Idiopathic multicentric Castleman disease treated with siltuximab for 15 years: a case report.

Human herpes virus-8 (HHV8)-negative, idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder sustained by pro-inflammatory cytokines, including interleukin-6 (IL-6). According to the international evidence-based criteria developed by the Castleman Disease Collaborative Network (CDCN), siltuximab, which works by inhibiting IL-6, is the recommended choice for iMCD treatment. We report a case of a 63-year-old white male with iMCD who has been on maintenance therapy with siltuximab for 15 years - representing one of the longest treatment periods of any patient with iMCD treated with siltuximab. The patient initially presented with fatigue and night sweats, with progressive worsening of the symptoms. Whole-body positron emission tomography/computed tomography revealed hypermetabolic lymphadenopathy. The patient had histopathologically confirmed Castleman disease, plasma cell type, and was negative for HHV8 and human immunodeficiency virus. The patient had abnormally high C-reactive protein (CRP) levels, a surrogate measure for IL-6. The patient was treated with high-dose steroids but had recurring lymphadenopathy early on. He was enrolled in the phase I dose-finding clinical trial of siltuximab, during which he achieved marked clinical improvement and sustained inhibition of CRP. The patient was enrolled in the long-term safety study and continues to receive siltuximab at 11 mg/kg every 3 weeks. He is presently receiving commercial siltuximab and has remained asymptomatic, with no evidence of lymphadenopathy. The case study presented is consistent with the evidence that siltuximab is a safe and effective therapy for the long-term management of iMCD. In addition, this case highlights the importance of prompt diagnosis for patients with iMCD, as effective therapy is available for patients as described in the CDCN and National Comprehensive Cancer Network iMCD treatment guidelines. The case of a 63-year-old white male with idiopathic multicentric Castleman disease who was successfully treated with siltuximab for 15 years: Idiopathic multicentric Castleman disease (iMCD) is a group of rare lymphoproliferative disorders with shared histopathological features that affect lymph nodes in multiple regions of the body. The signs and symptoms of iMCD can be varied, with the disease being mild in some patients while life-threatening in others. A timely diagnosis of iMCD can be challenging but is required for effective management. We report a case of a patient who was diagnosed with iMCD. The patient was given high-dose steroids but continued to show progressive disease. He was then started on siltuximab, a targeted antibody therapy against a specific cytokine (interleukin-6) involved in inflammation. The patient responded well to the treatment, has shown evidence of long-term disease control, and has not reported any serious adverse events related to long-term siltuximab use. He has received 11 mg/kg of siltuximab every 3 weeks for the past 15 years. This case emphasizes the value of using siltuximab therapy for long-term management of this rare disorder. In addition, it highlights the importance of prompt diagnosis for patients with iMCD, as effective therapy is available, as described in iMCD treatment guidelines.

Lang E ，Sande B ，Brodkin S ，van Rhee F ... -  《-》

Long-Term Tolerance and Efficacy of Siltuximab (Anti-IL-6) in a Young Adult with Idiopathic Multicentric Castleman Disease During COVID-19.

Bedier H ，Isnard S ，Maedler-Kron C ，Routy JP ... -  《-》

Afebrile Pneumonia in a Patient With Multicentric Castleman Disease on Siltuximab: Infection Without Fever on Anti-Interleukin-6 Therapy.

Castleman disease is a lymphoproliferative disorder characterized by atypical lymph node hyperplasia and systemic symptoms; it can also affect the skin and blood counts. The condition is categorized by the extent of involvement (unicentric or multicentric) and the observed lymph node pathology (hyaline-vascular, plasma cell or mixed cellularity). Pathogenesis also has a role in the classification and treatment of multicentric Castleman disease; this variant can either be related to the presence of human herpesvirus-8 (HHV-8) infection or associated with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal proteins and skin changes) syndrome, or idiopathic. The principal cytokine responsible for causing idiopathic multicentric Castleman disease (IMCD) is interleukin-6 (IL-6). Therefore, treatment with agents that bind to IL-6 (such as siltuximab) or block the IL-6 receptor (such as tocilizumab) has been used. We report a woman with IMCD who was successfully being treated with siltuximab; her cutaneous manifestations and systemic disease (lung and lymph nodes) improved within three months. However, nine months after starting siltuximab, she developed a worsening cough and new infiltrates in the right lung on positron emission tomography/computed tomography (PET/CT) scan; there were no other constitutional symptoms such as fever, night sweats or fatigue. Differential diagnosis included Castleman disease recurrence, lung neoplasm and infection. Her pulmonary symptoms and infiltrates on scan resolved after treatment with systemic levofloxacin, indicating that she had an antibiotic-sensitive afebrile pneumonia. We postulate that her siltuximab therapy blocked the IL-6-associated fever and constitutional symptoms that normally are a hallmark of pneumonia. Therefore, patients who are receiving medications such as siltuximab and tocilizumab that block the IL-6 pathway and impair the acute phase inflammatory response may fail to manifest constitutional symptoms such as fever when infected.

Cohen PR ，Nikanjam M ，Kato S ，Goodman AM ，Kurzrock R ... -  《Cureus》

Siltuximab: a targeted therapy for idiopathic multicentric Castleman disease.

Fajgenbaum DC ，Kurzrock R 《-》

Dichotomic response to interleukin-6 blockade in idiopathic multicentric Castleman disease: two case reports.

Ferrero S ，Ragaini S 《-》