Human Herpesvirus 8 Infection in Patients With POEMS Syndrome–Associated Multicentric Castleman’s Disease

Promising immunotherapeutic approaches for primary effusion lymphoma

Primary effusion lymphoma (PEL) is a large B-cell neoplasm usually presenting as a serious effusion in body cavities without detectable tumor masses. It is an AIDS-related non-Hodgkin's lymphoma (HL) with human herpes virus 8 (HHV8)/Kaposi sarcoma-associated herpes virus (KSHV) infection. A combination antiretroviral therapy (cART) prolongs the lifespan of AIDS and AIDS-related malignant lymphoma patients, but PEL continues to have a dismal prognosis. PEL showed disappointing outcomes with standard chemotherapy such as CHOP or CHOP-like regimens. A PEL status highlights the urgent need for new therapeutic approaches and treatment strategies and improve clinical outcomes. This review discusses the current knowledge and some recent clinical trials for PEL in the platform of immunotherapy as well as promising future immunotherapeutic approaches for PEL.

The innate and T-cell mediated immune response during acute and chronic gammaherpesvirus infection

Immediately after entry into host cells, viruses are sensed by the innate immune system, leading to the activation of innate antiviral effector mechanisms including the type I interferon (IFN) response and natural killer (NK) cells. This innate immune response helps to shape an effective adaptive T cell immune response mediated by cytotoxic T cells and CD4+ T helper cells and is also critical for the maintenance of protective T cells during chronic infection. The human gammaherpesvirus Epstein-Barr virus (EBV) is a highly prevalent lymphotropic oncovirus that establishes chronic lifelong infections in the vast majority of the adult population. Although acute EBV infection is controlled in an immunocompetent host, chronic EBV infection can lead to severe complications in immunosuppressed patients. Given that EBV is strictly host-specific, its murine homolog murid herpesvirus 4 or MHV68 is a widely used model to obtain in vivo insights into the interaction between gammaherpesviruses and their host. Despite the fact that EBV and MHV68 have developed strategies to evade the innate and adaptive immune response, innate antiviral effector mechanisms still play a vital role in not only controlling the acute infection but also shaping an efficient long-lasting adaptive immune response. Here, we summarize the current knowledge about the innate immune response mediated by the type I IFN system and NK cells, and the adaptive T cell-mediated response during EBV and MHV68 infection. Investigating the fine-tuned interplay between the innate immune and T cell response will provide valuable insights which may be exploited to design better therapeutic strategies to vanquish chronic herpesviral infection.

KSHV/HHV8-positive large B-cell lymphomas and associated diseases: a heterogeneous group of lymphoproliferative processes with significant clinicopathological overlap

In this review, we focus on the current understanding of the diagnosis of human herpesvirus 8 (HHV8)-associated lymphoproliferative disorders-a group of entities that range from hyperplastic proliferations to frank lymphomas. These diseases tend to occur in immunodeficient patients, but may occur in immunocompetent individuals as well. In recent years, we have learned of occasional cases with overlapping features among HHV8 entities, such as lesions intermediate between primary effusion lymphoma and HHV8-positive diffuse large B-cell lymphoma, not otherwise specified or cases sharing features of multicentric Castleman disease and germinotropic lymphoproliferative disorder. There is also a significant clinical overlap between these entities. It is important to have a better understanding of the biology of these lesions and to refine diagnostic criteria of these lesions, as the use of immunosuppressive agents to treat a variety of diseases, the expanded use of transplant as a therapeutic modality for a variety of cancers and organ failure patients, and the extended longevity of HIV-positive patients will likely result in an increased incidence of these lymphoproliferative processes in the future.

POEMS Syndrome: 2019 Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal PCD, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. Risk factors include low serum albumin, age, pleural effusion, pulmonary hypertension, and reduced eGFR.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

POEMS syndrome: 2017 Update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with 3 of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy RISK-ADAPTED THERAPY: For those patients with a dominant sclerotic plasmacytoma, first-line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low-dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. The benefit of anti-VEGF antibodies is conflicting. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Cytokines in Endocrine Dysfunction of Plasma Cell Disorders

Monoclonal gammopathies (MG) are classically associated with lytic bone lesions, hypercalcemia, anemia, and renal insufficiency. However, in some cases, symptoms of endocrine dysfunction are more prominent than these classical signs and misdiagnosis can thus be possible. This concerns especially the situation where the presence of M-protein is limited and the serum protein electrophoresis (sPEP) appears normal. To understand the origin of the endocrine symptoms associated with MG, we overview here the current knowledge on the complexity of interactions between cytokines and the endocrine system in MG and discuss the perspectives for both the diagnosis and treatments for this class of diseases. We also illustrate the role of major cytokines and growth factors such as IL-6, IL-1β, TNF-α, and VEGF in the endocrine system, as these tumor-relevant signaling molecules not only help the clonal expansion and invasion of the tumor cells but also influence cellular metabolism through autocrine, paracrine, and endocrine mechanisms. We further discuss the broader impact of these tumor environment-derived molecules and proinflammatory state on systemic hormone signaling. The diagnostic challenges and clinical work-up are illustrated from the point of view of an endocrinologist.

