RESUMEN
BACKGROUND: Mastocytosis and monoclonal mast cell (MC) activation syndrome (MMAS) are heterogeneous conditions characterized by the accumulation of atypical MCs. Despite the recurrent involvement of KIT mutations, the pathophysiologic origin of mastocytosis and MMAS is unclear. Although hereditary α-tryptasemia (HαT, related to TPSAB1 gene duplication) is abnormally frequent in these diseases, it is not known whether the association is coincidental or causal. OBJECTIVE: We evaluated the prevalence of HαT in all mastocytosis subtypes and MMAS and assessed the pathophysiologic association with HαT. METHODS: Clinical data, laboratory data, KIT mutations, TPSAB1 duplication (assessed by droplet digital PCR), and HαT prevalence were retrospectively recorded for all patients with mastocytosis and MMAS registered in the French national referral center database and compared to a control cohort. To increase the power of our analysis for advanced systemic mastocytosis (advSM), we pooled our cohort with literature cases. RESULTS: We included 583 patients (27 with MMAS and 556 with mastocytosis). The prevalence of HαT in mastocytosis was 12.6%, significantly higher than in the general population (5.7%, P = .002) and lower than in MMAS (33.3%, P = .02). HαT+ patients were more likely to have anaphylactic reactions and less likely to have cutaneous lesions than HαT- patients (43.0% vs 24.4%, P = .006; 57.7% vs 75.6%, respectively, P = .006). In the pooled analysis, the prevalence of HαT was higher in advSM (11.5%) than in control cohorts (5.2%, P = .01). CONCLUSION: Here we confirm the increase incidence of anaphylaxis in HαT+ mastocytosis patients. The increased prevalence of HαT in all subtypes of systemic mastocytosis (including advSM) is suggestive of pathophysiologic involvement.
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Anafilaxia , Mastocitosis Sistémica , Mastocitosis , Humanos , Mastocitosis Sistémica/epidemiología , Mastocitosis Sistémica/genética , Mastocitosis Sistémica/patología , Estudios Retrospectivos , Prevalencia , Mastocitosis/epidemiología , Mastocitosis/genética , Mastocitosis/patología , Anafilaxia/patología , Mastocitos/patología , Triptasas/genéticaRESUMEN
Proteinase 3 (PR3) is the main target antigen of antineutrophil cytoplasmic antibodies (ANCAs) in PR3-ANCA-associated vasculitis. A small fraction of PR3 is constitutively exposed on the surface of quiescent blood neutrophils in a proteolytically inactive form. When activated, neutrophils expose an induced form of membrane-bound PR3 (PR3mb) on their surface as well, which is enzymatically less active than unbound PR3 in solution due to its altered conformation. In this work, our objective was to understand the respective role of constitutive and induced PR3mb in the immune activation of neutrophils triggered by murine anti-PR3 mAbs and human PR3-ANCA. We quantified immune activation of neutrophils by the measurement of the production of superoxide anions and secreted protease activity in the cell supernatant before and after treatment of the cells by alpha-1 protease inhibitor that clears induced PR3mb from the cell surface. Incubation of TNFα-primed neutrophils with anti-PR3 antibodies resulted in a significant increase in superoxide anion production, membrane activation marker exposition, and secreted protease activity. When primed neutrophils were first treated with alpha-1 protease inhibitor, we observed a partial reduction in antibody-induced neutrophil activation, suggesting that constitutive PR3mb is sufficient to activate neutrophils. The pretreatment of primed neutrophils with purified antigen-binding fragments used as competitor significantly reduced cell activation by whole antibodies. This led us to the conclusion that PR3mb promoted immune activation of neutrophils. We propose that blocking and/or elimination of PR3mb offers a new therapeutic strategy to attenuate neutrophil activation in patients with PR3-ANCA-associated vasculitis.
