[Castleman's disease, pathophysiology, advances in diagnosis and treatment]

Castleman's disease (CD) encompasses a heterogeneous set of reactive lymphoproliferative processes that share well-defined histologic features. CD is considered a rare or minority disease. The incidence of CD is not fully known, although it is estimated at less than 1 per 100,000 inhabitants. It has a bimodal distribution (30-40 years and then 60-80 years). The incidence is similar in both sexes, although the unicentric variant seems to have a slight predominance in women with a 2:1 ratio. CD is classified into a hyalinovascular form (this being the most frequent) and a plasmocellular form, related to the HIV and VHH-8 viruses, which together with other autoimmune mechanisms develop hyperproduction of interleukin-6 (IL-6) by B lymphocytes. There are different lines of treatment, where the use of anti IL-6 stands out, being siltuximab the most used as orphan drug in this pathology.

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.

TAFRO syndrome is associated with anti-SSA/Ro60 antibodies, in contrast to idiopathic castleman disease

TAFRO syndrome is an acute systemic inflammatory disease characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, and organomegaly. There have been increasing reports that TAFRO is a disease distinct from idiopathic multicentric Castleman disease and that TAFRO patients may be positive for anti-SSA antibodies. To assess anti-SSA antibody positivity and the clinical characteristics of the two diseases, we retrospectively compared 7 TAFRO and 10 iMCD patients in our hospital. The mean age of onset of TAFRO and iMCD was 48.0 (interquartile range [IQR], 41-53) and 45.0 (IQR, 35-53) years, respectively. The TAFRO and iMCD groups had 6 (86%) and 4 (40%) male patients, respectively, and the following pretreatment laboratory values: platelet count, 3.8 (IQR, 2.2-6.4) and 35.5 (IQR, 22.2-42.8) × 104/μL, respectively; C-reactive protein, 10.2 (IQR, 6.8-21.4) and 9.5 (IQR, 6.2-13.6) mg/dL, respectively; IgG, 1431 (IQR, 1112-1815) and 4725 (IQR, 3755-5121) mg/dL, respectively. RNA immunoprecipitation (5 cases for anti-SSA) or protein array (5 cases for anti-SSA/Ro60) detected anti-SSA antibodies in six (86%) TAFRO patients but not in iMCD patients; it did not detect anti-SSB antibodies in any of the patients. None of the patients were diagnosed with Sjögren syndrome. All iMCD patients treated with tocilizumab (TCZ) responded well. Meanwhile, two of six TAFRO patients treated with TCZ showed inadequate responses; thus, both patients were switched to rituximab, following which they achieved remission. TAFRO and iMCD have different clinical features. TAFRO may be categorized as a severe phenotype of the anti-SSA antibody syndrome.

[Clinical Anslysis of TAFRO Syndrome]

OBJECTIVE

To investigate the clinical characteristics, diagnosis, and treatment of one patient with TAFRO syndrome, and to strengthen the understanding of this rare type.

METHODS

The clinical manifestations, diagnosis and treatment process, and prognosis of the patient admitted in Gansu Provincial People's Hospital were retrospectively analyzed.

RESULTS

Combined with laboratory tests, bone marrow examination, imaging, pathology, etc, the patient was diagnosed with TAFRO syndrome. After three cycles of treatment with pomalidomide (2-3 mg/d, d1-21), cyclophosphamide (300 mg/m2, 0.54 g once a week) and dexamethasone (20 mg/d, two days a week), platelet count, serum creatinine and procalcitonin returned to normal, the systemic edema disappeared, and the patient's condition was alleviated. The therapeutic effect was good.

CONCLUSION

TAFRO syndrome is rare, involves multiple systems, progresses rapidly, and has a worse prognosis. The choice of the "Pomalidomide+cyclophosphamide+dexamethasone" regimen is help to improve the survival prognosis of patient with TAFRO syndrome.

The experience of diagnosis and treatment for TAFRO syndrome

Early identification, diagnosis and treatment of TAFRO syndrome are very importants. We retrospectively analysed 6 patients with TAFRO syndrome. Their clinical manifestations, treatment methods, survival and other aspects were summarized. All patients were pathologically diagnosed with Castleman's disease, with fever, an inflammatory storm state and varying degrees of anasarca. All patients received steroid therapy; four of them also received chemotherapy, and 1 received rituximab. Of the 3 patients with severe disease, only 1 patient who received the recommended dose of glucocorticoids survived. Early administration of glucocorticoids can improve the prognosis, especially in patients with severe disease, and adequate glucocorticoids are important.

Treatment consistent with idiopathic multicentric Castleman disease guidelines is associated with improved outcomes

Idiopathic multicentric Castleman disease (iMCD) is a rare hematologic disorder with an unknown etiology. Clinical presentation is heterogeneous, ranging from mild constitutional symptoms with lymphadenopathy to life-threatening multiorgan dysfunction. International, consensus treatment guidelines developed in 2018 relied upon a limited number of clinical trials and small case series; however, to our knowledge, real-world performance of these recommendations has not been subsequently studied. Siltuximab, a monoclonal antibody against interleukin 6 (IL6), is approved for the treatment of iMCD and recommended first-line, and tocilizumab, a monoclonal antibody directed against the IL6 receptor, is recommended when siltuximab is unavailable. Chemotherapy, rituximab, and immunomodulators are recommended as second- and third-line treatments based on limited evidence. Corticosteroid monotherapy is used by clinicians, although not recommended. Here, we draw upon the ACCELERATE Natural History Registry to inventory regimens and evaluate regimen response for 102 expert-confirmed iMCD cases. Siltuximab with/without (w/wo) corticosteroids was associated with a 52% response, whereas corticosteroid monotherapy was associated with a 3% response. Anti-IL6-directed therapy with siltuximab or tocilizumab demonstrated better response and more durability than was observed with rituximab w/wo corticosteroids. Cytotoxic chemotherapy was associated with a 52% response and was predominantly administered in patients characterized by thrombocytopenia, anasarca, fever, renal failure/reticulin fibrosis, and organomegaly. Our results provide evidence in support of current recommendations to administer anti-IL6 as first-line treatment, to administer cytotoxic chemotherapy in patients with severe refractory disease, and to limit corticosteroid monotherapy. Evidence remains limited for effective agents for patients who are refractory to anti-IL6-directed therapy. This trial was registered at www.clinicaltrials.gov as #NCT02817997.

