The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1--a meta-analysis of 15 prospective cohort studies

BACKGROUND

To evaluate the relation between elective cesarean section and vertical transmission of human immunodeficiency virus type 1 (HIV-1), we performed a meta-analysis using data on individual patients from 15 prospective cohort studies.

METHODS

North American and European studies of at least 100 mother-child pairs were included in the meta-analysis. Uniform definitions of modes of delivery were used. Elective cesarean sections were defined as those performed before onset of labor and rupture of membranes. Multivariate logistic-regression analysis was used to adjust for other factors known to be associated with vertical transmission.

RESULTS

The primary analysis included data on 8533 mother-child pairs. After adjustment for receipt of antiretroviral therapy, maternal stage of disease, and infant birth weight, the likelihood of vertical transmission of HIV-1 was decreased by approximately 50 percent with elective cesarean section, as compared with other modes of delivery (adjusted odds ratio, 0.43; 95 percent confidence interval, 0.33 to 0.56). The results were similar when the study population was limited to those with rupture of membranes shortly before delivery. The likelihood of transmission was reduced by approximately 87 percent with both elective cesarean section and receipt of antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, as compared with other modes of delivery and the absence of therapy (adjusted odds ratio, 0.13; 95 percent confidence interval, 0.09 to 0.19). Among mother-child pairs receiving antiretroviral therapy during the prenatal, intrapartum, and neonatal periods, rates of vertical transmission were 2.0 percent among the 196 mothers who underwent elective cesarean section and 7.3 percent among the 1255 mothers with other modes of delivery.

CONCLUSIONS

The results of this meta-analysis suggest that elective cesarean section reduces the risk of transmission of HIV-1 from mother to child independently of the effects of treatment with zidovudine.

Antiretroviral therapy during pregnancy and the risk of an adverse outcome

BACKGROUND

Some studies suggest that combination antiretroviral therapy in pregnant women with human immunodeficiency virus type 1 (HIV-1) infection increases the risk of premature birth and other adverse outcomes of pregnancy.

METHODS

We studied pregnant women with HIV-1 infection who were enrolled in seven clinical studies and delivered their infants from 1990 through 1998. The cohort comprised 2123 women who received antiretroviral therapy during pregnancy (monotherapy in 1590, combination therapy without protease inhibitors in 396, and combination therapy with protease inhibitors in 137) and 1143 women who did not receive antiretroviral therapy.

RESULTS

After standardization for the CD4+ cell count and use or nonuse of tobacco, alcohol, and illicit drugs, the rate of premature delivery (<37 weeks of gestation) was similar among the women who received antiretroviral therapy and those who did not (16 percent and 17 percent, respectively); the rate of low birth weight (<2500 g) was 16 percent among the infants born to both groups; and the rate of very low birth weight (<1500 g) was 2 percent for the group that received antiretroviral therapy and 1 percent for the group that did not. The rates of low Apgar scores (<7) and stillbirth were also similar or the same in the two groups. After adjustment for multiple risk factors, combination antiretroviral therapy was not associated with an increased risk of premature delivery as compared with monotherapy (odds ratio, 1.08; 95 percent confidence interval, 0.71 to 1.62) or delivery of an infant with low birth weight (odds ratio, 1.03; 95 percent confidence interval, 0.64 to 1.63). Seven of the women who received combination therapy with protease inhibitors (5 percent) had infants with very low birth weight, as compared with nine women who received combination therapy without protease inhibitors (2 percent) (adjusted odds ratio, 3.56; 95 percent confidence interval, 1.04 to 12.19).

CONCLUSIONS

As compared with no antiretroviral therapy or monotherapy, combination therapy for HIV-1 infection in pregnant women is not associated with increased rates of premature delivery or with low birth weight, low Apgar scores, or stillbirth in their infants. The association between combination therapy with protease inhibitors and an increased risk of very low birth weight requires confirmation.

