RESUMO
INTRODUCTION: Autoimmune haemolytic anaemia (AIHA) is defined as the increased destruction of red blood cells (RBCs) in the presence of anti-RBC autoantibodies and/or complement. Its pathogenesis is multifactorial and includes changes in mechanisms of cytokine production and functionality. A number of recent studies have implicated cytokines polymorphisms in the pathogenesis of autoimmune diseases. The aim of this study was to determine the frequency of polymorphisms of tumour necrosis factor alpha (TNF-α), lymphotoxin-α (LT-α), interleukin 10 (IL-10), interleukin 12 (IL-12) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) in patients with AIHA in comparison with healthy individuals. METHODS: The study population consisted of 17 patients with AIHA and 40 healthy controls. The polymorphisms for TNF-α-308, LT-α +252, IL-10 -592, IL-12 +1188 and CTLA-4 +49 were examined by polymerase chain reaction followed by specific restriction enzyme digestion. RESULTS: There was no significant difference in the phenotypic distributions of polymorphisms of the TNF-α, IL-10, IL-12 and CTLA-4 between the patients and controls. Compared with healthy controls, patients with AIHA had a significant higher frequency of LT-α (+252) AG phenotype (41%vs. 13%; P = 0.032). CONCLUSION: In this study, no significant differences on the frequency of TNF-α, IL-10, IL-12 and CTLA-4 polymorphisms between patients with AIHA and controls was found, suggesting that the targeted polymorphisms do not influence on the emergence and evolution of the disease. However, the LT-α +252 polymorphism might have an effect for AIHAI development, suggesting that further studies are necessary to clear up this question.
Assuntos
Anemia Hemolítica Autoimune/genética , Antígeno CTLA-4/genética , Citocinas/genética , Polimorfismo Genético , Adolescente , Adulto , Idoso , Feminino , Humanos , Interleucina-10/genética , Interleucina-12/genética , Linfotoxina-alfa/genética , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/genéticaRESUMO
BACKGROUND AND OBJECTIVES: Benefits of adopting restrictive guidelines for erythrocyte transfusions are still controversial. The objective of this study was to verify if a very strict guideline could reduce erythrocyte transfusions in preterm infants without adverse outcomes. MATERIALS AND METHODS: Two prospective cohorts of neonates with gestational age < 37 weeks and birth weight < 1500 g were studied. Neonates born in Period 1 were submitted to a strict guideline for erythrocyte transfusions. In Period 2, a new stricter protocol was introduced. Infants of both periods were compared regarding number of transfusions and clinical outcome. RESULTS: The median number of transfusions decreased from 2 (1 to 14) in Period 1 to 1 (1-9), P = 0.001, in Period 2. The linear regression multivariate analysis showed that the implementation of the stricter guideline was associated with a reduction in the number of transfusions received by patients by 0.55 (95% confidence interval: -0.08; -1.02) units/patients. Number of apnea episodes, weight at 28 days of life and days of hospital stay were similar in both periods. Intra-hospital death was lower in Period 2. CONCLUSION: A very strict guideline reduced the number of erythrocyte transfusions in preterm infants, without threatening their clinical course.