Multicentric Castleman's disease: a challenging diagnosis

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

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

IL-6 expression helps distinguish Castleman's disease from IgG4-related disease in the lung

Background

It is difficult to distinguish between multicentric Castleman’s disease (MCD) and IgG4-related lung disease (IgG4-LD), an IgG4-related disease (IgG4-RD) in the lung.

Methods

We focused on IL-6, which is elevated in MCD, to distinguish between MCD and IgG4-LD by RNAscope, a highly sensitive RNA in situ method. Six cases of MCD and four cases of IgG4-LD were selected.

Results

In all cases of MCD and IgG4-LD, 10 or more IgG4-positive cells were found in one high-power field. All MCD cases were inconsistent with the pathological IgG4-related comprehensive diagnostic criteria, but 2 of 6 cases had an IgG4/IgG ratio greater than 40%. In all IgG4-LD cases, histological features were consistent with the pathological IgG4-RD comprehensive diagnostic criteria. IL-6 expression was observed in all MCD and IgG4-LD cases except for one IgG4-LD biopsy. IL-6-expressing cells were mainly identified in the stroma. Sites of IL-6 expression were not characteristic and were sparse. IL-6 expression tended to be higher in MCD compared with IgG4-LD. A positive correlation was found between the IL-6 H-score and serum IL-6 level.

Conclusion

Differences in IL-6 expression may help distinguish between MCD and IgG4-LD. In addition, the presence of high IL-6 levels may help elucidate the pathological mechanisms of IgG4-LD.

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.

Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997

Human Herpesvirus-8 Negative Multicentric Castleman Disease in a Patient with Human Immunodeficiency Virus Treated with Highly Active Antiretroviral Therapy and Chemotherapy

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder with a high mortality rate in undiagnosed patients. Traditionally, human immunodeficiency virus (HIV) positive MCD occurs due to infection with human herpes virus-8 (HHV), which is thought to play a role in the pathogenesis of MCD. We present the case of a 49-year-old woman who was referred to our oncology clinic for generalized lymphadenopathy in a waxing and waning pattern for the last four years. She was found to be HIV positive. Here we report a rare case of HIV-positive, HHV-negative MCD that responded to prompt treatment with highly active antiretroviral therapy (HAART) followed by chemotherapy as evidenced by improved CD4+ T cell numbers and reduction in lymphadenopathy. The findings in this HHV seronegative patient may indicate an alteration in the virulence and tropism between HHV and HIV, and further demonstrate the need for continued investigation into the pathogenesis of Castleman disease.

High proportion of TAFRO syndrome in Thai adult Castleman's disease patients: a 10-year experience

Castleman’s disease (CD) is a rare lymphoproliferative disorder, and its prevalence in Thailand is not known. This 10-year period study investigated the prevalence of CD in Thailand, and the clinical characteristics and outcomes of Thai CD patients, with special focus on the existence and prevalence of TAFRO syndrome. TAFRO syndrome is defined as CD with thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly. Thirty-three CD patients diagnosed and treated at Siriraj Hospital during January 2007 to December 2016 were included. The prevalence of CD was 1.4 per 1,000,000 patients/10 years. Median age was 46 years, with slight female predominance. Six patients were assigned to the TAFRO group. A high proportion of TAFRO syndrome (18.2%) was found among Thai adult CD patients. In addition to routine TAFRO diagnostic criteria, significantly lower hemoglobin and albumin levels were observed in the TAFRO group than in the non-TAFRO group. Treatment outcomes of CD patients were complete remission (52%), stable disease (30%), and death (13%). Three-year overall survival in the non-TAFRO group and TAFRO group was 88 and 50%, respectively. While most CD patients had a good prognosis, severe cases with TAFRO syndrome had poor outcome.

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.

Siltuximab: A Review in Idiopathic (Human Herpesvirus-8-Negative) Multicentric Castleman Disease

Siltuximab (Sylvant™), an interleukin (IL)-6 chimeric immunoglobulin Gк monoclonal antibody, is a currently the only agent approved to treat human idiopathic (herpesvirus-8 negative) multicentric Castleman disease (iMCD), which is a rare lymphoproliferative disorder. iMCD is caused by dysregulated production of IL-6 in the lymph nodes, and is associated with high morbidity, and potentially fatal consequences. Siltuximab binds to human IL-6 with high affinity and specificity, thereby preventing it from binding to IL-6 receptors, and neutralizing IL-6 bioactivity. In clinical trials in patients with iMCD, siltuximab reduced levels of C-reactive protein (a biomarker for IL-6), and provided clinical responses. Relative to placebo, the addition of siltuximab to best supportive care improved tumor- and symptom-related outcomes, with patients also reporting improvements in MCD symptoms, functional status, and well-being. Siltuximab has an acceptable tolerability profile, with the majority of treatment-emergent adverse events being manageable and/or of mild severity. In the absence of a cure, siltuximab represents a significant achievement in the management of this difficult-to-treat orphan disease.

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.