Combination treatment with zidovudine, didanosine, and nevirapine in infants with human immunodeficiency virus type 1 infection

BACKGROUND

In infants and children with maternally acquired human immunodeficiency virus type 1 (HIV-1) infection, treatment with a single antiretroviral agent has limited efficacy. We evaluated the safety and efficacy of a three-drug regimen in a small group of maternally infected infants.

METHODS

Zidovudine, didanosine, and nevirapine were administered in combination orally to eight infants 2 to 16 months of age. The efficacy of antiretroviral treatment was evaluated by serial measurements of plasma HIV-1 RNA, quantitative plasma cultures, and quantitative cultures of peripheral-blood mononuclear cells.

RESULTS

The three-drug regimen was well tolerated, without clinically important adverse events. Within four weeks, there were reductions in plasma levels of HIV-1 RNA of at least 96 percent (1.5 log) in seven of the eight study patients. Over the 6-month study period, replication of HIV-1 was controlled in two infants who began therapy at 2 1/2 months of age. Plasma RNA levels were reduced by 0.5 to 1.5 log in five of the other six infants.

CONCLUSIONS

Although further observations are needed, it appears that in infants with maternally acquired HIV-1 infection, combined treatment with zidovudine, didanosine, and nevirapine is well tolerated and has sustained efficacy against HIV-1.

UCLA conference. Interferon: immunobiology and clinical significance

Interferons are proteins elaborated by infected cells that protect noninfected cells from viral infection. These proteins produce a temporary "antiviral state" by altering nucleotide metabolism and cytoplasmic enzyme induction. Interferons appear early after viral infection locally and systematically to limit spread of viral infection; they also affect cell differentiation, growth, surface, antigen expression, morphologic findings, and immunoregulation. Several human disorders have diminished interferon production. Newborns have normal interferon alpha but deficient interferon gamma production. Infants with congenital infections may also have defects in interferon production. Immunosuppressed patients receiving transplants (marrow, heart, of kidney) have diminished interferon production, particularly immediately after transplant. Deficiencies of interferon have also been noted in Down's syndrome, cellular immunodeficiencies, uremia, malnutrition, and hematopoietic malignancy. Leukocyte interferon has been of therapeutic value in herpes zoster infections, in patients with cancer, and in patients with hepatitis B infection. Interferon has not been proved to help children with congenital cytomegalovirus or rubella. Interferon can shrink lymphoid tumors, particularly non-Hodgkin's lymphoma.

Rapid serologic testing with immune-complex-dissociated HIV p24 antigen for early detection of HIV infection in neonates. Southern California Pediatric AIDS Consortium

BACKGROUND

Serologic detection of human immunodeficiency virus (HIV) infection in neonates is complicated by the presence of immune complexes, consisting of passively transferred maternal antibodies and HIV antigens. A new, rapid assay has been designed to disrupt these immune complexes in order to permit the detection of a specific HIV antigen. We evaluated the efficacy of this assay in detecting HIV infection in neonates.

METHODS

We measured p24 antigen in blood samples from both infected and uninfected children of HIV-infected mothers. The samples were treated with glycine hydrochloride to dissociate the immune complexes, followed by neutralization with TRIS-hydrochloric acid. A commercial HIV p24 antigen assay was then used, with an optical density greater than 0.120 at a wavelength of 450 nm defined as indicating a positive result.

RESULTS

Of eight cord-blood samples from neonates with proved HIV infection, five were positive for immune-complex-dissociated p24 antigen. For two other neonates the first postnatal sample, obtained on days 12 and 18, was positive. There was no follow-up sample for the eighth neonate. Of 22 uninfected neonates, 20 were negative on the cord-blood assay. Two neonates had positive cord-blood samples, but the first postnatal sample was negative. Thus, the tests with early postnatal samples identified the HIV-infection status correctly for all 29 children who could be evaluated. In a separate group of 78 children (median age, 188 weeks), the specificity of the test was 100 percent and the sensitivity 81 percent.

CONCLUSIONS

The immune-complex-dissociated HIV p24 antigen assay is a rapid, simple serologic test that may be of value in diagnosing HIV infection in neonates born to HIV-infected women.

