HIV-associated multicentric Castleman disease

From HIV to Coronavirus Disease 2019 (COVID-19): Hematologic Complications in Viral Pandemics

CONTEXT.—

From the onset of the human immunodeficiency virus (HIV) pandemic in the 1980s to the recent coronavirus disease 2019 (COVID-19) pandemic, multiple viral pandemics have occurred and all have been associated with hematologic complications of varying severity.

OBJECTIVE.—

To review the hematologic complications associated with the HIV and other viral pandemics, the current theories regarding their causation, and the incidence and clinical impact of these complications on infected patients.

DATA SOURCES.—

Peer-reviewed medical literature and the author's personal experience.

CONCLUSIONS.—

The HIV and other viral pandemics have been associated with a variety of hematologic complications that often cause significant morbidity and mortality in affected patients. HIV infection is associated with multiple hematologic disorders, many of which have a lower incidence in the era of highly active antiretroviral therapy but still represent a major clinical problem for HIV-infected patients. Our understanding of the pathogenesis of HIV-related hematologic complications, including HIV-associated lymphoproliferative disorders, has evolved in recent years. Other viral pandemics, including H1N1 influenza, severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus, and COVID-19, have also been associated with hematologic complications of varying severity. Our emerging understanding of the pathogenesis of the hematologic complications of HIV, COVID-19, and other viral pandemics may help in prevention, correct diagnosis, and treatment of these complications in current and future pandemics.

In silico Insights on IL-6: A Potential Target for Multicentric Castleman Disease

Background:

Multicentric Castleman Disease (MCD) is a confrontational lymphoproliferative disorder described by symptoms such as lymph node proliferation, unwarranted secretion of inflammatory cytokines, hyperactive immune system, and in severe cases, multiple organ dysfunction. Interleukin-6 (IL-6) is a pleiotropic cytokine which is involved in a large range of physiological processes in our body such as pro-inflammation, anti-inflammation, differentiation of T-cells and is reported to be a key pathological factor in MCD. In the case of MCD, it was observed that IL-6 is overproduced from T-cells and macrophages which disturb Hepcidin, a vital regulator of iron trafficking in macrophage. The present study endeavour to expound the inhibitor which binds to IL-6 protein receptor with high affinity.

Methods:

MolegroVirtual Docker software was employed to find the best-established drug from the list of selected inhibitors of IL-6. This compound was subjected to virtual screening against PubChem database to get inhibitors with a very similar structure. These inhibitors were docked to obtain a compound binding with high affinity to the target protein. The established compound and the virtual screened compound were subjected to relative analysis of interactivity energy variables and ADMET profile studies.

Results:

Among all the selected inhibitors, the virtual screened compound PubChem CID: 101119084 is seen to possess the highest affinity with the target protein. Comparative studies and ADMET analysis further implicate this compound as a better inhibitor of the IL-6 protein.

Conclusion:

Hence, this compound recognized in the study possesses high potential as an IL-6 inhibitor which might assist in the treatment of Multicentric Castleman Disease and should be examined for its efficiency by in vivo studies.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

The Potential Clinical Benefit of Tocilizumab Therapy for Patients with HHV-8-infected AIDS-related Multicentric Castleman Disease: A Case Report and Literature Review

Castleman disease (CD), also known as angiofollicular hyperplasia, is a rare disorder characterized by nonmalignant mediastinal lymph node enlargement provoked by excess interleukin-6 (IL-6) secretion. It could be unicentric or multicentric (MCD). Here, we describe a 27-year-old man with a prior history of AIDS, Kaposi sarcoma (KS), and latent syphilis who presented to the ED for persistent fatigue, fever, chills, night sweats, and productive cough. Infectious workup was negative, and the patient continued to have a high fever despite empiric antibiotic therapy. Bone marrow biopsy was performed and was negative for malignancy. The patient eventually underwent a left clavicular lymph node biopsy, which showed a plasma cell variant CD with positive immunostaining for human herpesvirus 8 (HHV-8), and high HHV-8 viral load. We started the patient on rituximab and liposomal doxorubicin, but unfortunately, the patient had a severe anaphylactic reaction to the rituximab, so we could not proceed with this treatment. We, therefore, started tocilizumab treatment, which improved the patient's general condition, and he was eventually discharged from our hospital. Upon follow-up 11-months later, a repeat CT scan of the chest and abdomen showed a near-complete treatment response with decreased lymphadenopathy throughout and hepatosplenomegaly. IL-6 overproduction in patients with CD is linked to the production of inflammatory cytokines and has a role in tumor angiogenesis, which makes it potential for IL-6 targeted therapy. The diagnosis of CD, especially MCD, requires a high index of suspicion, and a lymph node biopsy is essential in the diagnosis. Tocilizumab, an IL-6 receptor antibody, could potentially be considered as a practical therapeutic approach in managing HHV-8 positive MCD patients who do not tolerate or respond to initial rituximab therapy.