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Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos , Anticuerpos Anticitoplasma de Neutrófilos , Mieloblastina , Animales , Humanos , Ratones , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/metabolismo , Mieloblastina/inmunología , Mieloblastina/metabolismo , Neutrófilos/metabolismo , Inhibidores de Proteasas/metabolismo , Superóxidos/metabolismoRESUMEN
BACKGROUND AND AIMS: Systemic mastocytosis (SM) is characterized by the accumulation of atypical mast cells (MCs) in organs. Liver histology of SM has been marginally described and accurate histological classification is critical, given the consequences of aggressive SM diagnosis. We aimed to describe the histological features associated with liver SM using updated tools. METHODS: Using the database of the French Reference Centre for Mastocytosis, we retrospectively identified patients with a liver biopsy (LB) and a diagnosis of SM. All LB procedures were performed according to the local physician in charge and centrally reviewed by an expert pathologist. RESULTS: A total of 28 patients were included: 6 had indolent SM, 9 had aggressive SM, and 13 had SM with an associated hematologic neoplasm. Twenty-five (89%) patients presented hepatomegaly, and 19 (68%) had portal hypertension. The LB frequently showed slight sinusoid dilatation (82%). Fibrosis was observed in 3/6 indolent SM and in almost all advanced SM cases (21/22), but none of them showed cirrhosis. A high MC burden (>50 MCs/high-power field) was correlated with elevated blood alkaline phosphatase levels (p = .030). The presence of portal hypertension was associated with a higher mean fibrosis grade (1.6 vs. 0.8 in its absence; p = .026). In advanced SM, the presence of nodular regenerative hyperplasia (NRH) was associated with decreased overall survival (9.5 vs. 46.3 months, p = .002). CONCLUSIONS: MC infiltration induced polymorphic hepatic lesions and the degree of fibrosis is associated with portal hypertension. NRH identifies a poor prognosis subgroup of patients with advanced SM. Assessing liver histology can aid in SM prognostic evaluation.
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Hepatomegalia , Hígado , Mastocitosis Sistémica , Humanos , Mastocitosis Sistémica/patología , Mastocitosis Sistémica/complicaciones , Estudios Retrospectivos , Femenino , Hígado/patología , Masculino , Persona de Mediana Edad , Adulto , Biopsia , Hepatomegalia/patología , Hepatomegalia/etiología , Anciano , Hipertensión Portal/patología , Hipertensión Portal/etiología , Francia , Cirrosis Hepática/patología , Mastocitos/patología , Fosfatasa Alcalina/sangre , PronósticoRESUMEN
Systemic mastocytosis (SM) corresponds to a rare and heterogeneous spectrum of diseases characterized by the accumulation of atypical mast cells (MCs). Advanced mastocytosis (Adv-SM) is associated with poor survival; in contrast, patients with non-advanced SM (non-Adv-SM) usually have a normal life expectancy but may experience poor quality of life. Despite recent therapeutic progress including tyrosine kinase inhibitors, new treatment options are needed for refractory and/or intolerant patients with both severely symptomatic and Adv-SM. In vitro, the mTOR pathway is activated in MCs from patients bearing the KIT D816V mutation. Furthermore, rapamycin induces the apoptosis of KIT D816V MCs selectively. In this nationwide study, we report the outcomes of patients diagnosed with SM and treated with a mammalian target of rapamycin inhibitor (imTOR) within the French National Reference Center for mastocytosis (CEREMAST). All patients registered were relapsing, treatment-refractory, or ineligible for other cytoreductive therapy. Non-Adv-SM patients received imTOR as a monotherapy (rapamycin/everolimus), and Adv-SM patients received imTOR as a monotherapy or in combination with cytarabine. The objective response rate (ORR) in non-Adv-SM was 60% (partial response in 40% and major response in 20%), including reductions in skin involvement, mediator release symptoms, and serum tryptase. In the Adv-SM group, the ORR was 20% (including one major response and one partial response, both in patients with a KIT D816V mutation), which enabled a successful bridge to allogeneic stem cell transplantation in one patient. Our results suggest that imTOR treatment has potential benefits in patients with SM harboring a KIT D816V mutation.
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Inhibidores mTOR , Mastocitosis Sistémica , Sirolimus , Humanos , Mastocitosis Sistémica/tratamiento farmacológico , Proyectos Piloto , Femenino , Masculino , Persona de Mediana Edad , Adulto , Francia , Anciano , Sirolimus/uso terapéutico , Sirolimus/efectos adversos , Inhibidores mTOR/uso terapéutico , Proteínas Proto-Oncogénicas c-kit/genética , Proteínas Proto-Oncogénicas c-kit/antagonistas & inhibidores , Everolimus/uso terapéutico , Everolimus/efectos adversos , Resultado del Tratamiento , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Anciano de 80 o más AñosRESUMEN
BACKGROUND: Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized. METHOD: Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed. RESULTS: No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable. CONCLUSIONS: These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.
