Incubation period of HIV-1 in perinatally infected children. New York City Perinatal HIV Transmission Collaborative Study Group

AZT Availability in Illinois birthing hospitals: is the perinatal HIV prevention safety net in place?

OBJECTIVES

To prevent perinatal HIV transmission, providers must identify HIV status for all women in labor and newborns, and provide timely antiretroviral therapy if necessary. The objective of this study is to evaluate the availability and accessibility of zidovudine (AZT) in Illinois birthing hospitals.

METHODS

We surveyed all Illinois birthing hospital pharmacies by telephone in February 2005 regarding availability, accessibility, and protocols surrounding AZT use in the perinatal period.

RESULTS

All 137 pharmacies participated. Only 43.1% reported having syrup and IV AZT available and only 37.2% indicated the ability to have AZT available on labor and delivery within 30 min during off hours. Protocols for treating HIV positive women in labor and exposed newborns were available in only 37.2% of pharmacies while 72.4% had protocols for antiretroviral therapy for occupational post-exposure prophylaxis. Variables associated with pharmacies having AZT available included being a major academic hospital and serving a predominately (greater than 96%) white patient population. Timely provision of AZT was more likely to occur in urban, major academic hospitals serving a predominately white population.

CONCLUSIONS

In order to further reduce perinatal HIV transmission, availability and timely access to both syrup and IV AZT must be improved in Illinois birthing hospitals.

Immune pathogenesis of pediatric HIV-1 infection

Vertical exposure to HIV occurs at a time when functional capacity of the infant's immune system is attenuated through immaturity. Immune response capability is rooted in host genetic makeup, and the broad and fine specificity of innate and adaptive immune responses, respectively, shape the outcomes of HIV encounter in some instances and imprint viral changes through selective immune pressure in others. Findings from recent studies have profound implications for understanding immune pathogenesis of pediatric HIV infection and, in particular, highlight the importance of host genetics of both mother and child in determining whether an exposed child acquires HIV infection or not and, if infected, the rate of disease progression. This review focuses on the key host molecules, the CC chemokine CCL3 and HLA, which have taken center stage in these new developments.

Manifestações neurológicas em crianças e adolecentes infectados e expostos ao HIV-1

O envolvimento do sistema nervoso central SNC na infecção pelo HIV-1 em crianças pode estar evidente desde o início ou demorar muitos anos para se manifestar. Microcefalia, rebaixamento cognitivo, sinais piramidais, distúrbios do humor e do comportamento e complicações pelo uso da terapia antiretroviral são comuns. Este é um trabalho observacional, descritivo e seccional cuja finalidade é descrever as alterações do exame neurológico em um grupo de crianças e adolescentes expostos pelo HIV-1 durante o período perinatal. Foram avaliados 173 pacientes. Muitos pacientes tinham superposição de alterações de exame neurológico e/ou mais de um diagnóstico. As alterações mais comuns foram: retardo do desenvolvimento neuropsicomotor, atraso de linguagem, deficiência mental, síndrome piramidal, hiporreflexia. O exame neurológico foi alterado em 67% dos casos, mesmo naqueles pacientes soro-revertidos. Sugerimos que existe alto risco para doença neurológica nesse grupo de pacientes e que a progressão da infecção pelo HIV-1 acentua o aparecimento de co-morbidades e comprometimento de seu prognóstico.

Maternal versus paternal inheritance of HLA class I alleles among HIV-infected children: consequences for clinical disease progression

OBJECTIVE

When children acquire HIV infection from their mothers (with whom they share at least 50% of their HLA alleles), they acquire virus with a history of encounter with maternal HLA-mediated immune responses. We investigated whether maternal HLA selection pressures on the virus would adversely influence clinical outcomes of HIV-infected children.

METHODS

We tested whether time to AIDS diagnosis or death, among a cohort of 59 HIV-infected children in New York City followed from birth for up to 12 years, was associated with maternally- or paternally-inherited child HLA class I alleles, and with HLA similarity between mother and child.

RESULTS

HIV-infected children with an HLA allele usually associated with slow disease experienced a slower progression to AIDS or death only if the allele was paternally inherited. If the allele was present in the mother, no association was observed. Children who were homozygous or who shared both alleles with their mothers at more than one HLA class I locus were more likely to progress to AIDS or death than other children (relative hazard, 3.46; 95% confidence interval, 1.24-9.71).

CONCLUSION

Genetic similarity between mother and child may compromise the child's capacity to control HIV replication when the virus is acquired from the mother. HLA-mediated selective pressures on the virus in a transmitting mother-infant pair may undermine future HLA-mediated viral control in the child.

Predicting HIV disease progression in children using measures of neuropsychological and neurological functioning. Pediatric AIDS clinical trials 152 study team

BACKGROUND

Neuropsychological testing and 2 measures of neurological status, cortical atrophy, and motor dysfunction were assessed for their usefulness in predicting human immunodeficiency virus (HIV) disease progression in infants, children, and adolescents who participated in Pediatric AIDS Clinical Trials Group Protocol 152 (PACTG 152).

