Evaluation of Medication Withdrawal in Patients with Non-systemic Juvenile Idiopathic Arthritis in Japan Using a Web-based Survey.

OBJECTIVE: Although treatments for juvenile idiopathic arthritis (JIA) have seen considerable advancements, there remains a lack of clear guidelines on withdrawing medications. This study aimed to investigate the current strategies for discontinuing non-systemic JIA treatment. METHODS: A web-based questionnaire was distributed to Pediatric Rheumatology Association of Japan members. RESULTS: According to 126 responses, the most significant factors influencing JIA treatment tapering were the duration of clinically inactive disease, medication toxicity, and a history of arthritis flares. Respondents were often cautious about discontinuing medication if symptoms, e.g., 'morning stiffness' or 'intermittent joint pain', persisted. Among subtypes, oligoarticular JIA was more amenable to treatment tapering, whereas rheumatoid factor-positive polyarticular JIA proved less amenable. Most respondents started medication tapering after a continuous clinical inactive duration exceeding 12 months, and >50% of them required >6 months to achieve treatment discontinuation. Additionally, 40% of respondents consistently underwent imaging before treatment tapering. CONCLUSIONS: The relative risks of treatment continuation and withdrawal should be considered, and decisions should be made accordingly. To obtain improved understanding of and more robust evidence for the optimal strategies for safely discontinuing JIA treatment, it is crucial to continue investigations, including long-term outcomes.

Long-term efficacy and safety of canakinumab in the treatment of systemic juvenile idiopathic arthritis in Japanese patients: Results from an open-label Phase III study.

OBJECTIVES: The objective of the study was to report the efficacy and safety of canakinumab treatment in Japanese patients with systemic juvenile idiopathic arthritis (sJIA) over a 48-week study period. METHODS: Patients were administered canakinumab 4 mg/kg (maximum dose 300 mg) every 4 weeks, with no dose adjustments. The key outcome measures included adapted American College of Rheumatology paediatric (aACR pedi) 30/50/70/90/100 response, proportion of patients with inactive disease, and corticosteroid (CS) tapering. RESULTS: In total, 16/19 (84.2%) patients received canakinumab for ≥96 weeks reaching end-of-study (EOS) visit without premature discontinuation. Regardless of the level of joint involvement at baseline, high aACR pedi responses were observed throughout the study; at the EOS, aACR pedi 90/100 response rates were 84.2%/63.2%, respectively. The proportion of patients who successfully tapered CSs at EOS was 66.7% (12/18), of which 10 patients were steroid-free. The most common adverse events were infections (238.3 events/100 patient-years). Serious adverse events were observed in 52.6%. The event (n=1) adjudicated as possible macrophage activation syndrome was preceded by sJIA flare. No deaths were reported. CONCLUSIONS: Canakinumab treatment resulted in a sustained treatment response in sJIA patients over 48 weeks and was associated with CS tapering in majority of patients. No new safety findings were reported.

Epidemiology conduction of paediatric rheumatic diseases based on the registry database of the Pediatric Rheumatology Association of Japan.

OBJECTIVES: Although epidemiological surveys of paediatric rheumatic diseases in Japan have been conducted, they were single surveys with no continuity. This is the first report of the Pediatric Rheumatology Association of Japan registry database, which was established to continuously collect data for paediatric rheumatic diseases. METHODS: Pediatric Rheumatology International Collaborate Unit Registry version 2 (PRICUREv2) is a registry database established by the Pediatric Rheumatology Association of Japan. The registry data were analysed for the age of onset, time to diagnosis, sex differences, seasonality, and other factors. RESULTS: Our data showed the same trend regarding rates of paediatric rheumatic diseases reported in Japan and other countries. The age of onset was lower in juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis and higher in systemic lupus erythematosus and Sjögren's syndrome. The time to diagnosis was relatively short in JIA and systemic lupus erythematosus but longer in juvenile dermatomyositis and Sjögren's syndrome. Rheumatoid factor-positive polyarticular JIA showed a seasonality cluster with regard to onset. CONCLUSION: PRICUREv2 aided the retrieval and evaluation of current epidemiological information on patients with paediatric rheumatic diseases. It is expected that the data collection will be continued and will be useful for expanding research in Japan.

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis: 48-week results from an open-label phase III study in Japanese patients.

