Alterations in cardiac and pulmonary function in pediatric rapid human immunodeficiency virus type 1 disease progressors. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Study Group

Clinical Characteristics and Lung Function in Older Children Vertically Infected With Human Immunodeficiency Virus in Malawi

BACKGROUND

Antiretroviral therapy (ART) has led to increased survival of children with vertically acquired human immunodeficiency virus infection. Significant morbidity arises from respiratory symptoms, but aetiology and pulmonary function abnormalities have not been systematically studied.

METHODS

Human immunodeficiency virus-positive children aged 8-16 years were systematically recruited within clinics in Blantyre, Malawi. Clinical review, quality of life assessment, spirometry, and chest radiography were performed.

RESULTS

One hundred sixty participants had a mean of age 11.1 (range, 8-16) years and 50.0% were female. Cough was present in 60 (37.5%) participants, and 55 (34.4%) had moderate or severe dyspnoea. Thirty-four (22.1%) participants had digital clubbing. Thirty-three (20.6%) participants were hypoxic at rest. One hundred eighteen (73.8%) of the children were receiving ART; median CD4 count was 698 cells/µL in these compared with 406 cells/µL in ART-naive individuals (P < .001). From 145 spirometry traces (90.6%), mean forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were 1.06 and 0.89 standard deviations below predicted mean, respectively. Twenty-one (14.5%) traces demonstrated obstructive defects and 26 (17.9%) reduced FVC. Lung function abnormality was not associated with any clinical findings. Of the 51 individuals with abnormal lung function, the mean increase in FEV1 after salbutamol was 3.8% (95% confidence interval, 0.02-7.53). "Tramlines" and ring shadows were seen on chest radiographs in over half of cases.

CONCLUSIONS

Symptoms of chronic lung disease were highly prevalent with 2 main clinical phenotypes: "cough" and "hypoxia". Lung function abnormalities are common, poorly responsive to bronchodilators, and apparent throughout the age range of our cohort. Pathological causes remain to be elucidated. Cough and hypoxic phenotypes could be a useful part of diagnostic algorithms if further validated.

Lung function abnormalities in HIV-infected adults and children

Despite the advent of antiretroviral therapy (ART), the human immunodeficiency virus (HIV) epidemic remains a global health crisis with a high burden of respiratory disease among infected persons. While the early complications of the epidemic were dominated by opportunistic infections, improved survival has led to the emergence of non-infectious conditions that are associated with chronic respiratory symptoms and pulmonary disability. Obstructive ventilatory defects and reduced diffusing capacity are common findings in adults, and the association between HIV and chronic obstructive pulmonary disease is increasingly recognized. There is synergism between viral factors, opportunistic infections, conventional influences like tobacco smoke and biomass fuel exposure, and potentially, the immunological effects of ART on the development of HIV-associated chronic obstructive lung disease. Pulmonary function data for HIV-infected infants and children are scarce, but shows that bronchiectasis and obliterative bronchiolitis with severe airflow limitation are major problems, particularly in the developing world. However, studies from these regions are sorely lacking. There is thus a major unmet need to understand the influences of chronic HIV infection on the lung in both adults and children, and to devise strategies to manage and prevent these diseases in HIV-infected individuals. It is important for clinicians working with HIV-infected individuals to have an appreciation of their effects on measurements of lung function. This review therefore summarizes the lung function abnormalities described in HIV-positive adults and children, with an emphasis on obstructive lung disease, and examines potential pathogenic links between HIV and the development of chronic pulmonary disability.

O uso da L-carnitina como adjuvante no tratamento da miocardiopatia dilatada em criança com Aids

OBJETIVO: Apresentar a resposta cardiovascular à L-carnitina de um paciente com insuficiência cardíaca congestiva decorrente de miocardiopatia dilatada pelo vírus da imunodeficiência humana. DESCRIÇÃO DO CASO: Criança com quadro clínico de insuficiência cardíaca congestiva grave devido à miocardiopatia dilatada pela síndrome de imunodeficiência adquirida. O tratamento para as manifestações clínicas foi instituído, com pouca resposta clínica. Com objetivo de melhorar o desempenho energético/metabólico dos cardiomiócitos, foi instituída terapia com L-carnitina. Observou-se significativa melhora clínica do paciente, em relação ao desempenho cardíaco, mesmo antes do início do tratamento com os fármacos antirretrovirais. COMENTÁRIOS: A L-carnitina é um composto que facilita o transporte dos ácidos graxos de cadeia longa para dentro da mitocôndria. Nesse caso, o uso da L-carnitina parece ser clinica e bioquimicamente justificado.

