Clinical and Molecular Phenotypes of Low-Penetrance Variants of NLRP3: Diagnostic and Therapeutic Challenges.

OBJECTIVE: Cryopyrin-associated periodic syndromes (CAPS) result from gain-of-function mutations in the NLRP3 gene, which causes excessive release of interleukin-1ß (IL-1ß) and systemic inflammation. While pathogenetic NLRP3 variant phenotypes are well-characterized, low-penetrance NLRP3 variants represent a significant clinical challenge. The aims of this study were to determine the clinical phenotype, the in vitro biologic phenotype, and the effect of anti-IL-1 treatment in patients with low-penetrance NLRP3 variants. METHODS: A multicenter study of consecutive symptomatic patients with low-penetrance NLRP3 variants recruited from 7 centers between May 2012 and May 2013 was performed. The observed findings were transferred into a study database, from which they were extracted for analysis. Controls were patients with a known pathogenetic NLRP3 variant. Clinical presentation and CAPS markers of inflammation were captured. Functional assays of inflammasome activation, including caspase 1 activity, NF-κB release, cell death, and IL-1ß release, were performed. Treatment effects of IL-1 were determined. Comparisons between low-penetrance and pathogenetic NLRP3 variants were performed. RESULTS: The study included 45 patients, 21 of which were female (47%); 26 of the patients (58%) were children. NLRP3 low-penetrance variants identified in the patients were Q703K (n = 19), R488K (n = 6), and V198M (n = 20). In the controls, 28 had pathogenetic NLRP3 variants. Patients with low-penetrance NLRP3 variants had significantly more fever (76%) and gastrointestinal symptoms (73%); eye disease, hearing loss, and renal involvement were less common. Functional inflammasome testing identified an intermediate phenotype in low-penetrance NLRP3 variants as compared to wild-type and pathogenetic NLRP3 variants. All treated patients responded to IL-1 inhibition, with complete response documented in 50% of patients. CONCLUSION: Patients with low-penetrance NLRP3 variants display a distinct clinical phenotype and an intermediate biologic phenotype, including IL-1ß and non-IL-1ß-mediated inflammatory pathway activation.

Outcomes of 847 childhood-onset systemic lupus erythematosus patients in three age groups.

Objective The objective of this study was to assess outcomes of childhood systemic lupus erythematosus (cSLE) in three different age groups evaluated at last visit: group A early-onset disease (<6 years), group B school age (≥6 and <12 years) and group C adolescent (≥12 and <18 years). Methods An observational cohort study was performed in ten pediatric rheumatology centers, including 847 cSLE patients. Results Group A had 39 (4%), B 395 (47%) and C 413 (49%). Median disease duration was significantly higher in group A compared to groups B and C (8.3 (0.1-23.4) vs 6.2 (0-17) vs 3.3 (0-14.6) years, p < 0.0001). The median Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR-DI) (0 (0-9) vs 0 (0-6) vs 0 (0-7), p = 0.065) was comparable in the three groups. Further analysis of organ/system damage revealed that frequencies of neuropsychiatric (21% vs 10% vs 7%, p = 0.007), skin (10% vs 1% vs 3%, p = 0.002) and peripheral vascular involvements (5% vs 3% vs 0.3%, p = 0.008) were more often observed in group A compared to groups B and C. Frequencies of severe cumulative lupus manifestations such as nephritis, thrombocytopenia, and autoimmune hemolytic anemia were similar in all groups ( p > 0.05). Mortality rate was significantly higher in group A compared to groups B and C (15% vs 10% vs 6%, p = 0.028). Out of 69 deaths, 33/69 (48%) occurred within the first two years after diagnosis. Infections accounted for 54/69 (78%) of the deaths and 38/54 (70%) had concomitant disease activity. Conclusions This large multicenter study provided evidence that early-onset cSLE group had distinct outcomes. This group was characterized by higher mortality rate and neuropsychiatric/vascular/skin organ damage in spite of comparable frequencies of severe cumulative lupus manifestations. We also identified that overall death in cSLE patients was an early event mainly attributed to infection associated with disease activity.

Recurrent lipoatrophic panniculitis of children.

