[Immunologic and viral mechanisms implicated in HIV infection: the impact of treatment]

HIV-infection leads to the destruction of the immune system, mainly of the subgroup of CD4 lymphocytes. The main cell surface receptor for the VIH is the CD4 molecule. However the virus can penetrate into the cell through the CCR5 chemokine receptor that represents a new avenue for antiviral therapy. The early phase of HIV infection is characterised by an active viral replication mainly in lymph nodes. During the development of the infection, persistent viral replication leads to the destruction of CD4 lymphocytes and inhibits their turnover. Highly active antiretroviral therapy inhibits viral replication but can not eradicate the virus. However this treatment can efficiently restore immune function and allows to avoid opportunistic infections. Antiretroviral therapy could be associated with an immunotherapy (interleukin-2, therapeutic vaccination) in order to achieve a more satisfying T-cell specific response directed against the virus, which appears to be lost early in the course of the disease, except in the subgroup of patients with a low progression of the disease.

Persistent mitochondrial dysfunction and perinatal exposure to antiretroviral nucleoside analogues

BACKGROUND

Zidovudine is commonly administered during pregnancy to prevent mother-to-child HIV-1 transmission. We investigated mitochondrial toxic effects in children exposed to zidovudine in utero and after birth.

METHODS

We analysed observations of a trial of tolerance of combined zidovudine and lamivudine and preliminary results of a continuing retrospective analysis of clinical and biological symptoms of mitochondrial dysfunction in children born to HIV-1-infected women in France. Mitochondrial dysfunction was studied by spectrophotometry and polarography of respiratory-chain complexes in various tissues.

FINDINGS

Eight children had mitochondrial dysfunction. Five, of whom two died, presented with delayed neurological symptoms and three were symptom-free but had severe biological or neurological abnormalities. Four of these children had been exposed to combined zidovudine and lamivudine, and four to zidovudine alone. No child was infected with HIV-1. All children had abnormally low absolute or relative activities of respiratory-chain complexes I, IV, or both months or years after the end of antiretroviral treatment. No mutation currently associated with constitutional disease was detected in any patient.

INTERPRETATION

Our findings support the hypothesis of a link between mitochondrial dysfunction and the perinatal administration of prophylactic nucleoside analogues. Current recommendations for zidovudine monotherapy should however be maintained. Further assessment of the toxic effects of these drugs is required.

Disclosure of HIV seropositivity

Deciding whether or not to disclose one's HIV-positive status to another person is an important decision: the way each person experiences and copes with the illness is reflected in this choice. We conducted a study of 174 patients (29.3% of women) to examine how the decision to disclose or conceal was made, as well as its subjective and social consequences. We discovered that only 3.5% of the individuals remained silent about their illness. Most spoke about it, regardless of how they had been infected or of the advice they had received to be discrete. The confession often did not bring them the relief they sought. Revealing one's HIV-positive status is not a sign of social responsibility, or of a special trust in someone, but rather a compulsive act to release suppressed tension. Individuals who do not confess need attention; their silence is a sign of their inability to adapt to their illness, as well as of their self-imposed exclusion from society.

Broad, intense anti-human immunodeficiency virus (HIV) ex vivo CD8(+) responses in HIV type 1-infected patients: comparison with anti-Epstein-Barr virus responses and changes during antiretroviral therapy

The ex vivo antiviral CD8(+) repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4(+) T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8(+) responses and the CD4(+) counts or virus load. In contrast, the polyclonality of anti-HIV CD8(+) responses was positively correlated with the CD4(+) counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4(+) counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8(+) responses in two patients with stable CD4(+) counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8(+) T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8(+) responses at all stages of HIV infection and suggest that the CD8(+) hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8(+) T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8(+) responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8(+) responses may occur with depletion of CD4(+) T cells, but this could be restored by highly active antiretroviral treatment.

