CD95 (APO-1/Fas) expression on naive CD4(+) T cells increases with disease progression in HIV-infected children and adolescents: effect of highly active antiretroviral therapy (HAART)

We studied the expression of the CD95 receptor (APO-1/Fas) on peripheral blood T cell subpopulations in 37 HIV-1-infected children and adolescents stratified according to disease stage or antiretroviral treatment regimen and compared the results to values obtained in 12 healthy age-matched control subjects. CD95 expression on CD45RA(+) CD45RO(-)/CD62L(+) (resting/naive) and CD45RO(+) CD45RA(-) (primed/memory) CD4(+) and CD8(+) T cells was assessed quantitatively by four-color and three-color flow cytometry. CD4(+) T cells contained a population of predominantly CD95(-) resting/naive cells and a population of CD95(high) primed/memory cells, whereas CD8(+) T cells had a more uniform pattern of CD95 expression. The percentage of CD95(+) CD4(+) T cells increased with disease progression because of both an augmented median fluorescence intensity on resting/naïve cells and an increased percentage of CD95(high) cells. Patients with highly active antiretroviral combination therapy who maintained stable CD4 counts in the presence of elevated plasma viral load had nearly normal numbers of CD95(-) resting/naive CD4(+) T cells, whereas CD95 expression in the CD8(+) T cell subset was still elevated compared with control subjects. Low CD95 expression on resting/naive CD4(+) T cells may therefore indicate a low risk for disease progression in antiretrovirally treated and untreated patients.

Microtubule-dependent formation of podosomal adhesion structures in primary human macrophages

Podosomes are unique actin-rich adhesion structures of monocyte-derived cells such as macrophages and osteoclasts. They clearly differ from other substratum-contacting organelles like focal adhesions in morphological and functional regards. Formation of podosomes has been shown to be dependent on the small GTPase CDC42Hs and its effector Wiskott-Aldrich syndrome protein (WASp). In this study, we investigated the functional relation between podosomes and the microtubule system in primary human macrophages. We demonstrate that, in contrast to focal adhesions, assembly of podosomes in macrophages and their monocytic precursors is dependent on an intact microtubule system. In contrast, experiments using Wiskott-Aldrich syndrome (WAS) macrophages indicate that the microtubule system is not reciprocally dependent on podosomes. A potential linker between podosomes and microtubules may be WASp itself, considering that microinjection of the WASp polyproline domain prevents podosome reassembly. This polyproline domain is thought to link WASp to microtubules via CDC42 interacting protein 4 (CIP4). Consistently, macrophages microinjected with CIP4 constructs deficient in either the microtubule- or the WASp-binding domain also fail to reassemble podosomes. In sum, our findings show that microtubules are essential for podosome formation in primary human macrophages and that WASp and CIP4 may be involved in this phenomenon.

Long-term follow-up and outcome of 39 patients with chronic granulomatous disease

OBJECTIVES

To evaluate the clinical long-term course in patients with chronic granulomatous disease (CGD) with respect to different CGD subtypes and currently used antimicrobial prophylactic measures.

STUDY DESIGN

The records of 39 patients with CGD who were monitored during a period of 22 years were reviewed. All infections, infectious complications, and clinical outcomes were documented for a total observation period of 610 patient-years and were stratified with respect to different CGD subtypes.

RESULTS

Lymphadenitis, skin abscesses, and pneumonia occurred in 87%, 72%, and 59% of the patients, respectively. In 151 microbiologic isolates Staphylococcus aureus, Aspergillus species, Candida species, Pseudomonas species, and Salmonella species were the most frequently detected microorganisms. There were 167 severe infections requiring hospitalization and intravenous antimicrobial treatment, resulting in an incidence of 3.7 severe infections per 100 patient months (SI/100 PM). Long-term antibiotic prophylaxis significantly reduced the incidence of severe bacterial infections from 4.8 SI/100 PM to 1. 6 SI/100 PM (P =.0035). In contrast, fungal infections increased under antibiotic prophylaxis from a mean incidence of 0.2 SI/100 PM to 1.9 SI/100 PM (P =.04). We found a 50% survival rate through the fourth decade of life, with a plateau after the third decade of life. Patients with a complete absence of cytochrome b(558) showed an earlier manifestation of their disease and a higher incidence of infections and had significant lower survival than patients with only diminished cytochrome b(558) or autosomal recessive CGD.

CONCLUSIONS

Infections with Aspergillus species have become the major cause of infectious complications and death in patients with CGD. Prophylactic and therapeutic measures are needed to further increase life expectancy and quality for patients with CGD.