BACKGROUND: Recurrent panniculitis in children with lipoatrophy has been loosely described and reported under different names, but has never been systematically evaluated by immunohistochemical stains. OBJECTIVE: To depict the profile of children with recurrent idiopathic panniculitis. METHODS: Study of clinical, histopathological and immunohistochemical features in five cases with recurrent idiopathic panniculitis. RESULTS: Five children with repeated attacks of painful subcutaneous nodules in association with fever, malaise and abdominal pain or arthralgia, with subsequent lipoatrophy were reviewed. In two patients, extensive involvement led to loss of the cutaneous fatty tissue. Laboratory abnormalities included increased acute phase reactants, leukocytosis with mild neutrophilia, microcytic anaemia and elevated liver enzymes. Histopathology showed lobar panniculitis without vasculitis and with a mixed infiltrate, composed of neutrophils, mononuclear cells, lymphocytes, macrophages and myeloid cells. Neutrophils and myeloid cells were more prominent in early lesions, whereas macrophages predominated in late stages, leading to lipophagia and lipoatrophy. Immunohistochemistry showed positive staining for myeloperoxidase around the necrotic adipocytes in early stages and CD68/PGM1 macrophages in late stages. Intense STAT1 staining was observed in the inflammatory infiltrate. All patients improved with methotrexate and corticosteroids. CONCLUSION: We present five cases of lobar panniculitis and lipoatrophy in childhood. The clinico-pathologic presentation shares features with other autoinflammatory diseases.

Genetically defined autoinflammatory diseases.

Autoinflammatory diseases are hyperinflammatory, immune dysregulatory conditions that typically present in early childhood with fever and rashes and disease-specific patterns of organ inflammation. This review provides a historic background of autoinflammatory disease research, an overview of the currently genetically defined autoinflammatory diseases, and insights into treatment strategies derived from understanding of the disease pathogenesis. The integrative assessment of autoinflammatory conditions led to the identification of innate pro-inflammatory cytokine 'amplification loops' as the cause of the systemic and organ-specific disease manifestations, which initially centered around increased IL-1 production and signaling. More recently, additional innate pro-inflammatory cytokine amplification loops resulting in increased Type I IFN, IL-17, IL-18, or IL-36 signaling or production have led to the successful use of targeted therapies in some of these conditions. Clinical findings such as fever patterns, type of skin lesions, genetic mutation testing, and the prevalent cytokine abnormalities can be used to group autoinflammatory diseases.

Activated STING in a vascular and pulmonary syndrome.

BACKGROUND: The study of autoinflammatory diseases has uncovered mechanisms underlying cytokine dysregulation and inflammation. METHODS: We analyzed the DNA of an index patient with early-onset systemic inflammation, cutaneous vasculopathy, and pulmonary inflammation. We sequenced a candidate gene, TMEM173, encoding the stimulator of interferon genes (STING), in this patient and in five unrelated children with similar clinical phenotypes. Four children were evaluated clinically and immunologically. With the STING ligand cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), we stimulated peripheral-blood mononuclear cells and fibroblasts from patients and controls, as well as commercially obtained endothelial cells, and then assayed transcription of IFNB1, the gene encoding interferon-ß, in the stimulated cells. We analyzed IFNB1 reporter levels in HEK293T cells cotransfected with mutant or nonmutant STING constructs. Mutant STING leads to increased phosphorylation of signal transducer and activator of transcription 1 (STAT1), so we tested the effect of Janus kinase (JAK) inhibitors on STAT1 phosphorylation in lymphocytes from the affected children and controls. RESULTS: We identified three mutations in exon 5 of TMEM173 in the six patients. Elevated transcription of IFNB1 and other gene targets of STING in peripheral-blood mononuclear cells from the patients indicated constitutive activation of the pathway that cannot be further up-regulated with stimulation. On stimulation with cGAMP, fibroblasts from the patients showed increased transcription of IFNB1 but not of the genes encoding interleukin-1 (IL1), interleukin-6 (IL6), or tumor necrosis factor (TNF). HEK293T cells transfected with mutant constructs show elevated IFNB1 reporter levels. STING is expressed in endothelial cells, and exposure of these cells to cGAMP resulted in endothelial activation and apoptosis. Constitutive up-regulation of phosphorylated STAT1 in patients' lymphocytes was reduced by JAK inhibitors. CONCLUSIONS: STING-associated vasculopathy with onset in infancy (SAVI) is an autoinflammatory disease caused by gain-of-function mutations in TMEM173. (Funded by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases; ClinicalTrials.gov number, NCT00059748.).

Organ-specific autoantibodies and autoimmune diseases in juvenile systemic lupus erythematosus and juvenile dermatomyositis patients.