Human immunodeficiency virus-negative multicentric Castleman's disease coexistent with Kaposi's sarcoma on 18F-FDG PET/CT: A case report

Multicentric Castleman's disease and Kaposi's sarcoma are more frequently observed in human immunodeficiency virus (HIV)-infected patients; however, 40-50% of the cases are HIV-negative. The present study reports the case of a 61-year-old man who presented with palpable masses in the axillary and right inguinal areas. The blood test results revealed increased serum erythrocyte sedimentation rate and C-reactive protein level, with negative serological markers, including for HIV. The patient was investigated using contrast-enhanced computed tomography (CT) and fluorine- ¹⁸fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT; the images revealed multiple enlarged and intensely hypermetabolic lymph nodes in the cervical, thoracic and abdominopelvic areas. Excisional biopsy and immunohistochemical analysis were performed, which confirmed the diagnosis of HIV-negative multicentric Castleman's disease coexisting with Kaposi's sarcoma. The patient received steroid therapy followed by chemotherapy. After 4 cycles of chemotherapy, the follow-up ¹⁸F-FDG PET/CT scan revealed nearly complete remission of the hypermetabolic malignant lesions of the neck, axilla and thoracoabdominal region.

Inhibition of Tip60 Reduces Lytic and Latent Gene Expression of Kaposi's Sarcoma-Associated Herpes Virus (KSHV) and Proliferation of KSHV-Infected Tumor Cells

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus responsible for the development of Kaposi's sarcoma, primary effusion lymphoma (PEL), and Multicentric Castleman's disease in immunocompromised individuals. Despite the burden of these diseases there are few treatment options for afflicted individuals, due in part to our limited understanding of virus-host interactions. Tip60, a histone aceytltransferase (HAT) has been previously shown to interact with both the KSHV latency associated nuclear antigen protein (LANA), which is the main factor in maintaining the viral latent state, and ORF36, a viral kinase expressed in the lytic phase. We further investigated Tip60-virus interaction to ascertain Tip60's role in the viral life cycle and its potential as a target for future therapeutics. Through modulation of Tip60 expression in HEK293T cells harboring a plasmid containing the KSHV viral episome, Bac36, we found that Tip60 is vital for both lytic replication as well as efficient expression of latent genes. Interestingly, Tip60 small molecule inhibitors, MG149 and NU9056, similarly inhibited latent and lytic genes, and reduced virion production in wild-type KSHV+/EBV- PEL, BCBL-1 cells. Long-term treatment with these Tip60 inhibitors selectively decreased the viability of KSHV-infected B lymphoma cells compared to uninfected cells. From this study, we conclude that Tip60 is important for KSHV infection and its associated cancer development, and Tip60 is therefore a potential target for future antiviral and anticancer therapeutics.

A retrospective study of 34 patients with unicentric and multicentric Castleman's disease: Experience from a single institution

The aim of the present study was to share the experience of a single institute in the diagnosis, use of accessory examinations and treatment strategies of Castleman's disease (CD). The present study analyzed 34 patients (13 males and 21 females) with CD who were hospitalized between January 2006 and September 2014. The patients were divided into two groups based on the anatomical distribution of the disease: Unicentric CD (UCD) and multicentric CD (MCD). Histological data was obtained from lymph node biopsies. All clinical data were acquired by reviewing patients' medical records and contacting patients by telephone. A total of 27 patients had UCD and 7 patients had MCD. All 27 patients with UCD with benign symptoms underwent complete diagnostic surgical resection and survived, with the exception of 1 patient who succumbed to pancreatic head carcinoma 13 months after surgery. A total of 7 patients with MCD presented with systemic symptoms and 2 of these patients declined treatment following the definite diagnosis of CD. The remaining 5 patients were treated with various strategies, including surgical resection and further glucocorticoid treatment, intravenous siltuximab, rituximab in combination with cyclophosphamide, doxorubicin, vincristine and prednisone chemotherapy or hematopoietic stem cell transplantation. A total of 3 patients with MCD survived, with a median follow-up period of 69 months. The present study indicates that complete surgical resection is currently the standard treatment for UCD. Perioperative use of multidetector computed tomography and the laparoscopic approach have certain advantages in UCD. Molecular target therapy is effective in patients with stable MCD, and hematopoietic stem cell transplantation may be beneficial in certain patients with MCD and disease progression.

