Relationship between Changes in Thymic Emigrants and Cell-Associated HIV-1 Dna in HIV-1-Infected Children Initiating Antiretroviral Therapy

Objectives and methods

To investigate the relationship between cell-associated HIV-1 dynamics and recent thymic T-cell emigrants, HIV-1 DNA and T-cell receptor rearrangement excision circles (TREC, a marker of recent thymic emigrants) were measured in peripheral blood mononuclear cells in 181 samples from 33 HIV-1-infected children followed for 96 weeks after antiretroviral therapy (ART) initiation.

Results

At baseline, HIV-1 DNA was higher in children with higher TREC ( P=0.02) and was not related to age, CD4 or HIV-1 RNA in multivariate analyses ( P>0.3). Overall, TREC increased and HIV-1 DNA decreased significantly after ART initiation, with faster HIV-1 DNA declines in children with higher baseline TREC ( P=0.009). The greatest decreases in HIV-1 DNA occurred in children with the smallest increases in TREC levels during ART ( P=0.002). However, this inverse relationship between changes in HIV-1 DNA and TREC tended to vary according to the phase of HIV-1 RNA decline ( P=0.13); for the same increase in TREC, HIV-1 DNA decline was much smaller during persistent or transient viraemia compared with stable HIV-1 RNA suppression.

Conclusions

Overall, these findings indicate that TREC levels predict HIV-1 DNA response to ART and suggest that immune repopulation by thymic emigrants adversely affects HIV-1 DNA decline in the absence of persistent viral suppression, possibly by providing a cellular source for viral infection and replication.

Combination therapy with efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors in children infected with human immunodeficiency virus type 1. Pediatric AIDS Clinical Trials Group 382 Team

BACKGROUND

Consistent long-term viral suppression has been difficult to achieve in children with human immunodeficiency virus type 1 (HIV-1) infection. We tested the safety and antiviral efficacy of a novel combination consisting of efavirenz, nelfinavir, and one or more nucleoside reverse-transcriptase inhibitors in 57 children previously treated with only nucleoside reverse-transcriptase inhibitors.

METHODS

The children were monitored for 48 weeks after the initiation of therapy. We assessed plasma concentrations of efavirenz and nelfinavir, plasma HIV-1 RNA levels, and lymphocyte subpopulations.

RESULTS

At base line, the 57 HIV-1-infected children (age range, 3.8 to 16.8 years) had a median of 699 CD4 cells per cubic millimeter and 10,000 copies of HIV-1 RNA per milliliter of plasma. The most common treatment-related effects of at least moderate severity were rash (in 30 percent of children), diarrhea (in 18 percent), neutropenia (in 12 percent), and biochemical abnormalities (in 12 percent). Serious side effects were uncommon. The mean values for the area under the curve for efavirenz and nelfinavir corresponded to expected values. In an intention-to-treat analysis, 76 percent of children had plasma HIV-1 RNA levels of less than 400 copies per milliliter after 48 weeks of therapy and 63 percent had levels of less than 50 copies per milliliter. A high plasma HIV-1 RNA level at base line significantly decreased the likelihood that plasma levels of HIV-1 RNA would become undetectable during treatment.

CONCLUSIONS

In HIV-1-infected children who were previously treated with nucleoside reverse-transcriptase inhibitors, the combination of efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors was generally well tolerated and had a potent and sustained antiviral effect.

Reduction in T cell apoptosis in patients with HIV disease following antiretroviral therapy

Patients with HIV infection manifest increased T lymphocyte apoptosis. This study investigated the influence of antiretroviral therapy (ART) upon lymphocyte apoptosis in 23 HIV-infected adults naive to protease inhibitors. Patients were enrolled in a treatment trial consisting of Nelfinavir (NFV), d4T, or NFV + d4T for 24 weeks, followed by triple therapy (NFV + reverse transcriptase inhibitors) for an additional 24 weeks. Spontaneous T cell apoptosis in cultured PBMC decreased by 23.67 +/- 18.2% (P < 0.006) at 48 weeks and plasma HIV RNA decreased by 1.79 +/- 0.59 log(10) RNA copies/ml (P < 0.001). The absolute decrease and slope of T cell apoptosis correlated with plasma virus load and with activated CD8 T cells and was inversely correlated with CD4 T cells. We conclude that reduction in chronic antigenic stimulation and the absence of cellular signals elicited by viral products contribute to the rescue of T lymphocytes from apoptosis, which facilitates immunologic recovery in ART-treated patients.