Human herpesvirus 8-related diseases: Histopathologic diagnosis and disease mechanisms

The emergence of HIV/AIDS more than three decades ago led to an increased incidence of diseases caused by HHV8 co-infection, particularly Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. Over time, the development of highly effective AIDS therapies has resulted in a decreased incidence of HHV8-associated entities, which are now more commonly found in patients with undiagnosed and/or untreated AIDS. Due to their rarity, some of these diseases may be difficult to recognize without appropriate clinical information. This article provides an overview of HHV8-related disorders, with a focus on their morphologic and phenotypic features, and includes a brief overview of laboratory methods used to detect HHV8. Disease mechanisms by which the HHV8 virion promotes tumorigenesis are also reviewed.

Siltuximab and hematologic malignancies. A focus in non Hodgkin lymphoma

INTRODUCTION

The role of interleukin-6 (IL-6) in tumorigenesis and in particular in haematological malignancies is crucial. On the basis of the favourable results obtained in the subset of multicentric Castleman disease (MCD), Siltuximab, a chimeric, human-murine, immunoglobulin (Ig) Gk monoclonal antibody directed against human IL-6 has been evaluated in haematological malignancies such as multiple myeloma, myelodisplastic syndromes and non Hodgkin lymphomas. Areas covered: This review discusses available data related to the role of IL-6 as a therapeutic target, the characteristics of Siltuximab in term pharmacokinetics and pharmacodynamics properties and a detailed analysis of the studies involving haematological malignancies with a peculiar focus on non Hodgkin lymphoma. Expert opinion: The results obtained with Siltuximab in haematological malignancies and in particular with non Hodgkin lymphoma are inferior to those obtained in MCD. The complex interaction between malignant clones, inflammatory background and host response could justify this difference. New interesting areas of study are the role of Siltuximab in early phase of multiple myeloma (smoldering multiple myeloma) and if there may be a possible future application in the treatment of Waldenström macroglobulinemia.

POEMS syndrome: update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. The benefit of anti-VEGF antibodies is conflicting. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Systemic expression of Kaposi sarcoma herpesvirus (KSHV) Vflip in endothelial cells leads to a profound proinflammatory phenotype and myeloid lineage remodeling in vivo

KSHV is the causative agent of Kaposi sarcoma (KS), a spindle-shaped endothelial cell neoplasm accompanied by an inflammatory infiltrate. To evaluate the role of KSHV vFLIP in the pathogenesis of KS, we constructed mice with inducible expression of vFLIP in endothelial cells. Abnormal cells with endothelial marker expression and fusiform appearance were observed in several tissues reminiscent of the spindle cells found in KS. Serum cytokines displayed a profound perturbation similar to that described in KSHV inflammatory cytokine syndrome (KICS), a recently described clinical condition characterized by elevated IL6 and IL10. An increased myeloid component with suppressive immune phenotype was found, which may contribute to functional changes in the microenvironment and cellular heterogeneity as observed in KS. These mice represent the first in vivo demonstration that vFLIP is capable of inducing vascular abnormalities and changes in host microenvironment with important implications for understanding the pathogenesis and treating KSHV-associated diseases.

Kaposi’s sarcoma (KS) is the most common cancer in men infected with HIV, and also among the most frequent malignancies in Sub-Equatorial Africa. KS is a tumor of endothelial cell origin that is caused by infection with a gamma-herpesvirus, called KS herpesvirus (KSHV) or human herpesvirus 8 (HHV-8). KSHV vFLIP is a viral oncoprotein expressed during latent infection. We report here the generation and characterization of mice expressing KSHV vFLIP in an inducible manner in endothelial cells. Transgenic mice showed: 1) systemic endothelial abnormalities, with the presence of fusiform cells reminiscent of the spindle cells found in KS, 2) development of a profound perturbation in serum cytokines, reminiscent of the cytokine storm characteristic of KSHV-associated cytokine syndrome (KICS), and 3) remodeling of myeloid differentiation with expansion of myeloid cells displaying a suppressive immunophenotype that potentially favors host immune evasion, angiogenesis and tumor progression. This is the first example of significant changes in myeloid differentiation, vascular abnormalities and cytokine perturbation entirely initiated by ectopic expression of a single viral gene, making this mouse model a useful system to dissect the mechanisms viruses use to manipulate the host microenvironment culminating in sabotage of immunity and development of vascular lesions.

