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The article describes the case of an eight-year-old Japanese boy with anti-signal recognition particle (SRP) antibody-associated immune-mediated necrotizing myopathy (SRP-IMNM). The patient had symptoms such as muscle weakness, muscle pain and gait disorder. He was given tacrolimus in combination with methotrexate and corticosteroid for the treatment of his condition.

X-linked NF-κB essential modulator (NEMO) deficiency is a primary immunodeficiency characterized by combined immunodeficiency and ectodermal dysplasia. Monocytes from the patients demonstrate a severely impaired response to tissue necrosis factor or lipopolysaccharide, whereas hyper-inflammation is found in some patients. Juvenile myelomonocytic leukemia (JMML) is a pediatric malignancy caused by hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF) and aberrant RAS signaling activation. Patients with JMML demonstrate characteristic manifestations such as splenomegaly, monocytosis and the presence of myeloid or erythroid precursors in the peripheral blood. Here, we present the case of a male infant with ectodermal dysplasia, bacterial septicemia, Pneumocystis pneumonia, severe inflammation and transient manifestations mimicking JMML. Genetic analysis revealed a deep intronic germline variant of IKBKG. Full-length IKBKG cDNA and NEMO protein expression were almost inexistent. Peripheral mononuclear cells (PBMCs) from the patient showed increased RAS signaling activation with GM-CSF or Phorbol 12-myristate 13-acetate without the RAS-associated gene variant, although the increased RAS signaling activation in induced-pluripotent stem cell-derived myeloid lineage and bone marrow-derived mesenchymal cells was not evident. The patient with NEMO deficiency demonstrated JMML-like manifestation and severe inflammation. PBMCs of the patient demonstrated increased RAS signaling activation with unknown pathophysiology.

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., (© 2024 Takeda et al.)

Objectives: The clinical symptoms and complications of JDM differ depending on the type of muscle-specific autoantibodies (MSAs) present. We aimed to identify protein expression profiles specific for MSAs that characterize various clinical features by comprehensively analyzing the proteins present in the serum of patients with JDM., Methods: We analysed sera from patients with JDM that were positive for anti-melanoma differentiation-associated protein 5 (MDA5) antibodies (n = 5), anti-nuclear matrix protein 2 (NXP2) antibodies (n = 5) and anti-transcriptional intermediary factor 1 alpha or gamma subunit (TIF1-γ) antibodies (n = 5), and evaluated healthy controls (n = 5) via single-shot liquid chromatography-tandem mass spectrometry (MS) in data-independent acquisition mode, which is superior for comparative quantitative analysis. We identified different protein groups based on MSAs and performed pathway analysis to understand their characteristics., Results: We detected 2413 proteins from serum MS analysis; 508 proteins were commonly altered in MSAs, including many myogenic enzymes and IFN-regulated proteins. Pathway analysis using the top 50 proteins that were upregulated in each MSA group revealed that the type I IFN and proteasome pathways were significantly upregulated in the anti-MDA5 antibody group alone., Conclusion: Although JDM serum contains many proteins commonly altered in MSAs, the pathways associated with clinical features of MSAs differ based on protein accumulation. In-depth serum protein profiles associated with MSAs may be useful for developing therapeutic target molecules and biomarkers., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Symptomatic vitamin C deficiency, scurvy, is a relatively rare disease in developed countries, but it has been reported in patients with autism spectrum disorder or developmental delay who tend to have selective diets. Patients with scurvy often demonstrate musculoskeletal manifestations with unknown pathophysiology. Herein, we report a case of scurvy in an 11-year-old boy who presented with iron-deficiency anaemia, systemic osteomyelitis, myositis predominantly in the lower extremities, and right ventricular volume overload with mild pulmonary hypertension and was diagnosed with scurvy. He had a mild developmental disorder and a selective diet, which resulted in severe vitamin C deficiency. He received intravenous and oral vitamin C supplementation, which relieved his arthralgia and muscle pain in a week. Following 4 months of vitamin C supplementation, he demonstrated no abnormal manifestations on laboratory or imaging examination and recovered without sequelae. Inflammatory cytokine and chemokine evaluations demonstrated elevated levels of interleukin (IL)-6, IL-17A, and IL-23, which are associated with T-helper (Th) 17 cell activation. This study is the first to suggest the association between the inflammation seen in scurvy, rheumatic manifestations in the patient, and Th17 cell activation. Further analysis of the association between the inflammation and vitamin C supplementation may contribute to new insights for the comprehension and treatment of other inflammatory diseases, such as rheumatic diseases., (© Japan College of Rheumatology 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