OBJECTIVES: To assess the efficacy and safety of canakinumab in Japanese patients with systemic juvenile idiopathic arthritis (sJIA). METHODS: This was an open-label, single-arm active treatment study. sJIA patients, aged ≥2 to <20 years, were administered canakinumab 4 mg/kg every 4 weeks for ≤48 weeks. The co-primary endpoints were the proportion of patients who achieved an adapted American College of Rheumatology pediatric (ACR pedi) 30 criteria at week 8, and the proportion of patients who successfully tapered corticosteroids at week 28. Herein, the efficacy and safety results up to 48 weeks are reported. RESULTS: Of the 19 patients enrolled, 15 (78.9%) had previously used tocilizumab. All patients achieved ACR pedi 30 at week 8 and 73.7% (14/19) successfully tapered corticosteroids at week 28. At week 48, ACR pedi 50/70/90/100 responses were achieved by 100.0%/100.0%/87.5%/68.8% of patients. The most common adverse events (AEs) were infections (271.6 patient-years), 42.1% (8/19) patients had serious AEs. Two potential cases of macrophage activation syndrome were identified. No deaths were reported. CONCLUSION: Canakinumab was efficacious in Japanese patients with sJIA and was associated with substantial corticosteroid dose reduction in the majority of patients. The safety profile of canakinumab was consistent with that observed from previous studies. CLINICALTRIALS.GOV (IDENTIFIER: NCT02396212).

Characteristics and outcome of intractable vasculitis syndrome in children: Nation-wide survey in Japan.

OBJECTIVE: Primary systemic vasculitis (PSV) is a rare disorder in children and difficult to distinguish from other diseases. However, appropriate diagnosis and prompt treatment will affect on the morbidity and mortality of intractable PSV. In this study, we conducted a nationwide survey in Japan, to clarify epidemiology and clinical outcome of PSV. METHODS: We had sent survey questionnaires to most of the Japanese institutions that employed pediatricians, requesting the number of patients with refractory PSV who were diagnosed and treated between 2007 and 2011. Respondents were asked to provide detailed information on the clinical and laboratory features of each case they had managed. Those with Kawasaki disease or Henoch-Shönlein purpura vasculitis (IgA vasculitis) were excluded. RESULTS: Of all the institutions surveyed, 1123 (37.3%) patients responded, finally, total of 49 patients with intractable PSV, defined by those with resistant to treatment and steroid-dependent, or with any complication associated with prognosis, were selected. The diagnosis was Takayasu arteritis in 31, polyarteritis nodosa in 11, granulomatosis with polyangitis in 2, microscopic polyangitis in 1, and ANCA negative microscopic polyangitis in 1. In those with Takayasu arteritis, 67% were treated with an immunosuppressive agent, 22% with biological modifiers, and 16% with surgical procedures. In other types of disease, 88% of the patients were treated with an immunosuppressive agent, and 12% with biological modifiers. Two with Takayasu arteritis died being terminally ill. CONCLUSION: This nationwide survey establishes the heterogeneous characteristics of PSV in children. Although questionnaire-based, the results of our analysis should be useful in planning prospective studies to identify the most effective therapy for each subtype of multifaceted disease.

Long-term safety and efficacy of canakinumab in cryopyrin-associated periodic syndrome: results from an open-label, phase III pivotal study in Japanese patients.

OBJECTIVES: To assess the long-term safety and efficacy of canakinumab in Japanese patients with cryopyrin-associated periodic syndrome (CAPS). METHODS: In this open-label phase 3 study, Japanese patients aged ≥2 years with CAPS received canakinumab 2-8 mg/kg subcutaneously every 8 weeks. The duration of the core treatment phase was 24 weeks followed by 22 months extension phase. The primary objective was the proportion of patients free of clinical and serologic relapse at week 24. RESULTS: The study enrolled 19 Japanese patients (median age, 14 years; range, 2-48 years) with CAPS [MWS, 7 (36.8%); NOMID, 12 (63.2%)] for a median of 109 weeks. Fifteen patients (79%) achieved a complete response by day 15, 18 (94.7%) by week 24 and all by week 48. At the end of the study, 18 (95%) were free from relapse and 11 (57.9%) were assessed as having no disease activity by the PGA. Thirteen (68%) patients (MWS, 4; NOMID, 9) had their canakinumab dose increased during the trial. All patients experienced at least one adverse event (AE), the most common being infections (100%) and 5 (26.3%) reported serious AEs. No deaths were reported and the only patient who discontinued the study early withdrew consent. CONCLUSIONS: Regular canakinumab treatment every 8 weeks at dose levels from 2-8 mg/kg, based on the clinical need, represents a successful strategy to induce rapid and complete response while maintain long-term disease control in Japanese patients with CAPS. The safety profile of canakinumab was consistent with that observed from previous studies.