POEMS syndrome: 2014 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal PCD, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the PCD is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. The benefit of anti-VEGF antibodies is conflicting. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Multicentric Castleman's disease: a challenging diagnosis

Multicentric Castleman's disease (MCD) is a sytemic disorder with flares of non-specific symptoms suggestive of a chronic inflammatory syndrome. It is typically accompanied by generalized lymphadenopathy and multiorgan involvement. Histologically, two main variants of Castleman's disease exist, the hyalin vascular type and the plasma cell variant. Upon localization unicentric (localized), and multicentric (diffuse, systemic) subtypes can be distinguished with more different disease outcomes. Patients often exhibit acute phase reactions and several autoimmune phenomena, and are at high risk for developing malignancies. Both the idiopathic and the HHV-8-driven infectious forms of MCD represent distinct disease entities with a less favorable prognosis. The induction of human IL-6 excess via yet unknown upstream mechanisms, and overexpression of viral IL-6 by HHV-8 can pivotally influence MCD biology. Based on the role of IL-6 in pathogenesis, MCD is also designated as IL-6 lymphadenopathy. To date there are no direct therapeutic evidences, but having been translated to daily practice the main regulatory factors may serve as promising therapeutic targets.

Castleman disease

Castleman and Towne described a disease presenting as a mediastinal mass resembling thymoma. It is also known as "giant lymph node hyperplasia", "lymph node hamartoma", "angiofollicular mediastinal lymph node hyperplasia", and "angiomatous lymphoid hyperplasia". The pathogenesis is unknown, but the bulk of evidence points toward faulty immune regulation, resulting in excessive B-lymphocyte and plasma-cell proliferation in lymphatic tissue. In addition to the mediastinal presentation, extrathoracic involvement in the neck, axilla, mesentery, pelvis, pancreas, adrenal gland, and retroperitoneum also have been described. There are 2 major pathologic variations of Castleman disease: (1) hyaline-vascular variant, the most frequent, characterized by small hyaline-vascular follicles and capillary proliferation; and (2) the plasma-cell variant, in which large lymphoid follicles are separated by sheets of plasma cells. The hyaline-vascular cases usually are largely asymptomatic, whereas the less common plasma-cell variant may present with fever, anemia, weight loss, and night sweats, along with polyclonal hypergamma-globulinemia. Castleman disease is a rare lymphoproliferative disorders. Few cases have been described world widely. In this article we reviewed the classification, pathogenesis, pathology, radiological features and up to date treatment with special emphasis on the role of viral stimulation, recent therapeutic modalities and the HIV-associated disease.

POEMS syndrome: update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with 3 of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. The benefit of anti-VEGF antibodies is conflicting. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

[POEMS syndrome. An interdisciplinary clinical challenge]

POEMS syndrome is a rare paraneoplastic syndrome due to a plasma cell dyscrasia, which includes peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma cell proliferation and skin changes. Elevated levels of VEGF (vascular endothelial growth factor) in the serum of patients are suggested to play a pivotal role in the pathophysiology. A 60-year-old male presented with POEMS syndrome and painful edema, skin thickening of the distal extremities and livid-erythematous discoloration. The sclerotic changes resulted in a severe limitation of joint flexibility. Furthermore, the patient showed clubbing, white nails and a facial lipoatrophy. In addition to the skin changes, the patient was diagnosed with polyneuropathy, monoclonal gammopathy (type lambda), high elevated VEGF-levels, hepatomegaly, lymphadenopathy, hypothyreosis, hypogonadism and thrombocytosis in the course of POEMS syndrome. Treatment with 4 cycles of bortezomib and dexamethasone resulted in improvement of symptoms.

POEMS syndrome: 2011 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. The benefit of anti-VEGF antibodies is conflicting. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Castleman's disease of the neck: report of 4 cases with unusual presentations

Purpose

Most of the previously reported cases of Castleman’s disease (CD) in the neck were of the hyaline vascular type and the most common sign was an asymptomatic neck mass. To achieve a more general recognition of CD in the neck, we present four cases of CD in the neck with unusual presentations.

