A 12-month study of the effects of oral zidovudine on neurodevelopmental functioning in a cohort of vertically HIV-infected inner-city children

OBJECTIVE

To examine the effects of oral zidovudine on the neurodevelopmental functioning of HIV-infected children.

METHODS

Oral zidovudine was administered to 54 symptomatic children with vertically transmitted HIV infection (Centers for Disease Control and Prevention class P2). All children were recruited from an inner-city pediatric HIV/AIDS outpatient clinic and ranged in age from 2 months to 12 years and 11 months (mean age, 3 years) at entry. Neurodevelopmental functioning, height and weight, and lymphocyte subpopulation data were ascertained for all the children pretherapy, and 6 and 12 months post-therapy initiation.

RESULTS

Analysis of the 6- and 12-month post-initiation drug data found no significant change in neurodevelopmental functioning. Height and weight percentiles remained the same or improved in the majority of children. CD4+ cell counts declined over the treatment period with CD4+ counts < 500 x 10(6)/l observed in 15% of the children pre-therapy, and 33% after 1 year.

CONCLUSION

In contrast with previously published data, the present study observed no improvement in neurodevelopmental functioning in HIV-infected children treated with oral zidovudine.

Endocrine function in children with human immunodeficiency virus infection

We sought to determine if failure to thrive in pediatric patients with the human immunodeficiency virus could be explained based on endocrine dysfunction. Fourteen human immunodeficiency virus-infected pediatric patients, all of whom had adequate nutritional status, underwent endocrine evaluation. Growth hormone and cortisol responses to glucagon stimulation were adequate. Despite this, eight of the 12 subjects had low somatomedin C levels. Although all patients were clinically and biochemically euthyroid, 36% (5/14) demonstrated elevated baseline and peak thyrotropin levels in response to thyroid releasing hormone, suggesting a state of compensated hypothyroidism. Although the importance of these findings is unclear, it is possible that subtle alterations of thyroid regulation may contribute to failure to thrive in some pediatric patients infected with human immunodeficiency virus and may represent a potentially correctable defect.

Preservation of physiological growth hormone (GH) secretion in idiopathic short stature after recombinant GH therapy

This study was undertaken to assess the recovery of spontaneous GH secretion 48 h after the cessation of GH therapy in children with idiopathic short stature treated with recombinant DNA-generated human GH (rhGH-M). Eleven prepubertal children with GH responses of 10.0 ng/mL or more after provocation were divided into therapeutic (n = 7) and control (n = 4) groups. GH was sampled every 20 min for 24 h in six treated and three control patients. One treated and one control patient had 12-h overnight studies because of their weight. The sampling studies were carried out before GH therapy was initiated and 48 h after rhGH was discontinued after 12 months of therapy. Three patients in the treated group also underwent a 24-h study at the 6 month time point. The treated group started treatment with rhGH (0.1 mg/kg), given three times a week. The results showed that pre- and posttreatment GH secretory profiles were comparable with respect to the number of peaks, mean concentrations, peak amplitude, and secretory rate. At the 6 month point, the mean GH and peak GH amplitude (n = 3) were greater than the means of the treatment group (n = 7) at the 0 and 12 month points, but the difference was not statistically significant. Somatomedin-C rose in the treated group from 0.42 +/- 0.1 to 1.25 +/- 0.3 U/mL (mean +/- SD; P less than 0.01). In the control group it rose from 0.56 +/- 0.1 to 1.16 +/- 0.8 U/mL (mean +/- SD; P greater than 0.05) because one patient entered puberty in the 12-month period of observation; his somatomedin-C level rose from 0.72 to 2.5 U/mL. We conclude that exogenous GH therapy does not interfere with the maintenance of endogenous pulsatile secretion of GH. These data show that exogenous GH therapy does not interfere with the maintenance of endogenous pulsatile secretion of GH and provide evidence for the resilience of the GH secretory system in the growing child.