Double-balloon Enteroscopy for Pediatric Patients: Evaluation of Safety and Efficacy in 257 Cases.

OBJECTIVES: The safety and efficacy of double-balloon enteroscopy (DBE) in pediatric patients has not been well documented. We aimed to evaluate the clinical efficacy and safety of DBE in children, especially those under 10. METHODS: We retrospectively analyzed our database of DBE procedures performed between September 2000 and September 2013. Procedures performed in pediatric patients (under 18) were selected from a total of 3980, including double-balloon endoscopic retrograde cholangioscopy (DBERC). RESULTS: Two hundred fifty-seven DBE procedures were performed in 117 pediatric patients (median age 12.5 years). Antegrade (oral-route) DBE was performed in 166 procedures including 104 DBERC procedures (lowest body weight 13.5 kg, youngest age 3 years), and retrograde (anal-route) DBE in 91 (lowest body weight 12.0 kg, youngest age 2 years). The overall diagnostic yield for obscure gastrointestinal bleeding and abdominal pain was 58.8%. The purpose of DBERC was achieved in 76.9% of procedures. The overall complication rate in our series was 5.4% (1.9% with the DBERC cases removed); in patients under 10, it was 10.4% (7/67). No severe complications associated with enteroscope insertion and sedation were observed. Serum amylase levels tended to be elevated in patients who underwent oral-route DBE. CONCLUSIONS: DBE is safe and feasible for diagnostic evaluation of small bowel disorders in pediatric patients, even those younger than 10 years. Special attention for possible complications must, however, be paid during therapeutic DBE procedures, including DBERC, especially for patients under 10.

Functional dyspepsia and irritable bowel syndrome in teenagers: Internet survey.

BACKGROUND: Only a handful of studies have investigated children with functional dyspepsia (FD) and irritable bowel syndrome (IBS) classified according to the Rome III criteria, and limited information is available on the lifestyle of affected patients. METHODS: We conducted an Internet questionnaire survey of 2060 parents among the general public in Japan who lived with their children aged 10-15, who were screened for FD and IBS. RESULTS: The prevalence of FD and IBS was 2.8% and 6.1%, respectively, and 1.4% of the subjects met the criteria for both FD and IBS. The lifestyles of 155 subjects who met the criteria for FD, IBS, or both were compared with those of 1745 control subjects. In comparison with the controls, a significantly higher percentage of subjects with FD, IBS, or both thought that their sleep was insufficient, ate meals irregularly, were susceptible to stress and to dizziness on standing, had difficulty in getting out of bed or felt sluggish in the morning, had a tendency to faint when standing, and had migraine/chronic headache. CONCLUSIONS: Children with FD and IBS are susceptible to stress, have impaired sleep and eating habits, and have more frequent symptoms of comorbid orthostatic dysregulation and headache.

Clinical and laboratory features of fatal rapidly progressive interstitial lung disease associated with juvenile dermatomyositis.

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.

Mycophenolate mofetil as maintenance therapy for childhood-onset systemic lupus erythematosus patients with severe lupus nephritis.

OBJECTIVES: We evaluated histological changes occurring in renal biopsy specimens, between the time before initial induction therapy and after 12 months' maintenance therapy, as well as changes in laboratory parameters, SLE disease activity (SLEDAI), and dosage of corticosteroid (CS) in childhood-onset systemic lupus erythematosus (SLE) patients treated with mycophenolate mofetil (MMF). METHODS: A retrospective analysis was performed on nine patients diagnosed with childhood-onset SLE and lupus nephritis. They were treated with pulsed mPSL and intravenous cyclophosphamide as induction therapy and MMF (500-1500 mg/day) plus CS as maintenance therapy. Renal biopsy was performed before the initial induction therapy and after 12 months' maintenance therapy. RESULTS: Pathological findings at second biopsy were improved in eight of nine patients (89%). The findings of SLEDAI, urinalysis, and blood tests also showed improvement. CS doses could be tapered satisfactorily. Adverse events were observed in two patients. No patients treated with MMF experienced any disease flares during maintenance therapy. CONCLUSIONS: MMF as maintenance therapy might be useful in that not only the histological findings of lupus nephritis were improved, but also CS doses could be beneficially tapered. Nonetheless, this is a retrospective report of only nine cases and further prospective multicenter studies are necessary.

