A Non-targeted Proteomics Newborn Screening Platform for Inborn Errors of Immunity.

PURPOSE: Newborn screening using dried blood spot (DBS) samples for the targeted measurement of metabolites and nucleic acids has made a substantial contribution to public healthcare by facilitating the detection of neonates with genetic disorders. Here, we investigated the applicability of non-targeted quantitative proteomics analysis to newborn screening for inborn errors of immunity (IEIs). METHODS: DBS samples from 40 healthy newborns and eight healthy adults were subjected to non-targeted proteomics analysis using liquid chromatography-mass spectrometry after removal of the hydrophilic fraction. Subsequently, DBS samples from 43 IEI patients were analyzed to determine whether patients can be identified by reduced expression of disease-associated proteins. RESULTS: DBS protein profiling allowed monitoring of levels of proteins encoded by 2912 genes, including 1110 listed in the Online Mendelian Inheritance in Man database, in healthy newborn samples, and was useful in identifying patients with IEIs by detecting reduced levels of disease causative proteins and their interacting proteins, as well as cell-phenotypical alterations. CONCLUSION: Our results indicate that non-targeted quantitative protein profiling of DBS samples can be used to identify patients with IEIs and develop a novel newborn screening platform for genetic disorders.

Efficacy of steroid therapy for improving native liver survival after pediatric acute liver failure with immune activation.

AIM: Recent evidence suggests that acute liver failure (ALF) in some patients may reflect a dysregulated immune response, and that corticosteroids improve survival of the native liver in ALF patients with high serum alanine aminotransferase levels, which are an indication of liver inflammation. However, it is unclear whether steroids are effective for pediatric acute liver failure (PALF). The aim of this retrospective case-control study is to examine whether steroid therapy for PALF accompanied by immune activation improves the survival of native liver and to identify factors that predict responses to steroid treatment. METHODS: Of 38 patients with PALF treated at Kyoto University Hospital from February 2006 to August 2022, 19 receiving steroids who met the specific criteria for identifying the pathophysiology of immune activity in the liver (the "Steroid group"), and seven steroid-free patients who also met the criteria ("Nonsteroid group") were enrolled. Patients in the "Steroid group" were categorized as "responders" or "nonresponders" according to treatment outcome. Clinical and histological data were analyzed. RESULTS: Survival of the native liver in the Steroid group was significantly higher than that in the Nonsteroid group (68% vs. 0%, respectively; p = 0.0052). Nonresponders were significantly younger, with higher Model for End-stage Liver Disease and pediatric end-stage liver disease scores, higher prothrombin time - international normalized ratio, and higher serum ferritin levels than responders. Massive hepatic necrosis was more common in nonresponders. CONCLUSION: Steroid therapy is effective for PALF patients with liver inflammation; however, liver transplantation should be prioritized for young children with ALF accompanied by severe coagulopathy or massive hepatic necrosis.

Differences in the autoantibody phenotypes and long-term outcomes between juvenile- and adult-idiopathic inflammatory myopathies.

