Susanne M. Benseler

An activating NLRC4 inflammasome mutation causes autoinflammation with recurrent macrophage activation syndrome

Inflammasomes are innate immune sensors that respond to pathogen- and damage-associated signals with caspase-1 activation, interleukin (IL)-1β and IL-18 secretion, and macrophage pyroptosis. The discovery that dominant gain-of-function mutations in NLRP3 cause the cryopyrin-associated periodic syndromes (CAPS) and trigger spontaneous inflammasome activation and IL-1β oversecretion led to successful treatment with IL-1–blocking agents. Herein we report a de novo missense mutation (c.1009A>T, encoding p.Thr337Ser) affecting the nucleotide-binding domain of the inflammasome component NLRC4 that causes early-onset recurrent fever flares and macrophage activation syndrome (MAS). Functional analyses demonstrated spontaneous inflammasome formation and production of the inflammasome-dependent cytokines IL-1β and IL-18, with the latter exceeding the levels seen in CAPS. The NLRC4 mutation caused constitutive caspase-1 cleavage in cells transduced with mutant NLRC4 and increased production of IL-18 in both patient-derived and mutant NLRC4–transduced macrophages. Thus, we describe a new monoallelic inflammasome defect that expands the monogenic autoinflammatory disease spectrum to include MAS and suggests new targets for therapy.

Clinical and Laboratory Characteristics and Long-Term Outcome of Pediatric Systemic Lupus Erythematosus: A Longitudinal Study

OBJECTIVES To determine the frequency and characteristics of clinical signs, symptoms, laboratory findings, and medication use in children with pediatric systemic lupus erythematosus (pSLE) at presentation and during the course of the disease, and to examine correlations among disease manifestations, disease activity, and damage over time. STUDY DESIGN The study involved an analysis of medical records and the SLE database of an inception cohort of 256 patients with pSLE (female:male ratio, 4.7:1). RESULTS The most common clinical manifestations were arthritis (67%), malar rash (66%), nephritis (55%), and central nervous system (CNS) disease (27%). At diagnosis, patients with both renal and CNS disease had the highest SLE Disease Activity Index (SLEDAI) scores (P < .0001), but these scores were similar to those of the total group at 1 year (P = .11). Patients who developed renal and CNS disease more than 1 year after diagnosis had higher SLEDAI scores at disease onset. Some 34% of patients had Systemic Lupus International Collaborative Clinics Damage Index (SLICC-DI) scores >1 at a mean follow-up of 3.5 years. A greater proportion of patients with renal and CNS disease had SLICC-DI scores of >1, and these patients had higher mean scores compared with patients without major organ involvement (70% vs 11% [P < .0001] and 1.4 vs 0.1 [P < .0001], respectively). CONCLUSIONS Most of the patients in our cohort exhibited major organ involvement. These patients had the highest SLEDAI scores at diagnosis, which normalized at 1 year but preceded development of renal and CNS disease. The average SLICC-DI score was lower than that previously reported in patients with pSLE.

Central nervous system vasculitis in children.

Central nervous system (CNS) vasculitis is an increasingly recognized, often devastating inflammatory brain disease of children and adults. In primary or isolated CNS vasculitis/angiitis of childhood (cPACNS), the vascular inflammation is limited to the brain and spinal cord. Secondary CNS vasculitis occurs in a variety of conditions including infections, collagen vascular diseases, systemic vasculidities, and malignancies. Mimics of CNS vasculitis in children include dissections and noninflammatory vasculopathies. Diagnosis of primary CNS vasculitis in both adults and children is based on the Calabrese criteria. This review summarizes recent data on CNS vasculitis in children; reviews the clinical spectrum at presentation and the role of laboratory tests, neuroimaging, and brain biopsy; and discusses treatment strategies, outcome data, and overlapping conditions of cPACNS.

