Functionally inert HIV-specific cytotoxic T lymphocytes do not play a major role in chronically infected adults and children.

The highly sensitive quantitation of virus-specific CD8(+) T cells using major histocompatibility complex-peptide tetramer assays has revealed higher levels of cytotoxic T lymphocytes (CTLs) in acute and chronic virus infections than were recognized previously. However, studies in lymphocytic choriomeningitis virus infection have shown that tetramer assays may include measurement of a substantial number of tetramer-binding cells that are functionally inert. Such phenotypically silent CTLs, which lack cytolytic function and do not produce interferon (IFN)-gamma, have been hypothesized to explain the persistence of virus in the face of a quantitatively large immune response, particularly when CD4 help is impaired. In this study, we examined the role of functionally inert CTLs in chronic HIV infection. Subjects studied included children and adults (n = 42) whose viral loads ranged from <50 to >100,000 RNA copies/ml plasma. Tetramer assays were compared with three functional assays: enzyme-linked immunospot (Elispot), intracellular cytokine staining, and precursor frequency (limiting dilution assay [LDA]) cytotoxicity assays. Strong positive associations were observed between cell numbers derived by the Elispot and the tetramer assay (r = 0.90). An even stronger association between tetramer-derived numbers and intracellular cytokine staining for IFN-gamma was present (r = 0.97). The majority (median 76%) of tetramer-binding cells were consistently detectable via intracellular IFN-gamma cytokine staining. Furthermore, modifications to the LDA, using a low input cell number into each well, enabled LDAs to reach equivalence with the other methods of CTL enumeration. These data together show that functionally inert CTLs do not play a significant role in chronic pediatric or adult HIV infection.

Pediatric AIDS prognosis using somatic growth velocity.

OBJECTIVE: To describe the natural history of somatic growth in HIV infection by constructing age-specific growth velocity norms and to assess specific prognostic information available using these norms. DESIGN: Observations on 1338 HIV-infected children aged 3 months to 15 years who participated in one of four US clinical trials of pediatric anti-HIV therapies were pooled; baseline growth velocity data were obtained using the first 6 months of observation for each child. METHODS: Distributions of physical growth velocities in HIV-infected children in the Pediatric AIDS Clinical Trials Group were computed. Statistical smoothing of growth histories was employed to derive velocity estimates, and quantile regression analysis of growth velocities was performed to allow comparisons of growth rates in age- and gender-heterogeneous cohorts in the context of HIV infection. The quantile regressions provide corrected z-scores for growth velocity that appropriately compare HIV-infected children with one another for the purpose of distinguishing more from less favorable prognoses. RESULTS: Consistent deficits in growth velocity amongst HIV-infected children were revealed when compared with the Fels Institute velocity standards. Approximately 33% of height (and 20% of weight) age- and sex-corrected velocity measurements obtained in the first 6 months of clinical trial participation lay beneath the corresponding third percentiles of the Fels reference distributions, which are commonly regarded as critical indicators of growth failure. Proportional hazards regression tests indicated that both weight and height velocity contributed significant information on the risk of death among children with AIDS after adjusting for antiretroviral therapy received, CD4 cell counts, and age at trial enrollment. Comparing subjects who differ in initial weight velocity by one age- and sex-corrected SD, the relative hazard of death was 0.63 (95% confidence interval, 0.55-0.72; P < or = 0.0001) in favor of the child with greater weight velocity, controlling for antiretroviral therapy received, age and CD4 cell count at baseline. The analogous hazard ratio for height velocity was 0.68 (95% confidence interval, 0.57-0.79; P < or = 0.0001). CONCLUSIONS: Suitably normalized growth velocities are informative and inexpensive criteria for pediatric AIDS prognosis; the growth velocity distributions presented will be useful for comparing growth effects of new therapeutic strategies to those of single and combination antiretrovirals employed for maintenance of pediatric HIV infection in the mid-1990s.

Candidal mycetoma in the neonatal kidney.