Patients and Methods

We describe four cases of CD in the neck with unusual clinical manifestations, different histopathologic subtypes and discuss the problems arising in their clinical findings.

Results

Two cases were plasma cell type with multiple bilateral enlarged lymph nodes and systemic manifestations. Two cases presented as a solitary mass were hyaline vascular type. One case underwent twice local recurrence and evolved from the hyaline vascular CD to follicular dendritic cell sarcoma.

Conclusions

Cervical plasma cell CD may have a tendency to present as multiple masses on the both sides with systemic manifestations. It is necessary to pay more attention on the overgrowth of follicular dendritic cells in the hyaline vascular CD, which might represent a precursor of follicular dendritic cell sarcoma.

Bone marrow histopathology in POEMS syndrome: a distinctive combination of plasma cell, lymphoid, and myeloid findings in 87 patients

POEMS is an uncommon syndromic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. There are few descriptions of the bone marrow pathology of POEMS; therefore, peripheral blood smears and bone marrow aspirates and biopsies from 87 patients (143 total, 67 pretreatment, 76 posttreatment cases) with POEMS were studied. Plasma cell clonality was analyzed by flow cytometry, immunohistochemistry, and/or in situ hybridization. Monotypic plasma cells were detected in 44 pretreatment cases (66%); the majority of plasma cells expressed λ light chain (91%). The monotypic plasma cells typically were present in a background of increased polytypic plasma cells. Lymphoid aggregates were found in 33 (49%) pretreatment cases and in most cases were rimmed by plasma cells (97%). Megakaryocyte hyperplasia (36 cases) and clusters (62 cases) were frequent; however, none of the 43 cases tested had the JAK2(V617F) mutation. In summary, we have identified a novel constellation of features that should strongly suggest POEMS syndrome as part of the differential diagnosis. The constellation of λ-restricted monoclonal gammopathy, plasma cell rimming around lymphoid aggregates, and megakaryocytic hyperplasia in a bone marrow is highly suggestive of this diagnosis, especially in the context of a peripheral neuropathy.

Castleman's disease--a two compartment model of HHV8 infection

Castleman's disease is a primary infectious disease of the lymph node that causes local symptoms or a systemic inflammatory syndrome. Histopathology reveals a destroyed lymph node architecture that can range from hyaline-vascular disease to plasma-cell disease. Viral interleukin 6 (vIL-6) produced during the replication of human herpesvirus type 8 (HHV8) is the key driver of systemic inflammation and cellular proliferation. Stage progression of Castleman's disease results from switches between viral latency and lytic replication, and lymphatic and hematogenous spread. Multicentric plasma-cell disease in HIV-1 patients is associated with HHV8 infection. Polyclonal plasmablast proliferation escapes control in the germinal center with eventual malignant transformation into non-Hodgkin lymphoma. Surgery produces excellent results in unicentric disease, while multicentric disease responds to anti-CD20 therapy or IL-6 and chemotherapy. Lymphovascular endothelium and naive B cells are infectious reservoir-opening options for antiangiogenic and anti-CD19 strategies to enhance outcomes in patients with systemic disease.

POEMS syndrome

POEMS syndrome is a rare paraneoplastic syndrome secondary to a plasma cell dyscrasia. Recognition of the complex of a combination of peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasmaproliferative disorder, skin changes, papilledema, extravascular volume overload (peripheral edema, pleural effusions, ascites), sclerotic bone lesions, thrombocytosis, Castleman disease is the first step in effectively managing the disease. A rise in the blood levels of vascular endothelial growth factor is usually confirmatory. More than 95% of patients will have monoclonal lambda sclerotic plasmacytoma(s) or bone marrow infiltration. In patients with a dominant sclerotic plasmacytoma, first line therapy should include radiation to the lesion. Retrospective analysis and personal experience would dictate that systemic therapy be considered for patients with diffuse sclerotic lesions or absence of any bone lesion and for those who have not demonstrated stabilization of their disease 3 to 6 months after completing radiation therapy. For those patients with diffuse disease, systemic therapy is indicated. Useful approaches include therapy with corticosteroids, low dose alkylator therapy, and high dose chemotherapy with peripheral blood stem cell transplant. Until the pathogenesis is fully understood, these are the mainstays of treatment for patients with POEMS syndrome. The role of anti-VEGF therapies, immune modulatory drugs, and proteasome inhibitors has not yet been defined, but drugs with known high rates of treatment related neuropathy should not be considered as first line therapy.

