CCR5 genotypes and progression to HIV disease in perinatally infected children

The CCR5 molecule, a chemokine receptor, is the most important co-receptor for macrophage-tropic HIV-1. A 32-bp deletion in the gene encoding CCR5 (CCR5-del32) confers nearly complete resistance to HIV-1 infection in homozygotes, and slows the rate of progression to AIDS in heterozygous adults. The aim of this study was to describe the CCR5 genotypes and the characteristics of HIV disease progression in perinatally infected children. From a total of 51 children analyzed for the CCR5-del32 mutation, 18 (35%) were considered to be rapid progressors, 28 (55%) were moderate progressors and 5 (10%) were slow progressors. A portion of the CCR5 gene was amplified by PCR from genomic DNA followed by agarose gel electrophoresis. Forty-nine children (96%) carried the homozygous wild type genotype for CCR5 while 2 (4%) carried the heterozygous wt/del32 genotype. In the population studied, the CCR5 genotype was unable to account for the differences in pattern of the disease progression among the three groups (rapid, moderate and slow progressors), and the allele frequency of CCR5-del32 was too low to allow statistical comparisons with adequate resolving power. Studies on larger populations may help to further elucidate the role of this allele and other host factors in the regulation of HIV-1 pathogenesis in children.USP HCFM Institute of Tropical Medicine of São PauloUNIFESP Federal University of São PauloUNIFESP, UNIFESPSciEL

Seroprevalence of human herpesvirus 8 infection in children born to HIV-1- infected women in São Paulo, Brazil

Human herpesvirus-8 (HHV-8) appears to be transmitted mainly by sexual contact. However, several studies suggest that in developing countries the infection may be acquired early in life by routes other than sexual transmission. The present study estimated the seroprevalence of HHV-8 in Brazilian children born to HIV-1-infected mothers. The serum samples were collected in a cross-sectional cohort study from 99 children born to HIV-infected mothers (median age 3.27 years; range 1.5-13.8 years) attending the outpatient clinic of the Federal University of São Paulo. IgG antibodies to HHV-8 latency-associated nuclear antigen and lytic phase antigens were detected by immunofluorescence assays. The samples tested were collected from children aged 12 months or older to exclude the possibility of cross-placental antibody transport. The total prevalence of anti-lytic antibodies in this population (5/99; 5%) reveals that HHV-8 infection can occur during childhood. Children aged 1.5 to 2 years had a seroprevalence of 2% (1/50) and children aged 3.25 to 13.8 years had a seroprevalence of 8% (4/49). This difference was not statistically significant, probably because of the small size of the sample, but it suggests that HHV-8 infection occurs more commonly late in infancy. Further prospective studies are necessary to evaluate the timing and risk factors for primary HHV-8 infection in the pediatric population.Universidade de São Paulo Faculdade de Medicina Departamento de Moléstias Infecciosas e ParasitáriasUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Centro de Atendimento da Disciplina de Infectologia PediátricaUNIFESP, EPM, Centro de Atendimento da Disciplina de Infectologia PediátricaSciEL

Detecção de anticorpos IgM nas infecções primárias e secundárias pelo citomegalovírus em pacientes submetidos a transplante renal

Foram acompanhados 27 pacientes submetidos a transplante renal para avaliação do comportamento dos anticorpos IgM e IgG CMV-específicos. Dos 27 casos estudados, 17 (63,0%) tinham anticorpos IgG, detectados pela reação de fixação de complemento (RFC), antes de serem submetidos ao transplante, e 10 (37,0%) eram soro negativos. A pesquisa de anticorpos IgM (técnica de imunofluorescência indireta) foi negativa em todas as amostras pré transplante. Num período de acompanhamento que variou de 28 a 425 dias (média de 115 dias) após o transplante, observou-se que 20 dos 27 (74,1%) apresentaram evidências sorológicas de infecçáo pelo CMV, ocorrendo a maioria dos casos (14/20, 70%) em pacientes que já tinham anticorpos para o CMV antes do transplante. A pesquisa de anticorpos IgM CMV-específicos foi positiva em 12 dos 14 pacientes com evidências sorológicas de reinfecção ou reativação da infecção pelo CMV, e em 100% (6/6) dos pacientes com infecção primária. Dentre os 10 pacientes acompanhados por mais de 4 meses, somente 1 (10%) negativou o IgM neste período