OBJECTIVE: To investigate differences in autoantibodies, clinical features, and long-term outcomes between juvenile-idiopathic inflammatory myopathy (IIM) and adult-IIM METHODS: Autoantibodies, clinical characteristics, and drug-free conditions for a maximum of 20 years were retrospectively analyzed in 320 Japanese IIM patients (juvenile-IIM, n = 34; adult-IIM, n = 286) using the Kyoto University Registry. RESULTS: Autoantibodies observed in juvenile-IIM were anti-TIF1-γ (15 %), anti-MDA-5 (15 %), anti-ARS (9 %), and anti-NXP-2 (6 %). Those observed in adult-IIM were anti-ARS (32 %), anti-MDA-5 (23 %), anti-TIF1-γ (8 %), anti-SRP (8 %), anti-Mi-2 (2 %), and anti-NXP-2 (1 %). The cumulative drug-free condition rate was higher in juvenile-IIM than in adult-IIM up to 20 years (juvenile-IIM vs. adult-IIM, 34 % vs. 18 %, p = 0.0016). Anti-TIF1-γ was associated with lesser muscle symptoms (60 % vs. 90 %), malignancy (0 % vs. 57 %), and glucocorticoid use (40 % vs. 86 %) in juvenile-IIM compared to adult-IIM, while juvenile-IIM more achieved drug-free conditions (60 % vs. 25 %). Both juvenile-IIM and adult-IIM with anti-MDA-5 demonstrated a high frequency of amyopathic dermatomyositis, interstitial lung disease (ILD), and multi-immunosuppressive therapy, with high drug-free conditions (50 % vs. 49 %). Both juvenile-IIM and adult-IIM with anti-ARS showed frequent skin rashes, muscle symptoms, and ILD, frequent need for multi-immunosuppressive therapy, and low drug-free condition rates (0 % vs. 3 %). Both juvenile-IIM and adult-IIM with anti-NXP-2 showed frequent skin rashes and muscle symptoms, low ILD frequency, and frequent use of methotrexate and glucocorticoids, which did not achieve drug-free conditions (0 % vs. 0 %). CONCLUSIONS: Drug-free condition was achieved more frequently in juvenile-IIM patients than adult-IIM patients. Specific autoantibodies were associated with different clinical characteristics and outcomes between juvenile-IIM and adult-IIM.

Pathogenic role and diagnostic utility of interferon-α in histiocytic necrotizing lymphadenitis.

PURPOSE: Histiocytic necrotizing lymphadenitis (HNL) is an inflammatory disease of unknown etiology clinically characterized by painful lymphadenopathy. This study aimed to investigate the role of interferon (IFN)-α in the pathogenesis of HNL and the clinical significance of serum IFN-α levels for the diagnosis and monitoring of HNL disease activity. METHODS: This study enrolled 47 patients with HNL and 43 patients with other inflammatory diseases that require HNL differentiation including malignant lymphoma (ML), bacterial lymphadenitis, and Kawasaki disease. Expression of IFN-stimulated genes (ISGs) and MX1 in the lymph nodes was measured by real-time quantitative reverse transcription polymerase chain reaction and immunofluorescence staining, respectively. Enzyme-linked immunosorbent assay was used to quantify serum cytokine levels. The results were compared with the clinical features and disease course of HNL. RESULTS: Patients with HNL had a significantly elevated ISG expression in the lymph nodes compared with those with ML. MX1 and CD123, a specific marker of plasmacytoid dendritic cells (pDCs), were colocalized. In patients with HNL, serum IFN-α levels were significantly elevated and positively correlated with disease activity. The serum IFN-α level cutoff value for differentiating HNL from other diseases was 11.5 pg/mL. CONCLUSION: IFN-α overproduction from pDCs may play a critical role in HNL pathogenesis. The serum IFN-α level may be a valuable biomarker for the diagnosis and monitoring of disease activity in patients with HNL.

Successful Second CBT for Graft Failure After First CBT for Adult-Onset Familial Hemophagocytic Lymphohistiocytosis Type 3: A Case Report.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare inherited autosomal recessive immune deficiency that usually manifests during infancy or early childhood, rarely occurring in adults. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for FHL. However, optimal conditioning regimens for adult-onset FHL have not yet been established. Herein, we report a case of adult-onset FHL. A 37-year-old man presented with fever, liver dysfunction, and pancytopenia, which improved temporarily with corticosteroid therapy. However, he later developed encephalitis and myelitis. Genetic analysis revealed rare variants of UNC13D (c.2367+1 g>a and c.2588 g>a), which were compound heterozygous pathogenic mutations. FHL type 3 was diagnosed, and treatment based on the hemophagocytic lymphohistiocytosis (HLH) 1994 protocol was initiated. The patient underwent cord blood transplantation (CBT) with myeloablative conditioning using fludarabine, melphalan, and total-body irradiation (TBI), which resulted in graft rejection. The patient was successfully rescued by a second CBT following reduced-intensity conditioning with fludarabine, cyclophosphamide, and TBI. Although graft failure is an important complication especially in CBT, it could be managed by appropriate treatment, and that cord blood would be a promising alternative source with the advantages of rapidity and avoidance of related donors with a high risk of harboring the same genetic mutation.