We report a Japanese boy with Graves' disease (GD) which developed during drug-free remission of juvenile dermatomyositis (JDM). He had been diagnosed with JDM at the age of 6 years by typical skin rashes, muscle weakness, elevated serum transaminase levels, and typical findings of both magnetic resonance imaging and muscle biopsy. Although anti-melanoma differentiation antigen 5 autoantibody was positive, there was no complication of interstitial lung disease. He showed good response to methylprednisolone pulse therapy followed by oral prednisolone in combination with weekly methotrexate (MTX) and achieved drug-free remission after 3.5 years of treatment. Nevertheless, serum levels of soluble interleukin-2 receptor (sIL-2R) gradually elevated to 3185 U/ml despite no signs of relapse or malignancy. Hyperactivity and attention deficit was also noted. One year and 3 months after the cessation of MTX, he presented with abdominal pain, tachycardia, and apparent goitre. Laboratory tests showed elevated free triiodothyronine, undetectable thyroid stimulating hormone (TSH), and positive anti-TSH receptor antibodies. 99mTc scintigraphy showed high levels of thyroid uptake. He was diagnosed with GD and treated with 15 mg/day of thiamazole. Although transient drug eruption was observed, his thyroid functions are currently well-controlled on 5 mg/day of thiamazole. In conclusion, to our knowledge, this is the first report in English literature describing complication of GD with JDM. Unexpected elevation of sIL-2R could be a clue to the diagnosis of GD during the follow-up of JDM., (© Japan College of Rheumatology 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: This study aimed to investigate the clinical characteristics, treatment and prognosis of juvenile idiopathic inflammatory myopathies (JIIM) in Japan for each myositis-specific autoantibody (MSA) profile., Methods: A multicentre, retrospective study was conducted using data of patients with JIIM at nine paediatric rheumatology centres in Japan. Patients with MSA profiles, determined by immunoprecipitation using stored serum from the active stage, were included., Results: MSA were detected in 85 of 96 cases eligible for the analyses. Over 90% of the patients in this study had one of the following three MSA types: anti-melanoma differentiation-associated protein 5 (MDA5) (n = 31), anti-transcriptional intermediary factor 1 alpha and/or gamma subunits (TIF1γ) (n = 25) and anti-nuclear matrix protein 2 (NXP2) (n = 25) antibodies. Gottron papules and periungual capillary abnormalities were the most common signs of every MSA group in the initial phase. The presence of interstitial lung disease (ILD) was the highest risk factor for patients with anti-MDA5 antibodies. Most patients were administered multiple drug therapies: glucocorticoids and MTX were administered to patients with anti-TIF1γ or anti-NXP2 antibodies. Half of the patients with anti-MDA5 antibodies received more than three medications including i.v. CYC, especially patients with ILD. Patients with anti-MDA5 antibodies were more likely to achieve drug-free remission (29 vs 21%) and less likely to relapse (26 vs 44%) than others., Conclusion: Anti-MDA5 antibodies are the most common MSA type in Japan, and patients with this antibody are characterized by ILD at onset, multiple medications including i.v. CYC, drug-free remission, and a lower frequency of relapse. New therapeutic strategies are required for other MSA types., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Treatment of intractable Pneumocystis jirovecii pneumonia (PCP) patients with primaquine (PQ) in combination with clindamycin (CLDM) was conducted by the Research Group on Chemotherapy of Tropical Diseases (RG-CTD), as a kind of compassionate use. Primaquine was not nationally licensed at the time but imported by RG-CTD for the use in a clinical research to investigate safety and efficacy in malaria treatment. Eighteen Japanese adult patients thus treated were