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OBJECTIVE: Pediatric rheumatology faces a looming supply-demand crisis. While strategies have been proposed to address the supply shortfall, investigation into the increased demand for pediatric rheumatic care has been limited. Herein, we analyze new patient visits to a large tertiary care pediatric rheumatology center to identify emerging trends in referrals and areas for potential intervention to meet this increased demand. METHODS: All patients referred to and seen by the University of Alabama at Birmingham Pediatric Rheumatology Division between January 2019 and December 2021 for a new patient evaluation were identified. Patient data was retrospectively abstracted, de-identified, and analyzed to develop trends in referrals and frequency of rheumatic disease, non-rheumatic disease, and specific diagnoses. RESULTS: During the study period, 2638 patients were referred to and seen in by the pediatric rheumatology division. Six hundred and ten patients (23.1%) were diagnosed with rheumatic disease. The most common rheumatic disease was juvenile idiopathic arthritis (JIA) at 45.6%, followed by primary Raynaud phenomenon (7.4%), recurrent fever syndromes (6.9%), vasculitides (6.7%), and inflammatory eye disease (6.2%). Of the 2028 patients (76.9%) diagnosed with a non-rheumatic condition, benign musculoskeletal pain was the most common (61.8%), followed by a combination of somatic conditions (11.6%), and non-inflammatory rash (7.7%). CONCLUSION: In this analysis of new patient referrals to a large pediatric rheumatology center, the majority of patients were diagnosed with a non-rheumatic condition. As a worsening supply-demand gap threatens the field of pediatric rheumatology, increased emphasis should be placed on reducing non-rheumatic disease referrals.
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Arthrite juvénile , Rhumatismes , Rhumatologie , Enfant , Humains , Études rétrospectives , Rhumatismes/diagnostic , Rhumatismes/épidémiologie , Arthrite juvénile/diagnostic , Orientation vers un spécialisteRÉSUMÉ
Juvenile idiopathic arthritis is a common chronic childhood disease, with a prevalence of â¼1 per 1000 children. Arthritis can also be a manifestation of other inflammatory conditions, such as inflammatory bowel disease (IBD). Studies suggest a genetic influence in IBD, including mutations in CARD8. CARD8 is a negative regulator of the NLRP3 inflammasome, and mutations in this gene are hypothesized to induce gastrointestinal inflammation. However, few studies have evaluated this association and most have included a limited number of patients. We present a case of a pediatric patient with IBD-associated arthritis and a CARD8 mutation. Our patient is a 7-year-old female who was initially evaluated by rheumatology for right leg pain and an intermittent rash. She had clinically active arthritis on exam and was started on methotrexate with only slight improvement. Additional workup revealed sacroiliitis by imaging, elevated inflammatory markers, no anemia, and a variant of unknown significance in CARD8. Adalimumab was recommended but before medication initiation, our patient's symptoms progressed to worsening joint pain, fatigue, fevers, nausea, vomiting, diarrhea, and hematochezia. Infectious testing was negative. Fecal calprotectin was >8000 µg/g. A colonoscopy revealed IBD most consistent with Crohn's disease. Adalimumab was ultimately added, and she has responded well to combination therapy. This case report highlights the association between CARD8 mutations and IBD, especially in the setting of IBD-associated arthritis.