Prevention of ultraviolet-light-induced herpes labialis by sunscreen

Sunlight exposure is reported by some patients to precede onset of recurrent herpes labialis. Ultraviolet (UV) B light is known to be a stimulus for the reactivation of herpes simplex virus (HSV) infections. We assessed the effect of a sunblocking agent on UV-light-induced reactivation of recurrent herpes labialis in a double-blind, placebo-controlled crossover trial. 38 patients were exposed on two separate occasions to four minimum erythema doses of UV light at an area of previous labial herpes recurrence. A solution containing sunscreen was applied to the lips before one exposure and a matched placebo before the other. After placebo and UV exposure, herpes labialis developed in 27 (71%) of the 38 patients, with a mean time to recurrence of 2.9 (SEM 0.2) days. In contrast, when sunscreen was applied before UV exposure, no lesions developed, but 1 of the 35 patients shed virus at the exposure site. We conclude that UV light is a potent stimulus for inducing reactivation of herpes labialis, and that application of sunscreen may be effective in the prevention of sunlight-induced recurrent infection.

Vidarabine therapy of varicella in immunosuppressed patients

In order to assess further the clinical usefulness of vidarabine therapy of chicken pox, a double-blind, placebo-controlled trial was performed in immunocompromised patients. Thirty-four patients entered the trial; 19 received vidarabine and 15 the placebo. All patients had disease less than or equal to 72 hours in duration and 23 had lymphoproliferative malignancies. Both patient populations were balanced for underlying disease, preceding chemotherapy, and duration of chicken pox. No patient received zoster immune globulin. Drug therapy accelerated cessation of new vesicle formation (P = 0.015) and decreased median daily lesion counts (P = 0.06 on days 2 and 3). Fever (greater than or equal to 37.8 degrees C orally) resolved more rapidly in the drug-treated group. By day five, 70% of drug-treated subjects were afebrile in contrast to 35% of placebo recipients (P = 0.066). One drug recipient developed mild pneumonitis during the study which resolved with therapy, whereas eight placebo recipients developed varicella-related complications which led to death in two patients (P less than 0.01). These results were achieved with minimal evidence of laboratory or clinical toxicity related to drug administration. The findings indicate that vidarabine has a good therapeutic index (efficacy/toxicity) for treatment of chicken pox in immunocompromised patients when given early in the course of the infection.

Risk of acquisition of genital herpes simplex virus type 2 in sex partners of persons with genital herpes: a prospective couple study

In a prospective study of factors associated with genital herpes simplex virus (HSV) type 2 transmission in couples in whom 1 partner had clinical genital HSV and the other did not, 11 (19%) of the 57 history-negative partners had HSV-2 antibody by Western blot at entry. In follow-up (mean, 16 months) of 29 HSV-2-seronegative partners, overall 4 (14%) seroconverted compared with 3 (23%) of 13 HSV-1- and -2-seronegative partners and 1 (6%) of 16 HSV-1-seropositive partners. Since all seroconverters were women, the risk of transmission may be higher in HSV-seronegative women. No significant differences were found between HSV-2-seronegative partners and seroconverters regarding duration of relationships, number of partner recurrences, intercourse frequency, or contraceptive method. However, 2 seroconverters were exposed to lesions without barrier contraception. This study suggests that infection is commonly asymptomatic and that although the overall risk of genital HSV transmission in couples is low (10%/year), the risk may be significantly increased in women and in seronegative individuals.

Role of maternal autologous neutralizing antibody in selective perinatal transmission of human immunodeficiency virus type 1 escape variants