analyzed. Prior to the treatment with PQ-CLDM, most of the patients had been treated with trimethoprim-sulfamethoxazole first, all of which being followed by pentamidine and/or atovaquone treatment. This combination regimen of PQ-CLDM was effective in 16 (89%) patients and developed adverse events (AEs) in five (28%) patients. AEs included skin lesions, methemoglobinemia, and hepatic dysfunction, though none of them were serious. As a second-line or salvage treatment for PCP, PQ-CLDM appears to be a better option than pentamidine or atovaquone. Currently in Japan, both PQ and CLDM are licensed drugs but neither of them is approved for treatment of PCP. Considering the potentially fatal nature of PCP, approval of PQ-CLDM for treating this illness should be urged., Competing Interests: Declaration of competing interest All authors have no conflict of interest to declare., (Copyright © 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: To assess the performance of the EULAR/ACR idiopathic inflammatory myopathies (IIMs) classification criteria to classify juvenile IIMs (JIIMs) in an Asian paediatric population., Methods: Sixty-eight JIIM patients and 49 non-JIIM patients diagnosed at seven major paediatric rheumatology centres in Japan between 2008 and 2015 were enrolled. Retrospective data were collected, and each patient's data form was submitted. The expert group reviewed the forms and re-examined the diagnoses. The EULAR/ACR criteria were then applied and the probability of having JIIM was determined for each case. The sensitivity and specificity of the EULAR/ACR criteria were compared with those of other existing criteria., Results: The sensitivity/specificity of the EULAR/ACR classification criteria were 92.1/100% with muscle biopsy data (n = 38); 86.7/100% without muscle biopsy data (n = 30) and 89.7/100% in our total cohort (n = 68). The sensitivity of Bohan and Peter's criteria and Tanimoto's criteria were 80.9 and 64.7% in our total cohort, respectively. Among 68 physician-diagnosed JIIM patients, seven cases (three JDM and four overlap myositis) were not classified as JIIM because the probability did not reach the cut-off point (55%). The three JDM patients all presented with only one of the three skin manifestations that are listed in the criteria: Gottron's sign., Conclusion: Our validation study with Japanese JIIM cases indicates that the EULAR/ACR classification criteria for IIM generally perform better than existing diagnostic criteria for myositis., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Although acute poststreptococcal glomerulonephritis (APSGN) and acute rheumatic fever (ARF) are well-known complications of group A streptococcus infection, concomitant occurrence of both diseases is rare. We report an 11-year-old Japanese girl with primary Sjögren's syndrome complicated by acute renal failure about 2 weeks after the onset of pharyngitis. Although histopathological findings of the kidney were not confirmative, APSGN was suggested by the spontaneous recovery of her renal function, typical latent period with high levels of antistreptolysin O and low serum levels of C3 but not of C4. In addition, cardiac hypomotility and regurgitation of the 4 valves progressed in the convalescent phase of APSGN, which was accompanied by elevation of serum C-reactive protein and plasma brain natriuretic peptide (BNP) levels. Myocarditis was suggested by delayed gadolinium-enhancement of cardiac walls on cardiac magnetic resonance imaging. She was diagnosed with APSGN and ARF and was treated with a combination of short course prednisolone and prophylactic penicillin G. There is no relapse of renal or cardiac symptoms during 6 years follow-up. Unexpected elevation of plasma BNP in a convalescent stage of APSGN suggests the development of ARF. Underlying Sjögren's syndrome (SS) may modify the histopathological findings and make it difficult to differentiate APSGN from CTD-associated nephritis such as lupus nephritis (LN) even by renal biopsy.