Serum levels of anti-SRP54 antibodies reflect disease activity of necrotizing myopathy in a child treated effectively with combinatorial methylprednisolone pulses and plasma exchanges followed by intravenous cyclophosphamide.

We describe the effectiveness of combinatorial therapy with plasma exchanges and methylprednisolone pulses followed by intravenous cyclophosphamide in a young girl with anti-signal recognition particle 54 (SRP54) antibody-associated myopathy. We also use a newly described quantitative assay to demonstrate the close association between the titers of anti-SRP54 antibodies and disease activity. This is the first report of a pediatric patient indicating that the serum levels of anti-SRP54 antibodies are also beneficial for monitoring the disease activity of progressive necrotizing myopathy.

Carbapenemase-producing Enterobacterales isolated from hospital sinks: molecular relationships with isolates from patients and the change in contamination status after daily disinfection with sodium hypochlorite.

Objective: This study aimed to investigate the contamination status of hospital sinks with carbapenemase-producing Enterobacterales (CPE), the efficacy of daily cleaning with sodium hypochlorite, and the relationships between CPEs isolated from contaminated sinks and patients. Design: Pre/postintervention surveys of the CPE-contaminated sinks. Setting: Hospital wards including pediatric intensive care unit in a children's hospital. Participants: Consenting CPE-colonized patients admitted between November 2018 and June 2021 in our hospital. Methods: Environmental culture of 180 sinks from nine wards in our hospital was performed three times with an interval of 2 years (2019, 2021, 2023). Molecular typing of the isolated strains from the sinks and patients was performed. After the first surveillance culture, we initiated daily disinfection of the sinks using sodium hypochlorite. Results: Before the intervention, we detected 30 CPE-positive sinks in 2019. After the intervention with sodium hypochlorite, we observed a substantial decline in the number of sinks contaminated with CPE; 13 in 2021 and 6 in 2023. However, the intervention did not significantly reduce the number of CPE-contaminated sinks used for the disposal of nutrition-rich substances. The CPE isolates from the patients and those from the sinks of the wards or floors where they were admitted tended to have similar pulse-field gel electrophoresis patterns. Conclusion: Contaminated sinks could be reservoirs of disseminating CPE to the patients. Daily disinfection of sinks with sodium hypochlorite may be effective in eliminating CPE, although the effect could be weaker in sinks with a greater risk of contact with nutrition-rich substances.

Safety and efficacy of canakinumab in Japanese patients with phenotypes of cryopyrin-associated periodic syndrome as established in the first open-label, phase-3 pivotal study (24-week results).

OBJECTIVES: Cryopyrin-associated periodic syndrome (CAPS), a rare hereditary auto-inflammatory disease, is associated with mutations in the NLRP3 gene resulting in elevated interleukin-1ß (IL-1 ß) release. CAPS generally occurs in early childhood with most patients presenting with periodic fever, skin rash, osteoarthropathy, aseptic meningitis, sensorineural hearing loss and optic neuritis. Canakinumab, a fully human anti-IL-1ß monoclonal antibody which binds selectively to IL-1ß, has demonstrated good efficacy with CAPS. This is the first study to evaluate the safety and efficacy of canakinumab in Japanese patients with CAPS. METHODS: In this open-label study, 19 Japanese CAPS patients aged ≥2 years received canakinumab either 150 mg s.c. or 2 mg/kg for patients with a body weight ≤ 40 kg every 8 weeks for 24 weeks. The primary objective was to assess the proportion of patients who were free of relapse at week 24. RESULTS: A complete response was achieved in 18 (94.7%) patients with some requiring a dose and/or a frequency adjustment to attain full clinical response. The majority of patients (14/18; 77.8%) were in remission, i.e. free of relapse at week 24. Auto-inflammatory disease activity as assessed by physician's global assessment declined from baseline to end of the study (score of absent in 10.5% at baseline versus 31.6% at end of the study). Two patients had serious adverse events (SAEs), which resolved with standard treatment. One patient reported a mild injection-site reaction. No malignancies or deaths were reported during the study. CONCLUSIONS: Canakinumab 150 mg s.c. every 8 weeks was well-tolerated, highly efficacious and offered a convenient dosing regimen for treating Japanese patients with CAPS.

Clinical analysis of 50 children with juvenile dermatomyositis.