METHODS

A cohort of 722 antiretroviral therapy-naive children with symptomatic HIV infection were assessed at study entry and at later intervals. Assessments included neurodevelopmental testing, neuroradiologic imaging, and neurological examination of motor function. CD4 cell count and plasma RNA viral load also were measured.

RESULTS

Children with the lowest neuropsychological functioning (IQ < 70) at baseline had the highest risk for later HIV disease progression (56%), compared with those with borderline/low (IQ = 70-89) functioning (26%), or with average or above (IQ > 90) functioning (18%). This was also true of week 48 neuropsychological functioning. Motor dysfunction (especially reduced muscle mass) at entry also predicted disease progression. Furthermore, motor dysfunction and week 48 neuropsychological functioning provided predictive information beyond that obtainable from surrogate markers of HIV disease status (eg, CD4 count, HIV RNA level). Children with cortical atrophy also were at higher risk for later disease progression, but when CD4 count and RNA viral load were known, cortical atrophy information provided no additional predictive information.

CONCLUSIONS

Measures of neuropsychological and motor function status provide unique information regarding pediatric HIV disease progression. As such, these findings have important implications for predicting long-term outcomes (eg, longevity) in pediatric patients.

Survival in children with perinatal HIV infection and very low CD4 lymphocyte counts

OBJECTIVES

To evaluate clinical conditions associated with mortality in HIV-infected children with CD4+ counts <100 cells/microl.

METHODS

The Pediatric Spectrum of HIV Disease Project is a longitudinal medical record review study with eight study sites in the United States, which have been enrolling children since 1989. Survival time from baseline very low CD4 count (<100 cells/microl) to death was estimated using the Kaplan-Meier method. Cox proportional hazards models were used to evaluate the effect of clinical variables on mortality.

RESULTS

Of 522 children (>/=1 year of age) with serial CD4+ T-lymphocyte measurements, the median age at the first very low CD4 count was 4.8 years. The estimated median survival following the first very low CD4 count was 36 months. The following factors present at the first very low CD4 count were independently associated with a higher risk of death: younger age, weight-for-age >2 standard deviations below the mean, and previously diagnosed AIDS. The subsequent development of cytomegalovirus (CMV)-associated disease, Mycobacterium avium intracellulare (MAI) infection, wasting syndrome, or esophageal candidiasis was also independently associated with a higher risk of death.

CONCLUSION

Survival in HIV-infected children with very low CD4 counts before introduction of highly active antiretroviral therapy was highly variable. Poor nutritional status and the development of CMV disease or MAI infection were associated with the shortest survival times.

Predictive value of the HIV paediatric classification system for the long-term course of perinatally infected children

BACKGROUND

To compare the Centers for Disease Control and Prevention (CDC) paediatric classification system with the long-term course of perinatal human immunodeficiency virus type 1 (HIV-1) infection.

METHODS

Prospective study on 366 perinatally infected children followed-up from birth and checked at least every 2 months. Survival, smoothed hazard, adjusted hazard ratio of death, and transition probabilities in clinical and immunological categories were outcome measures.

RESULTS

Survival was 49% (95% CI : 40-58%) at 8 years. The risk of death was high before the age of 2, relatively low between ages 2 and 7, and contained thereafter. Children did not advance through the categories sequentially. Survival at 8 years was 61.7% (95% CI : 49.8-73.6%) in those children who had passed through clinical category A; the hazard ratio of death was 2.5 (95% CI : 1.7-3.8) for 175 (47.9%) children who skipped this category. Transition probability in clinical category B was 39.9% (95% CI : 32.3-45.6%) after one year, but 59.1% (95% CI : 51.4-66.8%) after 5 years. Before 2 years of age, the probability of entry into category C (40%; 95% CI : 35-45%) was higher than that of entry into immunological category 3 (28%; 95% CI : 22-34%). Conclusions The classification system stands comparison with the clinical reality, but the CD4-positive cell thresholds in infancy should be adjusted and category B indicator diseases better distributed to improve their predictive value.

Antiretroviral therapy of pediatric HIV infection: making hope a reality

Over the past 3 years, the treatment and prognosis of HIV-1 infection have been revolutionized by a better understanding of the pathogenesis of HIV-1 infection, the ability to monitor viral replication and drug resistance in the host, and the availability of potent combination chemotherapy. While most of the studies that have led to this transformation have been done in adults, the results can be applied to the care of children. Data from trials of highly active antiretroviral therapy (HAART) in children are now being presented or published. Although the basic principles of antiretroviral therapy of HIV-1 infection do not differ between adults and children, there are important differences in the natural history of the disease and in issues related to medication administration and adherence to therapy. Progression of disease may be more rapid in children and is often very rapid in infants. Administration of medication to infants and children can be difficult, especially when the medication tastes bad. Finally, whereas an adult patient is free to decline therapy, however foolish such a decision may seem to the health-care professional, the failure to administer effective medication to a child for a condition that threatens serious morbidity or death constitutes medical neglect. In this review we will discuss the basic principles underlying pediatric antiretroviral therapy and address the issue of adherence, the major impediment to treatment success.