Remission of nephrotic syndrome due to AA amyloidosis and initiation of glomerular repair after surgical resection of localized Castleman's disease

International evidence-based consensus diagnostic and treatment guidelines for unicentric Castleman disease

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 CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)-associated MCD, POEMS-associated MCD, and HHV-8-/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. 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 as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

UCD with MCD-like inflammatory state: surgical excision is highly effective

Unicentric Castleman disease (UCD) is a rare lymphoproliferative disorder presenting as a single nodal mass with characteristic histopathology. Patients with UCD are typically asymptomatic with normal laboratory markers, whereas patients with multicentric Castleman disease (MCD) demonstrate multicentric lymphadenopathy and cytokine storm-induced systemic inflammatory symptoms. This retrospective analysis of 116 UCD cases identified 19 (16.4%) cases with an MCD-like inflammatory state (UCD-MIS). We compared treatments and outcomes between cases of UCD-MIS and UCD-non-MIS to evaluate the role of surgery and illuminate biological behavior of UCD-MIS. There were differences in the distribution of histopathological subtypes (plasmacytic histopathology was more frequently seen, 52.6% vs 13.4%; P < .001) between the 2 groups. However, both groups demonstrated good responses to surgical treatment, suggesting that UCD-MIS in some patients still shared common biological behavior with UCD in other patients. Sixteen (94.2%) patients with UCD-MIS underwent complete surgical excision alone, and the systemic inflammation resolved completely in all of them. This high response rate suggests surgical treatment as a potential cure for this unique subset of patients. After a median follow-up duration of 64 months (range, 2-239 months), neither lymphadenopathy nor the inflammatory state recurred. However, inflammation may progress in patients with irresectable disease, and treatment options other than surgery should be considered in these patients.

Overview of Castleman disease

Castleman disease (CD) describes a group of at least 4 disorders that share a spectrum of characteristic histopathological features but have a wide range of etiologies, presentations, treatments, and outcomes. CD includes unicentric CD (UCD) and multicentric CD (MCD), the latter of which is divided into idiopathic MCD (iMCD), human herpes virus-8 (HHV8)-associated MCD (HHV8-MCD), and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD (POEMS-MCD). iMCD can be further subclassified into iMCD-thrombocytopenia, ascites, reticulin fibrosis, renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS). Advances in diagnosis, classification, pathogenesis, and therapy are substantial since the original description of UCD by Benjamin Castleman in 1954. The advent of effective retroviral therapy and use of rituximab in HHV8-MCD have improved outcomes in HHV8-MCD. Anti-interleukin-6-directed therapies are highly effective in many iMCD patients, but additional therapies are required for refractory cases. Much of the recent progress has been coordinated by the Castleman Disease Collaborative Network (CDCN), and further progress will be made by continued engagement of physicians, scientists, and patients. Progress can also be facilitated by encouraging patients to self-enroll in the CDCN's ACCELERATE natural history registry (#NCT02817997; www.CDCN.org/ACCELERATE).

Treating Protein Misfolding Diseases: Therapeutic Successes Against Systemic Amyloidoses

Misfolding and extracellular deposition of proteins is the hallmark of a heterogeneous group of conditions collectively termed protein misfolding and deposition diseases or amyloidoses. These include both localized (e.g. Alzheimer’s disease, prion diseases, type 2 diabetes mellitus) and systemic amyloidoses. Historically regarded as a group of maladies with limited, even inexistent, therapeutic options, some forms of systemic amyloidoses have recently witnessed a series of unparalleled therapeutic successes, positively impacting on their natural history and sometimes even on their incidence. In this review article we will revisit the most relevant of these accomplishments. Collectively, current evidence converges towards a crucial role of an early and conspicuous reduction or stabilization of the amyloid-forming protein in its native conformation. Such an approach can reduce disease incidence in at risk individuals, limit organ function deterioration, promote organ function recovery, improve quality of life and extend survival in diseased subjects. Therapeutic success achieved in these forms of systemic amyloidoses may guide the research on other protein misfolding and deposition diseases for which effective etiologic therapeutic options are still absent.

AA amyloidosis associated with Castleman disease: A case report and review of the literature

RATIONALE

AA amyloidosis (AA) is caused by a wide variety of inflammatory states, but is infrequently associated with Castleman disease (CD). CD describes a heterogeneous group of hematologic disorders that share characteristic lymph node histopathology. CD can present with a solitary enlarged lymph node (unicentric CD, UCD) or with multicentric lymphadenopathy (MCD), constitutional symptoms, cytopenias, and multiple organ dysfunction due to an interleukin-6 driven cytokine storm.

PATIENT CONCERNS

We are reporting a case of a 26-year-old woman with no significant past medical history who presented with a 3-month history of fatigue and an unintentional 20-pound weight loss.

