Titre : Carence en vitamine B12

Carence en vitamine B12 : Questions médicales fréquentes

Termes MeSH sélectionnés :

Complement Pathway, Alternative
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"url": "https://questionsmedicales.fr/mesh/D014806?mesh_terms=Complement+Pathway,+Alternative&page=3#section-complications" }, { "@type": "MedicalWebPage", "name": "Facteurs de risque", "headline": "Facteurs de risque sur Carence en vitamine B12", "description": "Qui est le plus à risque de carence en B12 ?\nLes maladies auto-immunes augmentent-elles le risque ?\nLes médicaments peuvent-ils influencer le risque ?\nLes troubles digestifs sont-ils un facteur de risque ?\nLes antécédents familiaux jouent-ils un rôle ?", "url": "https://questionsmedicales.fr/mesh/D014806?mesh_terms=Complement+Pathway,+Alternative&page=3#section-facteurs de risque" } ] }, { "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "Comment diagnostiquer une carence en vitamine B12 ?", "position": 1, "acceptedAnswer": { "@type": "Answer", "text": "Un diagnostic se fait par des analyses sanguines mesurant les niveaux de vitamine B12." } }, { "@type": "Question", "name": "Quels tests sont utilisés pour confirmer la carence ?", "position": 2, "acceptedAnswer": { "@type": "Answer", "text": "Les tests incluent la mesure de la vitamine B12, de l'homocystéine et de la méthylmalonyl-CoA." } }, { "@type": "Question", "name": "Quels signes cliniques indiquent une carence ?", "position": 3, "acceptedAnswer": { "@type": "Answer", "text": "Des signes comme l'anémie, la fatigue, et des troubles neurologiques peuvent indiquer une carence." } }, { "@type": "Question", "name": "La carence en B12 peut-elle être asymptomatique ?", "position": 4, "acceptedAnswer": { "@type": "Answer", "text": "Oui, certaines personnes peuvent avoir une carence sans présenter de symptômes visibles." } }, { "@type": "Question", "name": "Quel rôle joue l'historique médical dans le diagnostic ?", "position": 5, "acceptedAnswer": { "@type": "Answer", "text": "L'historique médical aide à identifier des facteurs de risque comme des troubles d'absorption." } }, { "@type": "Question", "name": "Quels sont les symptômes courants de la carence en B12 ?", "position": 6, "acceptedAnswer": { "@type": "Answer", "text": "Les symptômes incluent fatigue, faiblesse, engourdissements et troubles de l'humeur." } }, { "@type": "Question", "name": "La carence en B12 peut-elle causer des problèmes neurologiques ?", "position": 7, "acceptedAnswer": { "@type": "Answer", "text": "Oui, elle peut entraîner des troubles neurologiques comme des démences ou des neuropathies." } }, { "@type": "Question", "name": "Comment la carence affecte-t-elle la peau ?", "position": 8, "acceptedAnswer": { "@type": "Answer", "text": "Elle peut provoquer des changements cutanés comme une pâleur ou des lésions cutanées." } }, { "@type": "Question", "name": "Y a-t-il des symptômes digestifs associés ?", "position": 9, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des symptômes comme des nausées, des diarrhées ou des troubles digestifs peuvent survenir." } }, { "@type": "Question", "name": "Les symptômes varient-ils selon l'âge ?", "position": 10, "acceptedAnswer": { "@type": "Answer", "text": "Oui, les symptômes peuvent être plus prononcés chez les personnes âgées en raison de l'absorption réduite." } }, { "@type": "Question", "name": "Comment prévenir la carence en vitamine B12 ?", "position": 11, "acceptedAnswer": { "@type": "Answer", "text": "Une alimentation équilibrée incluant des sources de B12 et des suppléments si nécessaire aide." } }, { "@type": "Question", "name": "Les personnes âgées doivent-elles prendre des suppléments ?", "position": 12, "acceptedAnswer": { "@type": "Answer", "text": "Oui, les personnes âgées peuvent avoir besoin de suppléments en raison d'une absorption réduite." } }, { "@type": "Question", "name": "Les végétaliens peuvent-ils éviter la carence ?", "position": 13, "acceptedAnswer": { "@type": "Answer", "text": "Ils doivent prendre des suppléments de B12 ou consommer des aliments enrichis pour éviter la carence." } }, { "@type": "Question", "name": "Les tests réguliers sont-ils recommandés ?", "position": 14, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des tests réguliers sont conseillés pour les personnes à risque de carence." } }, { "@type": "Question", "name": "Les maladies digestives augmentent-elles le risque ?", "position": 15, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des maladies comme la maladie de Crohn peuvent affecter l'absorption de la vitamine B12." } }, { "@type": "Question", "name": "Comment traiter une carence en vitamine B12 ?", "position": 16, "acceptedAnswer": { "@type": "Answer", "text": "Le traitement inclut des suppléments oraux ou des injections de vitamine B12 selon la gravité." } }, { "@type": "Question", "name": "Quelle est la durée du traitement ?", "position": 17, "acceptedAnswer": { "@type": "Answer", "text": "La durée dépend de la gravité, mais peut durer de quelques mois à plusieurs années." } }, { "@type": "Question", "name": "Les aliments peuvent-ils aider à corriger la carence ?", "position": 18, "acceptedAnswer": { "@type": "Answer", "text": "Oui, consommer des aliments riches en B12 comme la viande, le poisson et les produits laitiers aide." } }, { "@type": "Question", "name": "Les personnes végétariennes sont-elles à risque ?", "position": 19, "acceptedAnswer": { "@type": "Answer", "text": "Oui, elles peuvent être à risque en raison d'un apport alimentaire limité en vitamine B12." } }, { "@type": "Question", "name": "Les traitements sont-ils différents pour les enfants ?", "position": 20, "acceptedAnswer": { "@type": "Answer", "text": "Les traitements sont similaires, mais les doses peuvent varier selon l'âge et le poids." } }, { "@type": "Question", "name": "Quelles complications peuvent survenir ?", "position": 21, "acceptedAnswer": { "@type": "Answer", "text": "Des complications incluent l'anémie mégaloblastique, des troubles neurologiques et des problèmes cardiaques." } }, { "@type": "Question", "name": "La carence peut-elle entraîner des problèmes cognitifs ?", "position": 22, "acceptedAnswer": { "@type": "Answer", "text": "Oui, une carence prolongée peut causer des troubles cognitifs et des pertes de mémoire." } }, { "@type": "Question", "name": "Y a-t-il un risque accru de maladies cardiovasculaires ?", "position": 23, "acceptedAnswer": { "@type": "Answer", "text": "Oui, une carence en B12 peut augmenter le risque de maladies cardiovasculaires en élevant l'homocystéine." } }, { "@type": "Question", "name": "Les complications sont-elles réversibles ?", "position": 24, "acceptedAnswer": { "@type": "Answer", "text": "Certaines complications peuvent être réversibles avec un traitement approprié, d'autres non." } }, { "@type": "Question", "name": "La carence en B12 peut-elle affecter la grossesse ?", "position": 25, "acceptedAnswer": { "@type": "Answer", "text": "Oui, elle peut entraîner des complications pendant la grossesse, comme des malformations congénitales." } }, { "@type": "Question", "name": "Qui est le plus à risque de carence en B12 ?", "position": 26, "acceptedAnswer": { "@type": "Answer", "text": "Les personnes âgées, les végétariens, et ceux ayant des troubles d'absorption sont à risque." } }, { "@type": "Question", "name": "Les maladies auto-immunes augmentent-elles le risque ?", "position": 27, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des maladies comme la gastrite atrophique peuvent affecter l'absorption de la B12." } }, { "@type": "Question", "name": "Les médicaments peuvent-ils influencer le risque ?", "position": 28, "acceptedAnswer": { "@type": "Answer", "text": "Oui, certains médicaments comme les inhibiteurs de la pompe à protons peuvent réduire l'absorption." } }, { "@type": "Question", "name": "Les troubles digestifs sont-ils un facteur de risque ?", "position": 29, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des troubles comme la maladie cœliaque peuvent nuire à l'absorption de la vitamine B12." } }, { "@type": "Question", "name": "Les antécédents familiaux jouent-ils un rôle ?", "position": 30, "acceptedAnswer": { "@type": "Answer", "text": "Oui, des antécédents familiaux de carence peuvent augmenter le risque chez certains individus." } } ] } ] }

Sources (10000 au total)

Alternative Complement Pathway Inhibition with Iptacopan in IgA Nephropathy.

