RESUMO
A girl with a history of autoimmune disease developed life-threatening agranulocytosis. A bone marrow biopsy demonstrated selective granulocytic hypoplasia. No antineutrophil antibodies were found. In vitro bone marrow culture of granulocytic progenitor cells suggested T cell-mediated inhibition of colony formation, which was reduced by in vitro treatment of marrow cells with either hydrocortisone or an antibody directed against T-lymphocytes and complement. The patient responded to treatment with antithymocyte globulin after administration of corticosteroids and other immunosuppressants failed to increase her neutrophil count significantly. Attempts to stop ATG treatment resulted in precipitous drops in her neutrophil counts, which reversed with readministration of ATG. She then received weekly ATG infusions for over 24 months until she was able to maintain a normal neutrophil count. A trial of ATG therapy may be indicated in severe neutropenia when in vitro culture results indicate a possible autoimmune basis.
Assuntos
Agranulocitose/terapia , Soro Antilinfocitário/uso terapêutico , Agranulocitose/complicações , Agranulocitose/imunologia , Anemia Hemolítica Autoimune/complicações , Criança , Ensaio de Unidades Formadoras de Colônias , Feminino , HumanosRESUMO
Seven children and adolescents are described with mixed connective tissue disease. The patients had varying clinical features, commonly characterized by Raynaud phenomenon, arthritis, abnormal pulmonary function, and esophageal dysmotility. All patients had speckled antinuclear antibodies and high titers (greater than 1:100,000) of antibodies to ribonuclease-sensitive extractable nuclear antigen. We prepared extractable nuclear material from radioactively labeled HeLa cells, analogous to classic extractable nuclear antigen. Sera from all seven patients precipitated ribonucleoprotein containing the small nuclear ribonucleic acid species U1 from the HeLa cell extract. Antibody to U1 ribonucleoprotein was not found in sera from 51 of 53 children and adults having a variety of autoimmune and other diseases, nor in sera from nine normal individuals. The U1 ribonucleoprotein appears to be the component of extractable nuclear antigen characteristically reacting with sera from patients with mixed connective tissue disease. The finding of a distinct molecular marker in all children studied with mixed connective tissue disease indicates that this is a distinct disease entity and not a heterogeneous population of immune disorders.
Assuntos
Doença Mista do Tecido Conjuntivo/imunologia , Nucleoproteínas/imunologia , RNA/imunologia , Ribonucleoproteínas/imunologia , Adolescente , Anticorpos/análise , Antígenos Nucleares , Criança , Feminino , Humanos , Masculino , RNA Nuclear PequenoRESUMO
Opsonic defects have been reported in unimmunized patients with sickle cell disease. We found significant increases (P less than 0.001) in serum opsonic activity, measured by a radiolabeled bacterial uptake assay, and in type 7 pneumococcal polysaccharide antibody concentration in 17 such patients 2 years of age or older after pneumococcal polysaccharide immunization. All 17 patients and six healthy controls achieved a type 7 antibody concentration of more than 300 ng antibody nitrogen per milliliter, believed to be the protective level of antibody in vivo. Six patients with sickle cell disease less than 2 years of age did not have a significant increase in type 7 antibody concentration after immunization. Only three of these six patients achieved a postimmunization type 7 antibody concentration exceeding 300 ng Ab N/ml. Overall, 16 of 23 patients with sickle cell disease (70%) had a twofold or greater increase in type 7 antibody concentration, and 13 of these (81%) had a corresponding increase in opsonic activity (P less than 0.001). Thus most patients who responded to pneumococcal polysaccharide immunization had a concurrent increase in opsonic activity in vitro.
Assuntos
Anemia Falciforme/imunologia , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/administração & dosagem , Proteínas Opsonizantes/imunologia , Adolescente , Fatores Etários , Anemia Falciforme/complicações , Criança , Pré-Escolar , Feminino , Humanos , Imunização , Lactente , Masculino , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Streptococcus pneumoniae/imunologiaRESUMO
Sjögren syndrome, consisting of keratoconjunctivitis sicca and xerostomia with or without another autoimmune disease, is uncommon in children. We describe our retrospective experience with eight pediatric patients with SS. All had recurrent parotid enlargement and abnormal salivary gland biopsies, six had keratoconjunctivitis sicca, and five had other autoimmune manifestations, although only two of these had other clearly defined autoimmune disorders (mixed connective tissue disease and hypergammaglobulinemic purpura). Our patients had a higher incidence of primary SS, parotid enlargement, and hematologic abnormalities than did children previously reported with SS. Children with SS demonstrate a clinical heterogeneity comparable to that seen in adults.