RESUMO
In a prospective study 101 newborns were enrolled into four groups: Group I included 38 unrelated newborns suffering from RDS and four sets of twin sibs (seven of whom had RDS; Group II included prematures free from RDS and any other disease; Group III included 21 newborns) delivered by C.S. and free from RDS and any other disease; Group IV included 20 infants of diabetic mothers free from RDS. HLA antigens were typed for all the newborns. The analysis of results could be summarized as follows. (1) Strong association between A3 antigen (RR = 19.4, WY2 = 59.8, S = 0.599) and B14 antigen (RR = 14.1, WY2 = 50.7, S = 0.489) and RDS. (2) HLA haplotypes were identical in twins sibs suffering from RDS and nonidentical in twins when one sib had RDS and the other is free. (3) The frequencies of A3 and B14 among the other three groups were insignificantly different from the general population and highly significantly low compared to RDS group. In conclusion, the development of RDS depends probably on the presence of susceptibility gene(s) in linkage disequilibrium with A3 and B14 antigens. Environmental factors, magnified by prematurity, in such susceptible newborns affect the production of surfactant leading to the development of RDS.
Assuntos
Antígenos HLA/genética , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Suscetibilidade a Doenças , Feminino , Antígenos HLA/análise , Antígeno HLA-A3/genética , Antígenos HLA-B/genética , Antígeno HLA-B14 , Haplótipos , Humanos , Recém-Nascido , Masculino , Linhagem , Estudos Prospectivos , Síndrome do Desconforto Respiratório do Recém-Nascido/imunologia , Fatores de Risco , Gêmeos Dizigóticos/genéticaRESUMO
Peripheral blood lymphocytes from 42 unrelated Egyptian patients with tuberculosis and 156 healthy persons were HLA phenotyped for the A,B and DR loci using the NIH lymphocytotoxicity tests. Statistical analysis of the results showed that A2 and B5 had significantly increased frequencies among patients with tuberculosis compared with the controls. Patients with A2 had more severe disease than did patients without A2 and the number with B5 antigen was less than those without the antigen. This observation suggests that A2 and B5 may influence susceptibility to tuberculosis, but not the course of the disease. Furthermore, a linkage disequilibrium was found between A2 and B5 antigen among tuberculous patients, but their association bore no relation to the severity of the disease.
Assuntos
Antígenos HLA/análise , Antígenos HLA-B , Tuberculose Pulmonar/imunologia , Adolescente , Criança , Pré-Escolar , Egito , Feminino , Ligação Genética , Antígeno HLA-A2 , Humanos , Lactente , Masculino , Fenótipo , Risco , Tuberculose Pulmonar/genéticaRESUMO
Serum growth hormone (GH), cortisol, free thyroxine (FT4), thyroid-stimulating hormone (TSH), and insulin like growth factor I (IGF-I) concentrations were measured in 15 children with sickle cell disease (SCD) together with their heights < 5th percentile for age and gender, and in 15 healthy age-matched children who had normal variant short stature (NVSS). GH response to an oral dose of clonidine (0.15 mg/m2) and cortisol response to ACTH stimulation were determined in the two groups. Children with SCD had significantly lower serum concentrations of IGF-I and decreased GH response to stimulation. Eight out of the 15 children with SCD did not mount an appropriate GH response to clonidine provocation (> 10 micrograms/l). CT scanning of the hypothalamic-pituitary area in those eight children with SCD revealed a partial or complete empty sella in all of them. It appears that defective GH release, and consequently low IGF-I production and slow growth velocity in children with SCD might be secondary to hypoxic-vascular insults to their hypothalamic-pituitary axis during one or more of the sickling episodes.