[POEMS syndrome]

The POEMS syndrome combines a constant polyneuropathy (P), organomegaly (O), endocrinopathy (E), monoclonal gammopathy (M) (or other plasma cell disorder) and skin changes (S). Other manifestations may be observed: anasarca, fever, sweating, clubbed fingers, renal damage, arterial obstruction, pulmonary hypertension, thrombocytosis, and polycythemia. Its pathogenesis is not well elucidated but elevated levels of vascular endothelial growth factor (VEGF) appear to characterize it. Consistent plasma cell disorders include a monoclonal component, often in small quantities with a lambda light chain isotype, and plasmacytoma, often solitary lesions. Treatment depends on specific characteristics of the disease and the patient (radiation therapy for plasmocytoma, autologous bone marrow transplantation in young subjects, corticosteroid therapy or chemotherapy in the elderly). The usefulness of thalidomide and bevacuzimab in refractory POEMS syndromes remains to be seen.

Castleman disease

PURPOSE OF REVIEW

Castleman disease was initially described over 50 years ago as a benign localized mass of lymph nodes found primarily in the mediastinum of asymptomatic patients. Subsequently, additional types were recognized that extend the spectrum of this heterogeneous group of diseases. Optimal standard therapies have not been established. Currently, most patients receive treatments derived from past experience with non-Hodgkin lymphoma that are not altogether satisfactory.

RECENT FINDINGS

Advances in understanding the biological basis of Castleman disease have provided new targets for therapeutic exploitation. Recognition of the role of interleukin-6 in disease perpetuation has led to the use of an antihuman interleukin-6 receptor monoclonal antibody, tocilizumab. Rituximab, an anti-CD20 monoclonal antibody, targets CD20-positive B lymphocytes, a prominent component of this disorder. Human herpes virus-8 and angiogenesis, both involved in the pathogenesis of Castleman disease, may provide additional unique therapeutic opportunities.

SUMMARY

Rational approaches to the treatment of Castleman disease have begun to have an impact on disease management; however, the role of these new agents remains to be established. As the complexity of Castleman disease is more fully understood, additional targets for new innovative therapies undoubtedly will be identified.

Absence of human herpesvirus 8 DNA sequences in lung biopsies from Israeli patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary hypertension is a severe pulmonary vascular disease leading to rapid deterioration and death. Histological and clinical evidence suggests that smooth muscle proliferation is part of the pathogenesis of the disease. Human herpesvirus 8 (HHV-8) is a gamma-herpesvirus that is implicated in malignancies and in Kaposi's sarcoma. Recently, the association of HHV-8 with idiopathic pulmonary arterial hypertension (PAH) has been found.

OBJECTIVE

The aim of this study was to investigate the presence of HHV-8 in the lung tissue of Israeli patients with PAH.

METHOD

The presence of HHV-8 sequences was investigated by polymerase chain reaction examination in 6 biopsies of patients with pulmonary hypertension. Three patients had idiopathic pulmonary hypertension, 2 patients pulmonary venoocclusive disease, and 1 patient pulmonary hypertension associated with mixed connective tissue disease.

RESULT

We did not find any association between HHV-8 and PAH in these Israeli patients, as all the samples were negative for polymerase chain reaction.

CONCLUSION

Our findings, together with the epidemiological data of HHV-8 prevalence and incidence rates of Kaposi's sarcoma and PAH in Israel, provide further evidence which argues against an association between HHV-8 infection and PAH.

Treatment options for POEMS syndrome

POEMS syndrome is a rare paraneoplastic syndrome secondary to a plasma cell dyscrasia. Recognition of the complex of a combination of peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasmaproliferative disorder, skin changes, sclerotic bone lesions, Castleman's disease, thrombocytosis, papilledema, peripheral oedema, pleural effusions, ascites, fingernail clubbing and white nails, is the first step in effectively managing the disease. More than 95% of patients will have monoclonal lambda sclerotic plasmacytoma(s) or bone marrow infiltration. In patients with a dominant sclerotic plasmacytoma, first-line therapy should include radiation to the lesion. Retrospective analysis and personal experience would dictate that systemic therapy be considered for patients with diffuse sclerotic lesions or absence of any bone lesion, and for those who have not demonstrated stabilisation of their disease 3-6 months after completing radiation therapy. For those patients with diffuse disease, systemic therapy is indicated. Useful approaches include therapy with corticosteroids, low dose alkylator therapy and high dose chemotherapy with peripheral blood stem cell transplant. Until the pathogenesis is fully understood, these are the mainstays of treatment for patients with POEMS syndrome.