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Anafilaxia , Vacunas contra la COVID-19 , COVID-19 , Hipersensibilidad a las Drogas , Vacunas , Anafilaxia/diagnóstico , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Hipersensibilidad a las Drogas/diagnóstico , Hipersensibilidad a las Drogas/etiología , Hipersensibilidad a las Drogas/terapia , Humanos , Vacunas Sintéticas , Vacunas de ARNmRESUMEN
Background: Hereditary angioedema (HAE) is characterized by unpredictable and potentially life-threatening attacks of cutaneous and submucosal swelling. Over the past decade, new agents, based on a better understanding of the underlying biologic mechanisms of HAE, have changed the face of long-term prophylaxis (LTP). Objective: The objective was to describe current practices and unmet needs with regard to LTP for HAE in expert centers in France. Methods: The study was conducted in France in 2020. Based on their experience with patients with HAE who had visited their center at least once in the past 3 years, physicians from 25 centers who are expert in the management of HAE were requested to fill in a questionnaire that encapsulated their active patient list, criteria for prescribing LTP, and medications used. They were asked about potential unmet needs with currently available therapies. They were asked to express their expectations with regard to the future of HAE management. Results: Analysis was restricted to 20 centers that had an active patient file and agreed to participate. There were 714 patients with C1 inhibitor (C1-INH) deficiency, of whom 423 (59.2%) were treated with LTP. Altered quality of life triggered the decision to start LTP, as did the frequency and severity of attacks. Ongoing LTP included androgens (28.4%), progestins (25.8%), lanadelumab (25.3%), tranexamic acid (14.2%), intravenous C1-INHs (5.6%), and recombinant C1-INH (0.7%). Twenty-nine percent of the patents with LTP were considered to still have unmet needs. Physicians' concerns varied among therapies: poor tolerability for androgens and progestins, a lack of efficacy for tranexamic acid and progestins, dosage form, and high costs for C1-INHs and lanadelumab. Physicians' expectations encompassed more-efficacious and better-tolerated medications, easier treatment administration for the sake of improved quality of life of patients, and less-expensive therapies. Conclusion: Despite the recent enrichment of the therapeutic armamentarium for LTP, physicians still expressed unmet needs with currently available therapies.
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Angioedemas Hereditarios , Ácido Tranexámico , Andrógenos/uso terapéutico , Angioedemas Hereditarios/tratamiento farmacológico , Angioedemas Hereditarios/prevención & control , Proteína Inhibidora del Complemento C1/uso terapéutico , Humanos , Progestinas/uso terapéutico , Calidad de Vida , Ácido Tranexámico/uso terapéuticoRESUMEN
We provide the first description of a series of 9 severe gynecological infections (mastitis and pelvic cellulitis) occurring in the French national cohort of women with STAT3 deficiency. Each episode had unique features in terms of clinical presentation, microbial documentation, location, treatment duration, and related persistent esthetic damage.
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Mastitis/genética , Parametritis/genética , Factor de Transcripción STAT3 , Estudios de Cohortes , Femenino , Humanos , Mutación , Factor de Transcripción STAT3/deficiencia , Factor de Transcripción STAT3/genética , Adulto JovenRESUMEN
Interleukin-1 receptor (IL1R)-associated kinase 4 (IRAK4) is a central regulator of innate immune signaling, controlling IL1R and Toll-like receptor (TLR)-mediated responses and containing both scaffolding and kinase activities. Humans deficient in IRAK4 activity have autosomal recessive primary immune deficiency (PID). Here, we characterized the molecular mechanism of dysfunction of two IRAK4 PID variants, G298D and the compound variant R12C (R12C/R391H/T458I). Using these variants and the kinase-inactive D329A variant to delineate the contributions of IRAK4's scaffolding and kinase activities to IL1R signaling, we found that the G298D variant is kinase-inactive and expressed at extremely low levels, acting functionally as a null mutation. The R12C compound variant possessed WT kinase activity, but could not interact with myeloid differentiation primary response 88 (MyD88) and IRAK1, causing impairment of IL-1-induced signaling and cytokine production. Quantitation of IL-1 signaling in IRAK4-deficient cells complemented with either WT or the R12C or D329A variant indicated that the loss of MyD88 interaction had a greater impact on IL-1-induced signaling and cytokine expression than the loss of IRAK4 kinase activity. Importantly, kinase-inactive IRAK4 exhibited a greater association with MyD88 and a weaker association with IRAK1 in IRAK4-deficient cells expressing kinase-inactive IRAK4 and in primary cells treated with a selective IRAK4 inhibitor. Loss of IRAK4 kinase activity only partially inhibited IL-1-induced cytokine and NF-κB signaling. Therefore, the IRAK4-MyD88 scaffolding function is essential for IL-1 signaling, but IRAK4 kinase activity can control IL-1 signal strength by modulating the association of IRAK4, MyD88, and IRAK1.