Juvenile dermatomyositis is the most common type of juvenile idiopathic inflammatory myopathy mainly affecting the skin and proximal muscles. We have published the Japanese version of 'Clinical practice guidance for juvenile dermatomyositis (JDM) 2018 'consisting of a review of articles in the field and evidence-informed consensus-based experts' opinion on the treatment strategy in collaboration with The Pediatric Rheumatology Association of Japan and The Japan College of Rheumatology under the financial support by 'Research on rare and intractable diseases, Health and Labor Sciences Research Grants'. This article is a digest version of the Japanese guidance.

Objectives: The aim of our study is to clarify the association of myositis-specific autoantibodies (MSAs) with clinical and laboratory features in Japanese patients with juvenile idiopathic inflammatory myopathies (JIIMs)., Methods: We retrospectively analyzed the frequency of MSAs and their association with clinical or laboratory findings in 25 Japanese patients with JIIMs in Hokkaido district., Results: Eighteen of the 25 patients (72%) were positive for MSAs; seven with anti-melanoma differentiation associated gene (MDA) 5 (28%), five with anti-transcriptional intermediary factor (TIF)-1γ (20%), four with anti-MJ/nuclear matrix protein (NXP)-2 (16%), two with anti-Jo-1 (8%), one with anti- HMG-CoA reductase, one with anti-signal recognition peptide (SRP) antibodies (4% each), including co-existence and transition of MSAs in one patient each. Anti-MDA5 antibodies were related to interstitial lung disease (ILD) and arthritis but not to amyopathic juvenile dermatomyositis. Drug-free remission was achieved, once ILD was overcome in this group. Anti-TIF-1γ antibodies were associated with typical rashes and mild myositis. Anti-MJ/NXP2 and anti-SRP antibodies were associated with severe muscle weakness. No patient was complicated with malignancy., Conclusion: Anti-MDA5 antibodies are prevalent and closely associated with ILD in our series compared with other countries. There was no apparent difference in clinical features associated with other MSAs among races.

Objectives: The purpose of this study is to evaluate systemic disease activity of pediatric Sjögren's syndrome (SS) using European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI)., Methods: We retrospectively reviewed medical records of patients with SS who have been diagnosed according to 1999 Japanese diagnostic criteria for SS before 16 years old at KKR Sapporo Medical Center, Hokkaido University Hospital, and affiliated hospitals. We analyzed clinical and laboratory data and calculated ESSDAI at both diagnosis and peak activity., Results: Twenty-five patients (2 boys and 23 girls) were enrolled. Only 4 patients had sicca symptoms at diagnosis. Mean ESSDAI scores at diagnosis and peak activity were 12.68 (2-31) and 15.08 (2-38), respectively. Only 3 patients were inactive (ESSDAI score <5) at diagnosis. Frequently involved domains at diagnosis were the biological (96%) followed by the constitutional (68%), glandular (44%), articular (44%), cutaneous domains (28%), renal (16%), and central nervous system (12%). At peak activity, biological domain (96%) was followed by the constitutional (72%), glandular (60%), articular (44%), cutaneous (28%), central nervous system (20%), and renal domains (16%)., Conclusion: Pediatric SS is suspected from active systemic manifestations. The items of ESSDAI are useful clues to the diagnosis of pediatric SS.

Palindromic rheumatism (PR), a rare disease in children, is characterized by recurrent arthritis or periarthritis and asymptomatic interval. We report evolution of PR to juvenile idiopathic arthritis in a Japanese girl with heterozygous complex L110P-E148Q allele of MEFV gene. Poor response to colchicine alone suggests that the MEFV substitution could increase the susceptibility to arthritis rather than caused arthritis associated with atypical Familial Mediterranean Fever. Weekly methotrexate is a choice for such cases.

Objectives: Acute leukemia often causes osteoarthralgia. The aim of this study is characterization of leukemia-associated osteoarthralgia in comparison with juvenile idiopathic arthritis (JIA)., Methods: We retrospectively reviewed clinical records of 31 patients with acute leukemia and 13 patients with articular JIA diagnosed between January 2008 and March 2013. Clinical and laboratory findings at the initial examination were compared among the three groups; 10 leukemia with and 21 leukemia without osteoarthralgia and 13 JIA groups., Results: Eleven of the 31 leukemic patients (35%) had osteoarthralgia before the diagnosis of leukemia. Peripheral leukemic cells were initially absent in 10 of the 31 leukemia patients including three with osteoarthralgia. Platelet counts over 300 × 10 9 /L were common in JIA, but not in osteoarthralgia group. Mean serum lactate dehydrogenase levels were higher in both of the leukemia groups than JIA group but often within normal or near-normal levels in the leukemia groups. Magnetic resonance imaging was examined in three leukemic patients and demonstrated osteomyelitis-like bone marrow edema in two and periarticular infiltration similar to synovitis in one patient. Three leukemic patients with osteoarthralgia showed partial and transient responses to antibiotic therapy., Conclusions: Leukemia-associated osteoarthralgia is often indistinguishable from rheumatic diseases by imaging and laboratory findings and should be confirmed by bone marrow examination.