Perinatal human immunodeficiency virus type 1 (HIV-1) transmission is characterized by acquisition of a homogeneous viral quasispecies, yet the selective factors responsible for this genetic bottleneck are unclear. We examined the role of maternal autologous neutralizing antibody (aNAB) in selective transmission of HIV-1 escape variants to infants. Maternal sera from 38 infected mothers at the time of delivery were assayed for autologous neutralizing antibody activity against maternal time-of-delivery HIV-1 isolates in vitro. Maternal sera were also tested for cross-neutralization of infected-infant-first-positive-time-point viral isolates. Heteroduplex and DNA sequence analyses were then performed to identify the initial infecting virus as a neutralization-sensitive or escape HIV-1 variant. In utero transmitters (n = 14) were significantly less likely to have aNAB to their own HIV-1 strains at delivery than nontransmitting mothers (n = 17, 14.3% versus 76.5%, P = 0.003). Cross-neutralization assays of infected-infant-first-positive-time-point HIV-1 isolates indicated that while 14/21 HIV-1-infected infant first positive time point isolates were resistant to their own mother's aNAB, no infant isolate was inherently resistant to antibody neutralization by all sera tested. Furthermore, both heteroduplex (n = 21) and phylogenetic (n = 9) analyses showed that selective perinatal transmission and/or outgrowth of maternal autologous neutralization escape HIV-1 variants occurs in utero and intrapartum. These data indicate that maternal autologous neutralizing antibody can exert powerful protective and selective effects in perinatal HIV-1 transmission and therefore has important implications for vaccine development.

Rapid increases in load of human immunodeficiency virus correlate with early disease progression and loss of CD4 cells in vertically infected infants

The relationship between viral burden, timing of transmission, and clinical progression was investigated in 110 children at risk for vertical human immunodeficiency virus (HIV) infection using quantitative polymerase chain reaction, coculture, and immune complex-dissociated p24 antigen assay. In a cross-sectional study, the mean HIV DNA copy number in 19 symptomatic children was significantly higher than in 31 infected, asymptomatic children (420 +/- 125 vs. 87 +/- 78; P < .0001). In a second group of 8 vertically infected infants followed prospectively from birth, 4 defined as infected in utero showed a more rapid increase in virus load, an accelerated loss of CD4 cells, and early progression to symptomatic disease (3-12 weeks) compared with 4 children with late in utero or intrapartum transmission (10-31 months). These data suggest that a direct relationship exists between HIV replication, the timing of transmission and onset and progression of HIV disease in vertically infected children.

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.

HIV-1 remission and possible cure in a woman after haplo-cord blood transplant

Previously, two men were cured of HIV-1 through CCR5Δ32 homozygous (CCR5Δ32/Δ32) allogeneic adult stem cell transplant. We report the first remission and possible HIV-1 cure in a mixed-race woman who received a CCR5Δ32/Δ32 haplo-cord transplant (cord blood cells combined with haploidentical stem cells from an adult) to treat acute myeloid leukemia (AML). Peripheral blood chimerism was 100% CCR5Δ32/Δ32 cord blood by week 14 post-transplant and persisted through 4.8 years of follow-up. Immune reconstitution was associated with (1) loss of detectable replication-competent HIV-1 reservoirs, (2) loss of HIV-1-specific immune responses, (3) in vitro resistance to X4 and R5 laboratory variants, including pre-transplant autologous latent reservoir isolates, and (4) 18 months of HIV-1 control with aviremia, off antiretroviral therapy, starting at 37 months post-transplant. CCR5Δ32/Δ32 haplo-cord transplant achieved remission and a possible HIV-1 cure for a person of diverse ancestry, living with HIV-1, who required a stem cell transplant for acute leukemia.

Human immunodeficiency virus type 1 (HIV-1) gp120-specific antibodies in neonates receiving an HIV-1 recombinant gp120 vaccine

Infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers were immunized at birth and at ages 4, 12, and 20 weeks with low-, medium-, or high-dose recombinant gp120 vaccine with MF59 adjuvant (HIV-1(SF-2); n=52) or with MF59 alone as a placebo (n=9). An accelerated schedule (birth and ages 2, 8, and 20 weeks) was used for an additional 10 infants receiving the defined optimal dose and for 3 infants receiving placebo. At 24 weeks, anti-gp120 ELISA titers were greater for vaccine-immunized than for placebo-immunized infants on both schedules, and 87% of vaccinees had a vaccine-induced antibody response. At 12 weeks, antibody titers of infants on the accelerated vaccine schedule exceeded those of infants receiving placebo (4949 vs. 551; P=.01), and 63% of the vaccinees met the response criteria. Thus, an accelerated schedule of gp120 vaccinations generated an antibody response to HIV-1 envelope distinct from transplacental maternal antibody by age 12 weeks. These results provide support for further studies of vaccine strategies to prevent mother-to-infant HIV-1 transmission.