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Síndromes de Inmunodeficiencia/genética , Quinasas Asociadas a Receptores de Interleucina-1/química , Quinasas Asociadas a Receptores de Interleucina-1/genética , Interleucina-1/genética , Factor 88 de Diferenciación Mieloide/genética , Línea Celular , Cristalografía por Rayos X , Humanos , Inmunidad Innata/genética , Síndromes de Inmunodeficiencia/inmunología , Síndromes de Inmunodeficiencia/patología , Interleucina-1/química , Quinasas Asociadas a Receptores de Interleucina-1/deficiencia , Mutación , Factor 88 de Diferenciación Mieloide/química , FN-kappa B/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Interleucina-1/química , Receptores de Interleucina-1/genética , Transducción de SeñalRESUMEN
PURPOSE: Subcutaneous immunoglobulin replacement therapy (IgRT) may be administered once a week with a pump or every other day with a syringe (rapid push). The objective of the study was to compare the impact of pump and rapid push infusions on patient's life quality index (LQI). METHODS: This study was a randomized, crossover, multicenter, non-inferiority trial conducted in adults with primary immunodeficiency (PID) accustomed to weekly infusions at home by pump. Patients used pump or rapid push for 3 months each according to the randomized sequence. Main criterion was PID-LQI factor I (treatment interference). Non-inferiority ratio was set at 90%. RESULTS: Thirty patients entered the study; 28 completed the two periods. IgRT exposure was similar during each period. At the end of each period, mean LQI factor 1 was 87.0 (IC95% [80.3; 94.3]) and 77.80 (IC95% [71.5; 84.7]) for pump and rapid push, respectively. There was a slightly larger effect of rapid push on treatment interference than with pump so that the primary endpoint could not be met. No difference was found on other LQI components, satisfaction (TSQM), or quality of life (SF36v2). Eight patients declared to prefer rapid push while 19 others preferred pump. Of rapid push infusions, 67.2% led to local reactions vs 71.8% of pump infusions (p = 0.11) illustrating its good tolerance. Rapid push and pump infusions achieved similar trough IgG levels with similar incidence of infections. Rapid push saved 70% of administration cost when compared to pump. CONCLUSIONS: Since IgRT is a lifelong treatment in PID patients, individualization of treatment is of paramount importance. Rapid push is a new administration method in the physician's armamentarium which is preferred by some patients and is cost-effective. CLINICALTRIALS. GOV IDENTIFIER: NCT02180763 CLINICAL IMPLICATIONS: Self-administration of small volumes of immunoglobulins at home, every other day, using a syringe (rapid push) is a cost-effective alternative to administration of larger volumes by pump once a week. This study compared subcutaneous infusions of immunoglobulins either weekly via a pump or every other day via a syringe (rapid push). Rapid push is preferred by some patients and is cost-effective, therefore completing a physician's armamentarium.