OBJECTIVE: To determine the natural history of renal mycetoma (fungal balls) in the neonate. DESIGN: Retrospective chart review of all neonatal intensive care unit patients with systemic candidiasis and sonographic evidence of renal mycetoma admitted to the Duke University Medical Center between January 1, 1993, and July 1, 1998. RESULTS: Fourteen patients were reviewed. Three died from fungemia, and 3 died from other causes months after completing treatment. Ten patients had urine cultures obtained within 1 week of diagnosis; each had a positive routine or fungal urine culture for candida. The rate of improvement of renal mycetoma by ultrasound was variable, ranging from 10 days to 4 months and was not predictive of survival or long-term renal function. All patients who were discharged from the hospital had creatinine

The introduction of human immunodeficiency virus into the North Carolina pediatric population.

The authors reviewed the means by which human immunodeficiency virus (HIV) seropositivity was acquired for the 134 seropositive children seen at Duke University Medical Center prior to September 1990. Perinatal transmission occurred in 111 (83%) and blood product transmission in 15 (11%). Of the 108 mothers (there were three sets of siblings) responsible for perinatal transmission, 44 (41%) had acquired their infection while residing in North Carolina. Intravenous (IV) drug use by the mother or her sexual partner was the significant risk factor for maternal infection in 91 (84%) of the total cases and in 38 (86%) of the 44 women infected in North Carolina. The proportion of women who acquired their HIV infection from a sexual partner who was an IV drug user was significantly greater for mothers who were resident in North Carolina when infected compared with mothers infected elsewhere (P less than .001). On the basis of admission to drug treatment programs during the 1990 fiscal year, cocaine is the predominant IV drug used in North Carolina. Admissions to cocaine abuse programs occurred throughout the state, and mothers who acquired HIV infection from IV drug use were more likely to live in counties with a higher frequency of cocaine abuse treatment.

Lymphocyte subsets in children younger than 2 years old: normal values in a population at risk for human immunodeficiency virus infection and diagnostic and prognostic application to infected children.

Data were collected prospectively from 116 children younger than 2 years old who were seen at the Duke Pediatric AIDS Clinical Trials Unit for known human immunodeficiency virus seropositivity. Forty-six (40%) of these children were human immunodeficiency virus-infected and 70 were not infected. Using 3-month blocks, 10th, 50th and 90th percentiles were calculated for the CD4+ and CD8+ cell counts, percentage of lymphocytes positive for CD4 and CD8 and T4:T8 ratios. Results from the infected and uninfected children were compared. By 3 to 6 months of age the infected patients had significantly lower CD4+ counts, percentage CD4+ cells and T4:T8 ratios, whereas the percentage of CD8+ lymphocytes was significantly higher. Absolute CD8+ counts were approximately the same in infected and uninfected children through age 2 years. Most infected children had one or more abnormal lymphocyte subset results (less than the 10th percentile for uninfected patients) by age 2: 83% had an abnormal CD4+ percentage; 78% had an abnormal T4:T8 ratio; and 67% had an abnormal CD4+ count. All 13 children who had an opportunistic infection (at any age) had an abnormal CD4+ percentage before age 2 years, and 12 of 13 had a low absolute CD4+ count or T4:T8 ratio. Among patients who died 10 of 11 had 1 or more low CD4+ count, 9 of 11 had an abnormal CD4+ percentage and 8 of 11 an abnormal T4/T8 ratio.

Immune reconstitution in human immunodeficiency virus-infected children receiving highly active antiretroviral therapy: a cohort study.

BACKGROUND: Highly active antiretroviral therapy (HAART) has brought about rapid declines in HIV-1 RNA concentrations and an increase in CD4+ counts in HIV-1-infected children. These changes are often accompanied by clinical improvement; however, the extent to which immune reconstitution occurs is not known. DESIGN: We compared two cohorts (n = 35) of HIV-1-infected children to evaluate the effects of HAART on immune recovery. Cohort 1 (C1) included clinically well children receiving HAART with a CD4 >22% at study initiation. Before HAART all children had moderately to severely suppressed immune function by CDC criteria (CD4 <25%) or CDC Category B or C disease. Cohort 2 (C2) included children with no current or past evidence of immunosuppression based on CDC criteria (CD4 >25%) and no evidence of clinical disease. Children in C2 were receiving a non-HAART regimen. METHODS: Immunophenotyping was performed to characterize CD4+ and CD8+ subsets with regard to maturation and activation. T cell rearrangement excision circles (TRECs) were measured to quantify recent thymic emigrants. RESULTS: No difference was found in percent CD4+ or percent CD8+ T cells or maturation markers between C1 and C2. There was significantly less expression of activation markers in both CD4+ and CD8+ cells in C1. There was no difference in TREC production between C1 and C2. CONCLUSION: Moderately to severely suppressed HIV-1-infected children receiving HAART are able to reconstitute their immune systems to a degree that is indistinguishable from that of stable, CDC Class A1 HIV-1-infected children with regard to CD4+ and CD8+ T cell subsets, expression of cellular maturation markers and TREC production.