Castleman Disease of the Thorax: Clinical, Radiologic, and Pathologic Correlation: From the Radiologic Pathology Archives

Castleman disease is a complex lymphoproliferative disease pathologically divided into two subtypes, the hyaline vascular variant (HVV) and the plasma cell variant (PCV). The HVV is the most common, is thought to represent a benign neoplasm of lymph node stromal cells, and is treated with surgical resection. It is most commonly found in the mediastinum, where it classically appears as a unicentric, avidly enhancing mass at computed tomography (CT) and magnetic resonance imaging. This appearance can mimic other avidly enhancing mediastinal masses, and location, clinical history, laboratory data, and nuclear medicine single photon emission CT (SPECT) and positron emission tomography (PET) studies can help narrow the differential diagnosis. Multicentric Castleman disease (MCD), which in the majority of cases is composed of the PCV, is an aggressive lymphoproliferative disorder associated with human herpesvirus infection, interleukin 6 dysregulation, and other systemic disorders. While it can be difficult to differentiate MCD from lymphoma, the presence of avidly enhancing lymph nodes can suggest the diagnosis. The purpose of this article is to review the clinical, immunologic, and pathologic findings associated with both unicentric Castleman disease and MCD and discuss how the imaging findings correlate with the pathophysiology of the disease.

KSHV and the Role of Notch Receptor Dysregulation in Disease Progression

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of two human cancers, Kaposi's Sarcoma (KS) and primary effusion lymphoma (PEL), and a lymphoproliferation, Multicentric Castleman's Disease (MCD). Progression to tumor development in KS is dependent upon the reactivation of the virus from its latent state. We, and others, have shown that the Replication and transcriptional activator (Rta) protein is the only viral gene product that is necessary and sufficient for viral reactivation. To induce the reactivation and transcription of viral genes, Rta forms a complex with the cellular DNA binding component of the canonical Notch signaling pathway, recombination signal binding protein for Jk (RBP-Jk). Formation of this Rta:RBP-Jk complex is necessary for viral reactivation to occur. Expression of activated Notch has been shown to be dysregulated in KSHV infected cells and to be necessary for cell growth and disease progression. Studies into the involvement of activated Notch in viral reactivation have yielded varied results. In this paper, we review the current literature regarding Notch dysregulation by KSHV and its role in viral infection and cellular pathogenesis.

Use of plasma human herpesvirus-8 viral load measurement: evaluation of practice in three UK HIV treatment centres

A retrospective audit of plasma human herpesvirus-8 (HHV-8) viral load testing was performed in three HIV treatment centres over 24 months. Reasons for testing (360 tests) were: symptoms of systemic inflammatory response syndrome (SIRS) (fever, lymphadenopathy and raised inflammatory markers); monitoring in known HHV-8 pathology other than Kaposi sarcoma (KS); investigation of known/suspected KS, and other/no reason. Of patients with multicentric Castleman disease (MCD), 14/16 (88%) had detectable plasma HHV-8, as did 27/45 (60%) with biopsy proven or clinically confirmed KS, and 6/19 (32%) with lymphoma. Neither of the two patients with MCD and no detectable HHV-8 had SIRS symptoms at the time of the test. There was wide variation between centres in the indications prompting HHV-8 testing, with a more conservative approach resulting in a higher proportion of positive results. Measuring plasma HHV-8 in the absence of SIRS symptoms, established HHV-8 disease monitoring, or confirmed/suspected KS is unlikely to yield detectable HHV-8 thus allowing potential cost savings.