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Inmunoglobulinas/administración & dosificación , Síndromes de Inmunodeficiencia/tratamiento farmacológico , Bombas de Infusión , Infusiones Subcutáneas , Adulto , Anciano , Estudios Cruzados , Femenino , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/efectos adversos , Inmunoglobulinas/efectos adversos , Síndromes de Inmunodeficiencia/complicaciones , Síndromes de Inmunodeficiencia/diagnóstico , Masculino , Persona de Mediana Edad , Calidad de Vida , Resultado del Tratamiento , Adulto JovenRESUMEN
We studied the distribution of peripheral B-cell subsets in patients deficient for key factors of the TLR-signaling pathways (MyD88, TIRAP/MAL, IL-1 receptor-associated kinase 4 [IRAK-4], TLR3, UNC-93B, TRIF). All TLRs, except TLR3, which signals through the TRIF adaptor, require MyD88 and IRAK-4 to mediate their function. TLR4 and the TLR2 heterodimers (with TLR1, TLR6, and possibly TLR10) require in addition the adaptor TIRAP, whereas UNC-93B is needed for the proper localization of intracellular TLR3, TLR7, TLR8, and TLR9. We found that IgM(+)IgD(+)CD27(+) but not switched B cells were strongly reduced in MyD88-, IRAK-4-, and TIRAP-deficient patients. This defect did not appear to be compensated with age. However, somatic hypermutation of Ig genes and heavy-chain CDR3 size distribution of IgM(+)IgD(+)CD27(+) B cells were not affected in these patients. In contrast, the numbers of IgM(+)IgD(+)CD27(+) B cells were normal in the absence of TLR3, TRIF, and UNC-93B, suggesting that UNC-93B-dependent TLRs, and notably TLR9, are dispensable for the presence of this subset in peripheral blood. Interestingly, TLR10 was found to be expressed at greater levels in IgM(+)IgD(+)CD27(+) compared with switched B cells in healthy patients. Hence, we propose a role for TIRAP-dependent TLRs, possibly TLR10 in particular, in the development and/or maintenance of IgM(+)IgD(+)CD27(+) B cells in humans.
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Linfocitos B/inmunología , Inmunoglobulina D/inmunología , Inmunoglobulina M/inmunología , Quinasas Asociadas a Receptores de Interleucina-1/genética , Glicoproteínas de Membrana/genética , Proteínas de Transporte de Membrana/genética , Factor 88 de Diferenciación Mieloide/genética , Receptores de Interleucina-1/genética , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunología , Adolescente , Adulto , Linfocitos B/patología , Niño , Preescolar , Citocinas/inmunología , Humanos , Inmunoglobulina D/análisis , Inmunoglobulina M/análisis , Mutación , Receptor Toll-Like 10/genética , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/análisis , Adulto JovenRESUMEN
BACKGROUND: Hereditary angioedema (HAE) is a rare and potentially life-threatening disease that manifests clinically as recurrent episodes of swelling affecting multiple anatomical locations. Long-term prophylaxis (LTP) aims to control the disease by preventing HAE attacks. Previously, treatments such as attenuated androgens have been used for LTP, but they have an unfavorable adverse effect profile. Today, these limitations may be overcome by patients transitioning to newer, targeted therapies including oral berotralstat and subcutaneous lanadelumab. This case series reports the transition process between different prophylactic therapies in a family with HAE in a real-world setting. RESULTS: Four adult patient cases from the same family who underwent transitions in HAE prophylaxis are presented. Three were female and one male. Two patients who transitioned to berotralstat were initially prescribed attenuated androgens. Two patients were not taking LTP at the time of initiating targeted treatment but had previously been prescribed tranexamic acid. The length of transition varied between the patients, with the longest time taken to stabilize on new therapy being 26 months. All patients received regular follow-up in person or by telephone and all four required an adjustment from their initial treatment plan. CONCLUSIONS: Transitioning between LTP in HAE may help improve control of attacks, avoid unwanted adverse effects, or better cater to individual patient preferences. Newer targeted therapies have been shown to be effective and should be discussed with patients. Shared decision-making is a tool that can aid these discussions. The transition journey between LTP therapies in HAE may not be straightforward and is specific to each patient. Physicians should consider complicating factors such as patient anxieties around changing treatment, adverse effects, preferred routes of administration, and speed of transition. Following patients closely during the transition period helps identify any issues, including difficulties with treatment adherence, and may allow the transition plan to be adapted when necessary.
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Andrógenos , Angioedemas Hereditarios , Humanos , Angioedemas Hereditarios/tratamiento farmacológico , Masculino , Femenino , Andrógenos/uso terapéutico , Adulto , Persona de Mediana Edad , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Neutralizantes/uso terapéuticoRESUMEN
Infant formulas have been shown to influence the development of the gut microbiota. Besides the probiotic- and prebiotic-containing formulas, fermented milk-based infant formulas offer an additional means for modulation of gut immunity and/or gut microbiota. These formulas are produced by the fermentation of cow's milk with specific lactic acid bacteria strains, followed by heat treatment; they do not contain viable bacteria or added prebiotic oligosaccharides but contain specific products resulting from the fermentation process. This review is focused on the effects of fermentation products, distinguishing them from those of living bacteria and prebiotic compounds on the immune system. Besides the possible modulation of gut microbiota composition, in vitro and in vivo studies suggest that specific fermentation products can actively participate in the establishment of immune balance and oral tolerance. Although further research is needed to confirm the clinical benefits observed in infants to better characterize the active fermentation compounds and to delineate the involved pathways, these fermented formulas appear to deserve interest.
