; timely intervention can prevent irreversible axonal degeneration. We present a case that highlights the approach to an adult presenting with a chronic demyelinating neuropathy.

Neurological impairment in a patient with concurrent cervical disc herniation and POEMS syndrome

PURPOSE

POEMS syndrome is a rare clonal plasma cell disease characterized by polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes. We report a rare case of neurological impairment in patients with concurrent cervical disc herniation and POEMS syndrome.

METHODS

A patient presented to a local hospital with C3/4 and C4/5 disc herniation, apparent spinal cord compression concomitant with neurological signs, and concurrent POEMS syndrome. Anterior cervical discectomy and fusion was performed.

RESULTS

The limb numbness was only slightly alleviated, and 10 days postoperatively the patient complained of muscle weakness of the extremities and was referred to our hospital. The patients exhibited non-typical neurological signs and an enlarged liver and spleen that could not be explained. Electroneuromyography and immunofixation electrophoresis produced abnormal results. We diagnosed concurrent POEMS syndrome, for which drug therapy was prescribed. The patient's symptoms receded.

CONCLUSION

Patients presenting with cervical spondylopathy and non-typical neurological signs and symptoms or other systemic problems should be evaluated for the presence of concurrent disease and ruled out differential diagnoses.

Peripheral nervous system involvement in lymphomas

The peripheral nervous system may be involved at any stage in the course of lymphoproliferative diseases. The different underlying mechanisms include neurotoxicity secondary to chemotherapy, direct nerve infiltration (neurolymphomatosis), infections, immune-mediated, paraneoplastic or metabolic processes and nutritional deficiencies. Accordingly, the clinical features are heterogeneous and depend on the localization of the damage (ganglia, roots, plexi, and peripheral nerves) and on the involved structures (myelin, axon, and cell body). Some clinical findings, such a focal or diffuse involvement, symmetric or asymmetric pattern, presence of pain may point to the correct diagnosis. Besides a thorough medical history and neurological examination, neurophysiological studies, cerebrospinal fluid analysis, nerve biopsy (in selected patients with suspected lymphomatous infiltration) and neuroimaging techniques (magnetic resonance neurography and nerve ultrasound) may be crucial for a proper diagnostic workup.

POEMS syndrome: clinical update

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes) is a rare paraneoplastic syndrome, caused by a plasma cell proliferative disorder, which is most commonly lambda restricted. The neurological hallmark, which forms one of the mandatory criteria for diagnosis, is a subacute onset demyelinating neuropathy, which can be rapidly disabling and painful. A number of multi-system features are also characteristic of this disorder, and certainly not restricted to those included in its acronym, which though limited, remains a useful and memorable name, helping distinguish POEMS syndrome from other paraproteinaemic neuropathies. The discovery of vascular endothelial growth factor (VEGF) in association with POEMS syndrome has been extremely useful in aiding clinical diagnosis, and monitoring response to treatment, as well as helping understand the underlying mechanism of disease. Interestingly, however, treatment targeting VEGF has been disappointing, suggesting other disease mechanisms or inflammatory processes are also important. Current understanding of the pathogenesis of POEMS syndrome is outlined in detail in the accompanying article by Cerri et al. Here, we review the clinical features of POEMS syndrome, differential diagnosis and available treatment options, based on current literature.

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.

POEMS syndrome: diagnostic delay and successful treatment with lenalidomide, cyclophosphamide and prednisone followed by autologous peripheral stem cell transplantation

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome is a rare systemic disease, often unrecognised in the primary care setting. POEMS syndrome is associated with plasma cell dyscrasias and upregulation of vascular endothelial growth factor leading to systemic oedema, papilloedema and pulmonary hypertension. A wide constellation of presenting symptoms often leads to late diagnosis. Unrecognised and untreated disease rapidly leads to death from neuropathic exhaustion or cardiopulmonary failure. Treatment is extrapolated from other plasma cell dyscrasias such as multiple myeloma. Autologous peripheral blood stem cell transplantation (PBSCT) is often an important component of treatment. There is no established standard of care for POEMS syndrome. Therapies include lenalidomide, bortezomib and targeted monoclonal antibodies. We present a patient with POEMS syndrome who achieved rapid complete response to triple therapy consisting of lenalidomide, cyclophosphamide and prednisone, followed by high-dose chemotherapy and PBSCT.

Diagnosis of Castleman Disease

Castleman disease (CD) is a rare and heterogenous group of disorders sharing in common an abnormal lymph node pathology. CD comprises distinct subtypes with different prognoses. Unicentric CD and multicentric CD are featured by specific systemic manifestations and may be associated with Kaposi sarcoma, non-Hodgkin and Hodgkin lymphoma, and POEMS syndrome. Multicentric CD is classically associated with systemic symptoms and poorer prognosis. In this article, the authors review how to diagnose the disease, keeping in context the clinical findings, biochemical changes and complications associated with CD.

The Peripheral Neuropathies of POEMS Syndrome and Castleman Disease

Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS) syndrome is a rare paraneoplastic disorder. The polyneuropathy can be the presenting symptom and is typically a painful, motor-predominant polyradiculoneuropathy often mimicking chronic inflammatory demyelinating polyradiculoneuropathy. The presence of a lambda monoclonal protein, elevated vascular endothelial growth factor, systemic features, and treatment resistance are clues to the diagnosis. Castleman disease (CD) is seen in a subset of these patients, and when present the neuropathy is similar but less severe. In contrast, in those patients with purely CD, the neuropathy is often a mild, painless distal sensory neuropathy.