Kaposi's sarcoma-associated herpesvirus: the role of lytic replication in targeted therapy

PURPOSE OF REVIEW

To discuss the role of Kaposi's sarcoma-associated herpesvirus (KSHV) lytic replication in viral-associated diseases and assess the progress on targeting KSHV lytic replication as a strategy to prevent KSHV-related malignancies.

RECENT FINDINGS

New inhibitors of viral lytic replication are being developed as well as novel modalities are being investigated to target cellular processes that the virus hijacks during its life cycle. Research has also focused on reactivating viral lytic replication in latently infected tumour cells (lytic induction therapy) to promote death of tumour cells.

SUMMARY

KSHV is linked to three malignancies: Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. Despite significant progress in understanding KSHV pathobiology, no therapeutic guidelines for the management of KSHV-related diseases exist, and current treatments are suboptimal and associated with toxicity. Antiherpesvirus drugs have shown inconsistent results in KSHV-associated malignancies that harbour the virus in a latent state. However, lytic replication plays a crucial role in the process of tumorigenesis. Therefore, not only antiviral agents directed against the virus replicative cycle but also agents that target cellular processes that are activated by the virus are being investigated. Antivirals may also be used in combination with inducers of the viral lytic stage.

Hematologic malignancies of the liver: spectrum of disease

The incidence of hematologic malignancies and their extranodal manifestations is continuously increasing. Previously unsuspected hepatic involvement in hematologic malignancies such as Hodgkin disease and non-Hodgkin lymphoma, posttransplant lymphoproliferative disorder, myeloid sarcoma (chloroma), multiple myeloma, Castleman disease, and lymphohistiocytosis may be seen by radiologists. Although the imaging features of more common hepatic diseases such as hepatocellular carcinoma, metastases, and infection may overlap with those of hepatic hematologic malignancies, combining the imaging features with clinical manifestations and laboratory findings can facilitate correct diagnosis. Clinical features that suggest a hematologic neoplasm as the cause of liver lesions include a young patient (<40 years of age), no known history of cancer, abnormal bone marrow biopsy results, fever of unknown origin, and night sweats. Imaging features that suggest hematologic malignancy include hepatosplenomegaly or splenic lesions, vascular encasement by a tumor without occlusion or thrombosis, an infiltrating mass at the hepatic hilum with no biliary obstruction, and widespread adenopathy above and below the diaphragm. Familiarity with the imaging features of hepatic hematologic malignancies permits correct provisional diagnosis and may influence therapeutic management. For example, when biopsy is performed, core biopsy may be needed in addition to fine-needle aspiration so that the tissue architecture of the neoplasm can be discerned. The predominant treatment of hematologic malignancies is chemotherapy or radiation therapy rather than surgery. Online supplemental material is available for this article.

Laparoscopic treatment for retroperitoneal hyaline-vascular type localized Castleman's disease (LCD) in the iliac vessel region

To improve the understanding, diagnostic levels, and therapeutic levels of retroperitoneal hyaline vascular type LCD in the iliac vessel region. Diagnostic and therapeutic processes of 4 patients with retroperitoneal LCD in the iliac vessel region were retrospectively analyzed. The median ages of the research patients was 31.3 years old, Pelvic vascular dual-source computed tomography (CT) indicated an abnormal pelvic irregular cloddy intensity shadow with heterogeneous densities and punctate calcified lesions. The enhanced scanning showed significantly enhanced lesions and multiple tortuous vascular images inside and around the lesions. Patients' preoperative diagnoses were all "pelvic mass with unknown characteristics", and retroperitoneal masses were successfully stripped off after the laparoscopic surgery. Intra operative findings indicated 1 mass located at the left obturator nerve, 1 at the left internal iliac artery, and 2 at the right external iliac artery. The postoperative pathological reports suggest a diagnosis of Castleman's disease. Retroperitoneal LCD in the iliac vessel region is generally asymptomatic. Preoperative imaging data may help with the diagnosis, but a confirmed diagnosis depends on the results of the pathological examination. Iliac artery embolization is performed prior to laparoscopic mass stripping if the masses have abundant blood supply, while lymphadenectomy is also applied to those with enlarged lymph nodes.

Hematologic malignancies of the pancreas

Hematologic malignancies are relatively uncommon neoplasms of abdominal soft tissue. This article discusses the clinical and imaging features of pancreatic lymphoma, pancreatic extraosseous multiple myeloma, granulocytic sarcoma (chloroma), posttransplant lymphoproliferative disorder, and Castleman disease. The combination of imaging findings and the appropriate clinical presentation should allow the radiologist to raise a provisional diagnosis of hematologic malignancy.