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Productos Lácteos Cultivados/inmunología , Fermentación , Fórmulas Infantiles/métodos , Lactobacillaceae/metabolismo , Leche/microbiología , Animales , Células Dendríticas/inmunología , Humanos , Lactante , Fórmulas Infantiles/química , Microbiota/fisiologíaRESUMEN
The DEFI study has collected clinical data and biological specimens from kindreds with CVID. Patients with demonstrated parental consanguinity (cCVID group) were compared to patients without parental consanguinity (ncCVID). A total of 24 of the 436 patients with CVID had consanguineous parents. Age at first symptoms and age at diagnosis were comparable in the two groups. Some complications were more frequent in cCVID patients: splenomegaly (62.5% vs. 29%; p = 0.001), granulomatous disease (29% vs. 12%; p = 0.02), and bronchiectasis (58% vs. 29%; p = 0.003). A high incidence of opportunistic infections was also observed in this population (29% vs. 5%; p < 0.001). Distribution of B-cell subsets were similar in the two groups. Naïve CD4+ T cells were decreased in cCVID patients (15% vs. 28%; p < 0.001), while activated CD4 + CD95+ (88% vs. 74%; p = 0.002) and CD8 + HLA-DR + T cells (47% vs. 31%; p < 0.001) were increased in these patients when compared to ncCVID patients. Parental consanguinity is associated with an increased risk of developing severe clinical complications in patients with CVID. Most of these patients presented with severe T-cell abnormalities and should be considered with a diagnosis of late-onset combined immune deficiency (LOCID). Systematic investigation for parental consanguinity in patients with CVID provides useful information for specific clinical care and genetic screening.
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Inmunodeficiencia Variable Común/diagnóstico , Inmunodeficiencia Variable Común/genética , Consanguinidad , Fenotipo , Adolescente , Adulto , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Niño , Inmunodeficiencia Variable Común/inmunología , Femenino , Francia , Estudios de Asociación Genética , Pruebas Genéticas , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Granulomatosis with polyangiitis (GPA) is a rare but serious necrotizing auto-immune vasculitis. GPA is mostly associated with the presence of Anti-Neutrophil Cytoplasmic Antibody (ANCA) targeting proteinase 3 (PR3-ANCA), a serine protease contained in neutrophil granules but also exposed at the membrane. PR3-ANCAs have a proven fundamental role in GPA: they bind neutrophils allowing their auto-immune activation responsible for vasculitis lesions. PR3-ANCAs bind neutrophil surface on the one hand by their Fab binding PR3 and on the other by their Fc binding Fc gamma receptors. Despite current therapies, GPA is still a serious disease with an important mortality and a high risk of relapse. Furthermore, although PR3-ANCAs are a consistent biomarker for GPA diagnosis, relapse management currently based on their level is inconsistent. Indeed, PR3-ANCA level is not correlated with disease activity in 25% of patients suggesting that not all PR3-ANCAs are pathogenic. Therefore, the development of new biomarkers to evaluate disease activity and predict relapse and new therapies is necessary. Understanding factors influencing PR3-ANCA pathogenicity, i.e. their potential to induce auto-immune activation of neutrophils, offers interesting perspectives in order to improve GPA management. Most relevant factors influencing PR3-ANCA pathogenicity are involved in their interaction with neutrophils: level of PR3 autoantigen at neutrophil surface, epitope of PR3 recognized by PR3-ANCA, isotype and glycosylation of PR3-ANCA. We detailed in this review the advances in understanding these factors influencing PR3-ANCA pathogenicity in order to use them as biomarkers and develop new therapies in GPA as part of a personalized approach.