DIAGNOSIS

A CT-scan of the abdomen and pelvis revealed hepatosplenomegaly and a mesenteric mass. Congo Red staining from a liver biopsy showed apple-green birefringence and serum markers were suggestive of an inflammatory process. Post-excision examination of the resected mass revealed a reactive lymph node with follicular hyperplasia with kappa and lambda stains showing polyclonal plasmacytosis consistent with CD.

INTERVENTIONS

The patient underwent surgery to remove the affected lymph node.

OUTCOMES

IL-6, anemia, leukocytosis, and thrombocytosis resolved or normalized 2 weeks after resection; creatinine normalized 9 months postsurgery. Twenty two months post-surgery her IFN-γ normalized, her fatigue resolved, her proteinuria was reduced by >90% and she had returned to her baseline weight.

LESSONS

Our case and literature review suggest that patients presenting with UCD or MCD along with organ failure should prompt consideration of concurrent AA amyloidosis.

Late onset renal failure and nephrotic syndrome after autologous stem cell transplant for Al amyloidosis

We present a patient with AL amyloidosis who had an autologous stem cell transplant (ASCT) over 9 years ago. She has since then developed slowly progressive renal insufficiency and the nephrotic syndrome. Hematologic evaluation has failed to identify recurrent disease and a renal biopsy demonstrated extensive amyloid deposition and substantial glomerulosclerosis. We suggest that the patient has chronic glomerulosclerosis as a consequence of renal damage associated with her disease process and her treatment.

Primary sclerosing cholangitis complicated by amyloid A amyloidosis: complete regression of the nephrotic syndrome by liver transplantation

Secondary amyloidosis may complicate chronic inflammatory conditions and mostly presents as a renal disease with nephrotic syndrome or renal insufficiency. Its prognosis is largely affected by control of the underlying disease. We report a patient with primary sclerosing cholangitis, who developed cirrhosis over a 4-year period. Therapy with steroids and azathioprine was necessary for symptom control. Despite this treatment, she developed secondary amyloidosis with nephrotic syndrome 4 years after the initial presentation. The inflammatory process in the bile ducts was considered the cause of amyloid A amyloidosis. To control the nephrotic syndrome, liver transplantation was performed with the removal of the diseased liver and bile duct system. Liver transplantation was followed by a progressive and complete disappearance of the nephrotic syndrome. This is the first report describing the occurrence of amyloid A amyloidosis in primary sclerosing cholangitis, and the reversal of a secondary amyloidosis-induced nephrotic syndrome as a result of liver transplantation.

Treatment of Castleman's disease

Castleman's disease (CD) was first described in 1954 and further defined in 1956 by Castleman. Since then much has been learned about the heterogeneity of this condition. Subsequently, three pathologic classifications have been developed (hyaline vascular variant, plasma cell variant, and mixed variant) and two clinical classifications (unicentric [unifocal or localized] and multicentric [multifocal or generalized]). The pathology found with the unicentric presentation is most commonly that of the HV variant. It responds well to surgical resection and is associated with a benign course. The multicentric presentation is rarely composed of lymph nodes with HV pathology, but rather with the plasma cell or mixed pathology. This presentation requires systemic therapy and prognosis is guarded. Associated systemic symptoms are common. There is an increased incidence of CD in patients with HIV. The human herpes virus-8 is associated with nearly all of the HIV-associated CD cases and nearly 50% of non-HIV cases. Interleukin (IL)-6 has also been shown to play a significant role in the pathogenesis of the disease. Paraneoplastic and autoimmune entities are not uncommon in the disorder. Variable benefit has been achieved with single agent chemotherapy, combination chemotherapy, interferon (IFN)-alpha, rituximab, anti-IL-6 receptor antibodies, and thalidomide. Patients with CD are at increased risk for developing frank malignant lymphoma.

No regression of renal AL amyloid in monoclonal gammopathy after successful autologous blood stem cell transplantation and significant clinical improvement

BACKGROUND

High-dose chemotherapy followed by autologous blood stem cell transplantation induces remission of plasma cell dyscrasia in patients with AL amyloidosis. The impact of this treatment on the glomerular amyloid mass is still unknown.

METHODS

In the present study, the quantity of the renal amyloid mass before and more than 3 years after high-dose melphalan treatment and autologous blood stem cell transplantation was assessed in two patients. At the time of the second renal biopsy, both patients were in complete remission without detectable serum and urinary monoclonal IgA-lambda and a normal percentage of plasma cells in the bone marrow.

RESULTS

In both patients with biopsy-proven AL amyloidosis, urinary protein excretion decreased from 7 g/24 h to <2 g/24 h more than 3 years after autologous blood stem cell transplantation. In contrast, glomerular amyloid deposits persisted, as shown in the second biopsy.

CONCLUSION

Despite complete remission of the plasma cell dyscrasia and improvement of glomerular permeability, the amount of glomerular amyloid mass did not regress.