Assuntos
Metotrexato , Prurigo , Alitretinoína , Ciclosporina , Humanos , Metotrexato/uso terapêutico , Prurigo/tratamento farmacológico , PruridoAssuntos
COVID-19 , Pérnio , Pérnio/epidemiologia , Surtos de Doenças , Humanos , Pandemias , SARS-CoV-2Assuntos
Infecções por Coronavirus/epidemiologia , Controle de Infecções/organização & administração , Pandemias/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Dermatopatias/diagnóstico , Telemedicina , COVID-19 , Estudos de Coortes , Infecções por Coronavirus/prevenção & controle , Dermatologia/métodos , Feminino , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Encaminhamento e Consulta/estatística & dados numéricos , Estudos RetrospectivosRESUMO
To emphasize the requirement for a J chain in native polymeric immunoglobulins for their selective transport into exocrine secretions, IgG, purified from two different antisera specific for the human J chain, was shown to: (i) bind in vitro to human polymeric IgA (pIgA) by density gradient ultracentrifugation; (ii) inhibit binding in vitro of rat secretory component to human pIgA; (iii) inhibit hepatic transport of human pIgA into rat bile in vivo; and (iv) inhibit apical transcytosis of pIgA in vitro by polarized human polymeric immunoglobulin receptor (pIgR)-expressing Madin-Darby canine kidney cells. Inhibition of biliary transport increased with the molar ratio of anti-J chain antibodies against pIgA and their incubation time. Anti-J chain F(ab')2 and Fab fragments also inhibited biliary transport, excluding a role for phagocytic clearance or excessive size of the immune complexes. Anti-human-Fc alpha Fab, bound to human pIgA in complexes of larger size than those with anti-J chain Fab, did not inhibit biliary transport of human pIgA. Propionic acid-denatured human pIgA, although containing J chains, was very poorly transported into rat bile. Altogether, our data strongly support, now also by in vivo experiments, the crucial role of the J chain of native pIgA in its selective pIgR-mediated transport into secretions, as suggested long ago by in vitro data only. Recent data on J chain-knockout mice, with low IgA levels in bile and feces, cannot explain the role of the J chain in contributing to the secretory component/pIgR-binding site of normal pIgA, but otherwise agree with our study.