Idiopathic multicentric castleman's disease mimicking immunoglobulin G4-related disease responding well to Bortezomib: a case report

BACKGROUND

Castleman's disease (CD) is a rare disease that has clinical and pathological similarities to lymphoma and is characterized by a high frequency of associated immunological dysfunction. ImmunoglobulinG4-related disease (IgG4-RD) is a collection of systemic disorders that affect numerous organs and are also referred to as IgG4-associated sclerosing diseases. CD and IgG4-RD are difficult to separate because they may manifest similar commin clinical features.

CASE PRESENTATION

This case describes a 53-year-old female who, during routine medical check-up, exhibited a progressive increase in serum globulin levels and a simultaneous worsening of anemia symptoms, raising concern for a clonal plasma cell disease such as myeloma. However, bone marrow punctures did not reveal any abnormal plasma cells. Also, serum and urine immunofixation electrophoresis demonstrated no abnormal monoclonal protein bands. In addition, several laboratory findings excluded chronic liver disease, chronic infections caused by bacteria or viruses. Later, we found elevated serum IgG4 levels (10,700 mg/L), and identified multiple enlarged lymph nodes throughout the patient's body. Axillary lymph node aspiration revealed no abnormal lymphocytes, ruling out the possibility of lymphoma. Pathological morphology of the axillary lymph revealed a large number of plasma cells in the lymphatic follicles. In addition, there was a reduction in lymphatic follicle size and apoptosis of the germinal centres. Immunohistochemistry revealed IgG4+/IgG + in > 40% of cells, and more than 100 IgG4 + cells per high powered field (HPF) of specimen. As of now, finding strongly suggested IgG4-RD. This patient was treated with glucocorticoids and various immunosuppressive drugs, such as prednisone, cyclosporine, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine and hydroxychloroquine. Unfortunately, the patient did not recover. Ultimately, idiopathic multicentric Castleman disease (iMCD) was diagnosed in relation to the patient's clinical presentation and laboratory tests, and after combination chemotherapy (VCD: Bortezomib, Cyclophosphamide and Dexamethasone), durable remission was achieved without serious adverse effects. During the follow-up period of one year and ten months, the patient remained stable.

CONCLUSION

The diagnosis of Castleman must be distinguished from other disorders such as IgG4-RD, malignant lymphoma, reactive hyperplasia of various lymph nodes (mostly caused by viral infections), plasmacytoma, advanced HIV and rheumatic diseases. Besides observing systemic symptoms, laboratory tests such as immunoglobulin levels, complement levels, interleukin levels, and C-reactive protein levels should also be performed in order to determine a diagnosis.

Higher rate of progression in HIV- than in HIV+ patients after rituximab for HHV8+ multicentric Castleman disease

Rituximab has revolutionized the treatment of Kaposi sarcoma-associated herpesvirus/human herpesvirus 8-associated multicentric Castleman disease (HHV8+ MCD), converting a rapidly fatal illness into a relapsing disease. HHV8+ MCD mainly affects patients with HIV infection but can also be observed in patients without HIV infection. We retrospectively analyzed a cohort of 99 patients (73 who tested HIV+ and 26 who tested HIV-), with HHV8+ MCD treated with rituximab-based therapy. Baseline characteristics were similar in patients who had HIV- and HIV+ results, although those who tested HIV- were older (65 vs 42 years) and presented less frequently with Kaposi sarcoma (15% vs 40%). Ninety-five patients (70 HIV+ and 25 HIV-) achieved complete remission (CR) after rituximab-based therapy. After a median follow-up of 51 months, 36 patients (12 HIV- and 24 HIV+) experienced disease progression. The 5-year progression-free survival (PFS) was 54%. The 5-year PFS was lower in HIV- patients than in HIV+ patients : 26% and 62%, respectively (P = .02). A multivariate prognostic factors analysis including time-dependent covariates revealed that HIV- status, reoccurrence of HHV8 DNA >3 log copies per mL, and serum C-reactive protein (CRP) >20 mg/mL were independently associated with an increased risk of progression after rituximab-induced CR (P = .001; P = .01; and P = .01, respectively). The lower rate of progression observed in the population with HIV+ results despite a longer follow-up period might have resulted from the possible immune restoration upon antiretroviral therapy. HHV8 viral load and serum CRP monitoring after rituximab therapy provide information on the progression risk and may help in the decision to resume specific therapy.

Severe TAFRO Syndrome Mimicking Hepatorenal Syndrome Successfully Treated with a Multidisciplinary Approach: A Case Report and Literature Review

Finding the ideal balance between efficacy and safety of immunosuppression is challenging, particularly in cases of severe TAFRO syndrome. We herein report a 60-year-old man diagnosed with grade 5 TAFRO syndrome mimicking hepatorenal syndrome that was successfully treated by glucocorticoid, tocilizumab, and cyclosporin despite virus infection. Furthermore, by examining 14 peer-reviewed remission cases, we revealed that the recovery periods among inflammation, renal dysfunction, and thrombocytopenia were quite different, with recovery from thrombocytopenia notably slow. All patients requiring dialysis were successfully withdrawn from dialysis, and the reversibility from kidney injury was good. This clinical information will help clinicians plan treatments and tailor the intensity of immunosuppression.

A Multicentric Castleman Disease Associated with Mixed Warm and Cold Antibody-Mediated AHA Responsive to Siltuximab

Castleman disease is non-clonal lymphoproliferative disorders defined by hypertrophy of lymph nodes. The multicentric form (MCD), in which multiple lymph node stations are involved, is not associated with HHV8 infection, but considered idiopathic, although IL-6 appears to play a central role in its pathogenesis. Here, we report the case of a patient who presented with mixed autoimmune hemolytic anemia (AIHA) and adenopathy that was very challenging to diagnose due to very low values of hemoglobin and refractoriness of obtaining any improvement of AIHA with standard first and second lines of therapy (steroids, rituximab, immunoglobulin, erythropoietin, and cyclosporine). When we safely proceeded to lymph node biopsy, a diagnosis of MCD was established. This permitted the treatment with siltuximab, an anti-IL-6 monoclonal antibody. After only 1 week, hemoglobin raised and he was discharged. After 1 year, he was still in remission. This case underlines the challenges in diagnosis of MCD, and the first case of response to siltuximab after the failure of rituximab to relieve mixed AIHA.

TAFRO syndrome: A disease that known is half cured

Thrombocytopenia, anasarca, fever, reticulin fibrosis/renal failure, and organomegaly (TAFRO) syndrome is rare in clinical practice. It is a systemic inflammatory disease caused by a cytokine storm. Its clinical manifestations include thrombocytopenia, systemic edema, fever, bone marrow fibrosis, renal insufficiency, and organ enlargement. The high mortality rate of TAFRO syndrome is due to the difficulty of acquiring biopsy samples for diagnosis and the rapid disease progression. This disease is poorly understood by clinicians. Early detection, accurate diagnosis, and timely treatment play key roles in prolonging the survival of the patients. This review summarizes the latest progress in the pathogenesis, diagnostic criteria, and treatment regimens of TAFRO syndrome, aiming to help clinicians better understand TAFRO syndrome and improve its diagnosis and treatment.