Use of saliva specimens for monitoring indinavir therapy in human immunodeficiency virus-infected patients

Indinavir concentrations were determined in plasma and saliva over a random period of 4 h. On average, levels in saliva were 70% +/- 38% of the corresponding levels in plasma. These findings suggest that saliva might serve as an appropriate specimen for monitoring of plasma indinavir levels in patients treated with indinavir.

Comparison of ritonavir plus saquinavir- and nelfinavir plus saquinavir-containing regimens as salvage therapy in children with human immunodeficiency type 1 infection

BACKGROUND

In this retrospective study we compared the antiretroviral effect of regimens consisting of simultaneous administration of two protease inhibitors (PI) with at least one nucleoside reverse transcriptase inhibitor on plasma viral load (VL) and CD4 cell count in HIV-infected children intensively pretreated with nucleoside reverse transcriptase inhibitors and PIs.

METHODS

Eleven HIV-infected children were changed to antiretroviral combination regimens including two PIs and followed for a median time of 24 weeks. Group A comprised six patients who were given ritonavir + saquinavir (SQV) and Group B consists of five patients who were changed to nelfinavir + SQV. Patients were treated with these combinations with 2 PIs because of treatment failure (increasing viral load) of prior PI therapy or clinical signs of disease progression.

OUTCOME MEASURES

Serial determinations of plasma viral load (Amplicor, Roche) and CD4 cells were performed every 4 to 8 weeks. The detection limit of the Amplicor-reverse transcriptase-PCR assay was 50 copies/ml (1.7 log10).

RESULTS

In Group A the median VL reduction was 1.1 log10 after 3 months and 1.4 log10 after 6 months. In Group B median VL decreased 0.1 and 0.2 log10 after 3 and 6 months. In both groups during the study period none of the patients reached undetectable VL. The relative changes of CD4 cells above baseline in Group A showed a median increase of 7% after 3 months and 23% after 6 months. In Group B after 3 months CD4 cells did not increase, and after 6 months the median relative increase was only 7%. Both combination therapies were well tolerated, not necessitating any drug interruption during study period.

CONCLUSIONS

In children with intensive prior antiretroviral treatment, a salvage therapy including two PIs demonstrated antiretroviral efficacy in some patients. In this study the reduction of the VL as well as the increase of CD4 cells was more pronounced with ritonavir + SQV than with nelfinavir + SQV. With both combinations complete suppression of HIV replication was not achieved. Therefore the long term effect of these combinations may be limited by the emergence of resistant HIV strains.

Effect of recombinant human interferon alpha B/D (rHu-IFN-alpha B/D) in combination with acyclovir in experimental HSV-1 encephalitis

The efficacy of recombinant human interferon alpha B/D in experimental HSV-1 encephalitis was investigated in the murine system. Recombinant Hu-IFN-alpha B/D significantly reduced the mortality in a mouse encephalitis model (about 30%, P = 0.021), whereas natural mouse interferon was inactive. Combination of acyclovir with Hu-IFN-alpha B/D had an additive effect.

Preliminary experiences with triple therapy including nelfinavir and two reverse transcriptase inhibitors in previously untreated HIV-infected children

OBJECTIVE

In an intent-to-treat study increase in CD4 cell count, reduction of viral load, clinical benefit and adverse reactions were examined in HIV-infected previously treatment-naive children taking triple therapy.

METHODS

sixteen HIV-infected children in category A or B on antiretroviral triple therapy were followed-up for a period of 12 months. In group I eight patients received zidovudine, lamivudine and nelfinavir; in group II eight patients received stavudine, didanosine and nelfinavir. Viral load and CD4 cell count were measured every 4-8 weeks. Plasma nelfinavir levels were assessed once in all patients at baseline and monitored in patients with increasing viral load.

RESULTS

No significant differences were observed between treatment groups in terms of CD4 cell counts and viral load. A median viral load reduction of 2.8 log10 (range, 1.4-4.2 log10) was achieved over a period of 12 months in both groups. Viral load < 500 copies/ml was found in 69% of patients and viral load < 50 copies/ml in 44% of patients after 12 months. Median CD4 cell count increased from 656 x 10(6) to 850 x 10(6) cells/l after 3 months and was maintained at 813 x 10(6) cells/l after 12 months of treatment. Main side-effects were diarrhoea, rash and hyperlipidaemia. Except for application problems, both regimens were well tolerated. Appropriate formula and individual counselling must be performed during the first weeks of treatment in order to achieve good compliance in paediatric patients.

CONCLUSION

Triple antiretroviral therapy shows a stronger and more sustained reduction of viral load in HIV-infected children compared with studies combining two nucleoside analogues.