Cardiac effects of antiretroviral therapy in HIV-negative infants born to HIV-positive mothers: NHLBI CHAART-1 (National Heart, Lung, and Blood Institute Cardiovascular Status of HAART Therapy in HIV-Exposed Infants and Children cohort study)

OBJECTIVES

The aim of this study was to investigate the possible effects of antiretroviral therapy (ART) in utero on cardiac development and function in human immunodeficiency virus (HIV)-negative children.

BACKGROUND

ART reduces vertical HIV transmission. Long-term cardiotoxicity after in utero exposure to ART is unknown in children but has occurred in young animals.

METHODS

Using a prospective multisite cohort study design, echocardiograms taken between birth and 24 months were compared in 2 groups of HIV-negative infants of HIV-positive mothers: 136 infants exposed to ART (ART+) and 216 unexposed infants (ART-).

RESULTS

Mean left ventricular (LV) mass z-scores were consistently lower in ART+ girls than in ART- girls: differences in mean z-scores were -0.46 at birth (p = 0.005), -1.02 at 6 months (p < 0.001), -0.74 at 12 months (p < 0.001), and -0.79 at 24 months (p < 0.001). Corresponding differences in z-scores for boys were smaller: 0.13 at 1 month (p = 0.42), -0.44 at 6 months (p = 0.01), -0.15 at 12 months (p = 0.37), and -0.21 at 24 months (p = 0.21). Septal wall thickness and LV dimension were smaller than expected in ART+ infants, but LV contractility was consistently about 1 SD higher at all ages (p < 0.001). In ART+ infants, LV fractional shortening was higher than in ART- infants; girls showed a greater difference.

CONCLUSIONS

Fetal exposure to ART is associated with reduced LV mass, LV dimension, and septal wall thickness z-scores and increased LV fractional shortening and contractility up to age 2 years. These effects are more pronounced in girls than in boys. Fetal ART exposure may impair myocardial growth while improving depressed LV function.

Estimating the net effect of HIV on child mortality in African populations affected by generalized HIV epidemics

For a given prevalence, HIV has a relatively higher impact on child mortality when mortality from other causes is low. To project the effect of the epidemic on child mortality, it is necessary to estimate a realistic schedule of "net" age-specific mortality rates that would operate if HIV were the only cause of child death observable. We assume that this net pattern would be independent of mortality from other causes. We used African studies that measured the survival of HIV-infected children (direct data) or survival of children of HIV-infected mothers (indirect data). We developed a mathematic procedure to estimate the mortality of infected children from indirect data sources and obtained net HIV mortality patterns for each study population. The net age-specific HIV mortality pattern for infected children can be described by a double Weibull curve fitted to empiric data; this gives a functional representation of age-specific mortality rates that decline after infancy and rise in the preteens. The fitted curve that we would expect if HIV were the only effective cause of death shows 67% net survival at 1 year and 39% at 5 years. The curve also predicts 13% net survival at 10 years using constraints based on survival of infected adults.

Postmortem cardiomegaly and echocardiographic measurements of left ventricular size and function in children infected with the human immunodeficiency virus. The Prospective P2C2 HIV Multicenter Study

BACKGROUND

Cardiomegaly, seen postmortem in over 50% of HIV-infected children, may occur in the absence of clinical or histopathologic cardiac disease. Premortem echocardiography has also demonstrated clinical and subclinical cardiac disease, including increased left ventricular mass (LVM) and functional abnormalities. No studies have compared these echocardiographic measures of heart size and function with postmortem findings in this population. We sought to determine the postmortem prevalence, clinicopathologic relationships and importance of cardiomegaly in HIV-infected children.