OBJECTIVE: We performed a retrospective review of medical records to assess the clinical characteristics of 50 Japanese children with juvenile dermatomyositis (JDM). METHODS: Fourteen boys and 36 girls who visited Yokohama City University Hospital between 1983 and 2008 were enrolled. Gender, age at disease onset and diagnosis, presenting clinical features, laboratory data at onset, complications, treatment, and outcome were reviewed. RESULTS: Mean age at disease onset was 6.9 years. Clinical manifestations at the first visit were muscle pain and/or weakness (90 %), malar rash (90 %), Gottron's papules (86 %), and heliotrope rash (80.0 %). Elevated serum levels of creatine kinase were found in 57.0 % of patients and aldolase in 95 %. T2-weighted magnetic resonance (MR) images with fat suppression demonstrated positive findings in 89.5 % of patients. Initial treatment was prednisolone (PSL) orally or pulsed methylprednisolone (mPSL) i.v. Pulsed mPSL therapy showed efficacy superior to PSL [flare in 8 of 19 (42 %) vs. 18 of 25 (72 %)]. Children refractory to initial treatment were given additional pulsed mPSL and/or cyclophosphamide (IVCY; n = 19) i.v.. Four patients with interstitial pneumonia responded well to IVCY. CONCLUSIONS: Our findings support the notion that JDM might be considered as both a systemic inflammatory and noninflammatory vasculopathy best treated by IVCY, as shown in previous literature.

Guidance on the use of canakinumab in patients with cryopyrin-associated periodic syndrome in Japan.

Cryopyrin-associated periodic syndrome (CAPS) is an orphan disease with incidence of about one in 1,000,000 persons. This autoinflammatory disease develops in the neonatal period or early childhood, with various inflammatory symptoms occurring repeatedly throughout the patient's lifetime. It is caused by abnormality of the NLRP3 protein which mediates the intracellular signal transduction mechanism of inflammatory processes, resulting in continuous overproduction of interleukin (IL)-1ß, which induces chronic inflammation and progressive tissue damage. Definitive diagnosis of CAPS is difficult, and treatment has also been difficult because of a lack of effective medications in Japan. Clinical studies of human anti-human IL-1ß monoclonal antibody (canakinumab) treatment were conducted in Japan, and approval was granted for therapeutic use of canakinumab for CAPS in September 2011. Similar to other biological drugs, canakinumab is clinically highly effective. However, sufficient attention to the method of use and adverse drug reactions is necessary. This guidance describes the use of canakinumab in Japan for CAPS in relation to exclusion criteria, method of use, evaluation criteria, and adverse drug reactions.

Radiologic analysis of the effect of tocilizumab on hands and large joints in children with systemic juvenile idiopathic arthritis.

OBJECTIVES: To assess the efficacy of tocilizumab for preventing damage to the joints of systemic juvenile idiopathic arthritis (sJIA) patients, we examined serial radiographs of the hands and large weight-bearing joints of these patients before and after treatment with this agent. METHODS: Nine patients with sJIA receiving 8 mg/kg of tocilizumab intravenously every 2 weeks were studied. The mean follow-up period was 82 months. The number of active joints and laboratory markers of inflammation were assessed before and after tocilizumab treatment, together with radiologic evaluation of the hips, knees, ankles, shoulders, and elbows. The latter examination included soft tissue swelling, juxta-articular osteoporosis, epiphyseal irregularity, joint-space narrowing, cyst formation, erosion, and localized growth abnormalities. Modified Larsen scores for the large joints and the Poznanski score were also recorded. RESULTS: After tocilizumab treatment, the number of active joints and serum inflammatory markers decreased (p < 0.01). There was a decrease in radiologic abnormalities at the final follow-up (p < 0.01) with the exception of localized growth abnormalities. Radiologic improvement was observed in 47 joints (52%), but ten (11%) worsened. Total Larsen score was decreased from 15.8 to 10.9 at the final follow-up. Although the Poznanski score did not change after tocilizumab treatment, it was closely correlated with the total Larsen score (r = 0.53, p < 0.05). CONCLUSIONS: We describe radiologic improvement of the majority of damaged large joints in sJIA following tocilizumab therapy, but some deteriorated further despite stabilization of systemic inflammatory responses. Further studies with a larger number of patients are needed.

Clinical Features of COVID-19 in Pediatric Rheumatic Diseases: 2020-2022 Survey of the Pediatric Rheumatology Association of Japan.