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Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Granulomatosis con Poliangitis/inmunología , Mieloblastina/inmunología , Neutrófilos/inmunología , Anticuerpos Anticitoplasma de Neutrófilos/metabolismo , Biomarcadores/metabolismo , Granulomatosis con Poliangitis/metabolismo , Granulomatosis con Poliangitis/terapia , Humanos , Mieloblastina/metabolismo , Neutrófilos/metabolismo , Peroxidasa/inmunología , Peroxidasa/metabolismo , Unión Proteica , Recurrencia , Factores de RiesgoRESUMEN
Granulomatosis with polyangiitis (GPA) is a severe autoimmune vasculitis associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA) mainly targeting proteinase 3 (PR3), a neutrophilic serine proteinase. PR3-ANCA binding to membrane-bound PR3 on neutrophils induce their auto-immune activation responsible for vascular lesions. However, the correlation between PR3-ANCA level and disease activity remains inconsistent, suggesting the existence of non-pathogenic PR3-ANCA. In order to prove their existence, we immortalized B lymphocytes from blood samples of GPA patients in remission having persistent PR3-ANCA to isolate non-activating PR3-ANCA. We obtained for the first time a non-activating human IgG1κ anti-PR3 monoclonal antibody (mAb) named 4C3. This new mAb binds soluble PR3 with a high affinity and membrane-bound PR3 on an epitope close to the PR3 hydrophobic patch and in the vicinity of the active site. 4C3 is able to bind FcγRIIA and FcγRIIIB and has a G2F glycosylation profile on asparagine 297. 4C3 did not induce activation of neutrophils and could inhibit human polyclonal PR3-ANCA-induced activation suggesting that 4C3 is non-pathogenic. This characteristic relies on the recognized epitope on PR3 rather than to the Fc portion properties. The existence of non-pathogenic PR3-ANCA, which do not activate neutrophils, could explain the persistence of high PR3-ANCA levels in some GPA patients in remission and why PR3-ANCA would not predict relapse. Finally, these results offer promising perspectives particularly regarding the understanding of PR3-ANCA pathogenicity and the development of new diagnostic and therapeutic strategies in GPA.
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Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Anticuerpos Monoclonales/inmunología , Linfocitos B/inmunología , Granulomatosis con Poliangitis/inmunología , Mieloblastina/inmunología , Anciano , Anticuerpos Anticitoplasma de Neutrófilos/metabolismo , Anticuerpos Monoclonales/metabolismo , Afinidad de Anticuerpos , Especificidad de Anticuerpos , Linfocitos B/enzimología , Sitios de Unión de Anticuerpos , Biomarcadores/metabolismo , Estudios de Casos y Controles , Línea Celular , Mapeo Epitopo , Epítopos , Femenino , Glicosilación , Granulomatosis con Poliangitis/diagnóstico , Granulomatosis con Poliangitis/enzimología , Humanos , Masculino , Persona de Mediana Edad , Activación Neutrófila , Prueba de Estudio ConceptualRESUMEN
The large experience accumulated with the therapeutic use of monoclonal antibodies has revealed undesirable effects, among which opportunistic infections when prescribed in inflammatory or hematological diseases. This deleterious effect is a direct consequence of the immunosuppression induced by these antibodies through the blockade of several key pathways involved in both innate and adaptative immune responses, including migration of effector cells, depletion of B or T lymphocytes, inhibition of key cell-cell interactions. Four antibodies are concerned, targeting CD52, CD20, TNF-a and VLA-4, and major risks include activation of latent tuberculosis, or of normally silent viruses. Precise evaluation of these risks and understanding of their mechanisms have now led to the improvement of clinical safety, based on the detection of patients at risk, weighting of the benefit/risk ratio, and a very rigorous detection of latent infections before the onset of treatment by monoclonal antibodies know to induce immunosuppression.