Pharmacokinetics, safety, and activity of nevirapine in human immunodeficiency virus type 1-infected children

Phase I trials were conducted in human immunodeficiency virus type 1 (HIV-1)-infected children to examine the pharmacokinetics, safety, and antiretroviral activity of nevirapine, a nonnucleoside HIV-1 reverse transcriptase inhibitor. Nevirapine was rapidly absorbed, but the time to peak plasma concentrations increased with higher doses. Clearance was more rapid in chronic dosing studies than predicted by single-dose studies and was more rapid in younger children than in adolescent children. Rash, which occurred in 1 of the 21 study participants, was the single toxicity regarded as nevirapine-related. At doses > or = 240 mg/m2/day, 5 of 10 children experienced durable suppression of plasma p24 antigen to < 50% of baseline values through 8 weeks of nevirapine monotherapy. Viruses resistant to nevirapine were isolated from all children during therapy, but their isolation did not always predict loss of antiviral activity. The evaluation of nevirapine in combination therapy trials is underway in children.

Human immunodeficiency virus inhibits multilineage hematopoiesis in vivo

Human immunodeficiency virus type 1 (HIV-1)-infected individuals often exhibit multiple hematopoietic abnormalities reaching far beyond loss of CD4(+) lymphocytes. We used the SCID-hu (Thy/Liv) mouse (severe combined immunodeficient mouse transplanted with human fetal thymus and liver tissues), which provides an in vivo system whereby human pluripotent hematopoietic progenitor cells can be maintained and undergo T-lymphoid differentiation and wherein HIV-1 infection causes severe depletion of CD4-bearing human thymocytes. Herein we show that HIV-1 infection rapidly and severely decreases the ex vivo recovery of human progenitor cells capable of differentiation into both erythroid and myeloid lineages. However, the total CD34+ cell population is not depleted. Combination antiretroviral therapy administered well after loss of multilineage progenitor activity reverses this inhibitory effect, establishing a causal role of viral replication. Taken together, our results suggest that pluripotent stem cells are not killed by HIV-1; rather, a later stage important in both myeloid and erythroid differentiation is affected. In addition, a primary virus isolated from a patient exhibiting multiple hematopoietic abnormalities preferentially depleted myeloid and erythroid colony-forming activity rather than CD4-bearing thymocytes in this system. Thus, HIV-1 infection perturbs multiple hematopoietic lineages in vivo, which may explain the many hematopoietic defects found in infected patients.

Frequent recurrence and persistence of varicella-zoster virus infections in children infected with human immunodeficiency virus type 1

OBJECTIVE

To examine complications and treatment of varicella-zoster virus (VZV) infections in children infected with human immunodeficiency virus type 1 (HIV-1).

METHODS

Cases of VZV infection were identified retrospectively by reports to the department of health services and review of medical charts. The CD4+ cell counts were correlated with severity and frequency of VZV episodes.

RESULTS

We identified 117 episodes of VZV infection in 73 HIV-1-infected children between Aug. 21, 1986, and Dec. 1, 1993. The most common complications were recurrence and persistence; 38 children (53%) had 69 recurrent episodes of VZV infection. The majority of children (61%) had zoster during the first recurrent episode, and 32% had a disseminated eruption typical of varicella. There was a strong association between an increasing number of episodes of VZV infection and low CD4+ cell count (p = 0.0008). In a subgroup followed for at least 2 years after their primary varicella episode, 10 of 22 children had a recurrence. Persistence of VZV infection was documented in 10 of 73 children, whereas other complications were rare. Thirty-three children (45%) were hospitalized and received acyclovir intravenously.

CONCLUSION

Primary, recurrent, and persistent VZV infections are a frequent cause of morbidity and hospitalization for HIV-1-infected children. Studies of improved preventive and therapeutic agents are urgently needed in this population.

