Autoimmunity in IgA deficiency: revisiting the role of IgA as a silent housekeeper.
Both systemic and organ-specific autoimmune diseases are major manifestations of IgA deficiency (IgAD), the most common primary immunodeficiency. In addition, to discuss the clinical findings of IgAD patients, we proposed a hypothesis to explain the high association with autoimmune phenomena. Based on observations, interactions of monomeric IgA with FcalphaRI result in a partial phosphorylation of FcRgamma-associated FcalphaRI, notably in the immunoreceptor tyrosine-based activation motif (ITAM) inducing the recruitment of the SHP-1 tyrosine phosphatase. This leads to deactivation of several activating pathways of the immune system including immunoreceptors that bear ITAM motif and ITAM-independent receptors. Consequently, inflammatory reactions and auto-immune process would be prevented.
Jacob
Cristina M A
CM
Instituto da Criança, Hospital das Clinicas da Faculdade de Medicina, Universidade de São Paulo, Rua Oscar Freire 1961 apto 24. Cerqueira César CEP 05409.011 São Paulo, Brasil. miuki55@uol.com.br
Pastorino
Antonio C
AC
Fahl
Kristine
K
Carneiro-Sampaio
Magda
M
Monteiro
Renato C
RC
D000230:Adenocarcinoma / Q000209:etiology / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology / Q000209:etiology / Q000276:immunology; D015551:Autoimmunity; D001938:Brazil; D006801:Humans; D017098:IgA Deficiency / Q000150:complications / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology*; D018928:Immunity, Mucosal; D018448:Models, Immunological; D009894:Opportunistic Infections / Q000276:immunology; D015995:Prevalence; D011961:Receptors, Fc / Q000235:genetics / Q000276:immunology; D017634:Self Tolerance; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000209:etiology / Q000276:immunology
D011961:Receptors, Fc