Lack of absorption of didanosine after rectal administration in human immunodeficiency virus-infected patients

The feasibility of rectal administration of didanosine (DDI) was studied in six human immunodeficiency virus-infected patients. After oral intake of a DDI solution (100 mg/m2 of body surface area) combined with an antacid (Maalox), pharmacokinetic parametric values were in accordance with previously published data; the mean +/- standard deviation for terminal half-life was 59.5 +/- 15.0 min, that for peak concentration was 5.2 +/- 3.9 mumol/liter, and that for the area under the time-concentration curve (AUC) was 494 +/- 412 min.mumol/liter. After rectal administration of a similarly prepared DDI solution (100 mg/m2 of body surface area), plasma DDI levels were below the detection limit (0.1 mumol/liter) at all time points in five of the six patients, and in the remaining patient the AUC after rectal application was only 5% of that after oral administration. We conclude that oral administration of DDI cannot be easily replaced by rectal application.

Comparison of two antiretroviral triple combinations including the protease inhibitor indinavir in children infected with human immunodeficiency virus

OBJECTIVE

The effects of two antiretroviral triple combinations including the protease inhibitor indinavir on the surrogate markers, viral load and CD4 cells were evaluated.

METHODS

Fifteen patients with high viral load or disease progression under their prior antiretroviral therapy were switched to zidovudine/lamivudine/indinavir (Group A, n = 10) or stavudine/lamivudine/indinavir (Group B, n = 5). Serial determinations of viral load and CD4 cells were performed.

RESULTS

The median reduction of the viral load was 0.6 log after 3 months and 0.8 log after 6 months in Group A and 2.5 and 2.4 log after 3 and 6 months in Group B, respectively. After 3 and 6 months 3 of 10 patients in Group A and 3 of 5 patients in Group B had viral load reductions below the detection limit of the assay. Patients with an additional switch of nucleoside analogues at start of indinavir therapy (regardless of the specific reverse transcriptase inhibitor used) had significantly better reductions of the viral load than patients without such a switch (median 2.3 log vs. 0.2 log after 6 months, P < 0.05). In Group A the median of the relative increase of CD4 cells was 37% after 3 months and 57% after 6 months (P = 0.002); in Group B the medians of the relative increase of CD4 cells were 145 and 163% (not significant), respectively. Two patients from Group A and 1 from Group B developed renal calculi, which resolved after adequate hydration. One patient was withdrawn because of intractable vomiting attributed to indinavir.

CONCLUSION

In a small cohort of HIV-infected pediatric patients with extensive prior antiretroviral treatment, triple therapy including indinavir had a sustained effect on the decrease of the viral load and the increase of CD4 cells similar to results obtained in antiretrovirally experienced adults. This effect was significantly better in patients with an additional switch of a nucleoside analogue at start of triple therapy with indinavir than in patients without such a change.

Absorption and elimination kinetics of zidovudine in the cerebrospinal fluid in HIV-1-infected patients

Current knowledge of zidovudine (ZDV) levels in human cerebrospinal fluid (CSF) is limited to single sample determination and extrapolation to time after administration. Longitudinal studies have not been performed. Pharmacokinetic parameters of ZDV in CSF were determined in six HIV-1-infected patients. CSF samples were collected by an intraspinal catheter over a period of 6 hours after a single intravenous (IV) dose of ZDV (2.5 mg/kg). ZDV concentrations were measured by high-performance liquid chromatography (HPLC). ZDV was cleared rapidly from plasma, with a mean terminal elimination half-life (t 1/2) of 75.5 +/- 4.9 minutes. ZDV penetrated slowly into the CSF, reaching maximal concentration (Cmax) 2 hours after the start of the infusion in all patients. ZDV was cleared from the CSF with a mean t 1/2 of 187.6 +/- 69.3 minutes. Mean Cmax in the CSF was 1.3 +/- 1.2 micromol/l (17% of that of plasma), and mean area under the concentration time curve (AUC) was 358 +/- 200 micromol x minutes/l (75% of that of plasma). There was a significant correlation between plasma and CSF for Cmax (r = 0.88, p = .009) and AUC (r = 0.89, p = .014). Calculated trough levels in CSF for a 12-hour dosing interval were 0.090 +/- 0.065 micromol/l and thus about twice the 50% inhibitory concentration (IC50) of susceptible HIV strains. The CSF-plasma ratio of ZDV increased in a nearly linear fashion with time after drug administration. Thus, ZDV has a distinct pharmacokinetic profile in CSF compared with other compartments of the body.