Efficacy and safety of tumor necrosis factor inhibitors for systemic juvenile idiopathic arthritis: a systematic review.

OBJECTIVES: This systematic review assessed the efficacy and safety of tumor necrosis factor (TNF) inhibitors in patients with systemic juvenile idiopathic arthritis (JIA). METHODS: Studies were searched using PubMed, Embase, Cochrane, Ichushi-Web, and clinical trial registries (from 2000 to 2021). The risk of bias was assessed using the Cochrane Risk of Bias version 2 for randomized controlled trials (RCTs) and the manual for development clinical practice guidelines by Minds, a project promoting evidence-based medicine in Japan, for observational studies. RESULTS: One RCT and 22 observational studies were included. In the RCT on infliximab, the American College of Rheumatology pediatric (ACR Pedi) 30/50/70 responses at 14 weeks were 63.8%/50.0%/22.4%, with relative risks of 1.30 (95% confidence interval [CI]: 0.94-1.79)/1.48 (95% CI: 0.95-2.29)/1.89 (95% CI: 0.81-4.40), respectively. In the observational studies, ACR Pedi 30/50/70 responses for etanercept at 12 months were 76.7%/64.7%/46.4%, respectively. Infliximab treatment caused anaphylaxis in 17% and an infusion reaction in 23% of patients. The incidence of macrophage activation syndrome, serious infection and malignancy caused by TNF inhibitors was 0%-4%. CONCLUSIONS: Thus, although TNF inhibitors were relatively safe, they were unlikely to be preferentially administered in patients with systemic JIA because of their inadequate efficacy. Further studies, particularly well-designed RCTs, are necessary to confirm the efficacy and safety of TNF inhibitors for systemic JIA.

Efficacy and safety of abatacept for systemic juvenile idiopathic arthritis: a systematic review.

OBJECTIVES: This systematic review assessed the efficacy and safety of abatacept in patients with systemic juvenile idiopathic arthritis (JIA). METHODS: Studies published between 2000 and 2021 were searched using PubMed, Embase, Cochrane, Ichushi-Web and clinical trial registries. The risk of bias was assessed according to the manual for development clinical practice guidelines by Minds, a project to promote evidence-based medicine in Japan. RESULTS: Seven observational studies were included. American College of Rheumatology pediatric 30/50/70 responses at 3, 6 and 12 months were 64.8%/50.3%/27.9%, 85.7%/71.4%/42.9% and 80.0%/50.0%/40.0%, respectively. Outcomes on systemic symptoms, joint symptoms and activities of daily living were not obtained. No macrophage activation syndrome or infusion reaction occurred. Serious infection occurred in 2.6% of cases. CONCLUSIONS: Abatacept improved the disease activity index. In addition, abatacept was as safe as interleukin-6 (IL -6) and IL-1 inhibitors. However, both the efficacy and safety data in this systematic review should be reviewed with caution because their quality of evidence is low or very low. Further studies are needed to confirm the efficacy and safety of abatacept for systemic JIA, especially its efficacy on joint symptoms.

A de novo dominant-negative variant is associated with OTULIN-related autoinflammatory syndrome.

OTULIN-related autoinflammatory syndrome (ORAS), a severe autoinflammatory disease, is caused by biallelic pathogenic variants of OTULIN, a linear ubiquitin-specific deubiquitinating enzyme. Loss of OTULIN attenuates linear ubiquitination by inhibiting the linear ubiquitin chain assembly complex (LUBAC). Here, we report a patient who harbors two rare heterozygous variants of OTULIN (p.P152L and p.R306Q). We demonstrated accumulation of linear ubiquitin chains upon TNF stimulation and augmented TNF-induced cell death in mesenchymal stem cells differentiated from patient-derived iPS cells, which confirms that the patient has ORAS. However, although the de novo p.R306Q variant exhibits attenuated deubiquitination activity without reducing the amount of OTULIN, the deubiquitination activity of the p.P152L variant inherited from the mother was equivalent to that of the wild-type. Patient-derived MSCs in which the p.P152L variant was replaced with wild-type also exhibited augmented TNF-induced cell death and accumulation of linear chains. The finding that ORAS can be caused by a dominant-negative p.R306Q variant of OTULIN furthers our understanding of disease pathogenesis.