Syphilis in HIV-infected mothers and infants: results from the NICHD/HPTN 040 study

BACKGROUND

Untreated syphilis during pregnancy is associated with spontaneous abortion, stillbirth, prematurity and infant mortality. Syphilis may facilitate HIV transmission, which is especially concerning in low- and middle-income countries where both diseases are common.

METHODS

We performed an analysis of data available from NICHD/HPTN 040 (P1043), a study focused on the prevention of intrapartum HIV transmission to 1684 infants born to 1664 untreated HIV-infected women. This analysis evaluates risk factors and outcomes associated with a syphilis diagnosis in this cohort of HIV-infected women and their infants.

RESULTS

Approximately, 10% of women (n=171) enrolled had serological evidence of syphilis without adequate treatment documented and 1.4% infants (n=24) were dually HIV and syphilis infected. Multivariate logistic analysis showed that compared with HIV-infected women, co-infected women were significantly more likely to self-identify as non-white (adjusted odds ratio [AOR] 2.5, 95% CI: 1.5-4.2), to consume alcohol during pregnancy (AOR 1.5, 95% CI: 1.1-2.1) and to transmit HIV to their infants (AOR 2.1, 95% CI: 1.3-3.4), with 88% of HIV infections being acquired in utero. As compared with HIV-infected or HIV-exposed infants, co-infected infants were significantly more likely to be born to mothers with venereal disease research laboratory titers≥1:16 (AOR 3, 95% CI: 1.1-8.2) and higher viral loads (AOR 1.5, 95% CI: 1.1-1.9). Of 6 newborns with symptomatic syphilis, 2 expired shortly after birth, and 2 were HIV-infected.

CONCLUSION

Syphilis continues to be a common co-infection in HIV-infected women and can facilitate in utero transmission of HIV to infants. Most infants are asymptomatic at birth, but those with symptoms have high mortality rates.

Lymphoproliferative responses to recombinant HIV-1 envelope antigens in neonates and infants receiving gp120 vaccines. AIDS Clinical Trial Group 230 Collaborators

Children of mothers infected with human immunodeficiency virus type 1 (HIV-1) were immunized at birth and at 1, 3, and 5 months with 1 of 3 doses of recombinant gp120 vaccines prepared from SF-2 or MN strains of HIV-1. A total of 126 children were not infected; 21 received adjuvant only. Vaccine recipients developed lymphoproliferative responses on >/=2 occasions, responding more often to homologous HIV-1 antigens than did adjuvant recipients (56% vs. 14%; P<.001). Responses were appreciated after 2 immunizations and were maintained for >84 weeks after the last immunization. An accelerated immunization schedule (birth, 2 weeks, 2 months, and 5 months) with the lowest dose of the SF-2 vaccine produced responses in all 11 vaccinees by 4 weeks. Responses to heterologous envelope antigens were also detected. Immune responses to vaccination are achievable at an age when some infection (perinatal or breast milk exposure related) may be prevented.

Treatment of mucocutaneous herpes simplex virus infections unresponsive to acyclovir with topical foscarnet cream in AIDS patients: a phase I/II study

The efficacy and toxicity of foscarnet cream for the treatment of mucocutaneous herpes simplex virus lesions or lesions that were clinically unresponsive to systemic acyclovir treatment (median, 30.5 days) in AIDS patients were studied in a phase I/II, open-label, nonrandomized multicenter trial. In the study, 20 patients with advanced stages of AIDS were treated with foscarnet 1% cream five times a day for a mean duration of 34.5 days. Response of index lesions (n = 20) was judged to be completely healed (8 lesions), excellent (4 lesions), or good (1 lesion) in 65% of lesions. The median time to first negative herpes simplex virus culture of index lesion was 8 days. Among 15 patients with pain at baseline, 11 had complete resolution of pain and 2 had at least a 50% reduction. Clinical adverse events included skin ulceration (4 patients), application site reactions (3 patients), fever (3 patients), and headache (3 patients). Five (25%) patients developed new lesions due to herpes simplex virus at sites other than those being treated topically while enrolled in the study. Topical foscarnet 1% cream appears to be a safe and effective treatment for acyclovir-unresponsive mucocutaneous herpes simplex virus infection in AIDS patients.