CCR5 delta32 deletion and reduced risk of toxoplasmosis in persons infected with human immunodeficiency virus type 1. The SEROCO-HEMOCO-SEROGEST Study Groups

This study attempted to determine whether the CCR5 Delta32 deletion affected progression to certain first AIDS-defining illnesses in human immunodeficiency virus type 1-infected patients enrolled in the French SEROCO/HEMOCO/SEROGEST cohorts. Toxoplasmosis onset as a first AIDS-defining illness was significantly delayed in 253 heterozygous patients, compared with 1404 wild type patients. The relative risk of toxoplasmosis associated with heterozygosity was 0. 39 (95% confidence interval, 0.16-0.96) after adjustment for age, CD4 cell count, and primary specific prophylaxis. A nonsignificant protective trend was observed with regard to the onset of mycobacterial, cytomegalovirus, and herpesvirus diseases, but these events were less frequent than toxoplasmosis. Progression to other conditions (e.g., wasting, non-Hodgkin's lymphoma, Kaposi's sarcoma) was similar in the 2 groups as was the frequency of toxoplasmosis as a subsequent AIDS-defining illness. As chemokines are involved in numerous infectious processes, the Delta32 deletion could delay progression to certain opportunistic infections such as toxoplasmosis.

Clinical and biological characteristics of human immunodeficiency virus-infected and uninfected intravascular drug users in Ho Chi Minh City, Vietnam

To define the medical characteristics of intravascular drug users in Ho Chi Minh City, Vietnam, we examined 280 men, of whom 235 were infected with human immunodeficiency virus (HIV), being treated in a rehabilitation center. The patients used mainly opium, often in shooting galleries (50%). The prevalence of oral candidiasis (58%) and zoster infection (20%) was high in HIV-seropositive patients, whereas oral hairy leukoplasia and Kaposi's sarcoma were absent. The prevalence of acquired immunodeficiency syndrome was 24%. More than 80% of the patients had infections with hepatitis C virus, hepatitis B virus, cytomegalovirus, or human T cell lymphotropic virus type-1. The CD4+ cell counts correlated well with viral load. Only HIV-1 subtype E was detected in the 30 patients tested. A cohort study of HIV-infected subjects in this population seems feasible, and would permit introduction of anti-retroviral therapy The large number of HIV-seronegative subjects sharing the same at-risk practices as the HIV-infected subjects raises the possibility of natural protection in this population.

Prolonged survival without neurological improvement in patients with AIDS-related progressive multifocal leukoencephalopathy on potent combined antiretroviral therapy

To evaluate the benefit of combined antiretroviral therapy including protease inhibitors (CART) on survival time and neurological progression in patients with AIDS-related progressive multifocal leukoencephalopathy (PML), 81 consecutive PML cases, collected between January 1990 and June 1998, were reviewed. Fifteen patients were neuropathologically proven. JC virus detection in CSF was positive in 59 patients. At PML diagnosis, median CD4 cell count was low (median, 35 cells/microL) and plasma HIV load, determined in 41 patients, was high (median, 4.8 log10 copies/ml). Following PML diagnosis, there was a significant difference (P<10(-4)) in survival between patients who were untreated or treated with nucleoside analogs (n=50, median: 80 days) and patients who were started early on CART (n=23, median: 246 days). A third group of eight patients who received CART late during the course of PML was considered separately. At the study endpoint, 18 of all the CART-treated patients (n=31) were still alive. Plasma HIV load was undetectable in 67% of them. The median increase in CD4 cell count was 112 cells/microL from CART onset. In contrast, no significant improvement in neurological status was observed. Our results demonstrate a benefit of CART on survival of AIDS-related PML patients and suggest the need for an early, specific anti-JC virus treatment to limit the neurological deterioration.

Comparison of subcutaneous and intravenous interleukin-2 in asymptomatic HIV-1 infection: a randomised controlled trial. ANRS 048 study group

BACKGROUND

Intermittent interleukin-2 therapy for HIV-1 by continuous intravenous infusion leads to sustained increase of CD4 T cells. This method of administration is, however, inconvenient and has limiting toxic effects. We did a randomised study to compare safety and efficacy of antiviral treatment alone or combined with various interleukin-2 regimens in HIV-1-infected patients.

METHODS

94 symptom-free patients, naïve to antiretroviral treatment, with CD4-T-cell counts of 250-550 cells/microL at baseline were randomly assigned zidovudine and didanosine alone (n=26) or combined with interleukin-2 administered intravenously (12 million IU/day, n=22) or subcutaneously (3 million IU/m2 twice daily, n=24) for 5 days, or were given polyethylene-glycol-modified (PEG) interleukin-2 (2 million IU/m2 intravenous bolus, n=22) administered every 2 months from week 2 to week 50 (seven cycles). Safety and immunological and virological results were monitored until week 56.