METHODS

We reviewed clinical and postmortem cardiac findings in 30 HIV-infected children who were part of the Prospective P(2)C(2) HIV Study. Postmortem heart weight was compared with clinical measures of heart size and function, with cardiac pathology and with clinical measures reflecting chronic effects of HIV disease.

RESULTS

Postmortem cardiomegaly (heart weight z score >/=2) was identified in 53% of the children. Children with cardiomegaly had increased LVM, increased heart rate, more frequent clinical chronic heart disease and a higher prevalence of postmortem pericardial effusions compared to children without cardiomegaly (P</=.05). The association with LV end-diastolic dimension (LVEDD) did not reach statistical significance (P=.08). No association was found with LV posterior wall thickness (LVPWT), CD4(+) T-cell counts, HIV-1 viral load, hemoglobin, encephalopathy, myocardial histology or myocardial organisms.

CONCLUSIONS

Postmortem cardiomegaly was associated with echocardiographic measures of increased LVM. The pathogenesis appears not to be related to chronic anemia, HIV viral load, the degree of immune suppression or encephalopathy. Autonomic dysregulation, reflected by chronically increased heart rate, may be of pathoetiologic significance.

Cardiovascular status of infants and children of women infected with HIV-1 (P(2)C(2) HIV): a cohort study

BACKGROUND

Data from cross-sectional and short-term longitudinal studies have suggested that children infected with HIV-1 might have cardiovascular abnormalities. We aimed to investigate this hypothesis in a long-term cohort study.

METHODS

We measured cardiovascular function every 4-6 months for up to 5 years in a birth cohort of 600 infants born to women infected with HIV-1. We included 93 infants infected with HIV-1 and 463 uninfected infants (internal controls) from the same cohort. We also included a cross-sectionally measured comparison group of 195 healthy children born to mothers who were not infected with HIV-1 (external controls).

FINDINGS

Children infected with HIV-1 had a significantly higher heart rate at all ages (mean difference 10 bpm, 95% CI 8-13) than internal controls. At birth, both cohort groups of children had similar low left ventricular (LV) fractional shortening. At 8 months, fractional shortening was similar in internal and external controls, whereas in children infected with HIV-1, fractional shortening remained significantly lower than in controls for the first 20 months of life (mean difference from internal controls at 8 months 3.7%, 2.3-5.1). LV mass was similar at birth in both cohort groups, but became significantly higher in children with HIV-1 from 4-30 months (mean difference 2.4 g at 8 months, 0.9-3.9).

CONCLUSIONS

Vertically-transmitted HIV-1 infection is associated with persistent cardiovascular abnormalities identifiable shortly after birth. Irrespective of their HIV-1 status, infants born to women infected with HIV-1 have significantly worse cardiac function than other infants, suggesting that the uterine environment has an important role in postnatal cardiovascular abnormalities.

Thymic size on chest radiograph and rapid disease progression in human immunodeficiency virus 1-infected children

BACKGROUND

Early infection of the thymus, an organ central to the ontogeny of the immune system, has been proposed as a cause of rapid progression in pediatric HIV disease.

OBJECTIVE

To test the hypothesis that small thymic volume is associated with rapid disease progression in HIV-infected children.

DESIGN

Three pediatric radiologists established criteria for rating the size of the thymic profile on chest radiographs. All available baseline chest radiographs were reviewed in a random sequence, with radiologists blinded to study subjects' clinical status. A consensus was reached on whether the thymus was normal or small for age.

SETTING

A prospective multicenter study of the natural history of HIV-1 infection in children, the Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Infection (P2C2) Study.

PATIENTS

Fifty-eight HIV-infected children and 38 control children (uninfected but born to HIV-infected women) for whom chest radiographs in the first year of life were available.

MAIN OUTCOME MEASURE

Rapid progression of HIV disease, defined as CDC Clinical Category C (severely symptomatic) or Immunologic Category 3 (severe immunosuppression) by 1 year of age.