Evaluation of surrogate markers and clinical outcomes in two-year follow-up of eighty-six human immunodeficiency virus-infected pediatric patients.

OBJECTIVES: To evaluate the prognostic value of surrogate markers (HIV RNA copy number, CD4 counts and CDC clinical and immunologic categories) in HIV-infected children through a 2-year period. METHODS: Eighty-six HIV-infected children followed by the Duke Pediatric HIV Clinic in the fall of 1994 were evaluated for plasma HIV RNA concentration (viral load), CD4 lymphocyte percentage, age, antiretroviral treatment status and CDC clinical and immunologic categories. Follow-up evaluations were performed for approximately 2 years, and the time to progression to a new CDC category C diagnosis or death was noted. RESULTS: Of 86 children 22 had progression to new Category C diagnosis or death. Seven children died, 17 had a new Category C diagnosis and 2 had both. Among children who progressed, the median CD4 percentage at entry was 3% (absolute count, 75 cells/mm3), whereas children who had no disease progression entered with a median of 29% (868 cells/mm3). The overall median viral load at study entry was 4.58 log10 copies/ml (38,019 copies/ml, with a range of 1.7 to 6.78 logs). Children who had no disease progression had a median log copy number of 4.43, whereas 5.18 was the median for children whose disease progressed. Log copy number declined over time in children < 3 years of age, whereas it remained fairly consistent for children 3 years or older. Progression rates were determined by entry plasma HIV RNA concentration quartiles [quartile boundaries < 4.18, 4.58, > 5.08 log RNA copy/ml (< 15,136, 38,019 and > 120,226 copies/ml, respectively)]. Progression rates by quartile were 0 of 21, 4 of 22, 5 of 21 and 13 of 22. Kaplan-Meier survival curves defined by CD4% less than or greater than 15 and log RNA less than or greater than 5.0 (100,000) revealed that patients with CD4% less than 15 and plasma HIV RNA concentration > 5 log10 copies/ml did least well: 11 of 12 (92%) had a progression event at a median of 179 days. Patients with a high CD4 percentage and high viral load, or a low CD4 percentage and low viral load did similarly; 5 of 14 (36%) and 4 of 12 (33%) had progression events, respectively. Patients with high CD4 percentage and low viral load did best: only 2 of 48 (4%) had a progression event. CONCLUSIONS: The two most significant prognostic indicators of disease progression were the initial CD4 percentage and the plasma HIV RNA concentration, and a combination of CD4 percentage and virus load best predicted which children had progression events. Progression was less common in children who had < 100,000 HIV RNA copies/ml initially (6 of 60 vs. 16 of 26; P < 0.001; relative risk 0.16). Therefore it seems reasonable that in a child for whom complete suppression is not possible, a threshold of 100,000 (5 log10 copies/ml) can be used to mandate a change in therapy.

Effect of influenza immunization on immunologic and virologic characteristics of pediatric patients infected with human immunodeficiency virus.