Clinical management of Kaposi sarcoma herpesvirus-associated diseases: an update on disease manifestations and treatment strategies

INTRODUCTION

Kaposi sarcoma herpes virus (KSHV) is associated with several diseases including Kaposi sarcoma, a form of multicentric Castleman's disease, primary effusion lymphoma, and an inflammatory cytokine syndrome. These KSHV-associated diseases (KAD) can present with heterogenous signs and symptoms that are often associated with cytokine dysregulation that may result in multiorgan dysfunction. The inability to promptly diagnose and treat these conditions can result in long-term complications and mortality.

AREAS COVERED

Existing epidemiological subtypes of existing KSHV-associated diseases, specifically Kaposi sarcoma as well as the incidence of several KSHV-associated disorders are described. We review the KSHV latent and lytic phases as they correlate with KSHV-associated diseases. Given the complicated presentations, we discuss the clinical manifestations, current diagnostic criteria, existing treatment algorithms for individual KAD, and when they occur concurrently. With emerging evidence on the virus and host interactions, we evaluate novel approaches for the treatment of KAD. An extensive literature search was conducted to support these findings.

EXPERT OPINION

KSHV leads to complex and concurrent disease processes that are often underdiagnosed both in the United States and worldwide. New therapies that exist for many of these conditions focus on chemotherapy-sparing options that seek to target the underlying viral pathogenesis or immunotherapy strategies.

Rapid Clinical Improvement of Multicentric Castleman Disease (MCD) with Renal Involvement Following Treatment with Tocilizumab: AA Amyloidosis as a Possible Renal Involvement of MCD

Castleman disease (CD) is a lymphoproliferative disorder that manifests as hypergammaglobulinemia and severe inflammation with multiorgan involvement. However, renal involvement has been infrequently described in CD. We present a case of a 63-year-old Japanese male patient with multicentric CD (MCD) in whom kidney involvement, including impaired renal function and massive proteinuria, is present. He had a 2-year history of inflammatory arthritis and was referred to our clinic with newly developed proteinuria, renal dysfunction, and elevated levels of acute-phase proteins. Abdominal computed tomography scan revealed hepatosplenomegaly, including mesenteric and inguinal lymph node enlargements. The patient underwent inguinal lymph node resection. Excisional biopsy of the inguinal lymph node showed multiple lymphoid follicles and expansion of interfollicular areas by marked plasmacytosis consistent with mixed type CD. The patient was diagnosed with human herpes virus 8-negative MCD according to the international diagnostic criteria for CD. Diagnostic renal biopsy was not performed following the medical viewpoint. Tocilizumab (TCZ) treatment was highly effective in reducing proteinuria and stabilizing renal function, as well as improving other clinical symptoms. The patient responded to TCZ treatment, and the renal involvement was rapidly improved. Our preliminary immunohistochemical analysis indicated AA amyloid deposits in urinary epithelial cells suggesting a possible renal involvement of AA amyloidosis. TCZ could potentially be one of the therapeutic options in patients with MCD with renal involvement.

Psoas and Mediastinal Abscesses during Intravenous Tocilizumab Treatment in Multicentric Castleman Disease

Tocilizumab has been used to treat idiopathic multicentric Castleman disease (iMCD). As tocilizumab prevents interleukin-6 from exerting pro-inflammatory effects, there is some concern about a delayed diagnosis of severe infections during tocilizumab treatment. Although serious infections during tocilizumab therapy have been previously described in patients with rheumatoid arthritis, they have not been reported in iMCD. We herein report a case of disseminated Staphylococcus aureus infection after a superficial skin wound followed by psoas and mediastinal abscesses with pyogenic spondylodiscitis in an iMCD patient with diabetes. Physicians should be alert for the occurrence of disseminated S. aureus infection after even minor skin injury during tocilizumab therapy.

Therapy of Castleman's disease with siltuximab - case report and review of literature

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is characterized by constitutional symptoms, enlarged lymph nodes and laboratory test abnormalities, which are primarily related to the overproduction of interleukin-6 (IL-6). This form (iMCD) was treated earlier with cytostatics used for lymphoma, later with bio-logic therapy as rituximab, immunodulatory drugs and proteasome inhibitors, and in the last years with an anti-IL-6 antibody, siltuximab. Siltuximab is a human-mouse chimeric immunoglobulin G1k monoclonal antibody against human IL-6 approved in the European Union for the treatment of iMCD. In view of the limited treatment options for iMCD, this case report aimed to evaluate the efficacy and safety of siltuximab in the management of this condition.

CASE

We describe a young woman with iMCD diagnosed at the age of 25 years. For first line treatment, rituximab and dexamethasone were used without any cytostatic because the patient wished to give birth to a healthy child in the future. However, the response after this first line therapy was short. In addition, after 3 years from the start of rituximab + dexamethasone therapy, it was necessary to administer treatment for the relapse of iMCD. We decided for siltuximab in this young woman, still aged < 30 years, and started administration of siltuximab in 3-week intervals.

RESULTS

After administration of first two infusions of siltuximab, all inflammatory markers returned to normal value. Moreover, serum hemoglobin and albumin levels as well as C-reactive protein normalized after the first two administrations of siltuximab. The clinical response continue, siltuximab is still administered in 3-week intervals. PET/CT with fluorodeoxyglucose confirmed a very good anatomic and metabolic response to the treatment. Siltuximab demonstrated a favorable safety profile, and the prolonged treatment was well tolerated.

CONCLUSION

This result is encouraging and demonstrates the potential of siltuximab as treatment of CD. As earlier published, this case confirms that significantly elevated inflammatory markers in a patient with CD predict a good response to siltuximab.

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.

Characteristics of patients admitted to the ICU with Kaposi sarcoma herpesvirus-associated diseases

OBJECTIVE

There are four conditions caused by Kaposi sarcoma herpesvirus (KSHV): Kaposi sarcoma, KSHV-associated multicentric Castleman disease (MCD), primary effusion lymphoma (PEL), and KSHV inflammatory cytokine syndrome (KICS). These KSHV-associated disorders (KADs) often occur in people with HIV and can lead to multiorgan dysfunction requiring admission to the ICU. However, little is known about patient outcomes in this setting.