RESULTS

The mean age at the time of chest radiography was 3.5 months. Ten (17%) HIV-infected children had reduced thymic profile size, whereas no controls did (P = 0.006). Of the 58 (59%) HIV-infected children 34 were classified as rapid progressors, and 9 (26%) of them had reduced thymus size, compared with 1 (4%) of the non-rapid progressor children [odds ratio, 8.28; 95% confidence interval (CI), 1.0, 70.5; P = 0.035]. Baseline mean CD4+ count was 1642 (95% CI 1322 to 2009) cells/microl for those with normal thymus and 740 (95% CI 380 to 1275) cells/microl for those with reduced thymus (P = 0.007).

CONCLUSION

Early thymic involution is associated with rapidly progressive disease in HIV-infected children.

Maternal and infant factors associated with failure to thrive in children with vertically transmitted human immunodeficiency virus-1 infection: the prospective, P2C2 human immunodeficiency virus multicenter study

OBJECTIVE

Many children with human immunodeficiency virus-1 (HIV-1) have chronic problems with growth and nutrition, yet limited information is available to identify infected children at high risk for growth abnormalities. Using data from the prospective, multicenter P2C2 HIV study, we evaluated the relationships between maternal and infant clinical and laboratory factors and impaired growth in this cohort.

METHODS

Children of HIV-1-infected women were enrolled prenatally or within the first 28 days of life. Failure to thrive (FTT) was defined as an age- and sex-adjusted weight z score < or =-2.0 SD. Maternal baseline covariates included age, race, illicit drug use, zidovudine use, CD4+ T-cell count, and smoking. Infant baseline predictors included sex, race, CD4+ T-cell count, Centers for Disease Control stage, HIV-1 RNA, antiretroviral therapy, pneumonia, heart rate, cytomegalovirus, and Epstein-Barr virus infection status.

RESULTS

The study cohort included 92 HIV-1-infected and 439 uninfected children. Infected children had a lower mean gestational age, but birth weights, lengths, and head circumferences in the 2 groups were similar. Mothers of growth-delayed infants were more likely to have smoked tobacco and used illicit drugs during pregnancy. In repeated-measures analyses of weight and length or height z scores, the means of the HIV-1-infected group were significantly lower at 6 months of age (P <.001) and remained lower throughout the first 5 years of life. In a multivariable Cox regression analysis, FTT was associated with a history of pneumonia (relative risk [RR] = 8.78; 95% confidence interval [CI]: 3.59-21.44), maternal use of cocaine, crack, or heroin during pregnancy (RR = 3.17; 95% CI: 1.51-6.66), infant CD4+ T-cell count z score (RR = 2.13 per 1 SD decrease; 95% CI: 1.25-3.57), and any antiretroviral therapy by 3 months of age (RR = 2.77; 95% CI: 1.16-6.65). After adjustment for pneumonia and antiretroviral therapy, HIV-1 RNA load remained associated with FTT in the subset of children whose serum was available for viral load analysis.

CONCLUSIONS

Clinical and laboratory factors associated with FTT among HIV-1-infected children include history of pneumonia, maternal illicit drug use during pregnancy, lower infant CD4+ T-cell count, exposure to antiretroviral therapy by 3 months of age (non-protease inhibitor), and HIV-1 RNA viral load.

Epidemiology of cardiovascular involvement in HIV disease and AIDS

The epidemiology of cardiac complications related to HIV including cardiomyopathy, increased left ventricular mass, myocarditis, pericardial effusion, endocarditis, and malignancy are discussed. A large number of HIV-infected individuals will present with cardiac complications in the next decade as chronic viral infection, co-infections, drug therapy, and immunosuppression affect the heart. Understanding the nature and course of cardiac illness related to HIV infection will allow appropriate monitoring, early intervention and therapy, and will provide a baseline to evaluate the effects of new therapeutic regimens such as highly active antiretroviral therapy on the cardiovascular system.

Cardiac manifestations of HIV infection in infants and children

Cardiac manifestations of HIV infection in children are common, but etiologies, contributing factors, and the natural history are largely unexplored. The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Infection Study (P2C2 HIV Study) was initiated in 1989 by the National Heart, Lung and Blood Institute, USA. A primary objective of this study is to examine the epidemiology of cardiovascular problems associated with HIV infection in a cohort of children vertically infected. Findings of the study thus far show that cardiovascular problems associated with HIV infection including left ventricular dysfunction and increased left ventricular mass are common and clinically important indicators of survival for children infected with HIV.