Heterozygous dominant-negative mutations of STAT1 are responsible for autosomal-dominant Mendelian susceptibility to mycobacterial diseases (AD-MSMD). So far, only 7 mutations have been previously described and are localized to 3 domains: the DNA-binding domain, the SH 2 domain, and the tail segment. In this study, we demonstrated the first coiled-coil domain (CCD) mutation of c.749G>C, p.G250A (G250A) in STAT1 as a genetic cause of AD-MSMD in a patient with mycobacterial multiple osteomyelitis. This de novo heterozygous mutation was shown to have a dominant-negative effect on the gamma-activated sequence (GAS) transcriptional activity following IFN-γ stimulation, which could be attributable to the abolished phosphorylation of STAT1 from the wild-type (WT) allele. The three-dimensional structure of STAT1 revealed the G250 residue was located distant from a cluster of residues affected by gain-of-function mutations responsible for chronic mucocutaneous candidiasis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: We here describe treatment outcomes in two adenosine deaminase (ADA)-deficiency patients (pt) who received stem cell gene therapy (SCGT) with no cytoreductive conditioning. As this protocol has features distinct from those of other clinical trials, its results provide insights into SCGT for ADA deficiency., Patients and Methods: Pt 1 was treated at age 4.7 years, whereas pt 2, who had previously received T-cell gene therapy, was treated at age 13 years. Bone marrow CD34(+) cells were harvested after enzyme replacement therapy (ERT) was withdrawn; following transduction of ADA cDNA by the γ-retroviral vector GCsapM-ADA, they were administered intravenously. No cytoreductive conditioning, at present considered critical for therapeutic benefit, was given before cell infusion. Hematological/immunological reconstitution kinetics, levels of systemic detoxification, gene-marking levels, and proviral insertion sites in hematopoietic cells were assessed., Results: Treatment was well tolerated, and no serious adverse events were observed. Engraftment of gene-modified repopulating cells was evidenced by the appearance and maintenance of peripheral lymphocytes expressing functional ADA. Systemic detoxification was moderately achieved, allowing temporary discontinuation of ERT for 6 and 10 years in pt 1 and pt 2, respectively. Recovery of immunity remained partial, with lymphocyte counts in pts 1 and 2, peaked at 408/mm(3) and 1248/mm(3), approximately 2 and 5 years after SCGT. Vector integration site analyses confirmed that hematopoiesis was reconstituted with a limited number of clones, some of which were shown to have myelo-lymphoid potential., Conclusions: Outcomes in SCGT for ADA-SCID are described in the context of a unique protocol, which used neither ERT nor cytoreductive conditioning. Although proven safe, immune reconstitution was partial and temporary. Our results reiterate the importance of cytoreductive conditioning to ensure greater benefits from SCGT.

Objective: Rapidly progressive interstitial lung disease (RP-ILD) is a rare but potentially fatal complication of JDM. The aim of this study was to establish markers for the prediction and early diagnosis of RP-ILD associated with JDM., Methods: The clinical records of 54 patients with JDM were retrospectively reviewed: 10 had RP-ILD (7 died, 3 survived), 19 had chronic ILD and 24 were without ILD. Routine tests included a high-resolution CT (HRCT) scan of the chest and measurement of serum levels of creatine phosphokinase, ferritin and Krebs von den Lungen-6 (KL-6). Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies and IL-18 levels were measured by ELISA., Results: No differences were found in the ratio of juvenile clinically amyopathic DM between the three groups. Initial chest HRCT scan findings were variable and could not distinguish between RP-ILD and chronic ILD. Anti-MDA5 antibodies were positive in all 8 patients with RP-ILD and 10 of 14 with chronic ILD, but none of the patients without ILD. Serum levels of anti-MDA5 antibody, ferritin, KL-6 and IL-18 were significantly higher in the RP-ILD group than in the chronic ILD and non-ILD groups. Serum levels of IL-18 positively correlated with serum KL-6 (R = 0.66, P < 0.001)., Conclusion: High serum levels of IL-18, KL-6, ferritin and anti-MDA5 antibodies (e.g. >200 units by ELISA) are associated with RP-ILD. These can be used as an indication for early intensive treatment. Both alveolar macrophages and autoimmunity to MDA5 are possibly involved in the development of RP-ILD associated with JDM., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Chronic granulomatous disease (CGD) is a primary immunodeficiency disease characterized by recurrent life-threatening bacterial and fungal infections with granuloma formation. Species of the genus Fusarium are opportunistic environmental microorganisms that are rarely pathogenic in humans. We report here the first case of X-linked CGD complicated with epidural abscess caused by Fusarium falciforme infection. The abscesses extended along the dura mater for >7 years and finally resulted in fatal meningitis and cervical myelitis. Early intervention with hematopoietic stem cell transplantation should be considered, especially in patients with severe CGD, before the development of serious infectious complication., (© 2015 Japan Pediatric Society.)

