RESUMEN
BACKGROUND: Red blood cell (RBC) autoimmunization is a relatively uncommon cause of anemia in children and presents some differences from those of adults. Due to its frequency, autoimmune hemolytic anemia (AIHA) in childhood has prompted very few studies, and the literature consists mostly of sporadic case histories. The objective of this study was to stress the importance of an appropriate serologic diagnosis in suspected cases. STUDY DESIGN AND METHODS: This report describes the immunohematologic features of 100 patients with AIHA studied in the Immunohaematologic Unit of Blood Bank, "La Sapienza" University of Rome. The patients were diagnosed in the same department from 1983 to 2003. RESULTS: The peak incidence of AIHA was in the first 4 years of life. No sex predominance was noted. Warm AIHA was the most common type of acquired immune hemolytic anemia; it comprised 64 of the 100 patients, whereas 26 patients showed a cold AIHA. Associated AIHA showed a slightly more frequent incidence (54/100) compared to idiopathic forms of AIHA (46/100). CONCLUSIONS: In this study serologic records of 100 children with confirmed AIHA are reported. This series, much larger than any previously reported, is critically reviewed and analyzed to delineate the immunologic features of the disease in childhood.
Asunto(s)
Anemia Hemolítica Autoinmune/inmunología , Adolescente , Distribución por Edad , Anemia Hemolítica Autoinmune/epidemiología , Autoanticuerpos/sangre , Niño , Preescolar , Prueba de Coombs , Eritrocitos/metabolismo , Hemoglobinuria Paroxística/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Incidencia , Lactante , Isoanticuerpos/sangre , Italia/epidemiología , Estudios RetrospectivosRESUMEN
Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by the expansion of phosphatidylinositol glycan class A (PIG-A) defective haematopoietic cells, probably due to the immune-mediated alterations of the bone marrow environment selecting PIG-A- stem cells. The present study investigated the presence of alterations of the immune system in a population of 11 PNH patients. The production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), evaluated by intracellular cytokine analysis, and the frequencies of class I and II human leucocyte antigen (HLA) alleles were studied in comparison with healthy human subjects. Similar percentages of lymphocytes produced cytokines in PNH patients and controls after costimulation-independent activation; however, a negative correlation was found between the percentage of IFN-gamma producing cells and white cell or platelets counts. PNH patients showed an higher percentage, compared with controls, of IFN-gamma producing cells after costimulation-dependent activation. The frequency of HLA-A31 was higher in patients than in controls (27.2% vs. 4%), similarly to that of HLA-B7 (27.2% vs. 6%). With regard to class II alleles, 18% of PNH patients expressed DQB1*04 compared with none of 50 control cases. This study supports the hypothesis that immune alteration are present in PNH and that the immunogenetic background could influence the development of the disease.