Decline of CD3-positive T-cell counts by 6 months of age is associated with rapid disease progression in HIV-1--infected infants

Because HIV-1 infected infants with rapid progression (RP) of disease might benefit from early and intense antiretroviral therapy, the identification of predictive factors of RP becomes extremely important. Currently, the best predictive factors of RP in HIV-1 infected children are HIV-1 RNA levels and CD4-positive T-cell counts. A decrease in CD3-positive T-cell count has been identified as a predictive factor of AIDS development in HIV-1 infected adults. Our objective was to evaluate decreased number of CD3-positive T-cells as a predictive factor of RP in infants. Peripheral blood lymphocytes from HIV-1 infected infants (up to 6 months of age) were analyzed for an association of lymphocyte subsets with RP, which was defined as the occurrence of AIDS or death before 18 months of age. In infants with RP (n = 32), CD3-positive T-cell counts were 3093 cells/microL at <1 month of age, 3092 cells/microL at 1 to 3 months, and 2062 cells/microL at 3 to 6 months. Non-RP infants (n = 49) maintained their CD3-positive T-cells counts at approximately 4000 cells/microL for at least 6 months of life. CD3-positive and CD4-positive T-cell counts were significantly associated with RP. Our results suggest that a decreased CD3-positive T-cell count may be used to predict RP in HIV-1 infected infants (RR = 2.16, P =.001).

Ventricular dysfunction clinical research in infants, children and adolescents

These two issues of Progress in Pediatric Cardiology comprehensively illustrate the wealth of currently available information on the pathophysiology of heart failure, age-related myocardial responsiveness, energy metabolism, cardiopulmonary interactions, the pressure-volume relationship, the systemic inflammatory response, the management of heart failure, pediatric pharmacology, the use of heart failure therapies including digoxin, ACE inhibitors, beta-adrenergic blockers, inotropic agents, diuretics, vasodilators, calcium sensitizers, angiotensin and aldosterone receptor blockers, growth hormone, and future gene therapy. The etiology and course of ventricular dysfunction in children is poorly characterized. Furthermore, many changing developmental properties of the pediatric myocardium and differences in the etiologies of ventricular dysfunction in children compared with adults are illustrated in these articles, invalidating the concept that children can safely be considered small adults for the purpose of understanding heart failure pathophysiology and treatment. However, these articles reveal that strikingly little research in children with ventricular dysfunction exists in terms of well-designed large-scale studies of the epidemiology or multicenter controlled clinical therapeutic trials. A future research agenda is proposed to improve understanding etiologies, course and treatment of ventricular dysfunction in children that is based on organized and funded cooperative groups since no one pediatric cardiac center treats enough children with a particular etiology of ventricular dysfunction. In conclusion, significant understanding of basic mechanisms of pediatric ventricular dysfunction and effective therapies for adults with ventricular dysfunction exist. A multicenter pediatric cardiac ventricular dysfunction network would allow improved understanding of diseases and treatments, and result in evidence-based medicine for pediatric patients with ventricular dysfunction.

Evaluation of immune survival factors in pediatric HIV-1 infection

Peripheral blood CD4+ and CD8+ T cells, CD19+/20+ B cells, and serum immunoglobulins (Igs) have been implicated as survival factors for pediatric HIV-1 infection. To determine which of these immune factors might be important in predicting survival, we studied HIV-1 vertically infected (HIV-1+) children over a 5-year period. Peripheral blood lymphocytes and Igs were measured in 298 HIV-1+ children, who were classified as survivors or nonsurvivors, and in 463 HIV-1 vertically exposed and noninfected (HIV-1-) children. Measurements of other possible survival factors were included in this study: albumin, hemoglobin, lactic dehydrogenase (LDH), and HIV-1 RNA levels. Survivors had significantly higher CD4+ T-cell, CD8+ T-cell, and CD19+/CD20+ B-cell counts and serum IgG levels, but lower serum IgA and IgM levels than nonsurvivors. Serum albumin and blood hemoglobin levels were higher, but serum LDH and HIV-1 RNA levels were lower in the survivors compared to nonsurvivors. In univariable analysis, factors affecting survival were baseline CD4+ T-cell and CD8+ T-cell counts, IgG, albumin, hemoglobin, LDH, and HIV-1 RNA (all p < 0.001). In multivariable analysis, high baseline CD4+ T-cell count, IgG and albumin levels, and low baseline HIV-1 RNA load remained important factors for survival. Serum IgG level has been identified as an immune factor that independently predicts survival, in addition to the already established CD4+ T-cell count. The HIV-1 RNA and serum albumin levels also predicted survival.