METHODS

A retrospective study of patients with KADs admitted to the ICU between 2010 and 2021 was conducted, examining KAD admission diagnoses, HIV characteristics, selected cytokine profiles, and ICU interventions. Primary outcomes were 60-day and median overall survival from ICU admission to death from any cause.

RESULTS

Forty-seven patients (all but one with HIV coinfection) were included. At ICU admission, 44 patients (94%) were on antiretroviral therapy with a median CD4 + count of 88 cells/μl and HIV viral load of 23 copies/ml. The most common presentation was respiratory failure alone (19%) or with hypotension (17%). Twenty-two (47%) patients had presumed KICS (with or without Kaposi sarcoma) at admission and an additional KAD was diagnosed in 36% of these patients. IL-6 levels did not vary across KAD subtype. Twenty (43%) patients received KAD-directed therapy in the ICU. Sixty-day survival was 70% and median overall survival was 9 months.

CONCLUSION

The majority of patients with HIV and KADs admitted to the ICU had well controlled HIV. Additional KAD were diagnosed during ICU admission in a proportion of patients who presented with presumed KICS. Critical illness did not preclude a subset of patients from receiving KAD-directed therapy in the ICU.

Recent Advances in Castleman Disease

BACKGROUND

Castleman disease (CD) encompasses a spectrum of rare disorders with characteristic histopathological features. Unicentric Castleman disease (UCD) is a benign, local hyperplasia of lymphoid tissue that is usually curable. Multicentric Castleman disease (MCD) manifests as a potentially life-threatening systemic disease with complex symptomatology which is mostly due to an overproduction of interleukin-6 (IL-6) or dysregulation of IL-6-related signaling pathways. From a therapeutic perspective, it is important to distinguish idiopathic MCD (iMCD) from those cases that are associated with the human herpes virus 8 (HHV-8+MCD).

SUMMARY

During recent years, it has become increasingly clear that even HHV-8-negative MCD is not a homogeneous entity and that there are clinically distinct variants. International consensus guidelines for diagnosis and treatment have been developed for iMCD and UCD.

KEY MESSAGES

We herein summarize recent advances in diagnosis, treatment and novel insights into the pathogenesis of this disease.

TAFRO Syndrome That Responded to Prednisolone-only Treatment: Evaluating Changes in IL-6

Thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome is a systemic inflammatory disorder characterized by the above-mentioned symptoms. Because of the similarity in phenotypes between TAFRO syndrome and decompensated liver cirrhosis, an accurate diagnosis is often difficult. We herein report a 62-year-old Japanese patient with TAFRO syndrome who was misdiagnosed with intractable ascites associated with liver cirrhosis. Improvement of symptoms after treatment with prednisolone was associated with interleukin-6 rather than C-reactive protein. The pathogenesis of TAFRO syndrome, which has similar clinical manifestations to liver cirrhosis, remains unclear, and our findings may help elucidate the concept of this condition.

Optimisation of anti-interleukin-6 therapy: Precision medicine through mathematical modelling

Background

Dysregulated interleukin (IL)-6 production can be characterised by the levels present, the kinetics of its rise and its inappropriate location. Rapid, excessive IL-6 production can exacerbate tissue damage in vital organs. In this situation, therapy with an anti-IL-6 or anti-IL-6 receptor (IL-6R) monoclonal antibody, if inappropriately dosed, may be insufficient to fully block IL-6 signalling and normalise the immune response.

Methods

We analysed inhibition of C-reactive protein (CRP) – a biomarker for IL-6 activity – in patients with COVID-19 or idiopathic multicentric Castleman disease (iMCD) treated with tocilizumab (anti-IL-6R) or siltuximab (anti-IL-6), respectively. We used mathematical modelling to analyse how to optimise anti-IL-6 or anti-IL-6R blockade for the high levels of IL-6 observed in these diseases.

Results

IL-6 signalling was insufficiently inhibited in patients with COVID-19 or iMCD treated with standard doses of anti-IL-6 therapy. Patients whose disease worsened throughout therapy had only partial inhibition of CRP production. Our model demonstrated that, in a scenario representative of iMCD with persistent high IL-6 production not controlled by a single dose of anti-IL-6 therapy, repeated administration more effectively inhibited IL-6 activity. In a situation with rapid, high, dysregulated IL-6 production, such as severe COVID-19 or a cytokine storm, repeated daily administration of an anti-IL-6/anti-IL-6R agent, or alternating daily doses of anti-IL-6 and anti-IL-6R therapies, could neutralise IL-6 activity.

Conclusion

In clinical practice, IL-6 inhibition should be individualised based on pathophysiology to achieve full blockade of CRP production.

Funding

EUSA Pharma funded medical writing assistance and provided access to the phase II clinical data of siltuximab for analysis.

Cutaneous Plasmacytosis and Idiopathic Multicentric Castleman Disease: A Spectrum of Disease?

ABSTRACT

Cutaneous/systemic plasmacytosis (C/SP) is a plasma cell disorder characterized by reddish-brown patches, lymphadenopathy, and hypergammaglobulinemia. The degree to which C/SP overlaps with other plasma cell proliferative disorders and neoplasms is incompletely understood. We present the case of a patient with a several-year history of cutaneous plasmacytosis and evidence of systemic involvement with concurrent idiopathic multicentric Castleman disease (iMCD) involving a lymph node. There have been only a few reports of systemic iMCD preceded by a long, asymptomatic phase of cutaneous manifestations. We discuss the relationship between C/SP and iMCD and elaborate on the pathophysiological overlap of these 2 conditions and potential similarities in their pathogenesis. We suggest that the 2 diseases may represent the same entity presenting on a spectrum, with individuals diagnosed with C/SP at risk for progression to iMCD.

Successful treatment with tocilizumab for refractory anemia and slowly progressive renal glomerulosclerosis in multicentric Castleman disease: A case report

RATIONALE

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder accompanied by systemic symptoms characterized by polyclonal hypergammaglobulinemia and chronic inflammation due to overexpression of interleukin-6. Histological heterogeneity of renal involvement in MCD has been described, although the number of reports is limited. Tocilizumab, a humanized anti-interleukin-6 receptor antibody, has been reported to be effective for MCD.

PATENT CONCERNS

A 64-year-old man experienced refractory anemia and slowly progressive renal dysfunction with proteinuria, accompanied by persistent inflammation for 11 years.

DIAGNOSIS

Two renal biopsies were obtained. The first biopsy performed 7 years before admission revealed non-specific interstitial inflammation, whereas the second biopsy demonstrated global sclerosis in most glomeruli and interstitial fibrosis. The patient had multiple lymphadenopathies. Cervical lymph node biopsy histological findings were compatible with plasma cell type Castleman disease. The patient had no evidence of human hepatitis virus-8 infection.