Early hematopoietic cell transplantation for familial hemophagocytic lymphohistiocytosis in a regional treatment network in Japan.

Familial hemophagocytic lymphohistiocytosis (FHLH) is a fatal hyperinflammation syndrome arising from the genetic defect of perforin-mediated cytolysis. Curative hematopoietic cell transplantation (HCT) is needed before development of central nervous system (CNS) disease. We studied treatment outcomes of 13 patients (FHLH2 n = 11, FHLH3 n = 2) consecutively diagnosed from 2011 to 2022 by flow cytometric screening for non-myeloablative HCT in a regional treatment network in Kyushu, Japan. One patient with a novel PRF1 variant escaped screening, but all patients with FHLH2 reached diagnosis and 8 of them received HCT until 3 and 9 months of age, respectively. The earliest HCT was conducted 65 days after birth. Three pretransplant deaths occurred in newborns with liver failure at diagnosis. Ten posttransplant patients have remained disease-free, 7 of whom had no neurological involvement. Time from first etoposide infusion to HCT was shorter in patients without CNS disease or bleeding than in patients with those factors (median [range] days: 62 [50-81] vs. 122 [89-209], p = 0.016). Six of 9 unrelated patients had a PRF1 c.1090_1091delCT variant. These results suggest that the critical times to start etoposide and HCT are within 3 months after birth and during etoposide control, respectively. Newborn screening may increase the percentage of disease-free survivors without complications.

Human RELA dominant-negative mutations underlie type I interferonopathy with autoinflammation and autoimmunity.

Inborn errors of the NF-κB pathways underlie various clinical phenotypes in humans. Heterozygous germline loss-of-expression and loss-of-function mutations in RELA underlie RELA haploinsufficiency, which results in TNF-dependent chronic mucocutaneous ulceration and autoimmune hematological disorders. We here report six patients from five families with additional autoinflammatory and autoimmune manifestations. These patients are heterozygous for RELA mutations, all of which are in the 3' segment of the gene and create a premature stop codon. Truncated and loss-of-function RelA proteins are expressed in the patients' cells and exert a dominant-negative effect. Enhanced expression of TLR7 and MYD88 mRNA in plasmacytoid dendritic cells (pDCs) and non-pDC myeloid cells results in enhanced TLR7-driven secretion of type I/III interferons (IFNs) and interferon-stimulated gene expression in patient-derived leukocytes. Dominant-negative mutations in RELA thus underlie a novel form of type I interferonopathy with systemic autoinflammatory and autoimmune manifestations due to excessive IFN production, probably triggered by otherwise non-pathogenic TLR ligands.

A complementary approach for genetic diagnosis of inborn errors of immunity using proteogenomic analysis.

Advances in next-generation sequencing technology have identified many genes responsible for inborn errors of immunity (IEI). However, there is still room for improvement in the efficiency of genetic diagnosis. Recently, RNA sequencing and proteomics using peripheral blood mononuclear cells (PBMCs) have gained attention, but only some studies have integrated these analyses in IEI. Moreover, previous proteomic studies for PBMCs have achieved limited coverage (approximately 3000 proteins). More comprehensive data are needed to gain valuable insights into the molecular mechanisms underlying IEI. Here, we propose a state-of-the-art method for diagnosing IEI using PBMCs proteomics integrated with targeted RNA sequencing (T-RNA-seq), providing unique insights into the pathogenesis of IEI. This study analyzed 70 IEI patients whose genetic etiology had not been identified by genetic analysis. In-depth proteomics identified 6498 proteins, which covered 63% of 527 genes identified in T-RNA-seq, allowing us to examine the molecular cause of IEI and immune cell defects. This integrated analysis identified the disease-causing genes in four cases undiagnosed in previous genetic studies. Three of them could be diagnosed by T-RNA-seq, while the other could only be diagnosed by proteomics. Moreover, this integrated analysis showed high protein-mRNA correlations in B- and T-cell-specific genes, and their expression profiles identified patients with immune cell dysfunction. These results indicate that integrated analysis improves the efficiency of genetic diagnosis and provides a deep understanding of the immune cell dysfunction underlying the etiology of IEI. Our novel approach demonstrates the complementary role of proteogenomic analysis in the genetic diagnosis and characterization of IEI.