Determination of plaque inhibitory activity of adenine arabinoside (9-beta-D-arabinofuranosyladenine) for herpesviruses using an adenosine deaminase inhibitor

The in vitro susceptibility of type 1 and type 2 strains of Herpesvirus hominis to 9-beta-d-arabinofuranosyladenine (adenine arabinoside, ara-A) was measured in a system where deamination was inhibited. Under these conditions, it was possible to measure the activity of low concentrations of ara-A. It was determined that plaque inhibitory concentration for type 1 viruses was less than 3 mug/ml for all strains tested. The plaque inhibitory concentration for 7 of 10 type 2 strains was also less than 3 mug/ml. The method used identified and controlled the interaction between antiviral agent (ara-A) and the indicator system, human skin fibroblastic cells. Otherwise, metabolism of ara-A resulted in rapid enzymatic degradation and loss of antiviral activity.

Influence of HLA alleles on the rate of progression of vertically transmitted HIV infection in children: association of several HLA-DR13 alleles with long-term survivorship and the potential association of HLA-A*2301 with rapid progression to AIDS. Long-Term Survivor Study

The influence of host immunogenetics on the outcome of vertically transmitted HIV infection in children was examined in a multicenter cross sectional study of long term survivors and rapid progressors. Sequence-based typing was performed for the DRB1, DQB1 and HLA-A loci. 36.7% of 30 children surviving more than 8 years had one or more of the HLA-DR13 alleles, versus none of 14 rapidly progressing children who died within 2 years of age, p = 0.009, Haldane RR = 17.1. The alleles variably associated with this beneficial response to HIV were: DRB1*1301, DRB1*1302, DRB1*1303 and DRB1*1310, suggesting that the DR13 effect acted as a dominant trait. An additional 6 children were typed only by the SSOP method resulting in 44.4% of 36 long term surviving children with a DR13 allele and none of 14 rapid progressors, p = 0.002, Haldane RR = 23.3. No single DQB1 allele accounted for the HLA-DR13 allele association. In contrast, the presence of HLA A*2301 was associated with rapid progression to AIDS, 4% of long term survivors vs. 57.1% of 7 rapid progressors, p = 0.0006, RR = 0.031. Although the sample size is small, the marked differences in allele frequency along with differences between the peptide binding pockets of the HLA-A9 group of alleles including HLA A*2301 and the remainder of the HLA-A alleles suggest a structural basis for the dominant disadvantageous immune response to HIV conferred by A*2301.

Genetic and stochastic influences on the interaction of human immunodeficiency virus type 1 and cytotoxic T lymphocytes in identical twins

Human immunodeficiency virus type 1 (HIV-1) evolves in vivo under selective pressure from CD8+ T-lymphocyte (CTL) responses, which are in turn determined by host and viral genetic factors, such as restricting major histocompatibility complex molecules and the available viral epitope sequences. However, CTL are derived stochastically through the random gene rearrangements to produce T-cell receptors (TCR), and the relative impact of genetic versus stochastic processes on CTL targeting of HIV and immune-driven viral evolution is unclear. Here we evaluate identical twins infected with HIV-1 as neonates from a common blood transfusion, with subsequently similar environmental exposures, thereby allowing controlled comparisons of CTL targeting and viral evolution. Seventeen years after infection, their CTL targeting of HIV-1 was remarkably similar. In contrast, their overall TCR profiles were highly dissimilar, and a dominant epitope was recognized by distinctly different TCR in each twin. Furthermore, their viral epitopes had diverged, and there was ongoing viral phylogenetic divergence between the twins between 12 and 17 years after infection. These results indicate that while CTL targeting is predominately genetically determined, stochastic influences render the interaction of HIV-1 and host immunity, and therefore viral escape and CTL efficacy, unpredictable.