INTERVENTION

The patient was treated with 60 mg/d prednisolone followed by 8 mg/kg intravenous tocilizumab every 2 weeks.

OUTCOME

His anemia significantly improved, as well as a marked reduction in proteinuria and stabilization of renal function. He did not experience renal function during the 2-years follow-up period.

LESSONS

The heterogeneity of the renal manifestations of MCD sometimes makes early diagnosis difficult. We need to interpret the histological findings of the renal biopsy carefully. For advanced-stage renal diseases, tocilizumab might be an effective treatment strategy for MCD.

A Patient with Castleman's Disease Initially Manifesting Symmetrical Synovitis with Pitting Edema

Castleman's disease (CD), especially multicentric CD (MCD) has been known to manifest a variety of clinical features such as fatigue, anemia, fever and hypergammaglobulinemia. Here, we report a 72-year-old female patient who had complicated severe synovitis, as an initial manifestation of the disease, lastly diagnosed as MCD. Initially, she had been diagnosed as remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome because of bilateral leg pitting edema with significant c-reactive protein and matrix metalloproteinase-3 elevation but no disease-specific autoantibodies. Promptly, corticosteroid (CS) and additionally weekly methotrexate (MTX) was introduced, but her leg edema and inflammatory findings did not adequately come to be a remission. A lymph node biopsy from the groin region was performed because multiple lymph node swelling in ultrasound examination appeared even after introducing treatments, which revealed mixed-type CD. Multiple lymphadenopathies were observed in the axilla and inguinal region, finally, we diagnosed her as idiopathic MCD and introduced tocilizumab (TCZ) which significantly improved leg edema as well as inflammatory findings. As is shown in this case, manifestations included in RS3PE syndrome could be one of the clinical phenotypes in MCD, which should be considered as a differential diagnosis of MCD.

HHV-8-Associated Multicentric Castleman Disease, a Diagnostic Challenge in a Patient With Acquired Immunodeficiency Syndrome and Fever

Patients with acquired immunodeficiency syndrome (AIDS) are at an increased susceptibility to pathogens and associated malignancies which can present with a unique constellation of symptoms. In this article, we describe a case of Castleman disease in a patient with AIDS, nonadherent with antiretroviral therapy (ART), who presented with fevers, constant abdominal pain, nausea, and vomiting. After an extensive work up, a lymph node biopsy confirmed a diagnosis of human herpesvirus-8 (HHV-8)-associated multicentric Castleman disease. Patients presenting with AIDS and fever have broad differential diagnoses; therefore, reaching a diagnosis as rare as Castleman disease can be challenging. HHV-8 has a propensity to CD20 positive B cells, which allows rituximab to be an effect treatment.

Aseptic Meningitis-retention Syndrome Associated with Tocilizumab in a Patient with Idiopathic Multicentric Castleman Disease

This is the first report of tocilizumab-associated meningitis-retention syndrome in a patient with idiopathic multicentric Castleman disease. A 57-year-old man presented with headache, nuchal rigidity, impaired consciousness, pyramidal tract signs and urinary retention. A cerebrospinal fluid examination revealed increased cell counts and protein levels. These symptoms were improved by intravenous methylprednisolone. Tocilizumab-associated meningoencephalitis has been reported in patients with rheumatoid arthritis and juvenile idiopathic arthritis but not with multicentric Castleman disease. This case presents evidence of the increased probability of meningitis as a neurological complication of tocilizumab administration.

Human herpesvirus 8-associated multicentric Castleman disease in a patient with advanced HIV infection: A case report

RATIONAL

Multicentric Castleman disease (MCD) is a nonclonal lymphoproliferative disorder that is rarely reported from Southeast Asian countries. Here, we report a case of human herpesvirus 8 (HHV-8)-associated MCD in a patient with advanced human immunodeficiency virus (HIV) infection who presented with prolonged intermittent fever, urticarial rash, hepatosplenomegaly, and generalized lymphadenopathy.

PATIENT CONCERNS

A 34-year-old man with advanced HIV infection who was in good compliance with his antiretroviral treatment regimen presented with intermittent fever, weight loss, marked hepatosplenomegaly, and generalized lymphadenopathy. Recurrent symptoms of high-grade fever, abdominal discomfort, pancytopenia, and high C-reactive protein level occurred for 16 months.

DIAGNOSES

Histopathological findings of left inguinal lymph node revealed diffuse effacement of lymph node architecture with coexpression of HHV-8 latency-associated nuclear antigen 1 from immunohistochemical staining. The HHV-8 viral load was 335,391 copies/mL.

INTERVENTIONS

The patient was treated initially with one dose of intravenous rituximab (375 mg/m2) followed by subcutaneous rituximab (1400 mg) weekly for 5 weeks.

OUTCOMES

The patient's recurrent systemic symptoms subsided dramatically, and he has now been in remission for almost two years.

LESSONS

HHV8-associated MCD remains a diagnostic challenge in advanced HIV disease and should be suspected in those with recurrent flares of systemic inflammatory symptoms. Lymph node histopathology is essential for diagnosis and for excluding clonal malignancy. HHV-8 viral load is also useful for diagnosis and for monitoring disease activity.

Indolent T-Lymphoblastic Proliferation in Idiopathic Multicentric Castleman Disease

Benign and polyclonal proliferation of immature T cells in a lymph node with preserved morphological architecture is called indolent T-lymphoblastic proliferation (iT-LBP). Although overall rare, they have been described in association with both benign and malignant disorders including Castleman disease. We report the first case of idiopathic multicentric Castleman disease associated with iT-LBP, all previous reports of iT-LBP in Castleman disease were unicentric. A 37-year-old-male presented with 3 months of fevers and B-symptoms and was found to have enlargement of multiple bilateral lymph node sites on both sides of diaphragm along with splenomegaly. Anemia, elevated C-reactive protein, hypoalbuminemia, and elevated interleukin-6 levels were present. Biopsy of a lymph node showed features suggestive of idiopathic multicentric Castleman disease and iT-LBP. Bone marrow biopsy was unremarkable. Siltuximab and steroids were used to treat the condition.

A case of tocilizumab-refractory idiopathic multicentric Castleman's disease successfully treated with sirolimus

mTOR signaling may be a new therapeutic target for IL-6 inhibitor refractory iMCD-NOS.

Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases

Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.