OBJECTIVES: To our knowledge, no study assessed simultaneously a variety of organ-specific autoantibodies and the prevalence of organ-specific autoimmune diseases in juvenile systemic lupus erythematosus (JSLE) and juvenile dermatomyositis (JDM). Therefore, the purpose of this study was to evaluate organ-specific autoantibodies and autoimmune diseases in JSLE and JDM patients. METHODS: Forty-one JSLE and 41 JDM patients were investigated for autoantibodies associated with autoimmune hepatitis, primary biliary cirrhosis, type 1 diabetes mellitus (T1DM), autoimmune thyroiditis (AT), autoimmune gastritis and coeliac disease (CD). Patients with positive antibodies were investigated for the respective organ-specific autoimmune diseases. RESULTS: Mean age at diagnosis was higher in JSLE compared to JDM patients (10.3±3.4 vs. 7.3±3.1years, p=0.0001). The frequencies of organ-specific autoantibodies were similar in JSLE and JDM patients (p>0.05). Of note, a high prevalence of T1DM and AT autoantibodies was observed in both groups (20% vs. 15%, p=0.77 and 24% vs. 15%, p=0.41; respectively). Higher frequencies of ANA (93% vs. 59%, p=0.0006), anti-dsDNA (61% vs. 2%, p<0.0001), anti-Ro, anti-Sm, anti-RNP, anti-La and IgG-aCL were observed in JSLE (p<0.05). Organ-specific autoimmune diseases were evidenced only in JSLE patients (24% vs. 0%, p=0.13). Two JSLE patients had T1DM associated with Hashimoto thyroiditis and another had subclinical thyroiditis. Another JSLE patient had CD diagnosis based on iron deficiency anaemia, anti-endomysial antibody, duodenal biopsy compatible to CD and response to a gluten-free diet. CONCLUSIONS: Organ-specific diseases were observed solely in JSLE patients and required specific therapy. The presence of these antibodies recommends the evaluation of organ-specific diseases and a rigorous follow-up.

Complement and antibody primary immunodeficiency in juvenile systemic lupus erythematosus patients.

OBJECTIVE: To evaluate the frequency of primary immunodeficiencies (PID) in juvenile systemic lupus erythematosus (JSLE) patients. METHODS: Some 72 JSLE patients were analyzed for levels of immunoglobulin classes and IgG subclasses and early components of the classical complement pathway. Determination of C4 gene copy number (GCN) and detection of type I C2 deficiency (D) were also performed. RESULTS: PID was identified in 16 patients (22%): C2D in three, C4D in three, C1qD in two, IgG2D (<20 mg/dl) in four, IgAD (<7 mg/dl) in three, and IgMD (<35 mg/dl) in three; one of these patients presented IgA, C2 and C4D. Two patients had low C4 GCN and two had type I C2D. Demographic data, family history of autoimmune disease and PID, JSLE clinical findings, occurrence of infections, disease activity and therapies were similar in patients with and without PID (p > 0.05). Remarkably, the median of Systemic Lupus International Collaborating Clinics/ACR-damage index (SLICC/ACR-DI) was significantly higher in JSLE patients with PID compared with patients without these abnormalities (p = 0.0033), likewise the high frequency of SLICC/ACR-DI > 1 (p = 0.023). CONCLUSIONS: A high frequency of PID was observed in JSLE patients, suggesting that these defects may contribute to lupus development. Our findings indicate that these two groups of PID should be investigated in severe pediatric lupus.

Stevens-Johnson syndrome in a juvenile systemic lupus erythematosus patient.

