Thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome is a severe subtype of idiopathic multicentric Castleman’s disease, characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, and organomegaly. Renal complication of this disease can be life-threatening and sometimes requires hemodialysis, but it has not been elucidated in detail. Case-series was designed to evaluate the renal histology of patients with TAFRO syndrome treated at our hospital. Seven patients were eligible to the criteria. All of them had severe diuretic-resistant anasarca and 6 of 7 had mild proteinuria (<1 g daily). On light microscopy, all patients showed glomerular endotheliopathy characterized by endothelial cell swelling and a double contour of the glomerular basement membrane with mesangiolysis or mesangial loosening. Immunofluorescent staining and electron microscopy did not detect immune deposits in any patient. Electron microscopy revealed endothelial cell swelling with diffuse expansion of the subendothelial space, loss of mesangial architecture, and loss of endothelial cell fenestrations. Treatment with glucocorticoids and molecular-targeting agents, including tocilizumab and rituximab, improved renal dysfunction and anasarca. In 4 of 7 patients with persistent thrombocytopenia, hemorrhagic events occurred despite platelet transfusion or thrombopoietin receptor antagonist therapy. Severe diuretic-resistant anasarca with mild proteinuria and severe glomerular endotheliopathy were common characteristics of renal dysfunction due to TAFRO syndrome. In addition, endothelial changes mediated via interleukin (IL)-6 and vascular endothelial growth factor (VEGF) that lead to vascular hyperpermeability and water leakage might contribute to anasarca, because molecular-targeting therapy directed against IL-6 or VEGF improved renal dysfunction and severe endothelial damage.

An 84-year-old Japanese man was admitted due to anasarca, thrombocytopenia, systemic inflammation, and progressive renal insufficiency, resistance to diuretics, glucocorticoid therapy, and plasma exchange. Renal biopsy showed diffuse endocapillary proliferation and mesangiolysis without any immune deposits. Tocilizumab suppressed systemic inflammation, resulting in improvement of anasarca and renal dysfunction, but thrombocytopenia persisted and platelet-associated IgG antibody was elevated. Although romiplostim was effective for thrombocytopenia, the patient died of aspiration pneumonia after cerebral hemorrhage. Autopsy showed hyaline vascular-type Castleman disease-like lymphadenopathy and reticulin myelofibrosis with an increase of megakaryocytes. Renal finding showed that endocapillary injury improved, and collapsed glomeruli were noted. This patient fitted the criteria for TAFRO (thrombocytopenia [T], anasarca [A], fever [F], reticulin myelofibrosis [R], and organomegaly [O]) syndrome. The clinical course suggests that 2 factors, including overproduction of interleukin 6 and autoimmune-mediated thrombocytopenia via thrombopoietin receptor, may have contributed to the pathogenesis of TAFRO syndrome in this patient.

Objective To evaluate the efficacy and safety of first-line biological disease-modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA) with chronic kidney disease (CKD), including those undergoing haemodialysis (HD). Methods This retrospective cohort study included 425 patients with RA prescribed their first bDMARDs at two hospitals from 2004 to 2021. Patients were categorised by kidney function and bDMARD modality (TNFα inhibitors (TNFαis), interleukin-6 inhibitors (IL-6is), cytotoxic T-lymphocyte antigen-4 immunoglobulin (CTLA4-Ig)). The primary outcome was the 36-month drug retention rate, with secondary outcomes including changes in Disease Activity Score 28 (DAS28)-C reactive protein (CRP)/erythrocyte sedimentation rate (ESR), prednisolone dosage and reasons for discontinuation. Results The 36-month drug retention rates by estimated glomerular filtration rate (eGFR) (≥60, 30–60, <30 mL/min/1.73 m²) were as follows: all bDMARDs (45.2%, 32.0%, 41.4%), TNFαis (45.3%, 28.2%, 34.0%), IL-6is (47.4%, 66.7%, 71.4%) and CTLA-4Ig (50.0%, 31.3%, 33.3%). Even in groups with lower kidney function, the drug retention rate of bDMARDs was generally maintained. However, the retention rate of TNFαis was significantly lower in patients with eGFR <30 mL/min/1.73 m². IL-6is showed the highest retention rate and the lowest discontinuation rate due to ineffectiveness in this group (HR 0.11, 95% CI 0.02 to 0.85, p=0.03). All bDMARDs improved DAS28-CRP/ESR and reduced prednisolone dosage across all groups. Conclusion bDMARDs demonstrated effective and safe profiles in patients with RA with CKD, even among patients on HD. In particular, IL-6is had a significantly higher drug retention rate in patients with an eGFR of <30 mL/min/1.73 m² and fewer discontinuations due to ineffectiveness. IL-6is were more efficacious as monotherapy compared with the other bDMARDs.