OBJECTIVES: We evaluated the responses of HIV-infected children to a single dose of split-virus influenza vaccine and the relationship to viral load and other characteristics. METHODS: Fifty-three HIV-infected children ages 1.8 to 13.2 years were given influenza vaccine for the 1994 to 1995 influenza season (Wyeth-Ayerst: A/Texas H1N1, A/Shangdong H3N2 and B/Panama). Immunologic and virologic factors were assessed at the time of and 2 to 10 weeks after immunization. RESULTS: The differences between pre- and postimmunization CD4+ counts, CD4+:CD8+ ratios and viral load were not significant. Thirty-one of 53 children (58.4%) had a > 2-fold increase and 16 of 53 (30%) had a 4-fold rise in their postimmunization antibody titers for at least one component of the vaccine. Influenza immunization in the 1993 to 1994 flu season and administration of intravenous immunoglobulin around the time of immunization was not associated with immune response to the vaccine. Factors that were negatively associated with antibody response included increased time between samples (P = 0.004) and decreased preimmunization CD4+:CD8+ ratio (P = 0.02). CONCLUSIONS: Influenza immunization in this population is safe, and a positive antibody response to influenza immunization is not associated with significant clinical events or change in HIV-1 plasma viral burden.

Clinical and laboratory characteristics of a large cohort of symptomatic, human immunodeficiency virus-infected infants and children. AIDS Clinical Trials Group Protocol 152 Study Team.

BACKGROUND: A large cohort of antiretroviral therapy-naive, symptomatic, HIV-infected children were enrolled into a controlled therapeutic trial (AIDS Clinical Trials Group Protocol 152), providing an opportunity to describe their clinical and laboratory characteristics and determine age-related distinctions. METHODS: Study entry evaluations for 838 of 839 enrolled children were analyzed. Weight, head circumference (if < 30 months of age), neuroradiologic imaging of the head, developmental or cognitive status and neurologic examination were assessed. Laboratory studies included hemoglobin, absolute neutrophil count, CD4 cell count, serum amylase, alanine aminotransaminase, p24 antigen and HIV blood culture. Data were categorized by age (3 to < 12 months, 12 to < 30 months, 30 months to 6 years and > or = 6 years). RESULTS: Younger children had significantly higher rates of abnormalities before antiretroviral therapy, especially factors relating to growth and neurologic or cognitive function. Lower CD4+ cell counts and percentages as well as a positive serum p24 antigen correlated with lower weight-for-age Z scores and developmental indices. CONCLUSIONS: These data provide a description of the clinical characteristics of HIV-infected US children at the time antiretroviral therapy is initiated for HIV-related symptoms. The high rate of abnormalities of growth, development and cognitive ability that were observed in children < 30 months of age demonstrates that treatment strategies should be developed for earlier intervention.

Outcome measures of a chronic pain program: a prospective statistical study.

OBJECTIVE: To provide outcome data measuring objective and subjective variables of an individualized, multidisciplinary, comprehensive pain management program. DESIGN: The study is a prospective evaluation of 50 consecutive patients who completed the pain management program. Objective measures were medication use and return to work. Subjective measures included self-reports of pain levels and completion of a Personal Concerns and Goals Assessment (PCGA) examining issues of lifestyle and emotional well-being. These measures were compared at program onset and completion by using appropriate statistical analyses. RESULTS: Objective measures: Medication use by the study subjects decreased overall by 72% within all drug categories. Opioid use was eliminated. Regarding return to work, the study subjects increased their work hours by twofold overall. Of patients working fewer than 30 h per week at program onset, representing 62% of the study population, a fivefold return to work was observed. Subjective measures: Overall pain levels improved by 33%, with an 18 to 47% improvement in all descriptors (average pain levels on good or bad days, average number of good or bad days). Of the PCGA factors, patients improved 24 to 46% in all categories concerning lifestyle and emotional well-being. Correlative analysis of the data produced prognostic information as well as insights into chronic pain development. CONCLUSIONS: This study of objective and subjective outcome measures demonstrates that a comprehensive program employing specific principles and methods produces an effective approach for the management of chronic pain. Patients disabled by chronic pain regain a quality of life that allows them to resume a functioning, productive role.

Antiviral therapy for human immunodeficiency virus infection in children.