[Biochemical features of chronic inflammatory demyelinating polyradiculoneuropathy]

Although there are no specific biological markers of chronic inflammatory demyelinating polyneuropathies (CIDP), biological investigations have played an important role in determining the limits of the concept of CIDP. This is best exemplified by the individualisation of demyelinating neuropathies associated with IgM monoclonal proteins reacting with glycolipids. The signification of CIDP associated with diabetes mellitus, monoclonal IgG or IgA, or mutations of myelin proteins has recently been discussed as they may have implications in our understanding of the pathophysiology of CIDP and raise the question of knowing whether they confer to CIDP a particular clinical presentation or evolution.

The aetiology and management of Castleman disease at 50 years: translating pathophysiology to patient care

Fifty years ago, Dr Benjamin Castleman first described the unusual lymphoproliferative disorder that now bears his name. Over the subsequent decades, astute clinical and pathologic observations coupled with clever molecular biologic research have increased our understanding of the aetiology of Castleman disease (CD). This article proposes three broad CD variants based on both distinctive histopathology and clinical behaviour. The pivotal roles of infection with human herpesvirus 8 and interleukin-6 production in the development of CD are emphasized. Finally, the natural history of CD and the myriad of therapeutic options are reviewed in the context of a unified model of CD pathophysiology, and continued areas of uncertainty are discussed.

An Atypical Case of POEMS Syndrome with IgG Kappa M Protein and End Stage Renal Failure

POEMS syndrome is a rare plasma cell dyscrasia which is characterized by small amounts of monoclonal protein, and a multisystem complex manifested by various combinations of polyneuropathy, organomegaly, endocrinopathy and skin changes. Here, we presented an atypical case of POEMS syndrome with IgG kappa monoclonal protein, chronic demyelinating polyneuropathy, hepatosplenomegaly, hypothyroidism, gynecomastia and severe renal impairment. The finding of IgG kappa type of monoclonal protein in our patient was interesting because the majority of cases were reported to have lambda light chain. Also, the absence of typical skin and bone lesions were atypical. Though speculative, these atypical features may account for the unusual presentation of this case. Our patient rapidly progressed to end-stage renal failure and died of cachexia. Renal involvement in POEMS syndrome is rare but may show substantial clinical and pathological variations. Proteinuria, hematuria, renal dysfunction and renal failure requiring hemodialysis can be seen. The pathogenesis of renal dysfunction is unclear. As a conclusion, POEMS syndrome may present with diverse clinicopathologic manifestations. In this syndrome, renal involvement may lead to end stage renal failure and the course may be fatal due to severe polyneuropathy and wasting.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

A case report: isolated a heavy chain monoclonal gammopathy in a patient with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin change syndrome

A 45-year-old South-Korean man presented with abdominal distension, progressive paresthesia and motor weakness of both lower extremities. Our case was identified as polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin change (POEMS) syndrome based on diagnostic criteria. Circulating M components of POEMS syndrome consist mainly of IgG or IgA-lambda and rarely IgM-lambda, IgG-kappa or isolated light chains. In this case, the M-band on serum protein electrophoresis and isolated IgA heavy chain on serum immunofixation electrophoresis were demonstrated, but there was no abnormal light chain. We suggest that this case may be associated with a pattern of abnormal secretion of monoclonal protein or a coincidence of a heavy chain disease in POEMS syndrome, even though the latter possibility may be very rare.

New developments in IL-6 dependent biology and therapy: where do we stand and what are the options?

Interleukin-6 (IL-6) is a four-helical protein which, on target cells, binds to a specific IL-6-receptor and two molecules of the promiscuous signal transducing protein gp130. Structure-function analysis defined three molecular contact sites between IL-6 and its receptor subunits. Using this information, competitive antagonistic proteins as well as hyperagonistic proteins were developed. Possible therapeutic applications of IL-6 antagonists are in IL-6 dependent haematological disorders (Castleman's disease, POEMS syndrome, multiple myeloma) and bone diseases (Paget's disease, osteoporosis). Designer IL-6 antagonists could suppress inflammatory activity in rheumatic and autoimmune diseases and could prevent secondary amyloidosis. IL-6 antagonists could also prove advantageous in myocardial infarction and unstable angina pectoris. IL-6 antagonists might slow down development of (mesangioproliferative) glomerulonephritis. On the other hand, hyperagonistic variants of IL-6 have a potential in ex vivo expansion of bone marrow stem cells and as thrombopoietic agents. They might also be developed into drugs to support liver regeneration in vivo and to treat stress-induced cardiac insufficiency.