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Arthrite juvénile , Maladie de Crohn , Maladies inflammatoires intestinales , Femelle , Humains , Enfant , Arthrite juvénile/complications , Arthrite juvénile/diagnostic , Arthrite juvénile/traitement médicamenteux , Adalimumab/génétique , Maladies inflammatoires intestinales/complications , Maladies inflammatoires intestinales/diagnostic , Maladies inflammatoires intestinales/traitement médicamenteux , Maladie de Crohn/complications , Maladie chronique , Mutation , Protéines tumorales/génétique , Protéines adaptatrices de signalisation CARD/génétiqueRÉSUMÉ
OBJECTIVE: Many children with chronic musculoskeletal pain conditions experience stigma which can have negative downstream consequences. This study compares ratings of clinical pain (current pain intensity and pain interference), experimental pain (temporal summation, cold water tolerance, and cold pain intensity), and pain-related stigma among three groups of youth with rheumatic conditions. The relations among ratings of pain-related stigma and pain variables were explored. METHODS: Eighty-eight youth aged 8-17 years with a diagnosis of juvenile idiopathic arthritis (JIA = 32), juvenile fibromyalgia (JFM = 31), or non-specific chronic pain (NSCP = 25) completed measures of clinical pain ratings (average 7-day pain intensity, day of assessment pain (DoA), and pain interference), experimental pain (cold pain tolerance, cold pain intensity, and temporal summation of mechanical pain), and pain-related stigma. Data analysis compared pain-related stigma and pain ratings across the three groups and examined the relations among pain-related stigma and pain ratings. RESULTS: Youth with JFM reported higher ratings of clinical pain and pain-related stigma than their counterparts with NSCP or JIA. However, there were no differences in experimental pain. Pain-related stigma was associated with greater ratings of pain interference, particularly for those with JIA and NSCP. Pain-related stigma was also associated with greater average daily pain intensity but not DoA. CONCLUSION: Youth with medically unexplained pain report greater stigma and worse pain than their peers; thus, robust assessment of pain in this population is necessary. Future work should longitudinally explore the impact of pain-related stigma on pain outcomes and treatment responses.
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BACKGROUND: Primary (familial) hemophagocytic lymphohistiocytosis (pHLH) is a potentially lethal syndrome of infancy, caused by genetic defects in natural killer (NK) cell and CD8 T cell cytotoxicity, leading to hyperinflammation, elevated cytokine levels, and a disorganized immune response resulting in multi-organ system failure and frequently death. Secondary HLH (sHLH) can be triggered in the setting of malignances, diseases of chronic immune system activation, or by infectious etiologies. While pHLH is usually a result of homozygous gene mutations, monoallelic hypomorphic and dominant-negative mutations in pHLH genes have been implicated in sHLH. Coronavirus disease 2019 (COVID-19) has been an omnipresent viral infection since its arrival, and severe cases can present with cytokine storm and have clinical features and laboratory findings consistent with sHLH. Herein, we report an adolescent with severe COVID-19, decreased NK cell function, and features of sHLH. Her genetic evaluation identified a monoallelic missense mutation in the pHLH gene STXBP2, and NK cell assays of her blood showed decreased cytolysis and degranulation ex vivo. METHODS: Patient data was extracted through an electronic medical record review. Using a lentiviral approach, the patient's STXBP2 mutation and wild-type (WT) STXBP2 were separately transduced into the NK-92 human NK cell line. The WT and mutant STXBP2 transduced NK-92 cells were stimulated with NK-sensitive K562 erythroleukemia target cells in vitro, and NK cell degranulation and cytolysis were measured via CD107a expression and Live/Dead near-IR dye, respectively. RESULTS: Compared to WT STXBP2, the patient's STXBP2 mutation caused significantly decreased NK cell cytolysis and associated degranulation in vitro. CONCLUSION: These findings add weight to the hypothesis that some severe cases of COVID-19 may be accompanied by sHLH and hyperinflammation, especially in the setting of heterozygous pHLH genetic mutations. This has implications both diagnostically and therapeutically for severe COVID-19.
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OBJECTIVE: To assess the benefit of the recombinant human interleukin-1 receptor antagonist anakinra in treating pediatric patients with secondary hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) associated with rheumatic and nonrheumatic conditions. METHODS: A retrospective chart review of all anakinra-treated patients with secondary HLH/MAS was performed at Children's of Alabama from January 2008 through December 2016. Demographic, clinical, laboratory, and genetic characteristics, outcomes data, and information on concurrent treatments were collected from the records and analyzed using appropriate univariate statistical approaches to assess changes following treatment and associations between patient variables and outcomes. RESULTS: Forty-four patients with secondary HLH/MAS being treated with anakinra were identified in the electronic medical records. The median duration of hospitalization was 15 days. The mean pretreatment serum ferritin level was 33,316 ng/ml and dropped to 14,435 ng/ml (57% decrease) within 15 days of the start of anakinra treatment. The overall mortality rate in the cohort was 27%. Earlier initiation of anakinra (within 5 days of hospitalization) was associated with reduced mortality (P = 0.046), whereas thrombocytopenia (platelet count <100,000/µl) and STXBP2 mutations were both associated with increased mortality (P = 0.008 and P = 0.012, respectively). In considering patients according to their underlying diagnosis, those with systemic juvenile idiopathic arthritis (JIA) had the lowest mortality rate, with no deaths among the 13 systemic JIA patients included in the study (P = 0.006). In contrast, those with an underlying hematologic malignancy had the highest mortality rate, at 100% (n = 3). CONCLUSION: These findings suggest that anakinra appears to be effective in treating pediatric patients with non-malignancy-associated secondary HLH/MAS, especially when it is given early in the disease course and when administered to patients who have an underlying rheumatic disease.