Antiretroviral therapy for children is still at an early stage, although progress is being made slowly. Zidovudine administered at 180 mg/m2/dose every 6 hours is the current standard therapy for symptomatic children and those with low CD4 counts. This standard is likely to evolve as further testing clarifies the optimal dosage for ZDV in different populations. Children on ZDV need to be monitored very closely (at least monthly) for hematologic side effects, which are most common in the more seriously ill children. The role of some of the newer antiretrovirals, like ddI and ddC, which are likely to be licensed, has yet to be established. They have a different toxicity profile than ZDV and thus may work well in combination with it. The issue of peripheral neuropathy and the lack of an easy test to measure it makes using ddC or ddI in young, preverbal children a daunting proposition. As with ZDV, the optimum dosage and timing have yet to be fixed for ddC or ddI alone, and even less available are regimens for combination therapy. Antiretroviral drugs other than the dideoxynucleosides are less well developed. Some, like high-titer antiviral immunoglobulin, involve technology that is already available and thus will be relatively easy to study. Others, like the antisense oligomers, are such a new technology that there are many hurdles to be overcome as the agents move from the laboratory to the clinic. The goal of agents that work on sites other than reverse transcriptase is a reasonable one, but the work in perfecting such new categories of drug is difficult and slow. In the meantime, children with HIV should be symptomatically supported and offered the most effective antiretroviral regimens available.

Successful prophylaxis against Pneumocystis carinii pneumonia in HIV-infected children using smaller than recommended dosages of trimethoprim-sulfamethoxazole.

Prophylaxis against Pneumocystis carinii pneumonia (PCP) is an essential part of the management of children with human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS). No dose-ranging studies were ever performed; therefore, the amount of trimethoprim-sulfamethoxazole (TMP-SMX) needed to suppress PCP in children with HIV/AIDS is not known. The dose recommended by the Centers for Disease Control (CDC) has been thought to be just above the threshold needed for prevention, based on anecdotal breakthrough PCP in cancer patients who were improperly dosed. We have been giving prophylaxis based on body weight rather than surface area, and this, combined with growth of our children, has led to a large experience with dosages lower than the currently recommended 150 mg/m2. The medical records of children with HIV who met CDC guidelines for institution of PCP prophylaxis were reviewed. To ascertain the per square meter (m2) dosage each child was receiving, body surface area was calculated from height and weight measurements. Dosages were recalculated every 6 months and at each dosage change. Data regarding PCP infection, bacterial infections, and side effects of TMP-SMX were extracted. Data were compiled from 1,719.5 child-months of TMP-SMX prophylaxis, including 1,532.5 child-months below the currently recommended dose. Sixty-seven percent of our child-months were at or below two-thirds the CDC recommended dose. There were no cases of proven or suspected PCP. Incidence of other serious bacterial infections was low. Bacteremia and sepsis with Streptococcus pneumoniae was the most common proven bacterial infection, at a rate of 5.5 episodes per 100 child-years. The incidence of bacterial infection did not vary by the dose of TMP-SMX. TMP-SMX prophylaxis was well tolerated; most reactions were mild and self-limited and did not recur with re-institution of the drug. Only 6.1% of this cohort had TMP-SMX prophylaxis discontinued due to perceived toxicity. These data show that the currently recommended dose of TMP-SMX (150 mg/m2) may not be required to prevent PCP in children with HIV/AIDS. The drug is well tolerated at all dosage levels. The incidence of serious bacterial infection in this cohort of patients did not depend upon the amount of TMP-SMX prescribed. A prospective, controlled clinical trial of low-dose TMP-SMX for children with HIV infection is warranted.

Growth patterns reflect response to antiretroviral therapy in HIV-positive infants: potential utility in resource-poor settings.

Laboratory monitoring of HIV-infected children is the current standard of care in the United States to guide the appropriate use of antiretroviral therapy (ART). Although ART is becoming a reality in some developing countries, laboratory monitoring of ART is costly, necessitating creative approaches to monitoring. As an initial step to guide monitoring of HIV progression in low resource settings, we assessed the utility of the physical examination to predict clinical progression of HIV. We conducted a retrospective cohort study of HIV-infected children using data from Pediatric AIDS Clinical Trials Group Protocol 300. We developed a clinical predictive model, and compared the utility of the clinical model to the change in HIV RNA viral load as diagnostic tests of ART failure. The clinical model incorporated treatment regimen, age, and height velocity: a three-level clinical predictive model provided likelihood ratios of 0.3, 3.9, and 14. For decline in RNA the likelihood ratios were 0.2 (> 1 log decline), 1.4, and 3.5 (> log increase). We developed a simple clinical predictive model that was able to predict clinical progression of HIV after initiation of new ART. The clinical model performed similarly to using changes in HIV RNA viral load. These data should be validated internationally and prospectively, because the test subjects were from a resource rich environment and growth patterns in undernourished children may be impacted differently by HIV and its treatment. The model was most pertinent to children 36 months of age or younger, and was conducted in children receiving monotherapy and dual therapy.