The clinical, laboratory, and radiologic improvement due to siltuximab treatment in idiopathic multicentric Castleman's disease

BACKGROUND/AIMS

Idiopathic multicentric Castleman disease (iMCD) comprises approximately 30% of all cases of Castleman disease. It is characterized by constitutional symptoms, enlarged lymph nodes at multiple anatomical sites, and laboratory test abnormalities, which are primarily related to the overproduction of interleukin 6 (IL-6). Siltuximab is a human-mouse chimeric immunoglobulin G1κ monoclonal antibody against human IL-6. In view of the limited treatment options for iMCD, this study aimed to evaluate the efficacy and safety of siltuximab in the management of this condition.

METHODS

In this real-world retrospective study, we administered siltuximab to 15 patients with iMCD who previously received conventional chemotherapy and/or steroid pulse therapy. The median time to a durable symptomatic response was 22 days (range, 17 to 56). The serum hemoglobin and albumin levels and erythrocyte sedimentation rates significantly normalized after the first 3 months of siltuximab treatment. Lymph node involution, assessed using imaging, was relatively gradual, demonstrating a complete or partial response at 6 months.

RESULTS

On an average, the improvements in clinical, laboratory, and radiologic parameters of iMCD in responders were observed after one, three, and eight cycles of siltuximab treatment, respectively. Siltuximab demonstrated a favorable safety profile, and prolonged treatment was well-tolerated.

CONCLUSION

Despite the small sample size of the present study, the results are encouraging and demonstrate the potential of siltuximab as the first-line treatment of iMCD. Further large multicenter studies are needed to evaluate the clinical outcomes and adverse events associated with siltuximab.

Weathering the COVID-19 storm: Lessons from hematologic cytokine syndromes

A subset of patients with severe COVID-19 develop profound inflammation and multi-organ dysfunction consistent with a "Cytokine Storm Syndrome" (CSS). In this review we compare the clinical features, diagnosis, and pathogenesis of COVID-CSS with other hematological CSS, namely secondary hemophagocytic lymphohistiocytosis (sHLH), idiopathic multicentric Castleman disease (iMCD), and CAR-T cell therapy associated Cytokine Release Syndrome (CRS). Novel therapeutics targeting cytokines or inhibiting cell signaling pathways have now become the mainstay of treatment in these CSS. We review the evidence for cytokine blockade and attenuation in these known CSS as well as the emerging literature and clinical trials pertaining to COVID-CSS. Established markers of inflammation as well as cytokine levels are compared and contrasted between these four entities in order to establish a foundation for future diagnostic criteria of COVID-CSS.

Unicentric Castlemans disease. Symptoms, diagnostics and therapy

Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms - multicentric Castleman disease. The first-ever diagnostic and treatment guidelines were recently developed for UCD and published 2020. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti-interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic because of compression of vital neighbouring structures may be rendered amenable to resection by medical therapy (rituximab, steroids), radiotherapy, or embolization. In this article, we report about the symptoms of this disease and about the diagnostics recommendation published in the International, evidence-based consensus diagnostic criteria for HHV-8-negative/ idiopathic multicentric Castleman disease and about the therapeutic recommendation published in International evidence-based consensus diagnostic and treatment guidelines for unicentric Castleman disease published in the year 2020.

An open-label continuation trial of sirolimus for tocilizumab-refractory idiopathic multicentric Castleman disease: Study protocol for an investigator-initiated, multicenter, open-label trial (SPIRIT compliant)

BACKGROUND

Interleukin 6 (IL-6) inhibitors are the first-line treatment for idiopathic multicentric Castleman disease (iMCD); however, there is no established treatment for cases that are resistant to IL-6 inhibitors. Although sirolimus, a mammalian target of rapamycin inhibitor, has been suggested to be effective in patients with iMCD, the long-term safety and efficacy of sirolimus on individuals with IL-6 inhibitor-resistant iMCD have not been evaluated.

METHODS/DESIGN

In this investigator-initiated, multicenter, open-label trial, the long-term safety of sirolimus will be evaluated in patients participating in a placebo-controlled, randomized, double-blind, parallel-group trial on tocilizumab (TCZ)-resistant iMCD. The study will be conducted in 7 centers in Japan. This trial will be promptly started after the evaluation and examination for 16 weeks in the preceding study. The trial will be completed by the time the drug is approved for iMCD treatment in Japan. The primary endpoint is the incidence of adverse events. The secondary endpoints include the following: the levels of hemoglobin, albumin, and C-reactive protein; change in CHAP score; physician global assessment (100-mm visual analog scale); patient global assessment (100-mm visual analog scale); and lymph node changes in subjects with lymphadenopathy.

DISCUSSION

This clinical trial will provide evidence regarding the long-term safety of sirolimus as a potential novel therapeutic agent for patients with tocilizumab-resistant iMCD.

TRIAL REGISTRATION NUMBER

jRCT2051200050.

A Novel Predictive Model for Idiopathic Multicentric Castleman Disease: The International Castleman Disease Consortium Study

BACKGROUND

Patients with multicentric Castleman disease (MCD) who are negative for human immunodeficiency virus and human herpesvirus 8 are considered to have idiopathic MCD (iMCD). The clinical presentation of iMCD varies from mild constitutional symptoms to life-threatening symptoms or death. The treatment strategy varies from "watchful waiting" to high-dose chemotherapy. This diverse clinical presentation calls for a classification stratification system that takes into account the severity of the disease.

SUBJECTS, MATERIALS, AND METHODS

We analyzed the clinical, laboratory, and pathologic abnormalities and treatment outcomes of 176 patients with iMCD (median follow-up duration 12 years) from the U.S. and China to better understand the characteristics and prognostic factors of this disease. This discovery set of iMCD results was confirmed from the validation set composed of additional 197 patients with iMCD organized from The International Castleman Disease Consortium.

RESULTS

Using these data, we proposed and validated the iMCD international prognostic index (iMCD-IPI), which includes parameters related to patient characteristics (age > 40 years), histopathologic features (plasma cell variant), and inflammatory consequences of iMCD (hepatomegaly and/or splenomegaly, hemoglobin <80 g/L, and pleural effusion). These five factors stratified patients according to their performance status and extent of organ dysfunction into three broad categories: low risk, intermediate risk, and high risk. The iMCD-IPI score accurately predicted outcomes in the discovery study cohort, and the results were confirmed on the validation study cohort.

CONCLUSION

This study represents the largest series of studies on patients with iMCD in the field and proposed a novel risk-stratification model for iMCD-IPI that could be used to guide risk-stratified treatment strategies in patients with iMCD.