Utility and safety of rituximab in pediatric autoimmune and inflammatory CNS disease

Objective: To assess the utility and safety of rituximab in pediatric autoimmune and inflammatory disorders of the CNS. Methods: Multicenter retrospective study. Results: A total of 144 children and adolescents (median age 8 years, range 0.7–17; 103 female) with NMDA receptor (NMDAR) encephalitis (n = 39), opsoclonus myoclonus ataxia syndrome (n = 32), neuromyelitis optica spectrum disorders (n = 20), neuropsychiatric systemic lupus erythematosus (n = 18), and other neuroinflammatory disorders (n = 35) were studied. Rituximab was given after a median duration of disease of 0.5 years (range 0.05–9.5 years). Infusion adverse events were recorded in 18/144 (12.5%), including grade 4 (anaphylaxis) in 3. Eleven patients (7.6%) had an infectious adverse event (AE), including 2 with grade 5 (death) and 2 with grade 4 (disabling) infectious AE (median follow-up of 1.65 years [range 0.1–8.5]). No patients developed progressive multifocal leukoencephalopathy. A definite, probable, or possible benefit was reported in 125 of 144 (87%) patients. A total of 17.4% of patients had a modified Rankin Scale (mRS) score of 0–2 at rituximab initiation, compared to 73.9% at outcome. The change in mRS 0–2 was greater in patients given rituximab early in their disease course compared to those treated later. Conclusion: While limited by the retrospective nature of this analysis, our data support an off-label use of rituximab, although the significant risk of infectious complications suggests rituximab should be restricted to disorders with significant morbidity and mortality. Classification of evidence: This study provides Class IV evidence that in pediatric autoimmune and inflammatory CNS disorders, rituximab improves neurologic outcomes with a 7.6% risk of adverse infections.

Takayasu arteritis in children and adolescents

Takayasu arteritis is a devastating vasculitis of the aorta and its major branches. The clinical manifestations in paediatric patients are less specific than in adults: in children the disease presents with fever, arthralgias and hypertension. Intramural inflammation results in narrowing of the blood vessel lumen and therefore hypoperfusion of the parenchyma. Conventional angiography is the gold standard diagnostic procedure. Corticosteroids, cyclophosphamide, MTX and biological therapies such as TNF-α blocking agents are treatment options.

Feasibility and effectiveness of an aerobic exercise program in children with fibromyalgia: results of a randomized controlled pilot trial.

OBJECTIVE To determine the feasibility of conducting a randomized controlled trial of a 12-week exercise intervention in children with fibromyalgia (FM) and to explore the effectiveness of aerobic exercise on physical fitness, function, pain, FM symptoms, and quality of life (QOL). METHODS FM patients ages 8-18 years were randomized to a 12-week exercise intervention of either aerobics or qigong. Both groups participated in 3 weekly training sessions. Program adherence and safety were monitored at each session. Data were collected at 3 testing sessions, 2 prior to and 1 after the intervention, and included FM symptoms, function, pain, QOL, and fitness measures. RESULTS Thirty patients participated in the trial. Twenty-four patients completed the program; 4 patients dropped out prior to training and 2 dropped out of the aerobics program. Better adherence was reported in the aerobics group than in the qigong group (67% versus 61%). Significant improvements in physical function, functional capacity, QOL, and fatigue were observed in the aerobics group. Anaerobic function, tender point count, pain, and symptom severity improved similarly in both groups. CONCLUSION It is feasible to conduct an exercise intervention trial in children with FM. Children with FM tolerate moderate-intensity exercise without exacerbation of their disease. Significant improvements in physical function, FM symptoms, QOL, and pain were demonstrated in both exercise groups; the aerobics group performed better in several measures compared with the qigong group. Future studies may need larger sample sizes to confirm clinical improvement and to detect differences in fitness in childhood FM.

Efficacy and safety of anakinra therapy in pediatric and adult patients with the autoinflammatory Muckle-Wells syndrome

OBJECTIVE Muckle-Wells syndrome (MWS) is an inherited autoinflammatory disease caused by mutations in the NLRP3 gene that result in excessive interleukin-1 (IL-1) release. It is characterized by severe fevers, rashes, arthralgia, and conjunctivitis, leading to sensorineural deafness and amyloidosis. The recombinant IL-1 receptor antagonist anakinra blocks the biologic activity of IL-1. The aim of this study was to determine the short- and long-term efficacy and safety of anakinra therapy in children and adults with severe MWS. METHODS A single-center observational study was performed. Standardized assessments included clinical features, the Disease Activity Score (DAS) for MWS, classic and novel markers of inflammation, and patient-derived measures of health status. The primary outcome was a score of <10 on the DAS for MWS at 2 weeks and at the last followup visit. Measures of MWS disease activity were investigated using descriptive statistics and paired comparative analysis. RESULTS A total of 12 patients with severe MWS (5 children and 7 adults) received anakinra for a median of 11 months (range 5-14 months). The median followup was 11 months (range 5-14 months). Disease activity was significantly lower in all patients at 2 weeks (P = 0.0005). Organ manifestations of MWS improved, as did all patient-derived measures of health status, markers of inflammation, and hearing loss in 2 of the patients. Levels of the novel neutrophil activation biomarker S100A12 followed clinical disease activity. Treatment was well tolerated, and no serious adverse events were observed. CONCLUSION Anakinra was found to be a safe and effective treatment of severe MWS, leading to a significant improvement in disease activity at 2 weeks as well as long-term. Anakinra therapy should therefore be considered in children and adults with severe MWS disease requiring IL-1 blockade.