Pharmacokinetics of zidovudine after rectal administration in human immunodeficiency virus-infected patients

We evaluated the pharmacokinetics of rectally administered zidovudine (ZDV) in 10 human immunodeficiency virus-infected adults. After rectal administration of an aqueous ZDV solution (250 mg of ZDV), mean peak ZDV levels were 1.3 +/- 0.7 micromol/liter (mean +/- standard deviation) versus 5.0 +/- 2.2 micromol/liter (P < 0.0001) after oral intake of a 250-mg ZDV capsule. The half-life at beta phase was 87.8 +/- 39.6 min for rectally administered ZDV versus 55.8 +/- 20.1 min (P = 0.035) for orally administered ZDV. The mean area under the concentration-time curve from 0 min to infinity was 232 +/- 181 micromol/liter x min after rectal administration versus 362 +/- 110 micromol/liter x min after oral intake. Although the two routes were not bioequivalent, ZDV was absorbed considerably after rectal administration, with a pharmacokinetic profile resembling that of a sustained-release device.

Effect of antiretroviral combination therapy (zidovudine/didanosine or zidovudine/lamivudine) on quantitative plasma human immunodeficiency virus-ribonucleic acid in children and adolescents infected with human immunodeficiency virus

OBJECTIVE

To assess human immunodeficiency virus (HIV) ribonucleic acid load in children and adolescents with HIV infection who are being treated with antiretroviral combination therapy.

STUDY DESIGN

Five patients whose disease progressed with their prior antiretroviral therapy had treatment regimens changed to zidovudine (ZDV)/didanosine (DDI) (group A), and the regimens of six patients were changed to ZDV/lamivudine (3TC) (group B). Patients were followed every 4 to 8 weeks for an average period of 8.6 months. Serial determinations of viral copy numbers and CD4 cells were performed.

RESULTS

In group A patients' mean relative changes in CD4 cells showed a 20% increase after 4 months (difference not significant (NS)) and a return to baseline after 8 months; in group B patients' mean relative increases of CD4 cells were 72% (p = 0.046) and 50% (NS), respectively. In group A mean relative viral load increased 21% (0.08 log10, NS) and 71% (0.23(10) log, NS), whereas in group B viral load decreased 22% (0.1 log10, NS) and 74% (0.58 log10, p = 0.03) after 4 and 8 months, respectively. After starting antiretroviral combination therapy in group A, there was a slight trend of a decreasing ratio of viral load per number of CD4 cells, whereas in group B this ratio significantly decreased, indicating a marked suppression of viral turnover with ZDV/3TC treatment.

CONCLUSION

In a small cohort of pediatric patients, combination therapy with ZDV/3TC was well tolerated and had a strong and sustained effect on the decrease of viral loads similar to results obtained in adults. In patients with ZDV/DDI therapy the reduction of viral load was less pronounced, but treatment groups A and B were not comparable for statistic evaluation.

Differential effect of recombinant human and mouse interferons on replication of herpes simplex virus type 1 in mouse cells

Pretreatment of murine (BALB/3T3) cells with either murine or recombinant hybrid human B/D interferon (IFN) blocked the release of infectious herpes simplex virus type 1 (HSV-1) from treated cells. The block in replication was not due to an effect on attachment of HSV-1 to the target cells or to toxic effects of IFN. Immunoblot analyses showed that murine IFN significantly reduced the expression of virus-specific proteins in IFN-treated cells. In contrast, B/D IFN had no major effect on the expression of viral proteins in treated cells. In support of the above observation, electron microscopy of virus-infected cells displayed formation of nucleocapsids within the nucleus of IFN-treated cells. However, the expression of glycoproteins B and D was reduced in B/D IFN-treated cells. These results suggested that murine IFN blocked HSV-1 replication at an early stage whereas B/D IFN inhibited HSV-1 replication at a late stage in virus morphogenesis.

Pharmacokinetics of orally administered zidovudine in HIV-infected children and adults