POEMS Syndrome

POEMS syndrome is defined by the presence of a peripheral neuropathy (P), a monoclonal plasma cell disorder (M), and other paraneoplastic features, the most common of which include organomegaly (O), endocrinopathy (E), skin changes (S), papilledema, edema, effusions, ascites, and thrombocytosis. Virtually all patients will have either sclerotic bone lesion(s) or co-existent Castleman’s disease. Not all features of the disease are required to make the diagnosis, and early recognition is important to reduce morbidity. Other names for the syndrome include osteosclerotic myeloma, Crow-Fukase syndrome, or Takatsuki syndrome. Because the peripheral neuropathy is frequently the overriding symptom and because the characteristics of the neuropathy are similar to that chronic inflammatory demyelinating polyneuropathy (CIDP), patients are frequently misdiagnosed with CIDP or monoclonal gammopathy of underdetermined significance (MGUS)-associated peripheral neuropathy. Not until additional features of the POEMS syndrome are recognized is the correct diagnosis made and effective therapies initiated. Clues to an early diagnosis include thrombocytosis and sclerotic bone lesions on plain skeletal radiographs. Therapies that may be effective in patients with CIDP and MGUS-associated peripheral neuropathy (intravenous gammaglobulin and plasmapheresis) are not effective in patients with POEMS. Instead, the mainstays of therapy for patients with POEMS include irradiation, corticosteroids, and alkylator-based therapy, including high-dose chemotherapy with peripheral blood stem cell transplantation.

Scintigraphic evaluation of cardiac metabolism in multicentric Castleman's disease

A 72-year-old woman had insidious onset of heart failure, and was diagnosed as multicentric Castleman's disease. She underwent myocardial imaging with technetium-99m tetrofosmin, 1-123 beta-methyl-iodophenyl pentadecanoic acid (BMIPP). Technetium-99m tetrofosmin studies showed almost normal uptake of the left ventricular myocardium indicating normal myocardial perfusion. 1-123 BMIPP showed reduced uptake in the apical segment of the myocardium, indicating regional fatty acid metabolic abnormalities.

Castleman Disease of the Subcutis and Underlying Skeletal Muscle

Castleman disease of the subcutis and skeletal muscle is rare. We have collected a series of 6 cases of extranodal Castleman disease, located in the subcutis and skeletal muscles of the extremities and trunk. Tumors from mediastinal and retroperitoneal soft tissue and those histologically involving peripheral or truncal lymph nodes were excluded. There were four females and two males; ages ranged from 18 to 37 years (mean, 26 years). Locations included thigh (n = 3), anterior chest (n = 2), and upper arm (n = 1). Sizes ranged from 4.0 to 6.0 cm (mean, 5.2 cm). All patients presented with localized disease. One patient had involvement of the mediastinum 1 year prior to the appearance of his soft tissue lesion. None of the patients demonstrated systemic involvement or signs of the POEMS syndrome. Histopathologically, all cases were classified as hyaline-vascular type (HVCD). In 3 cases, follicular dendritic cell dysplasia was observed. In 1 case, the dysplasia was marked. The subcutaneous lesion of 1 patient revealed a maze of capillaries set in a lipomatous background with occasional lymphoid follicles possessing hyalinized lymphocyte-depleted centers. This lesion probably represented incipient HVCD. Molecular biologic studies did not reveal the presence of Epstein-Barr virus or human herpesvirus-8 DNA in the lesional tissue. There also were no monoclonal rearrangements of IgH. Four patients with follow-up included 2 patients with no evidence of disease at 10 and 13 years, respectively, and 2 patients with local recurrence at 2 and 6 months, respectively. In conclusion, soft tissue Castleman disease is a disease of young patients with a female predominance and a propensity to involve the trunk and limbs. It can be of large size and is generally solitary. There may be mild to marked follicular dendritic cell dysplasia. The HVCD predominates in this location. These lesions are usually unassociated with POEMS, Epstein-Barr virus, human herpesvirus-8, or monoclonal rearrangements of IgH.