Presentation and Outcome of Castleman's Disease in Immunocompetent Hosts

Castleman's disease (CD) is a heterogeneous lymphoproliferative disorder of unknown aetiology. Mostly, this disorder is seen in immunocompromised hosts. It is known to be associated with systemic disorders like HIV, HHV-8, lymphoma, and Kaposi sarcoma. As of today, the clinical behaviour and outcome of CD in immunocompetent host remains suboptimally studied. We analyzed consecutively treated cases of CD presented to our centre in last 12 years. Case record files were studied for patient's characteristics, clinical presentation, baseline laboratory and pathologic parameters, therapy and outcome. This study describes presentation and treatment outcome of CD in immunocompetent patients. Total 16 patients of CD were treated during the study period. The median age of patients at the time of presentation was 40.5 years (range 13-72 years). An equal number of patients (8 each) had unicentric and multicentric CD. Sixty-three percent patients had hyaline vascular subtype while 37 % patients had plasma cell or mixed variant. Majority of the patients had good performance status (ECOG PS 0, 1 in 10 (62.5 %) patients; PS2-4 in 6 (37.5 %) patients). The median duration of symptoms was 6 months (range 2-36 months). None of the patients in our study had associated HIV infection. Six patients presented with fever, out of which four had plasma cell variant of CD and three of them had multicentric involvement. In comparison to unicentric CD, patients with multicentric CD had lower albumin levels (4.15 vs. 3.38 g/dl, p = 0.006), haemoglobin levels (11.3 vs. 9.8, p = 0.06), and lower complete remission rates (62.5 % vs. none). Patients were treated according to the stage and clinical status with surgery, chemotherapy or combination of both modalities. Surgery was the predominant treatment for unicentric CD while multicentric CD was treated with various chemotherapy regimens. Eight patients were treated with chemotherapy (CHOP-based regimen-5, melphalan-prednisolone thalidomide-1, chlorambucil-prednisolone-1, and only corticosteroids-1). In the entire study group, ORR was 72 % (CR 36 %, PR 36 %), one patient died of progressive disease during chemotherapy. Two patients lost to follow-up before assessment of treatment response. Five-year overall survival was 100 and 87 % for unicentric and multicentric CD respectively. Castleman's disease is a rare lymphoproliferative disorder amongst Indian patients. It more commonly presents as hyaline vascular variant and affects middle-aged individuals. The most remarkable fact in our analysis was a lack of HIV positivity in any of the patient that is in contrast to the majority of the published literature. With multimodality therapy, high response rates and long-term survival were noted in the entire study group.

Castleman Disease

An understanding of the disease pathogenesis has led to the discovery of therapuetic agents that target human herpesvirus-8 replication, CD20, and IL-6 and IL-6R antibodies.

[Multicentric Castleman disease not associated with HHV-8 and HIV viruses]

Castleman's disease (CD) is a polyclonal lymphoproliferative disorder also known as giant nodular hyperplasia or angiofollicular lymph node hyperplasia. It is a rare disease often associated to human immunodeficiency virus (HIV) and human herpes virus 8 (HHV-8). Histopathological findings in Castleman's disease suggest an exaggerated response to antigenic stimuli seen in other diseases associated with immune activation, such as rheumatoid arthritis. An important aspect of its pathogenesis is the autonomous production of interleukin-6 (IL-6). In this disease, the clinical manifestations are associated to IL-6 serum levels, and surgical removal of the compromised lymph nodes or use of anti-IL-6 antibodies can slow down the symptoms. We describe a multicentric Castleman's disease in a young woman not associated to HHV-8 virus infection or immunosuppression. A short review of the literature follows the description of this clinical case.