Sujet(s)
Antagoniste du récepteur à l'interleukine-1/usage thérapeutique , Lymphohistiocytose hémophagocytaire/traitement médicamenteux , Syndrome d'activation macrophagique/traitement médicamenteux , Adolescent , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Études rétrospectives , Résultat thérapeutiqueRÉSUMÉ
BACKGROUND: Henoch-Schonlein purpura (HSP) is a small vessel vasculitis that is characterized by non-thrombocytopenic purpura, abdominal pain, arthritis, and glomerulonephritis. Typically, HSP is self-limited requiring only supportive care, but more severe cases may require corticosteroid (CS) treatment. Rarely, a subset of these patients has persistent rash, arthritis, abdominal involvement, or renal disease despite treatment with CS, or has disease recurrence on CS tapering. Refractory HSP has been effectively treated with a variety of CS sparing therapies. For life-threatening refractory HSP, the B cell depleting agent, rituximab (RTX), has been reported as beneficial for children with substantial renal or central nervous system involvement. However, RTX use for children with less severe HSP, but chronic CS dependent disease refractory to CS sparing immunomodulatory agents, has been less well explored. Herein, we describe 8 children treated with RTX for chronic refractory HSP and report a reduction in recurrent hospitalizations and eventual CS discontinuation. METHODS: This is a retrospective analysis of eight children who were treated with RTX for chronic CS dependent HSP during the years 2006-2014 at a single institution. A chart review of the electronic medical record was performed to determine the presenting symptoms, the type and duration of treatment received, and the number of hospitalizations prior to and after RTX. The number of hospitalizations and oral corticosteroid burden were analyzed using the Wilcoxon signed rank test. RESULTS: Prior to receiving RTX, seven patients had at least one hospitalization for HSP (median 1.5, range 0-3). Following RTX, only two patients were hospitalized, each a single time for recurrent abdominal pain. The median oral CS burden was 0.345 mg/kg/day before RTX and 0 mg/kg/day at 6 months (p = 0.078), 1 year (p = 0.0625), and 2 years (p = 0.03) following RTX infusion. Seven out of eight children met remission criteria, defined as no active rash, arthritis, nephritis (hematuria and proteinuria), or gastrointestinal distress following RTX. No serious adverse events were noted. CONCLUSION: Overall, RTX effectively reduced the number of hospital admissions and oral CS burden. RTX also helped most all children achieve clinical remission. RTX appears to be an effective and safe alternative for chronic CS dependent and immunomodulatory refractory childhood HSP.