Natural history of primary Epstein-Barr virus infection in children of mothers infected with human immunodeficiency virus type 1

The natural history of Epstein-Barr virus (EBV) infection in 556 infants born to 517 human immunodeficiency virus (HIV) type 1-infected mothers was studied in a prospective, multicenter, cohort study. HIV-1-infected children had a cumulative EBV infection rate similar to HIV-1-uninfected children at age 3 years (77.8% vs. 84. 9%) but had more frequent oropharyngeal EBV shedding (50.4% vs. 28. 2%; P<.001). The probability of shedding decreased with longer time from EBV seroconversion and was similar to that of HIV-1-uninfected children 3 years after seroconversion. HIV-1-infected children identified as rapid progressors shed EBV more frequently than nonrapid progressors (69.4% vs.41.0%; P=.01). HIV-1-infected children with EBV infection had higher mean CD8 cell counts. EBV infection did not have an independent effect on mean CD4 cell counts, percent CD4, IgG levels, HIV-1 RNA levels, lymphadenopathy, hepatomegaly, or splenomegaly. Early EBV infection is common in children born to HIV-1-infected mothers. Children with rapidly progressive HIV-1 disease have more frequent EBV shedding.

The systemic inflammatory landscape of COVID-19 in pregnancy: Extensive serum proteomic profiling of mother-infant dyads with in utero SARS-CoV-2

While pregnancy increases the risk for severe COVID-19, the clinical and immunological implications of COVID-19 on maternal-fetal health remain unknown. Here, we present the clinical and immunological landscapes of 93 COVID-19 mothers and 45 of their SARS-CoV-2-exposed infants through comprehensive serum proteomics profiling for >1,400 cytokines of their peripheral and cord blood specimens. Prenatal SARS-CoV-2 infection triggers NF-κB-dependent proinflammatory immune activation. Pregnant women with severe COVID-19 show increased inflammation and unique IFN-λ antiviral signaling, with elevated levels of IFNL1 and IFNLR1. Furthermore, SARS-CoV-2 infection re-shapes maternal immunity at delivery, altering the expression of pregnancy complication-associated cytokines, inducing MMP7, MDK, and ESM1 and reducing BGN and CD209. Finally, COVID-19-exposed infants exhibit induction of T cell-associated cytokines (IL33, NFATC3, and CCL21), while some undergo IL-1β/IL-18/CASP1 axis-driven neonatal respiratory distress despite birth at term. Our findings demonstrate COVID-19-induced immune rewiring in both mothers and neonates, warranting long-term clinical follow-up to mitigate potential health risks.

Population pharmacokinetics of lamivudine in human immunodeficiency virus-exposed and -infected infants

This study aimed to determine lamivudine disposition in infants and to construct an appropriate dose adjustment for age, given the widespread use of lamivudine for both the prevention of mother-to-child transmission of human immunodeficiency virus (HIV) and the treatment of HIV-infected infants. Using a pooled-population approach, the pharmacokinetics of lamivudine in HIV-exposed or -infected infants from four Pediatric AIDS Clinical Trials Group studies were assessed. Ninety-nine infants provided 559 plasma samples for measurement of lamivudine concentrations. All infants received combination antiretroviral therapy including lamivudine dosed at 2 mg/kg of body weight every 12 h (q12h) for the first 4 to 6 weeks of life and at 4 mg/kg q12h thereafter. Lamivudine's apparent clearance was 0.25 liter/h/kg at birth, doubling by 28 days. In the final model, age and weight were the only significant covariates for lamivudine clearance. While lamivudine is predominantly renally eliminated, the serum creatinine level was not an independent covariate in the final model, possibly because it was confounded by age. Inclusion of interoccasion variability for bioavailability improved the individual subject clearance prediction over the age range studies. Simulations based on the final model predicted that by the age of 4 weeks, 90% of infant lamivudine concentrations with the standard 2 mg/kg dose of lamivudine fell below the adult median concentration. This population pharmacokinetic analysis affirms that adjusting the dose of lamivudine from 2 mg/kg to 4 mg/kg q12 h at the age of 4 weeks for infants with normal maturation of renal function will provide optimal lamivudine exposure, potentially contributing to more successful therapy.