FINDINGS

CD4-T-cell count increased to higher than baseline by a mean of 564 cells/microL (subcutaneous group), 676 cells/microL (intravenous group), 105 cells/microL (PEG group), and 55 cells/microL (antiretroviral-therapy group, p=0.0001). 68% and 77% of patients in the subcutaneous and intravenous groups, respectively, achieved an 80% increase of CD4 T cells (p<0.001). In these two groups, 50% of patients restored a CD4/CD8-T-cell ratio of more than 1. The groups did not differ significantly for changes in plasma HIV-1 RNA loads throughout the study. The duration of common side-effects of interleukin-2 was shorter in the subcutaneous group, which enabled outpatient treatment. Naïve and memory CD4 T cells, CD28 expression on CD4 and CD8 T cells, and restoration of in-vitro proliferative response to mitogens and recall antigens increased in the intravenous and subcutaneous groups.

INTERPRETATION

Subcutaneous interleukin-2 is a convenient regimen that, as well as intravenous therapy, improves immunological function in HIV-1-infected patients receiving two nucleosides. Larger studies are needed to show whether immunological improvements translate into clinical benefit.

Safety and efficacy of ritonavir and saquinavir in combination with zidovudine and lamivudine

BACKGROUND

Ritonavir is a potent inhibitor of cytochrome P4503A4 that strongly increases saquinavir bioavailability. In this study we assessed the safety and antiretroviral efficacy of the combination of these two compounds in patients pretreated and receiving continued treatment with zidovudine and lamivudine who were protease inhibitor naive and who had a CD4 cell counts below 200/mm3.

METHODS

In this 48-week pilot study, all patients received 600 mg ritonavir and 400 mg saquinavir twice daily. Administration of zidovudine and lamivudine was continued without a change in previous doses. Viral load, CD4 cell count, and the emergence of resistance to the two protease inhibitors were evaluated repeatedly up to week 48.

RESULTS

Sixteen patients were included in the study. Previous nucleoside analog treatment duration was 48+/-22 months (mean +/- SD). Two patients quit taking both protease inhibitors within 2 weeks. The ritonavir dose had to be reduced in 10 other patients because of side effects. Between inclusion and week 48, plasma viremia varied from 4.87+/-0.43 to 3.00+/-1.29 log10 copies/mL and CD4 cell counts ranged from 98+/-61 to 250+/-139/mm3. Ten patients (63%) had viral loads below 200 copies/mL and 7 (44%) had viral loads below 50 copies/mL. A single key mutation that conferred ritonavir resistance I84V and V82A/V developed in two patients. A mutation at codon 54 developed in another patient. These mutations were associated with repeated cessations of antiretroviral treatment. No lipodystrophy was observed.

CONCLUSION

Ritonavir and saquinavir in combination are quite well tolerated and induce a high and sustained antiretroviral efficacy. A four-drug combination that includes these two protease inhibitors should be considered as a first line of treatment in patients with low CD4 cell counts.

Persistent alterations in T-cell repertoire, cytokine and chemokine receptor gene expression after 1 year of highly active antiretroviral therapy

OBJECTIVES

To examine T-cell repertoire modifications, the evolution of T-helper (TH)1/TH2 cytokine imbalance and modifications in chemokine receptor expression when the viral load is decreased by 2-3 log10 copies/ml under highly active antiretroviral therapy (HAART).

DESIGN

Sixteen patients previously treated with zidovudine and lamivudine, with CD4 cells below 300 x 10(6)/l and viraemia above 30000 copies/ml were treated by saquinavir and ritonavir together with both reverse transcriptase (RT) inhibitors (ANRS 069 trial). T-cell repertoire, chemokine receptor and lymphokine expression were studied from peripheral blood mononuclear cells sampled at weeks 0, 24 and 48.

METHODS

T-cell repertoire study was carried out using the Immunoscope method. Interleukin (IL)-12 receptor beta2, CC-chemokine receptor (CCR)-3, CXC-chemokine receptor-4 and CCR-5 expression in CD4+ cells was measured by kinetic quantitative PCR and IL-2, IL-4, IL-10, IL-13, interferon (IFN)-gamma were measured using a quantitative RT-PCR assay with homologous internal standards.