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Glucocorticoïdes/administration et posologie , /traitement médicamenteux , Facteurs immunologiques/usage thérapeutique , Rituximab/usage thérapeutique , Adolescent , Enfant , Enfant d'âge préscolaire , Maladie chronique , Femelle , Hospitalisation/statistiques et données numériques , Humains , Nourrisson , Mâle , Études rétrospectivesRÉSUMÉ
Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder caused by heterozygous mutations in the MAFB gene (v-maf musculoaponeurotic fibrosarcoma oncogene ortholog B). This is an autosomal dominant condition with a high frequency of sporadic cases. MCTO is characterized by osteolysis of the carpal, metacarpal, and tarsal bones beginning in early childhood with musculoskeletal rheumatologic symptoms such as pain and disability. Renal involvement can be seen in more than half of the patients; from ages 16 months to 42 years and manifests from proteinuria to end-stage renal failure requiring renal transplantation. The association of MAFB gene mutations with this genetic condition has aided in understanding the pathophysiology of the disease. We report here a 7-year-old Caucasian boy and his 33-year-old mother diagnosed with MCTO, with the boy having concomitant juvenile idiopathic arthritis. He was initially diagnosed with arthritis at age 5 years based on bilateral wrist synovial swelling, morning stiffness, and weakness with family history of his mother being diagnosed with erosive psoriatic arthritis leading to limb deformities. Initial therapy for the boy included methotrexate and infliximab with moderate response. Later, during the course of his disease, he underwent a genetic evaluation at age 7 years for history of learning disabilities and dysmorphic features. Maternal evaluation and radiographic examination led to a clinical diagnosis of MCTO in the mother, and subsequent testing for MAFB gene in the son revealed a mutation at c.206C > T (p.Ser69Leu), the most commonly reported genetic change in MCTO. Nevertheless, further imaging still confirmed ongoing arthritis, and therapy was adjusted based on its progression including abatacept, tocilizumab, and pamidronate. Our report highlights the possibility of concomitant inflammatory arthropathy in MCTO.
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BACKGROUND: Acute Multifocal Hemorrhagic Retinal Vasculitis (AMHRV) is a rare disease with unknown incidence that presents with abrupt onset of visual loss associated with retinal vasculitis, retinal hemorrhage, non-confluent posterior retinal infiltrates, vitreous cellular inflammation and papillitis in, otherwise, healthy adult individuals. The reported treatment options for Acute Multifocal Hemorrhagic Retinal Vasculitis are oral corticosteroids, intravitreal ganciclovir and laser photocoagulation or vitrectomy. We report a child with Acute Multifocal Hemorrhagic Retinal Vasculitis who was treated with aggressive immunosuppressive therapy resulting in a favorable visual outcome. CASE PRESENTATION: A retrospective case report of a 10-year-old African American girl who developed unilateral Acute Multifocal Hemorrhagic Retinal Vasculitis, which later on progressed bilaterally. We conducted a review of the clinical, laboratory and photographic records to evaluate her functional and anatomic outcome after aggressive immunosuppressive treatment. During the first 4 months of treatment of OD with intravitreal ganciclovir, intravitreal dexamethasone and systemic prednisone, the change in vision in OD improved from light perception (LP) to counting fingers (CF). During the next 18 months of aggressive systemic treatment of OD and the newly affected left eye (OS), the change in vision improved from CF in OD and CF in OS to 20/200 in OD and 20/80 in OS. Management during the 18-month interval included rituximab infusions, cyclophosphamide/methylprednisolone infusions, prednisone and mycophenolate. CONCLUSIONS: This is the first reported case of Acute Multifocal Hemorrhagic Retinal Vasculitis occurring in a child. Ophthalmologists should be aware of the need to treat severe Acute Multifocal Hemorrhagic Retinal Vasculitis with aggressive immunosuppressive agents in collaboration with rheumatologists to obtain the best possible visual outcome.
Sujet(s)
Cyclophosphamide/usage thérapeutique , Immunosuppresseurs/usage thérapeutique , Hémorragie de la rétine/traitement médicamenteux , Vascularite rétinienne/traitement médicamenteux , Maladie aigüe , Anti-inflammatoires/usage thérapeutique , Enfant , Association de médicaments , Femelle , Humains , Résultat thérapeutiqueRÉSUMÉ
Herein we report successful treatment of an adolescent Caucasian female with severe progressive localized scleroderma (mixed subtype, including generalized morphea and linear scleroderma of the trunk/limb) using infliximab and leflunomide. The patient demonstrated improvement after the first 9 months of therapy based on her clinical examination, objective measures, and patient and parent global assessments. Infliximab is a potential treatment option for pediatric localized scleroderma patients who have progression of disease or who are unable to tolerate the side effect profile of more standard systemic therapy. Larger longitudinal studies or case series are needed to confirm and further investigate infliximab's role in localized scleroderma.