Coronavirus disease 2019 (COVID-19) in children can be compounded by concurrent diseases and immunosuppressants. For the first time, we aimed to report the clinical features of concurrent COVID-19 and pediatric rheumatic disease (PRD) in Japan. Pediatric Rheumatology Association of Japan members were surveyed between 1 April 2020 and 31 August 2022. Outcome measurements included the clinical features of concurrent PRD and COVID-19. Questionnaire responses were obtained from 38 hospitals. Thirty-one hospitals (82%) had children with PRD and COVID-19. The female-to-male ratio in these children (n = 156) was 7:3, with half aged 11-15 years. The highest proportion of children with PRD and COVID-19 was accounted for by juvenile idiopathic arthritis (52%), followed by systemic lupus erythematosus (24%), juvenile dermatomyositis (5%), scleroderma (4%), and Takayasu arteritis (3%). Of children with PRD, a significant majority (97%) were found to be asymptomatic (10%) or presented with mild symptoms (87%) of the COVID-19 infection. No severe cases or deaths were observed. Regarding the use of glucocorticoids, immunosuppressants, or biologics for PRD treatment before COVID-19, no significant difference was found between asymptomatic/mild and moderate COVID-19 in children with PRD. Therefore, COVID-19 is not a threat to children with PRD in Japan.

High incidence of NLRP3 somatic mosaicism in patients with chronic infantile neurologic, cutaneous, articular syndrome: results of an International Multicenter Collaborative Study.

OBJECTIVE: Chronic infantile neurologic, cutaneous, articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID), is a dominantly inherited systemic autoinflammatory disease. Although heterozygous germline gain-of-function NLRP3 mutations are a known cause of this disease, conventional genetic analyses fail to detect disease-causing mutations in ∼40% of patients. Since somatic NLRP3 mosaicism has been detected in several mutation-negative NOMID/CINCA syndrome patients, we undertook this study to determine the precise contribution of somatic NLRP3 mosaicism to the etiology of NOMID/CINCA syndrome. METHODS: An international case-control study was performed to detect somatic NLRP3 mosaicism in NOMID/CINCA syndrome patients who had shown no mutation during conventional sequencing. Subcloning and sequencing of NLRP3 was performed in these mutation-negative NOMID/CINCA syndrome patients and their healthy relatives. Clinical features were analyzed to identify potential genotype-phenotype associations. RESULTS: Somatic NLRP3 mosaicism was identified in 18 of the 26 patients (69.2%). Estimates of the level of mosaicism ranged from 4.2% to 35.8% (mean ± SD 12.1 ± 7.9%). Mosaicism was not detected in any of the 19 healthy relatives (18 of 26 patients versus 0 of 19 relatives; P < 0.0001). In vitro functional assays indicated that the detected somatic NLRP3 mutations had disease-causing functional effects. No differences in NLRP3 mosaicism were detected between different cell lineages. Among nondescript clinical features, a lower incidence of mental retardation was noted in patients with somatic mosaicism. Genotype-matched comparison confirmed that patients with somatic NLRP3 mosaicism presented with milder neurologic symptoms. CONCLUSION: Somatic NLRP3 mutations were identified in 69.2% of patients with mutation-negative NOMID/CINCA syndrome. This indicates that somatic NLRP3 mosaicism is a major cause of NOMID/CINCA syndrome.

Long-term efficacy of plasma exchange treatment for refractory Kawasaki disease.

BACKGROUND: The treatment of Kawasaki disease patients who fail to respond to initial i.v. immunoglobulin (IVIG) therapy is controversial. The aim of the present study was to investigate the long-term efficacy of plasma exchange (PE) treatment for refractory Kawasaki disease. METHODS: A total of 125 Kawasaki disease patients refractory to IVIG were treated with PE. Coronary artery lesions (CAL) before PE, in the acute period, and during the late period were examined retrospectively. RESULTS: Residual sequelae requiring medical treatment occurred in six cases in the late period. The outcomes of treatment tended to be better when PE was begun in the early stage. Sequelae remained in 2.8% of patients in whom PE was initiated prior to day 9 after onset, and were present in 15% of patients in whom PE was started on or after day 10. The 105 patients whose coronary arteries were normal before PE had no sequelae (residual sequelae: 0%). Dilatation was present before PE in 14 patients, but remained in only two patients in the late period (residual sequelae, 14.3%). In four of the six patients in whom aneurysms had already formed before PE, the lesions had advanced into giant aneurysms, but in the other two patients they returned to the normal range (residual sequelae, 66.6%). CONCLUSIONS: The outcomes of PE for Kawasaki disease refractory to IVIG are favorable, and the effectiveness of this treatment is excellent, particularly if it is initiated before CAL arise.