RESULTS

Repertoire alterations were more frequent in CD4- than in CD4+ cells and persisted despite undetectable viraemia. Increased CCR-3 expression and spontaneous IFN-gamma as well as mitogenic induced IL-13 were observed at baseline and decreased slightly under HAART.

CONCLUSION

The CD8+ cell repertoire alterations were profound, whereas the CD4+ cell alterations were moderate and both persisted unchanged under HAART. The TH1/TH2 imbalance was more related to TH2 over-expression than to TH1 deficiency and persisted for at least 1 year under HAART.

Prognostic value of JC virus load in cerebrospinal fluid of patients with progressive multifocal leukoencephalopathy

JC virus (JCV) load was determined by using quantitative polymerase chain reaction in cerebrospinal fluid (CSF) of 12 patients with AIDS-associated progressive multifocal leukoencephalopathy (PML) and compared with clinical outcome. JCV loads varied widely (3-7 log10 JCV equivalents/mL of CSF) and were apparently not related to absolute CD4 cell counts or CSF and plasma human immunodeficiency virus type 1 loads. A significant correlation was observed between JCV load and survival time (Spearman's rank correlation, -0.83; P<. 01). Moreover, CSF JCV load decreased and then became undetectable in 1 PML patient receiving cidofovir treatment, and this was associated with clinical improvement. These results show that CSF JCV load may be useful as a prognostic parameter and in monitoring the effectiveness of anti-JCV therapies in PML patients.

A randomized trial of three maintenance regimens given after three months of induction therapy with zidovudine, lamivudine, and indinavir in previously untreated HIV-1-infected patients. Trilège (Agence Nationale de Recherches sur le SIDA 072) Study Team

BACKGROUND

The long-term effectiveness of potent three-drug antiretroviral regimens for the treatment of human immunodeficiency virus type 1 (HIV-1) infection is limited by problems related to compliance and tolerability. We investigated whether two-drug maintenance therapy would suppress viral replication after a three-month period of aggressive triple-drug induction therapy.

METHODS

A total of 378 HIV-1-infected adults who had not received previous antiretroviral treatment received three months of induction therapy consisting of 300 mg of zidovudine every 12 hours, 150 mg of lamivudine every 12 hours, and 800 mg of indinavir every 8 hours. The 279 patients in whom the plasma HIV-1 RNA titer fell below 500 copies per milliliter after two months of triple-drug therapy, and who completed the induction phase, were randomly assigned at month 3 to one of the following three open-label maintenance regimens: zidovudine, lamivudine, and indinavir; zidovudine and lamivudine; or zidovudine and indinavir. The primary end point was an increase in HIV-1 RNA levels to 500 copies or more per milliliter during the maintenance phase.

RESULTS

The proportion of patients who reached the primary end point was significantly higher among patients receiving zidovudine plus lamivudine (29 of 93 patients, P<0.001) or zidovudine plus indinavir (21 of 94, P=0.01) than among patients receiving continued triple-drug therapy (8 of 92). This higher failure rate in the groups treated with the two-drug maintenance regimens was also observed in the subgroup of patients with maximally suppressed HIV-1 RNA (below 50 copies per milliliter) at the time of randomization to maintenance therapy.

CONCLUSIONS

In HIV-1-infected adults not previously treated with antiretroviral drugs whose plasma HIV-1 RNA levels fell below 500 copies per milliliter after three months of induction therapy with zidovudine, lamivudine, and indinavir, two-drug maintenance therapy was less effective in sustaining a reduced viral load than continued three-drug therapy.

Safety of the maternal-infant zidovudine regimen utilized in the Pediatric AIDS Clinical Trial Group 076 Study

OBJECTIVE

To determine the safety of the zidovudine (ZDV) regimen utilized in the Pediatric AIDS Clinical Trial Group (ACTG) 076 study.

DESIGN

ACTG 076 was a randomized, double-blind, placebo-controlled trial which demonstrated that a ZDV regimen could prevent mother-to-child HIV-1 transmission. Infants were followed through 18 months of age and women were followed through 6 months postpartum.

METHODS

Maternal complications, pregnancy outcomes, growth and development of the uninfected infants, and HIV-1 disease progression in the women were monitored prospectively.