Stevens-Johnson syndrome (SJS) is a severe and rare immune-mediated cutaneous reaction usually induced by drugs or infections. Few case reports have demonstrated SJS associated with adult systemic lupus erythematosus (SLE), and rarely in juvenile SLE (JSLE) patients. However, to the best of our knowledge the prevalence of this life-threatening cutaneous disease in the pediatric lupus population has not been studied. Therefore, from January 1983 to December 2010, 5508 patients were followed-up at the Pediatric Rheumatology Unit of our University Hospital and 279 (5%) of them met the American College of Rheumatology (ACR) classification criteria for SLE. Only one (0.4%) of our JSLE patients had SJS and was described. This female patient was diagnosed with JSLE at 14 years old. After four years of follow-up, she was hospitalized due to congestive heart failure and renal insufficiency. During hospitalization, the patient developed sepsis with positive blood culture for Stenotrophomonas maltophilia and was treated with vancomycin and meropenem. One week later, she developed septic shock and chest x-ray showed acute widespread pulmonary infiltrate. Antimicrobials were changed to linezolid and trimethoprim-sulfamethoxazole. After four days, the blood culture isolated Staphylococcus aureus resistant to vancomycin, and she presented with erythematous cutaneous lesions involving her face, trunk, and limbs, with evolution in a few hours to diffuse hemorrhagic vesicles and blisters. Epidermal detachment was observed on 5% of the body surface area. Concomitantly, she had conjunctivitis, cheilitis, oral erosions, and hemorrhagic crust on the nasal mucosa. Vulva, vagina, and perianal erosions were also evidenced. The diagnosis of SJS was established and intravenous immunoglobulin was promptly administered. Three days later, she died of pulmonary hemorrhage. The autopsy findings demonstrated generalized infection and widespread subepidermal detachment with necrotic keratinocytes. In conclusion, SJS is a rare and severe vesiculobullous disease in a pediatric lupus population and is probably associated with infections and drug therapy.

Common variable immunodeficiency associated with hepatosplenic T-cell lymphoma mimicking juvenile systemic lupus erythematosus.

Common variable immunodeficiency (CVID) is a heterogeneous disorder with susceptibility to infections, autoimmune manifestations, and cancer. To our knowledge, CIVD with T-cell lymphoma mimicking juvenile systemic lupus erythematosus (JSLE) was not described in the literature, and one case was reported herein. An 8-year-old female was admitted in our Pediatric Immunology Unit with a clinical history of hypogammaglobulinemia, recurrent upper respiratory infections, and pneumonias. She had a marked decrease of three serum immunoglobulin isotypes, and the diagnosis of CVID was established. At the age of 17 years, she presented with oral ulceration, nonerosive arthritis, nephritis, serositis, cytopenia, positive antiphospholipid antibodies, and positive antinuclear antibody fulfilling the American College of Rheumatology (ACR) criteria for SLE. She was treated with intravenous methylprednisolone for three consecutive days, and intravenous immunoglobulin, and maintenance therapy of chloroquine, azathioprine and prednisone 40 mg/day. Two months later, she died of septic shock secondary to acute pneumonia. The necropsy showed hepatosplenic T-cell lymphoma with diffuse involvement of bone marrow, spleen, liver, and lungs. The lymphoma cells were positive for CD3 immunostaining and negative for CD20 and lysozyme. In conclusion, the association of CVID and hepatosplenic T-cell lymphoma may simulate JSLE diagnosis.

Chronic polyarthritis as the first manifestation of juvenile systemic lupus erythematosus patients.

OBJECTIVE: To evaluate the prevalence of chronic polyarthritis in juvenile systemic lupus erythematosus (JSLE) and to describe the manifestations, treatments, and outcomes in these patients. METHODS: From January 1983 to July 2010, 5419 patients were followed up at the Pediatric Rheumatology Unit of the University Hospital and 271 (5%) of them had JSLE (American College of Rheumatology [ACR] criteria). 'Rhupus' was classified as the overlap of juvenile idiopathic arthritis (International League of Associations for Rheumatology [ILAR] criteria) and JSLE. We evaluated demographic data, polyarthritis and other clinical manifestations, disease activity and damage, laboratory exams, radiographic findings, treatments, and outcomes. RESULTS: The prevalence of chronic polyarthritis in this JSLE population was 2.6% (7/271). This articular involvement was the initial manifestation in all seven JSLE patients. The median duration of chronic polyarthritis was 11 months (range 2-15 months). Interestingly, rhupus with chronic polyarthritis and limitation of movement, presence of rheumatoid factor, autoantibodies, and/or radiographic abnormalities (juxtaarticular osteopenia, joint-space narrowing, or erosions) was evidenced in three patients. No patient had deformities of hands and feet associated with Jaccoud's arthropathy or osteonecrosis. All patients were treated with nonsteroidal anti-inflammatory drugs (NSAIDs, naproxen 10-15 mg/kg/day) when polyarthritis diagnosis was established. Prednisone and antimalarials were administered at JSLE diagnosis. The three non-responsive rhupus patients were treated in conjunction with immunosuppressive drugs (methotrexate, azathioprine, and/or cyclosporine). CONCLUSIONS: Chronic polyarthritis was a rare lupus manifestation in active pediatric patients. The interesting overlap between chronic arthritis and lupus, called rhupus suggests a new entity with a different clinical profile and a poor response to treatment with NSAIDs alone. In addition, the occurrence of this association in JSLE patients could be classified as a clinical sub-group of JSLE with possible specific genetic determinants.