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Systemic polyarteritis nodosa (PAN) is a vasculitis that affects small to medium-size arteries. Onset in childhood is rare and can cause significant morbidity. Often, cutaneous manifestations can provide early clues toward diagnosis. This article describes a case of childhood systemic PAN that presented with fever, a necrotic skin lesion, and oral ulceration. Intestinal perforation complicated this case. Prompt recognition of childhood PAN is important to prevent serious complications.
Sujet(s)
Immunosuppresseurs/usage thérapeutique , Polyartérite noueuse/diagnostic , Polyartérite noueuse/traitement médicamenteux , Enfant d'âge préscolaire , Côlon/anatomopathologie , Diagnostic précoce , Humains , Mâle , Morbidité , Polyartérite noueuse/anatomopathologie , Peau/anatomopathologieRÉSUMÉ
OBJECTIVE: To review our experiences with high-dose infliximab (IFX) to treat juvenile idiopathic arthritis (JIA). We routinely use high doses of IFX (10-20 mg/kg) in children with recalcitrant or highly active JIA. Although biologics have revolutionized treatment of JIA, many patients have active disease despite therapy. Studies have shown benefits of high-dose IFX in several conditions, including inflammatory bowel disease, psoriasis, and idiopathic uveitis. The safety and effectiveness of high-dose IFX have not been evaluated in JIA. METHODS: We performed a retrospective review of children with JIA who received IFX ≥ 10 mg/kg. We recorded all serious adverse events (SAE), medically important infections, and infusion reactions. We also recorded the physician global assessment of disease activity (MD global) and active joint count (AJC) at initiation of high-dose IFX and 3, 6, and 12 months thereafter. RESULTS: Fifty-eight subjects received a total of 1064 infusions over 95 person-years. There were a total of 9 SAE (9.5/100 person-yrs), 7 of which were potentially related to therapy, and 6 infusion reactions (0.5%), none constituting anaphylaxis. Statistically significant improvements were observed in the AJC (median 0, range 0-31, vs 2, 0-39) and MD global (12, 2-31, vs 22, 5-80) over the first year. CONCLUSION: High-dose IFX appears safe in the management of JIA. Future prospective controlled studies are necessary to evaluate its safety and efficacy.
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Anticorps monoclonaux/usage thérapeutique , Antirhumatismaux/usage thérapeutique , Arthrite juvénile/traitement médicamenteux , Adolescent , Anticorps monoclonaux/administration et posologie , Anticorps monoclonaux/effets indésirables , Antirhumatismaux/administration et posologie , Antirhumatismaux/effets indésirables , Enfant , Enfant d'âge préscolaire , Association de médicaments , Femelle , Humains , Nourrisson , Infliximab , Mâle , Méthotrexate/administration et posologie , Méthotrexate/effets indésirables , Méthotrexate/usage thérapeutique , Études rétrospectives , Résultat thérapeutiqueRÉSUMÉ
We report two pediatric female patients with systemic lupus erythematosus (SLE) who presented with decreased vision. Both patients were found to have retinal vasculitis and occlusive disease. The first patient also presented with vitreous hemorrhage and later non-arteritic ischemic optic neuropathy. She was treated with panretinal photocoagulation and steroid therapy and later in her disease course was treated with rituximab and cyclophosphamide. Her vision remained decreased. The second patient was treated with rituximab and monthly cyclophosphamide infusions early in her disease course, and her vision improved dramatically. The difference in the presentations and outcomes of these two pediatric patients with SLE highlights the spectrum of severity of SLE retinopathy. We suggest that early recognition of disease and early intervention with B-cell depletion therapy in addition to a traditional cytotoxic agent should be considered in pediatric patients with SLE and occlusive retinopathy.
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Musculoskeletal pain is one of the most common presenting symptoms at the pediatrician's office. Etiology ranges from benign conditions to serious ones requiring prompt attention. This article addresses entities that present as musculoskeletal pain but are not associated with arthritis. The most common nonarthritic conditions are benign limb pain of childhood (growing pains), hypermobility, overuse syndromes with or without skeletal abnormalities, malignancies, and pain amplification syndromes. The| initial decision process, diagnosis, and treatment options for each of these conditions are discussed.