RESULTS

Maternal therapy was well tolerated. There was no serious pattern of adverse pregnancy outcomes associated with ZDV use. Amongst the ZDV-exposed infants, the only recognized toxicity was anemia within the first 6 weeks of life; the risk for anemia was not associated with premature delivery, duration of maternal treatment, degree of maternal immunosuppression, or maternal anemia. ZDV treatment was not associated with an increased incidence of newborn structural abnormalities. At 18 months of age, uninfected infants did not differ in growth parameters or immune function. No childhood neoplasias were reported in either group. In the women, at 6 months postpartum, there were no differences in clinical, immunologic, or virologic disease progression.

CONCLUSION

There were no identified problems that would alter current recommendations for the routine use of ZDV for the prevention of mother-child HIV-1 transmission.

[Incidence and evaluation of viral retinitis in patients infected with the HIV virus and treated with HIV protease inhibitors]

BACKGROUND

Since the beginning of the use of HIV-Protease Inhibitors (PI) to treat HIV-infected patients, a decrease of the incidence of extraocular opportunistic infections has been observed. We studied the incidence of CMV-retinitis in patients treated with a highly active antitetroviral therapy (HAART) containing PI over a mean follow-up of 12 months.

METHODS

Ninety-three HIV-infected patients treated with HAART containing PI were included. The mean initial CD4+ cell-count was 54/microliter (median: 22/microliter), and the mean plasma HIV-load was 5.46 log 10 RNA-copies/ml. Fundus examination was performed each month in case of a previously treated and controlled CMV-retinitis or if initial CD4 cells were below 50/microliter. In other patients, fundus examination was performed every 3 months. The mean follow-up was 362 days.

RESULTS

Among the 7 patients with a previously treated and controlled CMV-retinitis, one experienced a progression during the study (after 163 days of PI). Among the 59 patients with CD4 cells below 50/microliter and without previous CMV-retinitis before the beginning of PI, 5 experienced a CMV-retinitis (mean delay after the onset of HAART: 141 days), including 2 with relapse. When retinitis occurred, CD4 cells were below 32/microliter except in one case (147/microliter).

CONCLUSIONS

Compared to previously published reports, this study showed an increase of the time to progression of previously treated and controlled CMV-retinitis in patients treated with PI. Considering deeply immunocompromised patients (less than 50 CD4-cells/microliter), the risk of suffering from CMV-retinitis was 8.5% after 12 months of PI treatment. Longer follow-up remains necessary to confirm these results.

Regulation by endogenous INTERLEUKIN-10 of the expression of nitric oxide synthase induced after ligation of CD23 in human macrophages

The possible role of interleukin 10 (IL-10) as an endogenous inhibitor of CD23-driven inducible nitric oxide synthase (iNOS) expression in human macrophages was investigated. Cross-linking of CD23 by a monoclonal antibody induced iNOS mRNA, as detected by RT-PCR, and the production of NO measured as the stable derivative, nitrite. A linear correlation was observed between CD23 expression and iNOS activity or NO2- production. The iNOS activity reached a maximum 48 h after ligation of CD23, then declined rapidly until 72 h. In parallel, nitrite production was detected after 24 h and reached a maximum after 48 h. In addition, ligation of the CD23 molecule induced, in a time-dependent manner, the production of IL-10. As this cytokine is known to regulate iNOS induction and activity, we evaluated the effect of a neutralizing mAb to IL-10 on CD23-induced iNOS activity and nitrite production by CD23-bearing macrophages and found that both were significantly enhanced. Furthermore, the addition of exogenous IL-10 suppressed CD23-driven iNOS mRNA expression, iNOS activity and production of nitrite. These data suggest that, after CD23-ligation at the cell surface of human phagocytes, the secretion of IL-10 downregulates the CD23-induced NO production at the transcriptional level, thus providing an efficient feed-back mechanism.

Perinatal HIV-1 transmission: interaction between zidovudine prophylaxis and mode of delivery in the French Perinatal Cohort

CONTEXT

It is unclear whether elective cesarean delivery may have a protective effect against the transmission of human immunodeficiency virus 1 (HIV-1).

OBJECTIVE

To investigate whether mode of delivery has an impact on perinatal HIV-1 transmission in the presence of zidovudine prophylaxis.

DESIGN

A prospective cohort study.