Treatment for macrophage activation syndrome associated with systemic juvenile idiopathic arthritis in Japan.

OBJECTIVES: To clarify how pediatric rheumatologists treat systemic juvenile idiopathic arthritis (s-JIA) associated macrophage activation syndrome (MAS) in the real world and to assess the efficacy and safety of dexamethasone palmitate (DEX-P) in the treatment of s-JIA-associated MAS. METHODS: This multicenter, retrospective study was conducted at 13 pediatric rheumatology institutes in Japan. This study included 28 patients with s-JIA-associated MAS. Clinical findings, such as treatment details and adverse events, were evaluated. RESULTS: Methylprednisolone (mPSL) pulse therapy was selected as the first-line treatment in more than half of the patients with MAS. Cyclosporine A (CsA) was used as first-line therapy in combination with corticosteroids in half of the patients with MAS. DEX-P and/or CsA were selected as the second-line therapy in 63% of patients with corticosteroid-resistant MAS. Plasma exchange was selected as the third-line therapy for DEX-P and CsA-resistant MAS. All patients improved and there were no characteristically severe adverse events associated with DEX-P. CONCLUSIONS: The first-line treatment for MAS in Japan is mPSL pulse therapy and/or CyA. DEX-P could be an effective and safe therapeutic option for patients with corticosteroid-resistant MAS.

STING signalling is terminated through ESCRT-dependent microautophagy of vesicles originating from recycling endosomes.

Stimulator of interferon genes (STING) is essential for the type I interferon response against a variety of DNA pathogens. Upon emergence of cytosolic DNA, STING translocates from the endoplasmic reticulum to the Golgi where STING activates the downstream kinase TBK1, then to lysosome through recycling endosomes (REs) for its degradation. Although the molecular machinery of STING activation is extensively studied and defined, the one underlying STING degradation and inactivation has not yet been fully elucidated. Here we show that STING is degraded by the endosomal sorting complexes required for transport (ESCRT)-driven microautophagy. Airyscan super-resolution microscopy and correlative light/electron microscopy suggest that STING-positive vesicles of an RE origin are directly encapsulated into Lamp1-positive compartments. Screening of mammalian Vps genes, the yeast homologues of which regulate Golgi-to-vacuole transport, shows that ESCRT proteins are essential for the STING encapsulation into Lamp1-positive compartments. Knockdown of Tsg101 and Vps4, components of ESCRT, results in the accumulation of STING vesicles in the cytosol, leading to the sustained type I interferon response. Knockdown of Tsg101 in human primary T cells leads to an increase the expression of interferon-stimulated genes. STING undergoes K63-linked ubiquitination at lysine 288 during its transit through the Golgi/REs, and this ubiquitination is required for STING degradation. Our results reveal a molecular mechanism that prevents hyperactivation of innate immune signalling, which operates at REs.