Treatment of human immunodeficiency virus 1-infected infants and children with the protease inhibitor nelfinavir mesylate

An open-label study was conducted of nelfinavir mesylate, given with reverse transcriptase inhibitors to human immunodeficiency virus 1 (HIV-1)-infected infants and children 3 months to 13 years of age. Doses of nelfinavir mesylate of 20-30 mg/kg yielded drug exposures comparable to those seen in adults. The drug was well tolerated; mild diarrhea was the primary toxic effect observed. Seventy-one percent (39) of the 55 evaluable subjects had an initial decrease in plasma HIV-1 RNA, of at least 0.7 log10 copies/mL; suppression of plasma HIV-1 RNA levels to < 400 copies/mL was observed in 15. Children who began taking at least one new reverse transcriptase inhibitor near the time when nelfinavir mesylate was started, and those with a > or = 24% proportion of CD4 lymphocytes, had a greater chance of achieving and maintaining a decline in plasma HIV-1 RNA to < 400 copies/mL. Suppression of viremia was achieved in children as young as 3 months of age.

3-D corneal modeling system

New surgical procedures have been introduced recently that provide refractive correction to replace the use of eyeglasses or contact lenses. The procedures involve reshaping the cornea to compensate for the optical anomalies of astigmatism and nearsightedness. Although thousands of operations are currently performed in the U.S., there are no instruments available for monitoring the results. Thus, a critical need has arisen to inspect and measure the cornea's surface both before and after surgery. In this paper an instrument is presented which provides a detailed topographical model of an individual's cornea. The method uses a novel structured light source. The cornea is modeled as a convex mirror which forms a virtual image of the structured light source. A single image is recorded from the patient's cornea. The depth is obtained from triangulation between the acquired image and a reference image of a sphere. The reconstruction of the depth map is complicated by the fact that the magnification used in recording the image varies with the radius of curvature of the cornea. An iterative method is presented which solves for the radius of curvature despite the variation in magnification. The virtual image is digitized and the instantaneous curvature of the cornea is obtained. The instantaneous curvature is displayed in units of optical power (diopters). This display provides the ophthalmologist or optometrist with the essential optical properties of the cornea.

Psychiatric correlates of behavioral inhibition in young children of parents with and without psychiatric disorders

Behavioral inhibition is a laboratory-based temperamental category by the tendency to constrict behavior in unfamiliar situations and assumed to reflect low thresholds of limbic arousal. We previously found behavioral inhibition prevalent in the offspring of parents with panic disorder and agoraphobia. In this report, we examined the psychiatric correlates of behavioral inhibition by evaluating the sample of offspring of parents with panic disorder and agoraphobia, previously dichotomized as inhibited and not inhibited, and an existing epidemiologically derived sample of children, followed by Kagan and colleagues and originally identified at 21 months of age as inhibited or uninhibited. A third group of healthy children was added for comparison. Our findings indicate that inhibited children had increased risk for multiple anxiety, overanxious, and phobic disorders. It is suggested that behavioral inhibition may be associated with risk for anxiety disorders in children.

Behavioral inhibition in children of parents with panic disorder and agoraphobia. A controlled study

To investigate the role of "behavioral inhibition to the unfamiliar" as an early temperamental characteristic of children at risk for adult panic disorder and agoraphobia (PDAG), we compared children of parents with PDAG with those from psychiatric comparison groups. Fifty-six children aged 2 to 7 years, matched for age, socioeconomic status, ethnic background, and ordinal position, were blindly evaluated at the Harvard Infant Study laboratory, Cambridge, Mass. The rates of behavioral inhibition in children of probands with PDAG, with or without comorbid major depressive disorder (MDD), were significantly higher than for our comparison group without PDAG. Further, the data suggest a progression of increasing rates of inhibition from the comparison group without MDD (15.4%), to MDD (50.0%), and to comorbid PDAG and MDD (70%) and PDAG (84.6%). In contrast, the rate of behavioral inhibition in children of probands with MDD did not meaningfully differ from the comparison group without MDD. Behavioral inhibition to the unfamiliar, as defined and measured in the previous work of the Harvard Infant Study program, is highly prevalent in the offspring of adults in treatment for PDAG. These children appear to be at risk for distress and disability in childhood and also perhaps for development of psychiatric disorder in later childhood and aulthood.

Failure of inhibitor assay to determine isoamylase distribution

Isoamylase distribution in the urine of normal individuals and patients admitted to the hospital with hyperamylasemia was determined by a wheat inhibitor mmethod and compared to results obtained by cellulose-acetate electrophoresis. We report two cases where the inhibitor ethod failed to give accurate results in urine, as well as serum, when compared to both electrophoresis and column chromatography. The discrepant results were due to the unexpected inhibition of P isoamylase.

Separation of two hepatitis B human antibody fractions by cold-ethanol precipitation

Antibodies to three different samples of hepatitis B antigen-positive serum were found to be absent from a Cohn fraction II hepatitis B immune globulin preparation, but present in the whole plasma from which the immune globulin was made. Fractions containing the antibodies specific for the three antigen samples were isolated from the plasma by euglobulin precipitation, and the antibodies were characterized as to immunoglobulin class and precipitability in the Cohn fractionation procedure. They appear to be IgG antibodies which, however, were detectable only in Cohn fraction I, while the remainder of the HB specificity present in the original plasma was found, as expected, in fraction II.