SETTING

The 85 perinatal centers in the French Perinatal Cohort, from 1985 to 1996.

PATIENTS

A total of 2834 singleton children born to mothers with HIV-1 infection.

MAIN OUTCOME MEASURE

Human immunodeficiency virus 1 infection of the infant.

RESULTS

No zidovudine was used in 1917 pregnancies and zidovudine prophylaxis was used in 902 pregnancies. Cesarean deliveries were performed in 10.9% on an emergent basis and in 8.3% electively, prior to labor or membrane rupture. In 1917 mothers who did not receive zidovudine, of 1877 with information on mode of delivery, 17.2% transmitted HIV-1 to their child. Risk factors statistically significantly associated with transmission were maternal p24 antigenemia, cervicovaginal infections during pregnancy, amniotic fluid color, and rupture of membranes 4 hours or more before delivery. Mode of delivery was not related to transmission. In 902 mothers receiving zidovudine, transmission was 6.4% in 872 with information on mode of delivery, and elective cesarean delivery (n = 133) was associated with a lower transmission rate than emergent cesarean or vaginal delivery (0.8%, 11.4%, and 6.6%, respectively; P=.002). In a multivariate analysis of all mother-child pairs, including obstetrical risk factors, maternal p24 antigenemia, and zidovudine prophylaxis, interaction between mode of delivery and zidovudine prophylaxis was significant (P=.007). In the multivariate analysis of pregnancies with zidovudine prophylaxis, factors related to transmission rate were maternal p24 antigenemia, amniotic fluid color, and mode of delivery. Adjusted odds ratios (95% confidence intervals) were 1.6 (0.7-3.6) for emergent cesarean delivery and 0.2 (0.0-0.9) for elective cesarean delivery (P = .04) in comparison with vaginal delivery.

CONCLUSIONS

We observed an interaction between zidovudine prophylaxis and elective cesarean delivery in decreasing transmission of HIV-1 from mother to child. This observation may have clinical implications for prevention.

Quantitative ELISA-polymerase chain reaction at saturation using homologous internal DNA standards and chemiluminescence revelation

In this report, we describe the development and validation of a convenient, versatile and high throughput quantitative polymerase chain reaction (PCR) method. This assay is based on the use of only one concentration of an internal homologous standard (IS) easily obtained by replacing an 18 nt specific sequence using recombinant PCR. Target and IS amplicons are quantitated at the PCR plateau phase using ELISA which includes a hybridization step with either target or IS specific probes and luminometric revelation. Luminometry allows measurement of amplicon levels without the need for serial dilutions. Experimental values were obtained by comparing their target/IS signal ratios to those of an external scale. A linear dynamic range over four orders of magnitude and good reproducibility were obtained. We used this assay to investigate variations of IL-13 mRNA expression in HIV-infected patients under highly active antiretroviral therapy. Furthermore, we also report a variant of this method using Taqman assay in the ABI PRISM 7,700 apparatus.

A longitudinal study of seroreactivity against Mycoplasma penetrans in HIV-infected homosexual men: association with disease progression

We investigated the relationships between a putative cofactor of HIV infection, Mycoplasma penetrans, and the evolution of HIV disease. The evolution of titers of anti-M. penetrans antibodies in 58 randomly selected HIV-seropositive adult homosexual men was investigated. The median length of follow-up was 38 months. Thirty-six individuals was investigated. The median length of follow-up was 38 months. Thirty-six individuals (62.1%) remained M. penetrans seronegative (group 0). Fourteen patients (24.1%) had consistently low antibody titers or low antibody titer(s) in at least one sample and negative test(s) in the other(s). This pattern was possibly associated with latent or earlier infection (group 1). Eight patients (13.8%) had moderate to high antibody titers for long periods, indicating an active and persistent M. penetrans infection (group 2); four patients in this group presented a serological reactivation and thus probably developed an acute infection during the study; two had a stable and moderate level of antibody throughout the study; in two patients the antibody titers decreased substantially. Interestingly, CD4 cell counts declined more rapidly in group 2 than in group 0 (medians of -4.5 versus -2.1 cells/mm3/month, p < 0.05 and -0.16 versus 0 cell percentage/month, p < 0.05), whereas there was no significant difference between groups 1 and 0 (medians of -2.0 versus -2.1 cells/mm3/month and -0.15 versus 0 cell percentage/month). In patients with serological reactivation, the viral load was higher in sera with higher M. penetrans antibody titers. These findings suggest an association between active M. penetrans infection and progression of HIV disease.