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Lésions par microtraumatismes répétés/diagnostic , Instabilité articulaire/diagnostic , Douleur musculosquelettique/étiologie , Tumeurs/diagnostic , Anti-inflammatoires non stéroïdiens/usage thérapeutique , Enfant , Lésions par microtraumatismes répétés/complications , Lésions par microtraumatismes répétés/thérapie , Humains , Instabilité articulaire/complications , Instabilité articulaire/thérapie , Massage , Douleur musculosquelettique/thérapie , Tumeurs/complications , Procédures orthopédiques , Ostéochondrose/complications , Ostéochondrose/diagnostic , Ostéochondrose/thérapie , Techniques de physiothérapie , PronosticRÉSUMÉ
Heparin-induced thrombocytopenia (HIT) with thrombosis is the most severe side effect of heparin administration. HIT patients may die or have permanent sequelae, such as a stroke or limb amputation. Contaminated heparin is associated with anaphylactic reactions and deaths by activating the contact system. It is also associated with high incidence of HIT via a yet unknown mechanism. This chapter shows that: (1) the contact system can be activated by a variety of unrelated molecules; (2) kallikrein directly cuts prothrombin to generate functional thrombin through contact system activation; and (3) while heparin contaminants, oversulfated heparin by-product (OS-HB), induce thrombin generation in both normal and HIT patient plasmas through contact system activation, authentic heparin induces thrombin activities only in HIT patient plasmas containing autoantibodies against protein/heparin complex. These data suggest that the negatively charged IgG/protein/heparin or OS-HB complex activate the contact system and produce thrombin in human plasma and thrombin partially activates the platelets allowing subsequent platelet activation through IgG/Fc receptor II signaling. The newly discovered mechanism of heparin-induced thrombin activity could explain the increased incidence of HIT in patients exposed to contaminated heparin. Furthermore, the assays used in these studies would be valuable for HIT diagnosis, prevention, and treatment.
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Anticoagulants/effets indésirables , Héparine/effets indésirables , Thrombopénie/induit chimiquement , Thrombose/induit chimiquement , Animaux , Humains , Thrombopénie/immunologie , Thrombose/immunologieRÉSUMÉ
Rheumatoid arthritis (RA) is a heterogeneous autoimmune disease that affects 1% of the population worldwide. In the K/BxN mouse model of RA, autoantibodies specific for glucose-6-phosphate isomerase (GPI) from these mice can transfer joint-specific inflammation to normal mice. The binding of GPI/autoantibody to the cartilage surface is a prerequisite for autoantibody-induced joint-specific inflammation in the mouse model. Chondroitin sulfate (CS) on cartilage surface is the long sought high-affinity receptor for GPI. The binding affinity and structural differences between mouse paw/ankle CS and knee/elbow CS correlate with the distal to proximal disease severity in these joints. The data presented in this chapter indicate that autoantigen/autoantibodies in blood circulation activate contact system to produce vasodilators to allow immune complex, protein aggregates, and other plasma proteins to get into the joints. Cartilage surface CS binds and retains autoantigen/autoantibodies. The CS/autoantigen/autoantibody complexes could induce C3a and C5a production through contact system activation. C3a and C5a trigger degranulation of mast cells, which further recruit plasma contact system and complement proteins, immune cells, and immune activation factors to facilitate joint-specific tissue destruction. Therefore, either reducing autoantibody production or inhibiting autoantibody-induced contact system activation might be effective in RA prevention.