The pharmacokinetics of oral zidovudine in HIV-infected children and adults are reported. Fourty-six patients were investigated. For data analysis three groups of similar size were formed: young children 4 months-4 years, n = 15 (group 1), older children up to 13 years, n = 16 (group 2) and young adults, n = 15 (group 3). After a single oral dose repeated blood samples were taken 1/2 hourly during a period of 4 hours and zidovudine concentrations in plasma were determined by high performance liquid chromatography. For better comparison of dose dependent parameters peak concentrations (Cmax) and the area under the time-concentration curves (AUC) were normalized either to the dose/body weight (bw) or the dose/body surface area (bs), respectively. Time to reach peak concentrations and mean terminal elimination half-life times (t1/2 beta = 63.4 +/- 47.6, 74.9 +/- 54.9 and 56.9 +/- 16.4 min in group 1, 2 and 3, respectively, mean +/- SD) were not significantly different between the three groups. With normalization to dose/bw young children in comparison to adults had significantly lower Cmax (2.7 +/- 1.3 vs. 4.6 +/- 2.4 mumol/l, p = 0.016) and AUC (226 +/- 108 vs. 373 +/- 224 mumol.min/l, p = 0.038). Group 2 gave intermediate values. However, with normalization to dose/bs differences in Cmax (6.5 +/- 3.3, 7.3 +/- 4.2 and 6.8 +/- 3.6 mumol/l, in group 1, 2, and 3, respectively) and AUC (563 +/- 313, 691 +/- 351 and 555 +/- 342 mumol.min/l, in group 1, 2 and 3) were not significant between the three groups. It is likely that changes in body water content with age may account for most of these differences observed. In conclusion, a similar pharmacokinetic profile was found in children older than 3 months as compared to older children or adults.

High-dose intravenous immunoglobulins in the treatment of adolescent and adult HIV-infected hemophiliacs

In children infected with human immunodeficiency virus (HIV) placebo-controlled trials with intravenous immunoglobulins have resulted in a significant reduction in morbidity; however, the results of small trials in adolescents and adults have been inconsistent. In this study 17 HIV-infected hemophiliacs aged 9-30 years were treated with monthly intravenous immunoglobulins for an average of 32 months. At the end of the study, 8 years after the HIV infection, three patients (18%) had progressed to the acquired immunodeficiency syndrome (AIDS), and the average decrease in CD4 cells was 81 cells/microliter per year. The natural history of HIV infection in hemophiliacs in this age group shows a manifestation rate of AIDS between 11% and 26% 6-8 years after seroconversion and an average yearly decrease in CD4 lymphocytes of 68-110 cells/microliters. In conclusion, we observed no difference either in the manifestation rate of AIDS or in prognostic markers in this small cohort of HIV-infected hemophiliacs treated for more than 30% of their latency period with intravenous immunoglobulins compared to the well-documented natural history of HIV-infected hemophiliacs. However, none of the patients developed severe bacterial infections during the study period.

Improvement of superoxide production in monocytes from patients with chronic granulomatous disease by recombinant cytokines

Cytokines have been shown to modulate the respiratory burst of polymorphonuclear leukocytes and monocytes from normal controls. We have examined whether monocytes from children with chronic granulomatous disease (CGD) can be primed by cytokines other than interferon-gamma (IFN gamma), which has been demonstrated to improve the production of reactive oxygen species in vivo and in vitro. Monocytes isolated from peripheral blood were cultured without and with IFN gamma (500 U/mL), tumor necrosis factor-alpha (500 U/mL), interleukin-1 beta (IL-1 beta) (100 U/mL), and IL-3 (100 U/mL). After 3 days of culture, the phorbolmyristate acetate (2 ng/mL) and the formyl-methionyl-leucyl-phenylalanine (0.1 mumol/L)-stimulated superoxide-production was determined in a microtiter system. In nearly all of the 14 patients examined (5 autosomal, 5 X-chromosomal, and 4 of unknown inheritance), an improvement of superoxide production could be demonstrated. The most impressive effect with the cytokines newly tested was seen with monocytes from autosomal CGD patients treated with IL-3 and stimulated by phorbolmyristate acetate. In single patients cultivation of monocytes with IL-6 and granulocyte-macrophage colony-stimulating factor resulted in only slight improvement of superoxide production. Our findings indicate that cytokines other than IFN gamma can positively modulate the defective respiratory burst in CGD and that each patient reacts with an individual pattern to different cytokines.

[Reduction of pain perception of chronically ill children by intermittent infusion therapy]

Chronically ill children who require life-long i.v. infusions in regular intervals (i.e. Agammaglobulinemia, HIV-infection) can be traumatized by such painful procedures. Some children gradually accept such infusions, whereas other children become sensitized and react with increasing fear and resistance. We report on our experience with a combined method of local anaesthesia and active role-plays enacting the i.v. infusion on a puppet. In more than 230 applications (approximately 11 per child) in our outpatient clinic, 19/20 children reported significantly less pain sensations after the 2nd or 3rd application. The children learned to handle actively the threatening situation. The method of local anaesthesia with Lidocaine/Prilocaine and role playing is suitable to relieve pain and reduces distress of such invasive events as regular i.v. infusions are.