CCR5 chemokine receptor variant in HIV-1 mother-to-child transmission and disease progression in children. French Pediatric HIV Infection Study Group

CONTEXT

Studies suggest that adults with the CCR5delta32 deletion are less likely to become infected with the human immunodeficiency virus (HIV) and to develop HIV-related disease progression, but the effect of the mutation in children is not known.

OBJECTIVE

To study the effect of the CCR5 chemokine receptor mutant allele on mother-to-child transmission of HIV type 1 (HIV-1) and subsequent disease progression in infected children.

DESIGN

Multicenter, prospective study of infants born to mothers seropositive for HIV-1.

SETTING

A total of 52 medical centers participating in the French Pediatric HIV Cohort studies.

PARTICIPANTS

The CCR5delta32 deletion was studied in 512 non-African children, born between 1983 and 1996 to HIV-1-infected mothers. Among them, 276 children were infected and 236 were not.

MAIN OUTCOME MEASURES

HIV-1 infection status and, in infected children followed up since birth, incidence of category B and C disease events and severe immunosuppression as defined in the new pediatric Centers for Disease Control and Prevention (CDC) classification, according to CCR5 genotype.

RESULTS

The 32-base pair deleted allele was detected at a frequency of 0.05. Only 1 infant, not infected by HIV-1, was homozygous for the delta32 deletion. The 49 heterozygous children (9.6% of the total; 95% confidence interval [CI], 7.1-12.2) were equally distributed into the infected (9.8%) and uninfected (9.3%) groups. The incidence of stage C symptoms in heterozygous infected children was 9% at 36 months vs 28% in children homozygous for the normal allele (P<.004). The proportion of children at 8 years old with no stage B or C symptoms was 49% for heterozygous children and 11% for children homozygous for the normal allele (P<.003). The progression of severe immune deficiency (CD4 <15%, CDC stage 3) was also significantly different between the 2 groups (P<.001).

CONCLUSIONS

Heterozygosity for the CCR5delta32 deletion does not protect children from infection by the maternal virus but substantially reduces the progression of the disease in HIV-1-infected children.

Acceptability and impact of zidovudine for prevention of mother-to-child human immunodeficiency virus-1 transmission in France

We studied the propagation and the impact of zidovudine prevention on the human immunodeficiency virus-1 transmission rate from infected mothers to their infants in the French nationwide prospective cohort. Infection was diagnosed in the children on the basis of at least two positive human immunodeficiency virus-1 polymerase chain reaction tests, culture, or both. The transmission rate among treated women was compared with that among untreated women during the same period and with that among women enrolled in the cohort since 1986. The impact of zidovudine was analyzed according to the women's clinical and biologic characteristics, the mode of delivery, and use of zidovudine therapy before the pregnancy. Nearly 90% of women were treated as soon as the second half of 1994. In 1994 and 1995, 80% of mother-child pairs received at least one of the three phases of preventive treatment. Among the 663 mothers enrolled during these 2 years, only six refused the treatment. Zidovudine treatment was associated with a reduction in the transmission rate of nearly two-thirds, from 14% +/- 6% to 5% +/- 2% (p < 0.01). The degree of reduction was not influenced by the maternal CD4+ cell count or p24 antigenemia at delivery. Zidovudine treatment of the mother before the pregnancy considerably reduced the impact of preventive therapy; the transmission rate was significantly higher among pretreated mothers (20% versus 5%, p < 0.01) even after adjusting for maternal CD4+ cell count. Zidovudine prevention is now widely used in France and has had a major impact on the epidemiology of mother-child human immunodeficiency virus transmission. This justifies a policy of offering human immunodeficiency virus screening to all women before or shortly after the diagnosis of pregnancy.

Early protective effect of CCR-5 delta 32 heterozygosity on HIV-1 disease progression: relationship with viral load. The SEROCO Study Group

OBJECTIVE

To determine the influence of heterozygosity for the delta 32 mutant CCR-5 allele on HIV-1 disease progression.

DESIGN

HIV-1 disease progression and serum viral load were analysed according to the C-C chemokine receptor (CCR)-5 genotype in 412 Caucasian patients (319 men and 93 women) with a known date of seroconversion, who were enrolled in the SEROCO cohort (median follow-up, 74 months).