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Polyarthrite rhumatoïde/immunologie , Polyarthrite rhumatoïde/métabolisme , Autoantigènes/immunologie , Modèles animaux de maladie humaine , Glycosaminoglycanes/métabolisme , Animaux , Polyarthrite rhumatoïde/anatomopathologie , Glucose 6-phosphate isomerase/physiologie , Souris , Souris knockoutRÉSUMÉ
Systemic lupus erythematosus (SLE), heparin-induced thrombocytopenia (HIT), rheumatoid arthritis (RA) are marked by the presence of autoantibodies against negatively changed DNA, phospholipids, heparin, and chondroitin sulfate, respectively. Heparin/protein complexes induce contact system activation in HIT patient plasmas. The activated contact system generates thrombin. Thrombin is responsible for thrombosis, a common cause of death and disabilities for both HIT and SLE. In this chapter, we analyze plasma contact system proteins, thrombin- and kallikrein-like activities, glucosamine and galactosamine content from SLE-, RA-, osteoarthritis (OA)-, and psoriasis (Ps)-patient plasmas in addition to pooled 30+ healthy patient plasmas. We found that all SLE patient plasmas exhibited abnormal contact systems marked by the absence of high molecular weight kininogen, the presence of processed C1 inhibitor (C1inh), the display of abnormal thrombin- and kallikrein-like activities, and increased levels of plasma glucosamine and galactosamine. Different patterns of contact system activation distinguish SLE, RA, and Ps whereas no contact system activation is observed in normal and OA patient plasmas. The presence of paradoxical "lupus anticoagulants" in certain thrombosis-prone SLE patient plasmas, marked by delayed clotting in clinical plasma test, was explained by the consumption of contact system proteins, especially high molecular weight kininogen. Finally, we discovered that mouse and human SLE autoantibodies bind to cell surface GAGs with structural selectivity. In conclusion, markers of abnormal contact system activation represent potential new targets for autoimmune disease diagnosis, prevention, and treatment. These markers might also be useful in monitoring SLE activity/severity and in pinpointing patients with SLE-associated arthritis and psoriasis.
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Anticoagulants/effets indésirables , Polyarthrite rhumatoïde/immunologie , Autoantigènes/immunologie , Glycosaminoglycanes/métabolisme , Héparine/effets indésirables , Lupus érythémateux disséminé/immunologie , Thrombopénie/immunologie , Animaux , Polyarthrite rhumatoïde/induit chimiquement , Polyarthrite rhumatoïde/métabolisme , Glycosaminoglycanes/immunologie , Humains , Lupus érythémateux disséminé/induit chimiquement , Lupus érythémateux disséminé/métabolisme , Souris , Thrombine/métabolisme , Thrombopénie/induit chimiquement , Thrombopénie/métabolismeRÉSUMÉ
Oncogenic mutations create cancer cells. Cancer cells require thrombin for growth, angiogenesis, and metastasis. All cancer patients display a hypercoagulable state, which includes platelet activation, blood coagulation, complement activation, vasodilatation, and inflammation. This often results in thrombosis, the second leading cause of death in cancer patients. It is established that chemically oversulfated glycosaminoglycans (GAGs) induce thrombin generation through contact system activation in human plasma. Thrombin is responsible for thrombosis. In this chapter, we show that plasmas from lung cancer patients contain activated contact systems apparent by the absence of high molecular weight kininogen and processed C1inh, by abnormal kallikrein and thrombin activities, and by increased glucosamine, galactosamine, and GAG levels. Activated contact systems were also evident in plasmas from breast, colon, and pancreatic cancer patients. These data suggest that GAGs or other molecules produced by tumors induce abnormal thrombin generation through contact system activation. Therefore, the contact system and glycans represent new targets for cancer diagnosis, prevention, and treatment.
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Autoantigènes/immunologie , Glycosaminoglycanes/métabolisme , Tumeurs/immunologie , Tumeurs/métabolisme , Animaux , Glycosaminoglycanes/immunologie , Humains , Tumeurs/anatomopathologie , Thrombine/métabolismeRÉSUMÉ
Contaminated heparin was linked to at least 149 deaths and hundreds of adverse reactions. Published report indicates that heparin contaminants were a natural impurity, dermatan sulfate, and a contaminant, oversulfated chondroitin sulfate (OSCS). OSCS was assumed to derive from animal cartilage. By analyzing 26 contaminated heparin lots from different sources, our data indicate that the heparin contaminants were chemically sulfated or chemically sulfated/desulfated glycosaminoglycans (GAGs) consisting of heparan sulfate, chondroitin sulfate, and dermatan sulfate based on monosaccharide quantification, CE, heparin lyase digestion, and liquid chromatography/mass spectrometry analysis. Since currently recommended heparin quality control assays had failed to detect certain heparin contaminants, a simple method that detects most contaminants in heparin was developed. This assay detects specific heparin structures that most contaminants cannot mimic and can be performed in any laboratory equipped with an UV spectrometer.