The alternative complement pathway plays a key role in the pathogenesis of IgA nephropathy. Iptacopan specifically binds to factor B and inhibits the alternative pathway.... In this phase 3, double-blind, randomized, placebo-controlled trial, we enrolled adults with biopsy-confirmed IgA nephropathy and proteinuria (defined as a 24-hour urinary protein-to-creatinine ratio ... The main trial population included 222 patients in the iptacopan group and 221 in the placebo group. The interim efficacy analysis included the first 250 patients who underwent randomization in the ma... Among patients with IgA nephropathy, treatment with iptacopan resulted in a significant and clinically meaningful reduction in proteinuria as compared with placebo. (Funded by Novartis; APPLAUSE-IgAN ...

Complement activation profiles in anti-acetylcholine receptor positive myasthenia gravis.

Complement component 5 (C5) targeting therapies are clinically beneficial in patients with acetylcholine receptor antibody... In a case-control study, concentrations of C3a, C5a and sC5b9 were simultaneously quantified, indicating general activation of the complement system, whether via the classical and lectin pathways (C4a... Treatment-naïve patients with AChR-Ab... Markers indicative of complement activation are prominently increased in patients with AChR-Ab MG despite standard immunosuppressive therapies. Complement inhibition proximal to C5 cleavage should be ...

Association between circulatory complement activation and hypertensive renal damage: a case-control study.

The aim of this study was to investigate the potential importance of complement system activation, with particular emphasis on the complement alternative pathway (AP), in the pathogenesis of hypertens... Serum complement C3, complement Factor H (CFH) and AP activation were assessed in 66 participants with established essential hypertension with renal damage (RD). Fifty-nine patients with age- and sex-... Our study revealed that C3 and AP50 continuously increased from normal to NRD to RD (... Abnormal activation of complement, particularly complement AP, may be a risk factor for the development and progression of hypertensive renal damage....

Minimal role for the alternative pathway in complement activation by HIT immune complexes.

Anti-platelet factor 4 (PF4)/heparin immune complexes that cause heparin-induced thrombocytopenia (HIT) activate complement via the classical pathway. Previous studies have shown that the alternative ... These studies sought to examine the contributions of the alternative pathway to complement activation by HIT antibodies.... Using IgG monoclonal (KKO) and/or patient-derived HIT antibodies, we compared the effects of classical pathway (BBK32 and C1-esterase inhibitor [C1-INH]), alternative pathway (anti-factor B [fB] or fa... Classical pathway inhibitors BBK32 and C1-INH and the combined classical/alternative pathway inhibitor sCR1 prevented KKO/HIT immune complex-induced complement activation, including release of C3 and ... Collectively, these findings suggest the alternative pathway contributes little in support of complement activation by HIT immune complexes. Additional in vitro and in vivo studies are required to exa...

The contribution of the alternative pathway in complement activation on cell surfaces depends on the strength of classical pathway initiation.

The complement system is an important component of innate immunity. The alternative pathway (AP) amplification loop is considered an essential feed forward mechanism for complement activation. However... We evaluated the contribution of the AP to complement responses initiated through the CP on human RBCs by serum of AIHA patients and recombinant antibodies. Moreover, we studied complement activation ... We show that the amplification loop is redundant when efficient CP activation takes place. This is independent of the presence of membrane-bound complement regulators. The role of the AP may become si... The AP can be bypassed through efficient CP activation. The AP amplification loop has a role in complement activation during conditions of modest activation via the CP, when it can allow for efficient...

Urinary markers of the alternative and lectin complement pathway are increased in IgA vasculitis nephritis.

IgA vasculitis (IgAV) is the most common form of childhood vasculitis. Nephritis (IgAVN) occurs in 50% of patients and 1-2% progress to chronic kidney disease stage 5. The pathophysiology of nephritis... Children with IgAV were recruited and grouped according to proteinuria: IgAVN or IgAV without nephritis (IgAVwoN). Age and sex-matched healthy controls (HCs) were also recruited. Cross-sectional urine... A total of 50 children were included (IgAVN,... There is evidence of complement pathway products in the urine of children with IgAVN that warrants further investigation....