Rare diseases presenting with hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal hyperinflammatory disorder characterized by hypercytokinemia caused by excessive activation of cytotoxic T cells and macrophages. HLH is caused by a variety of factors and is classified into primary and secondary HLH. Familial HLH (FHL) types 1-5, X-linked lymphoproliferative syndrome types 1 and 2, and FHL syndrome with hypopigmentation are all examples of primary HLH. Secondary HLH, on the other hand, is linked to infections, malignant tumors, autoimmune diseases, and other diseases. The causes of HLH vary, and finding the underlying disease is critical for diagnosis and treatment. The majority of HLH is caused by the aforementioned conditions; however, approximately 10% of cases are caused by rare diseases such as inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Novel IEI, such as RhoG, MAP kinase activating death domain, TIM3, and ZNFX1 deficiencies, have recently been identified as causes of HLH. IEM patients are rarely associated with HLH. Surprisingly, children with lysinuric protein intolerance and lysosomal acid lipase deficiency (Wolman disease) frequently develop HLH. This review focuses on the most recent knowledge of HLH caused by rare diseases such as IEI and IEM.

Monogenic inflammatory bowel disease with STXBP2 mutations is not resolved by hematopoietic stem cell transplantation but can be alleviated via immunosuppressive drug therapy.

STXBP2, encoding syntaxin-binding protein 2, is involved in intracellular organelle trafficking and is associated with familial hemophagocytic lymphohistiocytosis type 5. Although STXBP2 mutations reportedly cause monogenic inflammatory bowel disease, the clinical course and underlying pathogenic mechanisms remain unclear. We identified a novel mutation in STXBP2 [c.1197delC, p.Ala400fs] in a boy with congenital intractable diarrhea and hemophagocytic lymphohistiocytosis (HLH). HLH was treated with intravenous prednisolone, cyclosporine, and dexamethasone palmitate. Hematopoietic stem cell transplantation (HSCT) along with prophylaxis for graft-versus-host-disease was performed at 5 months of age. Additionally, colonoscopies done before and after HSCT showed mild colitis with cryptitis. The patient showed elevated fecal calprotectin levels and persistent diarrhea even after HSCT and required partial parenteral nutrition. While anti-inflammatory treatment reduced diarrhea, it was not completely normalized even after HSCT, suggesting that the pathogenesis of inflammatory bowel disease associated with STXBP2 mutations involves both hyperinflammation and functional epithelial barrier defects.

Assessment of type I interferon signatures in undifferentiated inflammatory diseases: A Japanese multicenter experience.

Purpose: Upregulation of type I interferon (IFN) signaling has been increasingly detected in inflammatory diseases. Recently, upregulation of the IFN signature has been suggested as a potential biomarker of IFN-driven inflammatory diseases. Yet, it remains unclear to what extent type I IFN is involved in the pathogenesis of undifferentiated inflammatory diseases. This study aimed to quantify the type I IFN signature in clinically undiagnosed patients and assess clinical characteristics in those with a high IFN signature. Methods: The type I IFN signature was measured in patients' whole blood cells. Clinical and biological data were collected retrospectively, and an intensive genetic analysis was performed in undiagnosed patients with a high IFN signature. Results: A total of 117 samples from 94 patients with inflammatory diseases, including 37 undiagnosed cases, were analyzed. Increased IFN signaling was observed in 19 undiagnosed patients, with 10 exhibiting clinical features commonly found in type I interferonopathies. Skin manifestations, observed in eight patients, were macroscopically and histologically similar to those found in proteasome-associated autoinflammatory syndrome. Genetic analysis identified novel mutations in the PSMB8 gene of one patient, and rare variants of unknown significance in genes linked to type I IFN signaling in four patients. A JAK inhibitor effectively treated the patient with the PSMB8 mutations. Patients with clinically quiescent idiopathic pulmonary hemosiderosis and A20 haploinsufficiency showed enhanced IFN signaling. Conclusions: Half of the patients examined in this study, with undifferentiated inflammatory diseases, clinically quiescent A20 haploinsufficiency, or idiopathic pulmonary hemosiderosis, had an elevated type I IFN signature.

Real-world results with IgPro20 for hypo- or agammaglobulinemia in Japan.