Irreversible blindness in juvenile systemic lupus erythematosus.

Blindness caused by severe vasculitis or uveitis is rare in juvenile systemic lupus erythematosus (JSLE) patients. In a 27-year period, 5367 patients were followed at our Paediatric Rheumatology Division and 263 (4.9%) patients had JSLE (American College of Rheumatology criteria). Of note, two (0.8%) of them had irreversible blindness. One of them presented with cutaneous vasculitis and malar rash, associated with pain and redness in both eyes, impairment of visual acuity due to iridocyclitis and severe retinal vasculitis with haemorrhage. Another patient had peripheral polyneuropathy of the four limbs and received immunosuppressive drugs. Three weeks later, she developed diffuse herpes zoster associated with acute blindness due to bilateral retinal necrotizing vasculitis compatible with varicella zoster virus ocular infection. Despite prompt treatment, both patients suffered rapid irreversible blindness. In conclusion, irreversible blindness due to retinal vasculitis and/or uveitis is a rare and severe lupus manifestation, particularly associated with disease activity and viral infection.

Acute pancreatitis in juvenile systemic lupus erythematosus: a manifestation of macrophage activation syndrome?

Acute pancreatitis (AP) is a rare and life-threatening manifestation of juvenile systemic lupus erythematosus (JSLE). The objective of this study was to evaluate the prevalence and clinical features of AP in our JSLE population. AP was defined according to the presence of abdominal pain or vomiting associated to an increase of pancreatic enzymes and/or pancreatic radiological abnormalities. Of note, in the last 26 years, 5367 patients were followed up at our Pediatric Rheumatology Unit and 263 (4.9%) of them had JSLE diagnosis (ACR criteria). AP was observed in 4.2% (11/263) of JSLE patients. The median of age of the JSLE patients at AP diagnosis was 12.4 years (8.8-17.9). All of them had lupus disease activity at AP onset. Three patients were receiving corticosteroids before AP diagnosis. Interestingly, 10/11 JSLE patients fulfilled preliminary guidelines for macrophage activation syndrome, three of them with macrophage hemophagocytosis in bone marrow aspirate and hyperferritinemia. The hallmark of this syndrome is excessive activation and proliferation of T lymphocytes and macrophages with massive hypersecretion of proinflammatory cytokines and clinically it is characterized by the occurrence of unexplained fever, cytopenia and hyperferritinemia. AP treatment was mainly based on intravenous methylprednisolone. Four JSLE patients with AP died and two developed diabetes mellitus. In conclusion, AP was a rare and severe manifestation in active pediatric lupus. The association between AP and macrophage activation syndrome suggests that the pancreas could be a target organ of this syndrome and that pancreatic enzyme evaluation should also be carried out in all patients.

Anti-C1q antibodies in juvenile-onset systemic lupus erythematosus.

The objective of this study was to evaluate the presence of anti-C1q antibodies Hospital Israelita Albert Einstein Research Institute, São Paulo, Brazil in 67 juvenile systemic lupus erythematosus (JSLE) patients and 26 healthy controls and to assess the association of these antibodies with disease activity, nephritis, and presence of anti-double-stranded (ds)DNA. Anti-C1q antibodies were detected by ELISA. A higher frequency of anti-C1q antibodies was observed in JSLE patients compared to controls (20% vs. 0%, P = 0.016). Specificity of these antibodies was 100%[95% confidence interval (CI) 86.7-100%] and sensitivity was 19.4% (95% CI 10.7-30.8%) for a lupus diagnosis. The median anti-C1q antibodies was higher in JSLE patients compared to controls [median (range) 9.4 (5.5-127) vs. 7.3 (5-20) units, P = 0.004]. Remarkably, a positive Spearman's coefficient was found between anti-dsDNA and anti-C1q units (r = 0.42, P = 0.0004, 95% CI 0.19-0.60). Our results confirm a low frequency of anti-C1q antibody in our lupus populations, but the presence of anti-Clq antibodies appears to be a good marker for JSLE diagnosis.