Autoantibodies to autoimmune enteropathy-related 75 kDa antigen (AIE-75) and villin are disease markers of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome which is characterized by a peripheral tolerance defect. On the other hand, anti-tryptophan hydroxylase-1 (TPH-1) antibodies are detected in autoimmune polyendocrinopathy, candidiasis, ectodermal dystrophy (APECED), a central tolerance defect, especially when complicated with gastrointestinal dysfunction. However, to date, anti-AIE-75 and anti-villin antibodies or anti-TPH-1 antibodies have not been tested in APECED or IPEX syndrome, respectively. In the present study, we confirmed the disease specificity of both anti-AIE-75 and anti-TPH-1, although anti-villin antibodies were detected in some patients with APECED. Our observation suggests that immunotolerance to AIE-75 depends on the peripheral mechanism, whereas the tolerance to TPH-1 depends on the central mechanisms., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Heterozygous gain-of-function (GOF) mutations of STAT1 are responsible for chronic mucocutaneous candidiasis disease (CMCD), one of the primary immunodeficiency diseases characterized by susceptibility to mucocutaneous Candida infection. To date, 30 aa changes have been reported: 21 in the coiled-coil domain and 9 in the DNA-binding domain. In this study, we report two novel STAT1 GOF mutations of p.K278E in coiled-coil domain and p.G384D in DNA-binding domain in Japanese CMCD patients. Ectopic expression of these STAT1 mutants in HeLa cells was associated with increased phosphorylation of the mutant and the endogenous wild-type STAT1 due to impaired dephosphorylation, indicating heterodimers of the wild-type and mutant STAT1 cause impaired dephosphorylation, as did homodimers of the mutants. Because IL-17A production was not significantly reduced at least in one of the patients following PMA plus ionomycin stimulation, we further studied Th17-associated cytokines IL-17A, IL-17F, and IL-22 in response to more physiologically relevant stimulations. IL-17A and IL-22 production from PBMCs and CD4(+) cells was significantly reduced in four patients with STAT1 GOF mutations, including the previously reported R274Q in response to anti-CD3 plus anti-CD28 Abs or Candida stimulations. In contrast, IL-17F production was comparable to healthy controls in response to anti-CD3 plus anti-CD28 Abs stimulation. These results indicate impaired production of IL-17A and IL-22 rather than IL-17F was associated with the development of CMCD in these patients. Additionally, only the anti-IL-17F autoantibody was detected in sera from 11 of 17 patients with STAT1 GOF mutations, which may be useful as a marker for this disease., (Copyright © 2014 by The American Association of Immunologists, Inc.)

Mixed connective tissue disease (MCTD) is rare in pediatric rheumatic diseases. Pulmonary arterial hypertension (PAH) associated with MCTD usually progresses gradually and is difficult to note at the asymptomatic phase. We report a 11-year-old girl with MCTD complicated with rapidly progressive PAH. Although PAH was not detected by echocardiogram or chest CT scan at the initial examination, it became clear in 1 year and suddenly came to cardiac arrest during an invasive procedure. She was successfully treated with extracorporeal assist and both vasodilative and immunosuppressive medication. A combination of echocardiogram and plasma BNP levels could be a useful marker for the follow-up of such cases. PAH could develop early in the course of pediatric MCTD and needs attention to unexpected acute exacerbation, especially under emotional stress.

We report a 19-year-old patient with systemic-onset juvenile idiopathic arthritis (JIA) who developed a mediastinal germinoma during treatment with infliximab. Although the cancer risk of infliximab is controversial, this agent may have accelerated the growth of the germinoma. We conclude that the indications for tumor necrosis factor (TNF) inhibitors should be strictly decided and that a nationwide cohort study is necessary to assess the risk of cancer in patients with JIA exposed to biologics.