Multicentric Castleman's Disease and Kaposi's Sarcoma in a HIV-Positive Patient on Highly Active Antiretroviral Therapy

Castleman’s disease is a group of rare lymphoproliferative disorders. The plasmablastic multicentric Castleman’s disease is frequently discovered in HIV-infected individuals in association with Kaposi sarcoma (HHV-8). Thirty-five year old male presented to our care with the main compliant of severe back pain for one week. His past medical problems include acquired immune deficiency syndrome diagnosed 12 years prior and Kaposi sarcoma, currently on highly active antiretroviral therapy (HAART). Radiographic imaging revealed hepatomegaly and diffuse lymphadenopathy. The HIV viral load was <20 polymerase chain reaction copies/mL, absolute CD4 count was 453 cells/mcL (490-1740 cells/mcL) and CD8 count was 4142 cells/mcL (180-1170 cells/ mcL). Excisional biopsy of the left supraclavicular lymph node was performed with pathological findings of HHV8+ Kaposi sarcoma in the background of multicentric Castleman’s disease (plasmacytic variant). No evidence of transformation into large B-cell or plasmablastic lymphoma was noted. He was discharged on HAART and follow up to receive chemotherapy with cyclophosphamide, adriamycin, vincristine plus prednisone was started and rituximab plus prophylaxis for pneumocystis carinii. Multicentric Castleman’s disease has become more relevant in recent years due to its association with HIV and HHV-8 (Kaposi sarcoma) and its potential to progress into plasmablastic B-cell lymphoma. The progression of MCD to B-cell lymphoma is a concern, especially in patients with HIV infection because it precludes the worst outcome and a high mortality, despite treatment. The most intriguing part of this case is that MCD occurred in a HIV-positive on HAART. This case signals a warning that a high suspicion for MCD can be justified even in those HIV-positive patients on HAART because the possibly of progression to plasmablastic B-cell lymphoma.

Efficient infection of a human B cell line with cell-free Kaposi's sarcoma-associated herpesvirus

Kaposi's sarcoma-associated herpesvirus (KSHV) is causatively linked to two B cell lymphoproliferative disorders, multicentric Castleman's disease and primary effusion lymphoma. Latently infected B cells are a major KSHV reservoir, and virus activation from tonsillar B cells can result in salivary shedding and virus transmission. Paradoxically, human B cells (primary and continuous) are notoriously refractory to infection, thus posing a major obstacle to the study of KSHV in this cell type. By performing a strategic search of human B cell lymphoma lines, we found that MC116 cells were efficiently infected by cell-free KSHV. Upon exposure to recombinant KSHV.219, enhanced green fluorescent protein reporter expression was detected in 17 to 20% of MC116 cells. Latent-phase transcription and protein synthesis were detected by reverse transcription-PCR and detection of latency-associated nuclear antigen expression, respectively, in cell lysates and individual cells. Selection based on the puromycin resistance gene in KSHV.219 yielded cultures with all cells infected. After repeated passaging of the selected KSHV-infected cells without puromycin, latent KSHV was maintained in a small fraction of cells. Infected MC116 cells could be induced into lytic phase with histone deacetylase inhibitors, as is known for latently infected non-B cell lines, and also selectively by the B cell-specific pathway involving B cell receptor cross-linking. Lytic-phase transition was documented by red fluorescent protein reporter expression, late structural glycoprotein (K8.1A, gH) detection, and infectious KSHV production. MC116 cells were CD27(-)/CD10(+), characteristic of transitional B cells. These findings represent an important step in the establishment of an efficient continuous B cell line model to study the biologically relevant steps of KSHV infection. Kaposi's sarcoma-associated herpesvirus (KSHV) causes two serious pathologies of B cells, the antibody-producing cells of the immune system. B cells are a major reservoir for KSHV persistence in the body. Paradoxically, in the laboratory, B cells are extremely difficult to infect with KSHV; this problem greatly hinders scientific analysis of B cell infection. We describe our search for and successful identification of a stable human B cell line that can be efficiently infected by KSHV. Upon infection of these cells, the virus goes into a quiet latent phase, a characteristic feature of many herpesvirus infections. The virus can be triggered to enter an active lytic phase by treatments known to stimulate normal B cell functions. These findings suggest that the new B cell line will be a valuable model in which to study KSHV infection of this major target cell type.

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, multiple myeloma and skin changes) with cranial vault plasmocytoma and the role of surgery in its management: a case report

INTRODUCTION

POEMS syndrome (an acronym of polyneuropathy, organomegaly, endocrinopathy, multiple myeloma and skin changes) is a paraneoplastic disorder related to an underlying plasma cell dyscrasia. The development of such a syndrome is rare and its association with calvarial plasmocytoma is even less common, with only two previous reported cases. We describe, in detail, an unusual presentation of cranial plasmocytoma associated with POEMS syndrome and briefly discuss the possible role of surgery in the management of this disease.