RESULTS

The frequency of heterozygosity for the mutant allele was 17% and did not differ according to sex or risk factor of HIV infection. Heterozygotes were significantly less likely than patients with two functional alleles to have symptomatic primary infection. Their serum viral load was lower during the 6- to 24-month plateau phase after seroconversion. This difference persisted afterwards, although the rate of decline in CD4+ cells was similar. Kaplan-Meier survival curves showed slower progression to clinical AIDS in heterozygotes during the first 7 years following infection (P < 0.02), the two curves tending to join thereafter (overall log-rank test, P = 0.17). However, the interaction term with time did not reach significance in a Cox model. The overall relative risk of progression was 0.67 (95% confidence interval, 0.38-1.18) and was not influenced by adjustment for age at seroconversion or symptomatic primary infection. After adjustment for early viral load the relative risk was 0.83. Pneumocystis carinii pneumonia and toxoplasmosis were less likely to be the first AIDS-defining illness in heterozygotes than in the other patients (0 versus 24.7% of AIDS cases, P = 0.04), despite similar management.

CONCLUSION

Deletion of one CCR-5 gene allele appears to protect against HIV-1 disease progression, mainly during the early years of the infection. Heterozygosity for the deletion leads to persistently lower viral load, and also seems to protect against some opportunistic infections.

The 25-kDa soluble CD23 activates type III constitutive nitric oxide-synthase activity via CD11b and CD11c expressed by human monocytes

CD23, a low-affinity receptor for IgE, was recently shown to bind to CD11b and CD11c molecules on human monocytes. The 25-kDa soluble fragment of CD23 (sCD23), was tested for its capacity to elicit various signaling pathways in human monocytes. sCD23 was found to trigger an early increase in cGMP accumulation, through the generation of nitric oxide. This was a result of activating the L-arginine pathway, since the sCD23-mediated effect was inhibited in the presence of substituted nonmetabolizable L-arginine analogues. In addition, the increase in cGMP was suppressed by calcium chelators and inhibitors of the calcium/calmodulin complex, suggesting the involvement of a constitutive, calcium-dependent nitric oxide synthase (NOS). Indeed, the presence of an endothelial constitutive type III NOS mRNA was detected in nonactivated human monocytes, and the corresponding protein has been detected by flow cytometry. Moreover, sCD23 was shown to induce a calcium influx in monocytes, in accordance with an activation of a constitutive NOS through a transient increase in [Ca2+]i. As expected, these events were mimicked by mAbs against CD11b and CD11c, the macrophage receptors for CD23. In addition to these early events, sCD23 and the agonistic anti-CD11b and CD11c mAbs, which all trigger the release of proinflammatory mediators such as TNF-alpha, were shown to act through an NO-dependent process.

The 25-kDa soluble CD23 activates type III constitutive nitric oxide-synthase activity via CD11b and CD11c expressed by human monocytes

CD23, a low-affinity receptor for IgE, was recently shown to bind to CD11b and CD11c molecules on human monocytes. The 25-kDa soluble fragment of CD23 (sCD23), was tested for its capacity to elicit various signaling pathways in human monocytes. sCD23 was found to trigger an early increase in cGMP accumulation, through the generation of nitric oxide. This was a result of activating the L-arginine pathway, since the sCD23-mediated effect was inhibited in the presence of substituted nonmetabolizable L-arginine analogues. In addition, the increase in cGMP was suppressed by calcium chelators and inhibitors of the calcium/calmodulin complex, suggesting the involvement of a constitutive, calcium-dependent nitric oxide synthase (NOS). Indeed, the presence of an endothelial constitutive type III NOS mRNA was detected in nonactivated human monocytes, and the corresponding protein has been detected by flow cytometry. Moreover, sCD23 was shown to induce a calcium influx in monocytes, in accordance with an activation of a constitutive NOS through a transient increase in [Ca2+]i. As expected, these events were mimicked by mAbs against CD11b and CD11c, the macrophage receptors for CD23. In addition to these early events, sCD23 and the agonistic anti-CD11b and CD11c mAbs, which all trigger the release of proinflammatory mediators such as TNF-alpha, were shown to act through an NO-dependent process.