Le syndrome POEMS (ou syndrome de Crow-Fukase)

POEMS is an acronym for polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes. POEMS syndrome is also called Crow-Fukase syndrome, chiefly in Japan. The 5 above mentioned features are not always present at the first examination. The minimal criteria to establish the diagnosis are the presence of a demyelinating and axonal polyneuropathy associated with an IgA or IgG monoclonal gammopathy, the light chain being almost always lambda, and at least 2 of the 8 other features: sclerosing plasmocytoma, endocrinopathy, skin changes, organomegaly, Castleman's disease, anasarca, papillary edema or thrombocytosis. Among these features, only cutaneous glomeruloid angioma are specific. Ultrastructural identification of uncompacted myelin lamellae on the peripheral nerve biopsy is also a strong argument in favor of the diagnosis. An associated "osteosclerotic" bone lesion must be carefully searched, because its treatment may improve the other features of the syndrome, especially the neuropathy. Cytokines and the vascular growth endothelial factor might play a role in the pathogenesis of this rare multisystemic disorder.

Atypical Cellular Disorders

Some immunologic diseases are characterized by profound loss or primary dysfunction of a given population of cells. The atypical cellular disorders discussed here all bear some similarities in that abnormal proliferations of lymphocytes and macrophages or dendritic cells result in lymphadenopathy, skin rashes, bone lesions and infiltrations of nearly any other organ system. What are the similarities and the differences between Langerhans cell histiocytosis (LCH), sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease, and Castleman’s disease (CD)? Studies on LCH have some advantages since it was described before the others, and organized clinical trials have been done since the 1980s. The understanding of SHML benefited from a registry maintained by Drs. Rosai and Dorfman. CD was described fifty years ago and for one subtype has the most clearly defined etiology (HHV-8 infection) of the three atypical cellular disorders discussed here.

In Section I, Dr. Kenneth McClain examines the unanswered question of whether LCH is a malignant clonal disorder or an inflammatory response triggered by aberrant cytokine expression or a virus. Advocates of the malignant proliferation theory rest their case primarily on the following two points: Clonality of the CD1a+ Langerhans cells was demonstrated by analysis of the human androgen receptor in patients with single bone lesions (Low Risk) or multisystem disease including spleen, liver, bone marrow, or lung (High Risk). Although no consistent chromosomal abnormalities have been reported, loss of heterozygosity (LOH) has been defined by comparative genomic hybridization. Those in the “inflammatory response” camp note that non-clonal proliferation of Langerhans cells in adult pulmonary LCH also have LOH by the same method. The pathologic cells have not been successfully grown in culture or immune-deficient mice and don’t have a “malignant” morphology. While the basic scientific arguments continue, important advances in the treatment of LCH have been made by international collaborations of the Histiocyte Society. Risk groups have been clearly defined and the response to therapy after the initial 6 weeks is known to be the strongest prognostic variable for outcome.

In Section II, Dr. Yasodha Natkunam reviews the features of SHML, which most often presents as painless cervical lymphadenopathy, although many patients can have extranodal involvement as well. These sites include the skin, respiratory tract, bone, lung, gastrointestinal tract, and brain. The diagnosis rests on finding intact lymphocytes in the cytoplasm of activated macrophages as well as accumulation of mature plasma cells. Hemolytic or non-hemolytic anemias, hypergammaglobulinemia, and elevated erythrocyte sedimentatin rate (ESR) are often found with SHML. An intriguing finding of human herpesvirus (HHV)-6 viral proteins in SHML has been reported in several patients, but needs further study. SHML associated with lymphoproliferations triggered by defects in apoptosis are discussed since this mechanism may provide a clue to the etiology. Therapy for SHML varies greatly in reported case series. Many patients have spontaneous regression or resolution after surgical removal of isolated node groups. Others with systemic involvement may benefit from chemotherapy, but no clinical trials have been done.

In Section III, Dr. Steven Swerdlow clarifies key features of the four types of CD. Localized cases are divided into the hyaline vascular type and plasma cell type. Both are usually cured by surgical excision and have symptoms mainly of a mass lesion, although the latter often also has constitutional symptoms. The two types are distinguished largely by the nature of the follicles and the number of interfollicular plasma cells. Interleukin (IL)-6 expression is increased in the plasma cell type. Multicentric CD of the plasmablastic type is most often found in HIV-positive patients with coincident HHV-8 infection. Many have lymphomas or Kaposi sarcomas. Other cases of multicentric CD are also most like the plama cell type, however, with disseminated disease and constitutional symptoms. A wide variety of anti-neoplastic drugs, radiation therapy, anti-IL-6 and rituximab or atlizumab have been used with varying success in patients with multicentric CD. Clinical trials are needed for SHML and CD and registration of adult and pediatric patients on current LCH trials are encouraged.