Chronic mucocutaneous candidiasis (CMC) is a heterogeneous group of primary immunodeficiency diseases characterized by chronic and recurrent Candida infections of the skin, nails, and oropharynx. Gain-of-function mutations in STAT1 were very recently shown to be responsible for autosomal-dominant or sporadic cases of CMC. The reported mutations have been exclusively localized in the coiled-coil domain, resulting in impaired dephosphorylation of STAT1. However, recent crystallographic analysis and direct mutagenesis experiments indicate that mutations affecting the DNA-binding domain of STAT1 could also lead to persistent phosphorylation of STAT1. To our knowledge, this study shows for the first time that a DNA-binding domain mutation of c.1153C>T in exon 14 (p.T385M) is the genetic cause of sporadic CMC in two unrelated Japanese patients. The underlying mechanisms involve a gain of STAT1 function due to impaired dephosphorylation as observed in the coiled-coil domain mutations.

Acute disseminated encephalomyelitis (ADEM) is a monophasic, immune-mediated demyelinating disorder that can appear after either immunizations or, more often, infections. Magnetic resonance imaging of patients shows inflammatory lesions in the brain and spinal cord. An immune-mediated mechanism may play a role in this disease, although its precise pathogenesis remains unclear. In this study, a 2-year-old boy presented with ADEM, and he showed improvement on treatment with high-dose intravenous corticosteroids. At the age of 3 years, the presence of recurrent bronchitis, bronchiectasia, and lymphopenia suggested that the patient was suffering from combined immunodeficiency. The patient was finally diagnosed with delayed onset adenosine deaminase deficiency. Delayed onset adenosine deaminase deficiency is frequently associated with autoimmune diseases, including thyroiditis and cytopenia, both of which were observed in the patient. The ADEM in this patient may be a presentation of delayed onset adenosine deaminase deficiency.

X-linked chronic granulomatous disease (X-CGD) is a primary immunodeficiency disease of phagocytes caused by mutations in the cytochrome b(558)β (CYBB) gene. We, for the first time, detected somatic mosaicism in two unrelated male patients with X-CGD caused by de novo nonsense mutations (p.Gly223X and p.Glu462X) in the CYBB gene. In each patient, a small subset of granulocytes was normal in terms of respiratory burst (ROB) activity, gp91(phox) expression, and CYBB sequences. Cells with wild-type CYBB sequence were also detected in buccal swab specimens and in peripheral blood mononuclear cells. The normal cells were shown to be of the patient origin by fluorescent in situ hybridization analysis of X/Y chromosomes, and by HLA DNA typing. Two possible mechanisms for this somatic mosaicism were considered. The first is that the de novo disease-causing mutations in CYBB occurred at an early multicellular stage of embryogenesis with subsequent expansion of the mutated cells, leaving some unmutated cells surviving. The second possibility is that the de novo mutations occurred in oocytes which was followed by reversion of the mutations in a small subset of cells in early embryogenesis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Castleman disease (CD) is a rare lymphoproliferative disorder of unknown etiology. It is quite difficult to diagnose CD without typical localized signs or symptoms. We present a 5-year-old boy with unicentric plasma cell CD in the mesentery, which was too small to be detected by any conventional imaging. (18)F-fluorodeoxyglucose positron emission tomography image and a serum cytokine profile prompted us to perform a curative surgical excision, confirming his diagnosis. Our case also supported an important role of interleukin-6 in the pathophysiology of plasma cell CD.

A 43-year-old woman presented with a persistent high fever of 39 degrees C and edematous erythema accompanied by pustules on the face, trunk and extremities. Conjunctivitis and nodules were also observed in the right eye. On the basis of the clinical symptoms and histopathological findings. Sweet's syndrome was diagnosed. Eruptions quickly progressed to extensive necrosis and ulcers, mimicking clinical features of pyoderma gangrenosum. A bone marrow biopsy indicated myelodysplastic syndrome. Oral administration of 50 mg/day of prednisolone induced epithelialization of ulcers, with remaining scarring and pigmentation. Six months later, myelodysplastic syndrome had progressed to acute myelogenous leukemia.