RESUMO
TNF alpha contributes to the necrotizing enterocolitis (NEC) pathogenesis. To date, this clinical entity of neonates was never described in HIV-infected children. In 15 HIV-positive children with histological evidence of various intestinal lesions resembling NEC, we have studied serum TNF alpha and soluble TNF receptor concentrations by ELISAs, and archived paraffin embedded intestinal tissues by in situ hybridization with DIG-labeled RNA probes for TNF alpha messenger transcripts. We found increased levels of TNF alpha and soluble receptors, proving TNF alpha system activation. We detected TNF alpha messenger transcripts in all cases, regardless of the presence of microbial pathogens at intestinal level. Since HIV can infect many cells of the gastrointestinal tract, also triggering the secretion of TNF alpha, we concluded that factors contributing to NEC pathogenesis in HIV-infected children are complex. At least the nutritional and immunological status are involved, other viral co-infections, opportunistic microbes (such as mycobacteria), and pathogenic activities of HIV. All together enhance both circulating TNF alpha system and its cytotoxic effects at intestinal level.
Assuntos
Antígenos CD/sangue , Enterocolite Necrosante/sangue , Infecções por HIV/sangue , Receptores do Fator de Necrose Tumoral/sangue , Fator de Necrose Tumoral alfa/análise , Criança , Enterocolite Necrosante/complicações , Enterocolite Necrosante/metabolismo , Enterocolite Necrosante/patologia , Expressão Gênica , Infecções por HIV/complicações , Infecções por HIV/metabolismo , Infecções por HIV/patologia , Humanos , Lactente , Mucosa Intestinal/metabolismo , Intestinos/patologia , RNA Mensageiro/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa/genéticaRESUMO
The pandemic spread of tuberculosis (TB) and human immunodeficiency virus (HIV) represents a serious world problem. The diagnosis of TB in developing countries remains difficult, particularly in patients with concomitant HIV infection. Anergia to tuberculin frequently occurs in HIV-positive patients with pulmonary or extrapulmonary disease, and radiographic images are atypical or nondiagnostic. Children are often in an even more unfavorable situation: they cannot expectorate, and the biological samples required for bacteriological examination and culture are more difficult to obtain. We present in this work the correlation between the presence of serum antimycobacterial antibodies [as demonstrated by an in-house enzyme-linked immunosorbent assay (ELISA)] in 41 out of 279 HIV-infected children, and clinical, bacteriological, radiological, and pathological data that support the diagnosis of TB in these children. The prevalence of antimycobacterial antibodies in our group of HIV-positive children was 23.3%. In only 4 of the total cases investigated could the diagnosis of TB not be supported by the results of standard tests for TB. The control group showed an insignificant interference from bacillus Calmette-Guerin (BCG) vaccination.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática/normas , Mycobacterium tuberculosis/imunologia , Tuberculose/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Países em Desenvolvimento , Humanos , Lactente , Programas de Rastreamento/métodos , Prevalência , Romênia , Sensibilidade e Especificidade , Tuberculose/imunologiaRESUMO
During the summer of 1996 an unusual clustering of meningoencephalitis cases was recorded in the Capital City, Bucharest, and in some areas from South-East Romania. After an initial suspicion of an enteroviral etiology was discarded, the West Nile etiology was confirmed by specific antibodies demonstration through hemagglutination-inhibition and ELISA tests. This study included 251 patients with the diagnoses of West Nile acute encephalitis (166 cases), acute meningitis (57 cases) and acute febrile disease (33 cases). The patients' age ranged from 1 to 89 years (mean 51.1 years). The most frequent clinical manifestations were: fever (95.7% of cases), cephalalgia (92.6%), stiffness of the neck (89.1%), vomiting (62.5%), marked asthenia (46.5%), myalgia (28.9%). In addition, patients with encephalitis exhibited: alteration of consciousness (89.2% of cases), tremor of extremities (40.4%), ataxia (44%), paralysis (15.1%). The fatality rate was 15.1% in acute encephalitis, 1.8% in acute meningitis and 0% in the acute febrile disease.