Antiretroviral therapy: evaluating the new era in HIV treatment.

Tools for evaluating antiretroviral therapy are still evolving. Key components are available such as the laboratory assays themselves, but results from these assays are being analyzed and presented inconsistently, making interstudy comparisons difficult or impossible. In part, the problems in analysis and presentation reflect a lack of completed clinical trials in which new laboratory methods such as RNA copy numbers can be validated. Survival is the clearest valid end point in clinical trials of antiretroviral drugs. Beyond life and death, the next most important issue is quality of life. Because of the difficulty in agreeing what "quality of life" means, and the even greater problems measuring such an abstract concept, in most cases assessments are made of more quantifiable clinical elements: cognitive and motor function, growth, and the frequency of opportunistic infections. Laboratory markers of disease progression are very quantifiable but have meaning only when they predict clinical outcome. There is a consensus that CD4+ counts, CD4+ percentages, and HIV copy numbers measured by RNA PCR are important. There is not, however, a consensus approach to interpretation of data from any of these markers of HIV disease, particularly because the interpretation may vary based on the patient's level of clinical disease. With time and more clinical trials with which to clarify their use, these tools should become more uniformly applied, at which point cross-study comparisons might be possible. Progress is already being made in the development of new antiretroviral therapies, and with improved evaluation techniques the evolution of new anti-HIV treatments should become an even more efficient process.

Effect of human immunodeficiency virus infection on the growth of young children. Duke Pediatric AIDS Clinical Trials Unit.

We retrospectively analyzed the growth of 170 children less than 25 1/2 months of age who were referred for evaluation of human immunodeficiency virus (HIV) antibody status. By the age of 4 months, the 62 HIV-infected children were significantly smaller than the 108 uninfected children in both weight-for-age and length-for-age measurements; linear growth and weight gain were proportionally decreased.

Growth as a prognostic indicator in children with human immunodeficiency virus infection treated with zidovudine. AIDS Clinical Trials Group Protocol 043 Study Group.

OBJECTIVE: To assess measures of growth as prognostic indicators in response to zidovudine treatment in children with symptomatic human immunodeficiency virus infection. METHODS: We retrospectively assessed data from AIDS Clinical Trials Group Protocol 043, an open-label, phase II study of oral zidovudine therapy (180 mg/m2 per dose every 6 hours) in children with human immunodeficiency virus who have severe symptoms. Several variables were evaluated for their prognostic significance: CD4+ lymphocyte percentage; rates of weight gain and linear growth; entry weight, height, and weight-for-height z scores for age; race; gender; age; and route of transmission. RESULTS: The overall survival rate as of April 1, 1992 (4 years after study initiation), was 44%, with a median survival of 37.9 months. The risk of death was greatest in children with CD4+ lymphocyte percentages < 20% (relative risk, 3.49), but was also increased in children who had a weight-for-age z score < -2 on entry to the study (relative risk, 1.53) and in those who failed to gain weight at the 25th percentile rate or greater during the first 6 months of therapy (relative risk, 2.03). These three factors, as well as race and gender, were found to be significant predictors in a multivariate, proportional-hazards model of survival. Entry height-for-age and height growth rates did not have predictive value for survival in univariate or multivariate analyses. CONCLUSIONS: Weight-for-age and rate of weight gain are important, easily obtained, and inexpensive prognostic indicators in children with symptomatic human immunodeficiency virus treated with zidovudine. Both were less predictive of survival than the entry CD4+ lymphocyte percentage.