Idiopathic multicentric Castleman disease with TAFRO clinical subtype responsive to IL-6/JAK inhibition: A pediatric case series

Immunology and targeted therapy in Castleman disease

INTRODUCTION

Castleman disease (CD) is a benign lymphoproliferative disease causing severe systemic inflammation. Interleukin-6 (IL-6) is a major pathogenesis of multicentric CD (MCD), but only 30-60% of patients respond to IL-6 inhibitors. Novel agents for IL-6 inhibitor-refractory cases are needed. Clinical data and samples are being collected on a large scale and the clinical, pathological, and pathogenetic aspects are being elucidated.

AREAS COVERED

The pathological and clinical classification of CD is outlined. Focusing on idiopathic MCD (iMCD), this review identifies therapeutic targets and summarizes currently recommended drugs and promising therapeutic candidates.

EXPERT OPINION

The pathogenesis of MCD has been implicated in the activation of the Janus kinase (JAK)-transcriptional signaling activator (STAT) 3 pathway and the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanical target of rapamycin (mTOR) signaling pathway. iMCD-TAFRO (thrombocytopenia, anasarca, fever/elevated CRP, reticulin myelofibrosis/renal dysfunction, organ enlargement) is resistant to IL-6 inhibitors, and cyclosporine and mTOR inhibitors are sometimes effective. JAK inhibitors and mTOR inhibitors may be therapeutic agents for iMCD. Recently, we have shown that peripheral helper T (Tph) cell abnormalities are at the core of iMCD pathogenesis. Therapies targeting chemokine (C-X-C motif) ligand 13 (CXCL13) produced by Tph cells and blocking the Tph-CXCL13-B cell pathway may satisfy unmet need in refractory cases.

Biomarkers and Signaling Pathways Implicated in the Pathogenesis of Idiopathic Multicentric Castleman Disease/Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis, Renal Insufficiency, and Organomegaly (TAFRO) Syndrome

Idiopathic multicentric Castleman disease (iMCD) and TAFRO syndrome present a variety of symptoms thought to be caused by excessive inflammatory cytokines and chemokines, but the underlying mechanisms are unknown. iMCD is broadly classified into two types: iMCD-NOS and iMCD-TAFRO, which have distinct laboratory findings, pathological features, and responses to treatments. It is thought that iMCD-NOS, particularly the IPL type, responds favorably to IL-6 inhibitors due to its IL-6-centric profile. iMCD-TAFRO frequently progresses acutely and seriously, similar to TAFRO syndrome. Elevated levels of cytokines, including IL-1β, TNF-α, IL-10, and IL-23, as well as chemokines like CXCL13 and CXCL-10 (especially in iMCD-TAFRO), SAA, and VEGF, have been linked to the disease's pathology. Recent research has identified key signaling pathways including PI3K/Akt/mTOR and JAK-STAT3, as well as those regulated by type I IFN, as crucial in iMCD-TAFRO. These results suggest that dominant pathways may vary between subtypes. Further research into the peripheral blood and lymph nodes is required to determine the disease spectrum of iMCD-NOS/iMCD-TAFRO/TAFRO syndrome.

Idiopathic multicentric Castleman disease: An update in diagnosis and treatment advances

Idiopathic multicentric Castleman disease (iMCD) is a rare disease, and it is likely underdiagnosed because of the heterogeneity of clinical manifestations and laboratory findings. While the disease leads to significant morbidity and mortality, its causes are not yet fully elucidated. There have been significant advances in diagnosis and treatment of iMCD in the past decade, including the approval of the anti-IL-6 antibody siltuximab. In this review, we provide an update of the many new developments and publications surrounding iMCD.

Intraperitoneal hyaline vascular Castleman disease: Three case reports

BACKGROUND

Castleman disease (CD) was first reported in 1954. It is a rare non-malignant lymphoproliferative disease with unclear etiology. As the clinical manifestations of CD are different, there are difficulties in its diagnosis and treatment. Therefore, for patients with CD, it is important to establish the diagnosis in order to choose the appropriate treatment.

CASE SUMMARY

In this report, three patients with intraperitoneal CD treated at our center from January 2018 to June 2023 were reviewed, and the clinical and paraclinical examinations, diagnosis, and treatment were analyzed, and all three patients were diagnosed with CD by routine histopathological and immunohistochemical examinations.

CONCLUSION

CD is a complex and rare disease. Because there are no special clinical symptoms and laboratory abnormalities, the diagnosis often depends on routine pathological and immunohistochemical findings.