BACKGROUND: Subcutaneous immunoglobulin is one of the standard treatments for hypogammaglobulinemia in primary immunodeficiencies (PID) worldwide. In Japan, IgPro20 (Hizentra® ; l-proline-stabilized 20% human subcutaneous immunoglobulin) is approved for agammaglobulinemia or hypogammaglobulinemia due to PID or secondary immunodeficiency (SID); however, its safety and effectiveness has not previously been assessed in a real-world setting. METHODS: This multicenter, open label post-marketing surveillance study was conducted between January 2014 and March 2019. Patients who received IgPro20 due to PID or SID were included after informed consent. Physicians completed a case report form for each patient. Safety was determined from reported adverse events (AEs), adverse drug reactions, and serious AEs (SAEs); effectiveness was assessed by infection rates after the first IgPro20 dose. RESULTS: Of 85 patients receiving IgPro20 in the safety analysis, 39 developed AEs (45.9%; PID n = 28, SID n = 11). At least one adverse drug reaction was observed in 27 patients (31.8%; PID n = 21, SID n = 6), and the most common were injection site reactions (n = 17, 20.0%). Four patients (PID n = 3, SID n = 1) reported SAEs but two were unrelated to IgPro20 administration. The infection rate decreased from 0.54 per patient during the 6 months before IgPro20 to 0.39 per patient during IgPro20 treatment. Serious bacterial infections occurred in six patients before IgPro20 (7.9%; PID n = 2; SID n = 4) but in only one patient with SID during IgPro20 treatment (1.2%). CONCLUSIONS: In Japan, IgPro20 was considered safe and effective among patients with agammaglobulinemia or hypogammaglobulinemia due to PID or SID.

A randomised, double-blind, placebo-controlled phase III trial on the efficacy and safety of tocilizumab in patients with familial Mediterranean fever.

OBJECTIVES: To evaluate the efficacy and safety of tocilizumab (TCZ), an interleukin 6 receptor monoclonal antibody, in a subset of Japanese patients with familial Mediterranean fever (FMF). METHODS: We performed a double-blind, randomised, parallel-group trial, followed by an open-label extension trial, in patients with colchicine-resistant or -intolerant FMF (crFMF) (UMIN000028010). Patients were randomly assigned (1:1) to receive TCZ (162 mg every week) or placebo, administered subcutaneously, for 24 weeks. Rescue treatment was allowed if the rescue criteria were met. The primary endpoint was the number of fever attacks over the 24 weeks of treatment. Secondary endpoints included the frequency of accompanying symptoms during attacks, serum CRP and SAA values, and adverse events (AEs). The open-label extension study evaluated the long-term safety and efficacy of TCZ in patients who had completed the preceding study (UMIN000032557). RESULTS: We randomly assigned 23 patients to either TCZ (n=1) or placebo (n=12). The TCZ-placebo rate ratios were 0.691 (95% confidence intervals (CI), 0.189-2.531; p=0.577) for the fever attacks, based on the group rates per week. The recurrence of attacks was significantly lower in the TCZ group (hazard ratio = 0.457; 95% CI, 0.240-0.869). Fever attacks, accompanying symptoms, serum CRP and SAA values were controlled in most of the patients who received long-term TCZ. In these trials, the numbers and severity of AEs did not differ between groups. CONCLUSIONS: Although a primary endpoint was not met in the preceding trial, long-term administration of TCZ showed stable efficacy and safety for patients with crFMF.

Recurrent tandem duplication of UNC13D in familial hemophagocytic lymphohistiocytosis type 3.

Familial hemophagocytic lymphohistiocytosis type 3 is a fatal inborn error of immunity due to abnormal cytotoxic activity of T and NK cells and is caused by variants in UNC13D, which encodes Munc13-4. One published case was reported to carry a tandem duplication of UNC13D exons 7-12, and we here present another case with the exact same duplication breakpoints. The patient carried the tandem duplication from maternal origin, and a c.2346_2349 variant on the paternal allele. Single nucleotide polymorphism analysis around UNC13D revealed that the allele with tandem duplication was most likely a founder allele. Transposable element analysis showed that the breakpoints occurred within Alu elements in introns 12 and 6. Multiple sequence alignment revealed that Alu elements containing the truncated points are highly homologous. Sequence homology was thought to be a factor predisposing to the tandem duplication variant.