CASE PRESENTATION

We present the case of a 45-year-old Caucasian man who was admitted to our department presenting with progressive weakness in his lower limbs, enlarged lymph nodes and a large mass on the scalp with intense bone erosion. POEMS criteria were present and pathological studies confirmed a Castleman's variant plasmocytoma. Clinical status improved noticeably after the excision of the plasmocytoma and the treatment was completed with radiotherapy and steroid pulse therapy.

CONCLUSION

Cranial vault plasmocytoma and its association with POEMS syndrome are rare conditions with few previously reported cases. Although the role of surgery is not clearly defined in POEMS syndrome guidelines, the fact that there seems to be a better prognosis and clinical outcome when surgery is used as a part of the management in POEMS syndrome with cranial vault plasmocytoma is worth discussing.

Clinical features and outcome of patients with HIV-negative multicentric Castleman's disease treated with combination chemotherapy: a report on 10 patients

To investigate the clinical characteristics and outcome of patients with HIV-negative multicentric Castleman's disease (MCD) treated exclusively with combination chemotherapy, and review literature to improve the diagnosis and management of this disease. A retrospective study was performed on the medical records of 10 patients with HIV-negative MCD treated exclusively with combination chemotherapy at one medical institution from May 2004 to April 2012. And relevant clinical, pathological, radiographic, and laboratory data were examined in order to evaluate treatment responses, with symptom onsets and survival period serving as the endpoints of the assessment. All patients have multifocal lymphadenopathy, and the associated system symptoms are found in 80 % of the cases. All patients were treated with lymphoma-based chemotherapy alone. The duration of follow-up ranged from 5 to 77 months for nine patients. Four patients were treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) alone: One was alive with no evidence of disease, and three were alive with disease. Three patients received cyclophosphamide, vincristine, and prednisone (COP) alone: One remained alive with disease, and two experienced recurrences and passed away. Two had only minimal response to COP and were switched to CHOP, and they were still alive with disease. MCD is a more progressive clinical entity, and long-term follow-up is necessary. CHOP chemotherapy may be an effective treatment option for patients with MCD, whereas when to start chemotherapy, how many cycles of chemotherapy required, and the role of combined radiotherapy remain to be further studied.

[Castleman's disease: unusual presentation of Castleman's disease and review of literature]

Castleman disease is a rare disorder of the lymphoid system which can be classified into two clinical groups, monocentric disease versus multicentric disease, and two histological types, the hyaline vascular form versus the plasma cell form. We report three cases of monocentric Castleman disease. The first one is a classical form of Castleman's disease. The second one is characterized by an uncommon radiological presentation, with a calcification within the tumor. The third one is a plasma cell form with monoclonal proliferation associated with a monoclonal gammapathy. These three cases highlight the polymorphic clinical and radiological features of Castleman disease. They underlie the difficulty of surgical resection due to the tumor vascularization. Other diagnosis hypothesis and associated diseases will also be discussed (HIV, Kaposi's sarcoma, POEMS syndrome).

FDG-PET imaging in the diagnosis of HIV-associated multicentric Castleman disease: something is still missing

Now that [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) has become an established imaging tool in oncology, it is attracting interest in the field of infectious diseases. Several studies have used FDG-PET to examine the pathophysiology of HIV infection as well as other conditions such as lipodystrophic syndrome and HIV-related neurocognitive disorders. In clinical practice, FDG-PET has been proposed to assess fever of unknown origin or with lymphoproliferative disorders such as Castleman disease in individuals with HIV infection.

Castleman disease and associated autoimmune disease

PURPOSE OF REVIEW

Castleman disease can occur in association with autoimmune connective tissue disease and confound the clinical picture, resulting in delayed diagnosis and suboptimal treatment. This review focuses on the intersection of Castleman disease and autoimmunity with an emphasis on shared pathology and mutually beneficial treatments.

RECENT FINDINGS

Targeting CD-20, interleukin-6, and the nuclear factor-κB pathway has shown promise in achieving long-term remission in patients with Castleman disease and associated autoimmune features.

SUMMARY

Advances in understanding of pathogenic cell types and cytokines in Castleman disease have allowed the development of targeted therapies successful in the treatment of both Castleman disease and associated autoimmune disease.