Cardiac dysfunction and mortality in HIV-infected children: The Prospective P2C2 HIV Multicenter Study. Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection (P2C2 HIV) Study Group

BACKGROUND

Left ventricular (LV) dysfunction is common in children infected with the human immunodeficiency virus (HIV), but its clinical importance is unclear. Our objective was to determine whether abnormalities of LV structure and function independently predict all-cause mortality in HIV-infected children.

METHODS AND RESULTS

Baseline echocardiograms were obtained on 193 children with vertically transmitted HIV infection (median age, 2.1 years). Children were followed up for a median of 5 years. Cox regression was used to identify measures of LV structure and function predictive of mortality after adjustment for other important demographic and baseline clinical risk factors. The time course of cardiac variables before mortality was also examined. The 5-year cumulative survival was 64%. Mortality was higher in children who, at baseline, had depressed LV fractional shortening (FS) or contractility; increased LV dimension, thickness, mass, or wall stress; or increased heart rate or blood pressure (P0.02 for each). Decreased LV FS (P<0.001) and increased wall thickness (P=0.004) were also predictive of increased mortality after adjustment for CD4 count (P<0.001), clinical center (P<0.001), and encephalopathy (P<0.001). FS showed abnormalities for up to 3 years before death, whereas wall thickness identified a population at risk only 18 to 24 months before death.

CONCLUSIONS

Depressed LV FS and increased wall thickness are risk factors for mortality in HIV-infected children independent of depressed CD4 cell count and neurological disease. FS may be useful as a long-term predictor and wall thickness as a short-term predictor of mortality.

Prospective 5-year study of peripheral blood CD4, CD8, and CD19/CD20 lymphocytes and serum Igs in children born to HIV-1 women. The P(2)C(2) HIV Study Group

BACKGROUND

Peripheral blood CD4(+) and CD8(+) T cells, CD19(+)/20(+) B cells, and serum Igs are known to be altered by the progression of pediatric HIV-1 infection, but their evaluation as predictors of survival needs further definition.

OBJECTIVE

To determine the natural history of these immune factors and their importance in predicting survival, we studied 298 HIV-1 vertically infected (HIV-1(+)) children over a 5-year period.

METHODS

These immune factors and serum HIV-1 RNA levels were measured in two groups: (1) a birth cohort of children enrolled up to age 28 days postnatally, including 93 HIV-1(+) and 463 HIV-1 uninfected infants (HIV-1(-)), and (2) an older cohort of 205 HIV-1(+) children enrolled after the age of 28 days, who were classified as survivors or nonsurvivors.

RESULTS

In the birth cohort HIV-1(+) children had significantly lower CD4(+) T-cell counts, higher CD8(+) T-cell counts, and lower CD19(+)/20(+) B-cell counts and higher IgG, IgA, and IgM levels than HIV-1(-) children. In the older cohort survivors had significantly higher CD4(+) and CD8(+) T-cell and CD19(+)/CD20(+) B-cell counts and higher IgG, lower IgA, and lower IgM levels than did nonsurvivors. In univariable analysis factors affecting survival in the older cohort were baseline CD4(+) and CD8(+) T-cell and CD19(+)/20(+) B-cell counts and IgG and HIV-1 RNA levels (all P <.05). In multivariable analysis high baseline CD4(+) T-cell count and low baseline HIV-1 RNA load remained important.

CONCLUSION

The longitudinal mean profiles of CD4 and CD8 T-cell and CD19/20 B-cell counts and serum IgG levels helped to describe the natural progression of HIV-1 disease in children. However, only baseline CD4 T-cell count independently predicted survival.