Severe Ulcerative Colitis After Rituximab Therapy

B-cell–depletion therapy with rituximab is efficacious against steroid-dependent nephrotic syndrome (NS) in children and adults. Safety data are limited. Results of small studies have suggested that rituximab is usually well tolerated but that adverse events (such as severe mucocutaneous reactions, fatal infusion reactions, progressive multifocal leukoencephalopathy, and bowel perforation) can occur. We report here the first case (to our knowledge) of a pediatric patient with refractory minimal-change NS who developed severe immune-mediated ulcerative gastrointestinal disease 42 days after rituximab therapy. The disease was characterized by deep ulcers throughout the intestines and predominantly affected the colon. The child presented with severe abdominal pain, bloody diarrhea, weight loss, and fever. Her inflammatory markers were significantly elevated. Extensive evaluation revealed no evidence of infections and no characteristics of defined inflammatory bowel disease or Behçet disease. Colonoscopy revealed severe intestinal inflammation with deep ulcers. Histology of the colonic biopsy specimens revealed extensive infiltrates predominantly composed of CD8+ T lymphocytes and evidence of high forkhead box P3 (FOXP3) expression. During this significant gastrointestinal disease, the NS remained quiescent. Corticosteroid therapy successfully controlled the severe immune-mediated intestinal inflammation after rituximab therapy. NS relapsed subsequently when CD19+ and CD20+ B-cell populations recovered.

The role of the initial bone marrow aspirate in the diagnosis of hemophagocytic lymphohistiocytosis.

The identification of hemophagocytosis (HPC) in tissue or bone marrow (BM) represents only one of 5/8 criteria needed for the diagnosis of hemophagocytic lymphohistiocytosis (HLH). Yet, confirmation of HPC in bone marrow aspirates (BMA) is often relied upon to make therapeutic decisions. There is no standardized reporting criteria for the definition of “positive” BMA, and likely differs between institutions. The purpose of this study was to quantify the number of HPC in the initial BMA in patients diagnosed with HLH at our institution.

A followup study of antiphospholipid antibodies and associated neuropsychiatric manifestations in 137 children with systemic lupus erythematosus

OBJECTIVE To determine the prevalence of anticardiolipin antibodies (aCL), anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibodies, and lupus anticoagulant (LAC) in a large cohort of children with systemic lupus erythematosus (SLE), and to evaluate the associations with neuropsychiatric manifestations. METHODS A single-center retrospective cohort study with longitudinal followup of antiphospholipid antibodies (aPL) in 137 children with SLE (25 boys and 112 girls, mean age at diagnosis 13.0 years) was performed. Patients were followed up for a mean of 31 months. RESULTS At the time of diagnosis, 65% of the children were aCL positive, 41% had anti-beta(2)GPI antibodies, and 26% were LAC positive. Analysis of the association between presence of aPL and individual neuropsychiatric manifestations at diagnosis showed a statistically significant association of positive LAC with cerebrovascular disease (5 patients; P = 0.015). A persistently positive aCL was observed in 50%, anti-beta(2)GPI antibodies in 29%, and LAC in 16% of children over time. The prevalence of anti-beta(2)GPI antibodies, but not aCL and LAC, was found to be statistically significantly higher in children with neuropsychiatric disease compared with those without (P = 0.02). Comparison for specific neuropsychiatric manifestations showed a statistically significant association between a persistently positive LAC and chorea (2 patients; P = 0.02). CONCLUSION The prevalence of anti-beta(2)GPI antibodies was found to be higher in the group of SLE patients with neuropsychiatric disease compared with those without. Our data suggest an association between LAC and cerebrovascular disease at the time of SLE diagnosis and chorea over the disease course, but not between aPL and other neuropsychiatric manifestations.