HIV-1 superinfection is not a common event.

Evidence for human immunodeficiency virus type 1 (HIV-1) superinfection was investigated among a group of four previously HIV-1 infected transfusion recipients (and the four implicated HIV-1 infected donors) identified by the Transfusion Safety Study, and two groups of 4 and 5 Brazilian injection drug users, who consistently injected themselves using shared paraphernalia. To probe these cases for possible superinfection we used heteroduplex mobility analysis (HMA) of HIV-1 tat, a technique which is a reliable for establishing epidemiologic linkages and searching for minor strains in mixed infection settings. In all these cases with established, untreated HIV-1 infections, we were unable to detect HIV-1 superinfection, even though the involved individuals were at high risk for second strain acquisition. We therefore conclude that although superinfection can occur in a few cases, it is a rare event, and the vast majority of recombinant HIV-1s characterized to date resulted from acute coinfections, rather than superinfection.

Frequency of polymorphisms of genes coding for HIV-1 co-receptors CCR5 and CCR2 in a Brazilian population.

Entry of human immunodeficiency type 1 virus (HIV-1) into target cells requires both CD(4)and one of the chemokine receptors. Viruses predominantly use one, or occasionally both, of the major co-receptors CCR5 and CXCR4, although other receptors, including CCR2B and CCR3, function as minor co-receptors. A 32-nucleotide deletion (D32) within the b-chemokine receptor 5 gene (CCR5) has been described in subjects who remain uninfected despite extensive exposition to HIV-1. The heterozygous genotype delays disease progression. This allele is common among Caucasians, but has not been found in people of African or Asian ancestry. A more common transition involving a valine to isoleucine switch in transmembrane domain I of CCR2B (64I), with unknown functional consequences, was found to delay disease progression but not to reduce infection risk. As the Brazilian population consists of a mixture of several ethnic groups, we decided to examine the genotype frequency of these polymorphisms in this country. There were 11.5% CCR5 heterozygotes among the HIV-1 infected population and 12.5% among uninfected individuals, similar to data from North America and Western Europe. The prevalence of CCR2-64I homozygotes and heterozygotes was 0.06 and 15.2%, respectively, also similar to what is known for North America and Western Europe.

Frequency of polymorphisms of genes coding for HIV-1 co-receptors CCR5 and CCR2 in a Brazilian population

Entry of human immunodeficiency type 1 virus (HIV-1) into target cells requires both CD4and one of the chemokine receptors. Viruses predominantly use one, or occasionally both, of the major co-receptors CCR5 and CXCR4, although other receptors, including CCR2B and CCR3, function as minor co-receptors. A 32-nucleotide deletion (delta32) within the beta-chemokine receptor 5 gene (CCR5) has been described in subjects who remain uninfected despite extensive exposition to HIV-1. The heterozygous genotype delays disease progression. This allele is common among Caucasians, but has not been found in people of African or Asian ancestry. A more common transition involving a valine to isoleucine switch in transmembrane domain I of CCR2B (64I), with unknown functional consequences, was found to delay disease progression but not to reduce infection risk. As the Brazilian population consists of a mixture of several ethnic groups, we decided to examine the genotype frequency of these polymorphisms in this country. There were 11.5 percent CCR5 heterozygotes among the HIV-1 infected population and 12.5 percent among uninfected individuals, similar to data from North America and Western Europe. The prevalence of CCR2-64I homozygotes and heterozygotes was 0.06 and 15.2 percent, respectively, also similar to what is known for North America and Western Europe

Associaçäo esferocitose hereditária e traço falciforme: relato de um caso e revisäo da literatura / Hereditary spherocytosis associated with sickle cell trait: a case report and literature review

A associaçäo da esferocitose hereditária e o traço falciforme tem sido raramente relatado na literatura médica, com apenas 17 casos descritos que foram revistos neste trabalho. Apresentamos um caso adicional desta associaçä em paciente do sexo feminino, 21 anos, portadora do traço falciforme com história de anemia e crises de hemólise desde os sete anos de idade. Necessitou de hemoterapia em várias ocasiöes. Foi realizada ampla propedêutica, incluindo estudo familiar. Submetida a esplenectomia, houve melhora do quadro. Este caso enfatiza a necessidade de um estudo mais detalhado em pacientes portadores de traço falciforme com sinais evidentes de hemólise.