Clinical features and treatment outcomes of Castleman disease in children: a retrospective cohort in China

Castleman disease (CD) is a rare lymphoproliferative disorder of undetermined etiology. Unicentric CD (UCD) and multicentric CD (MCD) are two phenotypes of CD diagnosed by the histopathology of lymph nodes. We attempted to describe a pediatric CD cohort to optimize the management of this disease. We reviewed the medical records of pediatric patients diagnosed with CD between April, 2004, and October, 2022, at the Children's Hospital of Fudan University. Prognosis information was collected in January, 2023, by telephone inquiry. Twenty-two patients with UCD and 2 patients with MCD were identified, all with hyaline vascular (HV) type. The median ages at diagnosis were 10.75 years (IQR 8, 12.81) for UCD and 14.42 years (IQR 13.42, 15.42) for MCD. The most common lesion location of UCD was the neck (9/22, 40.91%) and abdomen (9/22, 40.91%). Systematic symptoms occurred on 10/22 (45.45%) patients with UCD and 1/2 (50%) patients with MCD, and abnormal laboratory indexes were detected in both. Resection and biopsy were performed on all patients. One out of two patients with MCD also received rituximab for upfront therapy. After a median of 4 years (IQR 1.5, 6) of follow-up time, the overall survival was 100% and the complete remission rate in UCD was 63%. There was no relapse or progression.

CONCLUSIONS

Our series demonstrated that HV-UCD was the most common type in children. Resection and biopsy were used for both deterministic diagnoses and treatments. Despite the high possibility to develop systematic inflammation, children with CD showed promising outcomes.

WHAT IS KNOWN

• Castleman disease is a rare lymphoproliferative disorder with limited cohort studies, especially in pediatrics. • The ubiquity of delayed confirmations and misdiagnoses points to a lack of knowledge about etiology and characteristics, which is a prerequisite for novel therapeutics.

WHAT IS NEW

• We retrospectively reviewed and analyzed the clinical and pathological symptoms, laboratory and imaging features, and treatment outcomes of a Chinese pediatric cohort with Castleman disease. • Our work may improve the recognition and optimize the management of this rare disease in children.

Treatment-resistant idiopathic multicentric Castleman disease with thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly managed with Janus kinase inhibitors: A case report

RATIONALE

Thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome are nonmalignant but life-threatening systemic inflammatory disorders. However, many patients are refractory to treatment, resulting in significant morbidity and mortality. Additionally, established treatment options are unavailable. Therefore, we present 2 cases of adults with the iMCD-TAFRO syndrome refractory to initial treatment but responded to Janus kinase (JAK) inhibitors with ruxolitinib. The report reveals that these rare adult cases of the refractory and treatment-resistant iMCD-TAFRO syndrome can be treated using JAK inhibitors.

PATIENT CONCERNS

Case 1 is a 36-year-old previously healthy male patient who presented with fever and general fatigue for 2 weeks. Case 2 is a 42-year-old previously healthy female patient who presented with fever and general fatigue.

DIAGNOSIS

The diagnosis met the 2015 criteria for TAFRO syndrome, as determined by All Japan TAFRO Syndrome Research Group in the Research Program for Intractable Disease by the Ministry of Health, Labor and Welfare (MHLW) Japan.

INTERVENTIONS

Treatment with tocilizumab and several immunosuppressants were ineffective. So, we performed ruxolitinib.

OUTCOMES

Each patient received ruxolitinib, the general condition improved, and CRP levels decreased.

LESSONS

These cases showed that ruxolitinib was effective for treatment-resistant/ refractory TAFRO syndrome. Further prospective studies are needed on using ruxolitinib with a small number of cases.

Approche thérapeutique des maladies de Castleman : l’émergence des thérapies ciblées

The spectrum of Castleman disease encompasses several different disorders. Nowadays three different forms of the disease are individualized: unicentric Castleman disease, multicentric HHV-8 associated Castleman disease and idiopathic multicentric Castleman disease. In the latter a severe form called TAFRO syndrome (thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly) tend to be individualized. Improvement in the classification and understanding of the physiopathology of CD have allowed improvement in treatment strategies. Treatment of rare but often severe manifestations, such as paraneoplastic pemphigus and bronchiolitis obliterans in unicentric CD and hemophagocytic syndrome and/or Kaposi' sarcoma in HHV8 associated CD, are better adapted. Most of current treatment strategies are based on retrospective and very few prospective studies. Both anti-IL6/6R and anti-CD20 biotherapies have greatly improved the management of certain forms of the disease. We report in this review the most relevant studies and national or international expert consensus statements for the treatment in the different types of CD. © 2022 Published by Elsevier Masson SAS on behalf of Société nationale française de médecine interne (SNFMI).

CXCL13 is a predictive biomarker in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare and poorly-understood cytokine storm-driven inflammatory disorder. Interleukin-6 (IL-6) is a known disease driver in some patients, but anti-IL-6 therapy with siltuximab is not effective in all patients, and biomarkers indicating success at an early time point following treatment initiation are lacking. Here we show, by comparison of levels of 1,178 proteins in sera of healthy participants (N = 42), patients with iMCD (N = 88), and with related diseases (N = 60), a comprehensive landscape of candidate disease mediators and predictors of siltuximab response. C-X-C Motif Chemokine Ligand-13 (CXCL13) is identified and validated as the protein most prominently up-regulated in iMCD. Early and significant decrease in CXCL13 levels clearly distinguishes siltuximab responders from non-responders; a 17% reduction by day 8 following siltuximab therapy initiation is predictive of response at later time points. Our study thus suggests that CXCL13 is a predictive biomarker of response to siltuximab in iMCD.