Pediatric HIV infection

Therapeutic role of CD8+ T cells in HIV-1 infection: targets and suppressors of viral replication

CD8+ T cells are pivotal in controlling viral replication in HIV-1-infected subjects. However, in chronic infection, HIV-1-specific CD8+ T cells fail to adequately control infection, presenting incomplete maturation and more severe functional impairment with advanced disease. Accumulating evidence has shown that CD8+ T cells can also be productively infected by HIV-1. Whether HIV-1 infection of CD8+ T lymphocytes impacts on their antiviral activity remains to be determined. This review explores the potential mechanisms of HIV-1 infection of CD8+ T cells, its likely contribution to the immunopathogenesis of HIV-1 infection and potential therapeutic interventions.

Neonatal HIV infection

The purpose of this article is to describe the pertinent issues related to mother-to-child transmission of HIV infection. Significant succcss has been achieved in developed countries to reduce the incidence of this devastating disease in neonates through screening of pregnant women, maternal antiretroviral therapy to reduce transmission, and cesarean section for delivery. Prophylaxis continues for the first six weeks of the newborn's life with antiretroviral therapy and careful monitoring of clinical well-being. Antiretroviral therapy offers significant reduction in the rate of mother-to child transmission, and this is presently the cornerstone of therapy for the HIV-infected pregnant woman. Clinical studies of treatment modalities continue to offer new hope to prevent transmission of the virus to the fetus. Care for the HIV infected newborn is highly complex and constantly evolving. All neonatal nurses should be aware of these issues so that they can be partners in the identification of new cases and the ongoing treatment of babies who are infected.

Alterações dermatológicas em crianças com Aids e sua relação com categorias clínico-imunológicas e carga viral

FUNDAMENTOS: Desde o início da epidemia da Aids as dermatoses têm sido freqüentemente descritas em pacientes com essa doença, com relatos de casos atípicos e estudos de séries de pacientes adultos; no entanto, há poucas publicações sobre alterações cutâneas em pacientes pediátricos com Aids. OBJETIVOS: Estudo prospectivo para avaliar a presença de dermatoses em 40 pacientes pediátricos com Aids. MÉTODOS: Quarenta pacientes, com idade inferior a 13 anos e portadores de Aids, foram estudados por um período de seis meses para avaliação de: número de alterações dermatológicas; suas características clínicas; distribuição conforme as categorias clínico-imunológicas e o valor da carga viral. RESULTADOS: A prevalência de dermatoses foi de 82,4%, na primeira consulta, e, no acompanhamento longitudinal, 92,5% dos pacientes tiveram alterações dermatológicas, com proporção de cinco diagnósticos por doente. As crianças com classificação clínico-imunológica grave e carga viral acima de 100.000 cópias/ml apresentaram maior número de alterações dermatológicas quando comparadas àquelas das categorias clínico-imunológicas leves. A proporção de diagnósticos por paciente na categoria clínica C foi de 6,8 e na A de 3,6; na categoria imunológica grave, de sete, e na leve de 3,7; e na carga viral > 100.000 de 7,3, e na < 100.000 de 4,2 (todos com significância estatística). CONCLUSÃO: As dermatoses foram freqüentes nas crianças com Aids e ocorreram em maior número nos pacientes pertencentes às categorias graves. A elevada freqüência de alterações da pele nos pacientes pediátricos com a doença indica ser imprescindível sua avaliação dermatológica minuciosa e freqüente.

The evolving art of caring for pregnant women with HIV infection

Care for the pregnant woman who has human immunodeficiency virus (HIV) is highly complex and constantly evolving. The purpose of this article is to describe the pertinent issues regarding women and HIV during pregnancy, including epidemiology of mother-to-child transmission, the effect of the disease on pregnancy, care issues in the perinatal period, and the issues in women's lives that place them at risk for HIV infection. Antiretroviral therapy offers significant reduction in the rate of mother-to-child transmission, and this is presently the cornerstone of therapy for the pregnant woman with HIV. Careful intrapartum management may also reduce the risk of transmission. Clinical studies of treatment modalities continue to offer new hope to prevent transmission of the virus to the fetus.

Costimulation of naive CD8(+) lymphocytes induces CD4 expression and allows human immunodeficiency virus type 1 infection

Human immunodeficiency virus type 1 (HIV-1) infection requires cell surface expression of CD4. Costimulation of CD8(+)/CD4(-) T lymphocytes by anti-CD3 and anti-CD28 antibodies or by allogeneic dendritic cells induced expression of CD4 and rendered these CD8 cells susceptible to HIV-1 infection. Naive CD45RA+ cells responded with greater expression of CD4 than did CD45RO+ cells. CD8(+) lymphocytes derived from fetal or newborn sources exhibited a greater tendency to express CD4, consistent with their naive states. This mechanism of infection suggests HIV-induced perturbation of the CD8 arm of the immune response and could explain the generally rapid disease progression seen in HIV-infected children.

Axonal sprouting in hippocampus of cats infected with feline immunodeficiency virus (FIV)

Neurologic dysfunction and neuropathology are common findings in patients infected with HIV and in cats infected with feline immunodeficiency virus (FIV). The pathogenesis of lentivirus-associated alterations in the central nervous system (CNS) is multifactorial. Because seizures, alterations in memory, and behavioral changes are clinical manifestations in adults and children infected with HIV, we explored the possibility that changes in neuronal structure may occur in the hippocampus. To do this, we examined the dentate gyrus of FIV-infected cats, an animal model of HIV infection. Neuropathologic findings included gliosis within the hilus of the dentate gyrus and granule cell axonal sprouting. Using the Timm's method, which labels axons of dentate gyrus granule cells, abnormally high amounts of staining were observed in the inner one third of the molecular layer in 45% of FIV-infected cats (n = 11) and in none of the controls (n = 19). Prominent axonal sprouting was seen in three FIV-infected cats that were infected as kittens, suggesting that younger cats may be more susceptible. Axon reorganization of the dentate granule cells has been hypothesized to underlie complex partial seizure activity in human temporal lobe epilepsy. These results suggest that FIV infection causes granule cell axon reorganization in the hippocampus of cats. A similar neuropathogenetic mechanism may contribute to neurologic dysfunction in HIV-infected patients.