IMPLICATIONS FOR PRACTICE

Patients with idiopathic multicentric Castleman disease (iMCD) can benefit from care based on clinical symptoms and disease severity. This study in 176 patients with iMCD constructed an iMCD-IPI score based on five clinical factors, including age >40 years, plasmacytic variant subtype, hepatomegaly and/or splenomegaly, hemoglobin <80 g/L, and pleural effusion, and stratified patients into three risk categories: low risk, intermediate risk, and high risk. The predictive value was validated in an independent set of 197 patients with iMCD from The International Castleman Disease Consortium. The proposed novel model is valuable for predicting clinical outcome and selecting optimal therapies using clinical parameters.

Systemic lupus erythematosus complicated with Castleman disease: a case-based review

Systemic lupus erythematosus (SLE) is a complex, chronic, multi-systemic autoimmune disease, characterized by miscellaneous clinical findings. Castleman disease (CD) is a rare lymphoproliferative disorder that may present with systemic symptoms. Herein, a SLE case complicated with CD is reported by comparing her clinical findings with previously reported patients. We reviewed the literature regarding cases of "Castleman disease" and "Systemic lupus erythematosus" by searching medical journal databases in MEDLINE, EMBASE, Scopus, and Web of Science. A case of a 16-year-old girl with SLE who had intraabdominal lymphadenopathy detected both by ultrasonography and abdominal magnetic resonance imaging is presented. The excision of the lymph node was performed by pediatric surgeons. Histopathological examination was compatible with CD. Hydroxychloroquine and steroid treatments were started after the operation. She achieved remission in 3 months. In the literature research, we found 10 articles describing 17 patients. To our best of knowledge, the presented case was the third pediatric case in the literature with SLE and coexistent CD. This case report and literature review suggests that CD should be considered while evaluating and following patients with autoimmune diseases.

Two cases of idiopathic multicentric Castleman disease with nephrotic syndrome treated with tocilizumab

We report two cases of idiopathic multicentric Castleman disease (iMCD) with nephrotic syndrome (NS) treated with tocilizumab. Case 1 was a 58-year-old man diagnosed with iMCD prior to the onset of NS. Renal biopsy revealed membranous nephropathy, which was considered to be secondary membranous nephropathy associated with iMCD. Case 2 was a 49-year-old woman diagnosed with iMCD prior to NS. Renal biopsy revealed renal amyloidosis positive for Congo red staining and amyloid A protein immunostaining. In both the cases, the proteinuria improved after the initiation of glucocorticoid and tocilizumab therapy. Tocilizumab may be a good therapeutic choice for iMCD with NS.

Randomized, double-blind, placebo-controlled, parallel-group trial of sirolimus for tocilizumab-resistant idiopathic multicentric Castleman disease: Study protocol for clinical trial

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder of unknown etiology with systemic symptoms that include fever, night sweats, weight loss, and fatigue. Although tocilizumab (TCZ), which is a recombinant, humanized, anti-human interleukin 6 receptor monoclonal antibody, has been recommended to treat patients with iMCD, 40% of patients with iMCD do not achieve complete remission with TCZ treatment.

METHODS/DESIGN

In this phase II, investigator-initiated, multicenter, double-blind, randomized, parallel-group trial, the efficacy and safety of sirolimus will be compared with placebo in patients with TCZ-resistant iMCD. The study will be conducted in 8 centers in Japan. Participants (n = 20) will be randomly assigned to receive 2 mg of oral sirolimus (n = 10) or placebo (n = 10) once daily for 16 weeks. The primary endpoint is a decrease in CHAP score by ≥1 from baseline at 16 weeks. Secondary endpoints include levels of hemoglobin, albumin, and C-reactive protein; change in CHAP score; SF-36 Health Survey Questionnaire; physician global assessment (100 mm visual analog scale); patient global assessment (100 mm visual analog scale) at 2, 4, 8, 12, and 16 weeks; change in lymphadenopathy at 16 weeks; and pharmacodynamic assessment, including the measurement of whole blood sirolimus level.

DISCUSSION

This clinical trial will provide evidence of efficacy and safety of sirolimus as a potential new therapeutic agent for patients with TCZ-resistant iMCD.

TRIAL REGISTRATION

This study was registered with the Japan Registry of Clinical Trials as jRCT2071190029 on October 8, 2019.

When the Quest for a Cure Is Personal

We asked three researchers how their personal connection to disease has affected them and what lessons it has taught them along the way.

HIV-associated multicentric Castleman disease: a report of 19 cases at an oncology institution

The aim of this study is to describe the clinical characteristics and outcome of multicentric Castleman disease (MCD) in HIV-infected patients at an oncological referral center in Mexico. Clinical records at the HIV-AIDS clinic of all patients diagnosed with MCD from 1994 to 2018 were reviewed. There were 19 patients, mean age was 31.3 ± 8.4 years, and 17 (89.5%) were males. Fifteen patients (79%) had also Kaposi sarcoma (KS). Main clinical characteristics were multiple lymphadenopathy (95%), systemic symptoms (63%), and hepatosplenomegaly (50%). Computed tomography scan and 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography showed multiple lymphadenopathy, inversion of the liver:spleen uptake ratio, with an increase in SUVmax (5.7). The histopathology report described plasma cells in 58%, mixed type in 26%, and hyaline vascular in 16%. Eleven patients (57.9%) received different chemotherapy regimens. Seven patients died (36.8%): four related to MCD progression or chemotherapy complications, median survival was eight months. For those patients who survived, median, follow-up was 28 months (p < 0.001). The incidence of MCD in people living with HIV is probably underestimated. In patients with lymphadenopathy, B symptoms, deranged inflammatory markers, and/or disseminated KS, a biopsy of an enlarged lymph node is warranted, and the histology should be reviewed by an experienced pathologist.

Treatment of multicentric Castleman disease through combination of tocilizumab, lenalidomide and glucocorticoids: Case report

RATIONALE

Castleman's disease (CD) is a rare lymphoproliferative disease. Compared to unicentric CD, multicentric Castleman disease (MCD) displays poorer prognosis and great variance to different therapies. Though chemotherapy, immunization therapy, and glucocorticoids have been used in the treatment of MCD, its optimal treatment is still controversial.

PATIENT CONCERNS

A 47-year-old woman was admitted due to poor appetite, general fatigue, puffiness of face, systemic rash, and abdominal distension. On physical examination, the patient displayed as general lymphadenopathy, splenomegaly, hepatomegaly, and shifting dullness.

DIAGNOSES

After biopsy of her swollen lymph node and laboratory tests, her initial diagnosis was hyaline vascular-CD.

