Castleman's disease accompanied by hypolipidemic cerebral hemorrhage and nephrosclerosis

Case report: Importance of early and continuous tocilizumab therapy in nephrotic syndrome associated with idiopathic multicentric Castleman disease: A case series

Idiopathic multicentric Castleman disease (iMCD) is a systemic and polyclonal lymphoproliferative disease involving multiple organs, including the kidneys, due to the overproduction of interleukin-6 (IL-6). Recently, several reports have suggested that excessive IL-6 actions in iMCD could have a causal relationship with the development of diverse histopathological renal manifestations that cause nephrotic syndrome. However, the treatment for such cases remains unclear. We report a series of three cases of nephrotic syndrome due to iMCD that helps to delineate the importance of early and continuous therapy with the anti-interleukin-6 receptor antibody tocilizumab. First, treatment was suspended for infectious control, and the patient presented with nephrotic syndrome due to diffuse mesangial and endocapillary hypercellularity without immune deposits complicating acute kidney injury. Second, iMCD was treated with prednisolone alone. The patient suddenly developed nephrotic syndrome due to immune-complex glomerulonephritis, not otherwise specified, complicated with acute kidney injury. In the third case, nephrotic syndrome secondary to membranous glomerulonephritis was diagnosed, with a skin rash and IgE antibodies to tocilizumab, and was therefore treated with prednisolone alone. In contrast to the first two cases, the third progressed to end-stage renal disease on hemodialysis. Taken together, this series suggests that clinicians should maintain clinical vigilance for iMCD as a possible underlying component of nephrotic syndrome, since iMCD presents with a variety of renal pathologies. Prompt initiation and continuous administration of tocilizumab are likely key determinants of renal outcomes in such cases. In particular, when tocilizumab is suspended due to infection or in the perioperative period, consideration of its expeditious resumption should be made, taking into account both the withdrawal period and systemic conditions.

Intracranial Hemorrhage in a Patient with TAFRO Syndrome Treated with Cyclosporine A and Rituximab

TAFRO syndrome, a rare subtype of idiopathic multicentric Castleman disease, manifests as thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly. Thrombotic microangiopathy, including renal dysfunction, is frequently associated with this syndrome. TAFRO syndrome can be life threatening and show rapid progression, and the diagnosis and management of this disorder remain challenging. A 48-year-old woman was diagnosed with TAFRO syndrome complicated by thrombotic microangiopathy based on the clinical and histopathological findings. After receiving high-dose steroids, her thrombocytopenia and anasarca did not improve. The patient subsequently received a combination of cyclosporine A and rituximab as second-line therapy, which resulted in a significant gradual improvement in the clinical symptoms. Meanwhile, her platelet count increased to more than 40 × 10⁹/L; however, she developed intracranial hemorrhage. Following surgical evacuation, the patient recovered with an achievement of sustained remission. Based on these findings, attention should be paid to life-threatening bleeding associated with local thrombotic microangiopathy even when intensive treatment is administered for TAFRO syndrome.

Mediterranean fever gene variants modify clinical phenotypes of idiopathic multi-centric Castleman disease

Four cases of idiopathic multi-centric Castleman disease (iMCD) reportedly have variants in hereditary autoinflammatory disease-related genes; however, the frequency and role of these variants in iMCD is still unknown. We therefore investigated such gene variants among patients with iMCD and aimed to reveal the relationship between iMCD and autoinflammatory disease-related genes. We reviewed 14 Japanese iMCD patients who were recruited between January 2015 and September 2019. All patients met both the Japanese tentative diagnostic criteria for Castleman disease and the international consensus diagnostic criteria for iMCD. We performed genetic analyses for 31 autoinflammatory disease-related genes by targeted next-generation sequencing. The MEFV gene variants were observed in 10 of 14 patients with iMCD. Although iMCD had a high percentage of exons 2 or 3 variants of MEFV, comparison of data from healthy Japanese subjects indicated that there was no significant difference in the percentage between healthy Japanese subjects and patients with iMCD. Variants of uncertain significance (VUS) in the TNFRSF1A and CECR1 genes were observed in two of the patients, respectively. We divided patients into two groups-those with MEFV variants (excluding E148Q variants) and those without MEFV variants-and compared the clinical characteristics between these two groups. Patients with MEFV variants, excluding E148Q variants, exhibited a significantly higher likelihood of fever and significantly lower levels of hemoglobin than those lacking MEFV variants. Our results indicated that patients with iMCD tended to have a high frequency of MEFV gene variants and the presence of such variants can affect iMCD clinical phenotypes.

TAFRO syndrome with refractory thrombocytopenia responding to tocilizumab and romiplostim: a case report

Thrombocytopenia, anasarca, fever, reticulin fibrosis, organomegaly (TAFRO) syndrome is a unique clinicopathologic subtype of multicentric Castleman's disease that has recently been identified in Japan. However, little is known about its renal histological changes and the optimal treatment for TAFRO syndrome. An 80-year-old Japanese woman was admitted to our hospital for evaluation of severe anasarca and weight gain (10 kg in a month). She had polyneuropathy, monoclonal plasma cell proliferative disorder with positive kappa M-protein, a sclerotic bone lesion, elevation of vascular endothelial growth factor (VEGF), skin changes, and extravascular volume overload, which fulfilled the diagnostic criteria for POEMS (polyneuropathy, organomegaly, endocrinopathy, and monoclonal protein, skin changes) syndrome. However, kappa-type M-protein and thrombocytopenia with positivity of platelet-associated immunoglobulin G antibody were unusual, and fitted the diagnostic criteria for TAFRO syndrome. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis with endothelial swelling and the infiltration of monocytes and neutrophils without specific immunoglobulin deposits. Her systemic symptoms were refractory to initial treatment with high-dose melphalan and glucocorticoids. Alternative therapy with an anti-interleukin-6 (IL-6) receptor antibody (tocilizumab) effectively controlled the symptoms, while a thrombopoietin receptor agonist (romiplostim) was effective for her thrombocytopenia. Results suggest that IL-6-VEGF axis and an autoimmune mechanism may be responsible for TAFRO syndrome with clinical features of POEMS and refractory thrombocytopenia, which can be successfully treated with combination of tocilizumab and romiplostim.