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Anticuerpos Monoclonales/efectos adversos , Infecciones Oportunistas/etiología , Alemtuzumab , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Anticuerpos Monoclonales de Origen Murino , Anticuerpos Antineoplásicos/efectos adversos , Anticuerpos Antineoplásicos/uso terapéutico , Antígenos CD/inmunología , Antígenos CD20/inmunología , Antígenos de Neoplasias/inmunología , Antígeno CD52 , Estudios de Cohortes , Glicoproteínas/inmunología , Humanos , Terapia de Inmunosupresión/efectos adversos , Integrina alfa4beta1/inmunología , Metaanálisis como Asunto , Infecciones Oportunistas/epidemiología , Recurrencia , Estudios Retrospectivos , Rituximab , Tuberculosis/etiología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/inmunología , Activación ViralRESUMEN
BACKGROUND: Iodinated and gadolinium-based contrast media (ICM; GBCM) induce immediate hypersensitivity (IH) reactions. Differentiating allergic from non-allergic IH is crucial; allergy contraindicates the culprit agent for life. We studied frequency of allergic IH among ICM or GBCM reactors. METHODS: Patients were recruited in 31 hospitals between 2005 and 2009. Clinical symptoms, plasma histamine and tryptase concentrations and skin tests were recorded. Allergic IH was diagnosed by intradermal tests (IDT) with the culprit CM diluted 1:10, "potentially allergic" IH by positive IDT with pure CM, and non-allergic IH by negative IDT. FINDINGS: Among 245 skin-tested patients (ICMâ¯=â¯209; GBCMâ¯=â¯36), allergic IH to ICM was identified in 41 (19.6%) and to GBCM in 10 (27.8%). Skin cross-reactivity was observed in 11 patients with ICM (26.8%) and 5 with GBCM (50%). Allergy frequency increased with clinical severity and histamine and tryptase concentrations (pâ¯<â¯0.0001). Cardiovascular signs were strongly associated with allergy. Non-allergic IH was observed in 152 patients (62%) (ICM:134; GBCM:18). Severity grade was lower (pâ¯<â¯0.0001) and reaction delay longer (11.6 vs 5.6â¯min; pâ¯<â¯0.001). Potentially allergic IH was diagnosed in 42 patients (17.1%) (ICM:34; GBCM:8). The delay, severity grade, and mediator release were intermediate between the two other groups. INTERPRETATION: Allergic IH accounted for < 10% of cutaneous reactions, and > 50% of life-threatening ones. GBCM and ICM triggered comparable IH reactions in frequency and severity. Cross-reactivity was frequent, especially for GBCM. We propose considering skin testing with pure contrast agent, as it is more sensitive than the usual 1:10 dilution criteria.
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OBJECTIVE: To assess quality of life and satisfaction regarding immunoglobulin-replacement therapy (IgRT) treatment according to the route (intravenous Ig [IVIg] or subcutaneous Ig [SCIg]) and place of administration (home-based IgRT or hospital-based IgRT). SUBJECTS AND METHODS: Children 5-15 years old treated for primary immunodeficiency disease (PIDD) with IgRT for ≥3 months were included in a prospective, noninterventional cohort study and followed over 12 months. Quality of life was assessed with the Child Health Questionnaire - parent form (CHQ-PF)-50 questionnaire. Satisfaction with IgRT was measured with a three-dimensional scale (Life Quality Index [LQI] with three components: factor I [FI], treatment interference; FII, therapy-related problems; FIII, therapy settings). RESULTS: A total of 44 children (9.7±3.2 years old) receiving IgRT for a mean of 5.6±4.5 years (median 4.1 years) entered the study: 18 (40.9%) were receiving hospital-based IVIg, two (4.6%) were receiving home-based IVIg, and 24 (54.6%) were treated by home-based SCIg. LQI FIII was higher for home-based SCIg than for hospital-based IVIg (P=0.0003), but there was no difference for LQI FI or LQI FII. LQI FIII significantly improved in five patients who switched from IVIg to SCIg during the follow-up when compared to patients who pursued the same regimen (either IVIg or SCIg). No difference was found on CHQ-PF50 subscales, LQI FI, or LQI FII. CONCLUSION: Home-based SCIg gave higher satisfaction regarding therapy settings than hospital-based IVIg. No difference was found on other subscales of the LQI or CHQ-PF50 between hospital-based IVIG and home-based SCIG.
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Graft endothelium has a key role in organ transplantation because it regulates graft infiltration by allogeneic activated T cells. Overexpression of death molecules that could induce apoptosis of alloreactive T cells might be an alternative to the immunosuppressive treatment currently used in graft transplantation. Several studies have shown that immune-privileged sites express Fas ligand (FasL) and induce apoptosis of activated T-cells. We propose that endothelial cells engineered to express FasL could inhibit alloreactive T cell-proliferation by inducing apoptosis. An expression vector was constructed with human FasL cDNA and used to transfect an endothelial cell line (ECV304 cells). We demonstrated that FasL-transfected ECV304 cells were effective in inducing apoptosis of Jurkat T cell lymphoma as an agonist anti-Fas antibody. Using a mixed lymphocyte-endothelial cell culture model we observed that FasL-transfected ECV304 cells which conserved their two principal costimulatory pathways inhibited alloreactive T cell-proliferation by inducing activated T-cell apoptosis. These results suggest that endothelial cells could be interesting candidates to convey a death signal and induce hyporesponsiveness of alloreactive T cells during organ transplantation.