Introduction: This study aimed to analyze the clinical course of TAFRO syndrome in patients through extended follow-up, focusing on recurrent cases and long-term remission. Methods: This was a retrospective case series study. We assessed the clinical course of patients diagnosed with TAFRO syndrome between January 2012 and September 2022 at Toranomon Hospital or Toranomon Hospital Kajigaya, excluding those patients who died during the initial hospitalization. Results: Twelve patients were included. Baseline characteristics, laboratory findings, treatment modalities, and outcomes were assessed. During the median follow-up period of 1474 days, two patients experienced recurrence following a reduction in tocilizumab (TCZ) dose, whereas two achieved remission for >400 days without TCZ treatment. The remaining eight patients maintained remission under the continued TCZ therapy. Recurrence diagnosis was complicated by the non-simultaneous presentation of the five manifestations of TAFRO syndrome. The patients who experienced recurrence showed milder manifestations and faster recovery than the initial onset. Glomerular endotheliopathy was evident in kidney biopsies during recurrence, which was similar to the initial presentation. In a case where only inflammation preceded other manifestation, a kidney biopsy was pivotal in distinguishing TAFRO syndrome relapse from other inflammatory conditions such as infection. Pretreatment serum IL-6 levels were within the reference range only in patients who experienced long-term remission without TCZ treatment. Conclusions: This is the first study to perform kidney biopsies on recurrent TAFRO cases, highlighting recurrence after TCZ dosage reduction, non-simultaneous manifestation of symptoms, the utility of kidney biopsies in recurrence diagnosis, and potential non-IL-6 pathogenesis factors. Pretreatment serum IL-6 levels may help identify patients suitable for maintenance therapy without TCZ. Further investigation is warranted to identify stratified treatment approaches based on individual etiologic factors.

Objectives: To evaluate the efficacy and safety of first-line targeted synthetic DMARDs (tsDMARDs) in patients with RA and chronic kidney disease (CKD). Methods: This retrospective cohort study included 216 patients with RA prescribed their first tsDMARDs at two hospitals between 2013 and 2022. Dose reduction and contraindication guidelines for tsDMARDs according to kidney function were followed. The patients were categorized by kidney function and tsDMARD modality. The primary outcome was the 24-month drug retention rate, and the secondary outcomes were changes in the Disease Activity Score 28-CRP (DAS28-CRP) level, prednisolone dosage and reasons for discontinuation. Results: The 24-month drug retention rates according to the estimated glomerular filtration rate (eGFR) (≥60%, 30–60% or <30 ml/min/1.73 m2) were as follows: all tsDMARDs (46.0%, 44.1%, 47.1%), tofacitinib (55.9%, 53.3%, 66.7%), baricitinib (64.2%, 42.0%) and peficitinib (36.4%, 44.1%, 40.0%). Even in groups with lower kidney function, the drug retention rate was maintained (adjusted hazard ratio was 1.14 [95% confidence interval, 0.81–1.62], P = 0.45). Patients had a decreased DAS28-CRP (P < 0.01) and a reduced prednisolone dosage (P < 0.01) over the six-month period following tsDMARD initiation. The incidence of herpes zoster and deep vein thrombosis (DVT) was higher in the group with an eGFR <30 ml/min/1.73 m2, but not statistically significant. Conclusions: tsDMARDs have demonstrated efficacy and safety in patients with RA and CKD; however, clinicians should consider the potential for herpes zoster and DVT in patients with eGFR <30 ml/min/1.73 m2.

A 60-year-old Japanese woman with polymyositis (PM) developed hemolytic anemia (hemoglobin of 7.3 g/dL), thrombocytopenia (platelet of 9.1×10⁴/µL), and acute kidney injury (Cre of 4.7 mg/dL) at 14 days after starting steroid therapy. Renal biopsy revealed glomerular endothelial swelling with fibrin thrombi and fragmented erythrocytes in the capillary lumens. Hemolytic uremic syndrome (HUS) with thrombotic microangiopathy (TMA) was diagnosed. Hemodialysis and plasma exchange/plasma transfusion were initiated, but HUS did not subside. After 45 days, the patient died of hemorrhagic respiratory failure. Autopsy showed fibrin thrombi filling the glomerular vascular pole and the small arteries in most glomeruli, resulting in glomerular collapse and glomerular basement membrane (GBM) duplication. Although renal involvement by PM is rare, HUS/TMA should be remembered as one of the serious renal complications of PM.