INTERVENTIONS

She was treated with combination of tocilizumab, lenalidomide, and glucocorticoids.

OUTCOMES

This patient achieved complete remission (CR) with all her indexes returned to be normal. Her blood routines and biochemical examinations were still normal during the following period.

LESSONS

We reported a case with multicentric Castleman's disease (MCD) which acquired quite good remission after combination treatment with tocilizumab, lenalidomide, and glucocorticoids. Our report provided powerful evidence for displaying the efficiency and safety of target therapy against unicentric Castleman disease.

Population pharmacokinetics of siltuximab: impact of disease state

PURPOSE

To characterize the effects of disease type and clinical characteristics on the pharmacokinetics of siltuximab, an IL-6 inhibiting monoclonal antibody.

METHODS

Siltuximab pharmacokinetic data were combined from seven phase I/II clinical trials. A population pharmacokinetic model was developed to characterize changes in siltuximab disposition with disease type, albumin, liver and renal function, and patient demographics.

RESULTS

A total of 7761 concentrations from 460 participants were used in the study. The data were well described by a two-compartment model. Castleman's disease, healthy volunteer status, albumin, and ALT were independent predictors of clearance. Monte Carlo simulations of the final model for an 11 mg/kg dose resulted in a longer median half-life for healthy volunteers (24.5 days) as compared to Castleman's disease (19.1 days) and other tumor types (22.2 days). Clearance varied 1.8-fold over the range of albumin values seen in the study (1.5-5.2 g/dL), while ALT resulted in minimal changes in clearance.

CONCLUSIONS

Albumin and disease state are important factors for siltuximab disposition and will likely need to be considered for dosing in future therapeutic applications.

Pathological findings of progressive renal involvement in a patient with TAFRO syndrome

TAFRO syndrome (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) is thought of as an atypical type of idiopathic multicentric Castleman's disease. Interleukin-6, vascular endothelial growth factor (VEGF), and other cytokines are considered etiological factors. A 45-year-old woman was admitted to hospital with unknown fever and abdominal pain. She had thrombocytopenia, anasarca, proteinuria/hematuria, and slight hepatosplenomegaly. Based on her clinical course and laboratory data, she was diagnosed as having TAFRO syndrome. Kidney biopsy showed a membranoproliferative glomerulonephritis (MPGN)-like lesion containing lobulations of glomeruli, endothelial cell swelling, double contours of the glomerular basement membrane, and mesangiolysis. She was treated with methylprednisolone pulse (500 mg/day) and oral prednisolone (60 mg/day) therapy. The pleural effusion and ascites disappeared, and renal function normalized. Cyclosporine was added to prevent relapse. She went home, with no relapse 8 months after hospitalization. MPGN-like lesions were found frequently in patients with TAFRO syndrome in recent reports. However, there are few reports of pathologically confirmed cases of progressive renal involvement in TAFRO syndrome. The relationship between VEGF expression in renal tissue and the pathogenesis of renal injury in TAFRO syndrome was investigated in the present case.

Rheumatoid arthritis-like active synovitis with T-cell activation in a case of idiopathic multicentric Castleman disease: A case report

RATIONALE

Idiopathic multicentric Castleman disease (iMCD) is a systemic disease with multiple regions of lymphadenopathy and systemic symptoms and associated with rheumatoid arthritis (RA) and collagen diseases. However, few reported have described the coexistence of iMCD and RA and the mechanisms by which iMCD induces arthritis remain elusive. We experienced a rare case of iMCD, wherein the patient exhibited symptoms of polyarthritis with high-grade fever.

PATIENT CONCERNS

A 34-year-old woman was admitted to our hospital for further evaluation of a high fever with polyarthritis. The levels of both rheumatoid factor and anticitrullinated protein antibody were negative. F-fluorodeoxyglucose/positron emission tomography-computed tomography showed lymphadenopathy with increased fluoro-2-deoxy-D-glucose uptake. Magnetic resonance imaging and musculoskeletal ultrasonography revealed active synovitis in the hands which was consistent with RA.

DIAGNOSES

We diagnosed iMCD based on human herpesvirus 8 negativity, HIV negativity, systemic lymphadenopathy, and pathologic findings of the lymph nodes. The patient did not satisfy the 2010 American College of Rheumatology and European League Against Rheumatism classification criteria for RA. Cytokine assay showed elevated serum levels of interleukin-17 and CXCL10, comparable to those in patients with RA.

INTERVENTIONS

We administered 15 mg/d of predonisolone.

OUTCOMES

After this treatment, the patient's symptoms showed improvement. As of this writing, we tapered the prednisolone to 7.5 mg/d, and the patient's remission has been maintained for >4 months.

LESSONS

The present case suggests that RA-like active synovitis may coexist in iMCD, resulting from aberrant T-cell activation and histologic examination using lymph node biopsy may help enable early diagnosis of iMCD.

Novel insights and therapeutic approaches in idiopathic multicentric Castleman disease

Castleman disease (CD) describes a heterogeneous group of hematologic disorders that share characteristic lymph node histopathology. Patients of all ages present with either a solitary enlarged lymph node (unicentric CD) or multicentric lymphadenopathy (MCD) with systemic inflammation, cytopenias, and life-threatening multiple organ dysfunction resulting from a cytokine storm often driven by interleukin 6 (IL-6). Uncontrolled human herpesvirus-8 (HHV-8) infection causes approximately 50% of MCD cases, whereas the etiology is unknown in the remaining HHV-8-negative/idiopathic MCD cases (iMCD). The limited understanding of etiology, cell types, and signaling pathways involved in iMCD has slowed development of treatments and contributed to historically poor patient outcomes. Here, recent progress for diagnosing iMCD, characterizing etio-pathogenesis, and advancing treatments are reviewed. Several clinicopathological analyses provided the evidence base for the first-ever diagnostic criteria and revealed distinct clinical subtypes: thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS), which are both observed all over the world. In 2014, the anti-IL-6 therapy siltuximab became the first iMCD treatment approved by the US Food and Drug Administration, on the basis of a 34% durable response rate; consensus guidelines recommend it as front-line therapy. Recent cytokine and proteomic profiling has revealed normal IL-6 levels in many patients with iMCD and potential alternative driver cytokines. Candidate novel genomic alterations, dysregulated cell types, and signaling pathways have also been identified as candidate therapeutic targets. RNA sequencing for viral transcripts did not reveal novel viruses, HHV-8, or other viruses pathologically associated with iMCD. Despite progress, iMCD remains poorly understood. Further efforts to elucidate etiology, pathogenesis, and treatment approaches, particularly for siltuximab-refractory patients, are needed.