Impaired antibody memory to varicella zoster virus in HIV-infected children: low antibody levels and avidity*.

OBJECTIVE: HIV-infected children have impaired antibody responses after exposure to certain antigens. Our aim was to determine whether HIV-infected children had lower varicella zoster virus (VZV) antibody levels compared with HIV-infected adults or healthy children and, if so, whether this was attributable to an impaired primary response, accelerated antibody loss, or failure to reactivate the memory VZV response. METHODS: In a prospective, cross-sectional and retrospective longitudinal study, we compared antibody responses, measured by enzyme-linked immunosorbent assay (ELISA), elicited by VZV infection in 97 HIV-infected children and 78 HIV-infected adults treated with antiretroviral therapy, followed over 10 years, and 97 age-matched healthy children. We also tested antibody avidity in HIV-infected and healthy children. RESULTS: Median anti-VZV immunoglobulin G (IgG) levels were lower in HIV-infected children than in adults (264 vs. 1535 IU/L; P<0.001) and levels became more frequently unprotective over time in the children [odds ratio (OR) 17.74; 95% confidence interval (CI) 4.36-72.25; P<0.001]. High HIV viral load was predictive of VZV antibody waning in HIV-infected children. Anti-VZV antibodies did not decline more rapidly in HIV-infected children than in adults. Antibody levels increased with age in healthy (P=0.004) but not in HIV-infected children. Thus, antibody levels were lower in HIV-infected than in healthy children (median 1151 IU/L; P<0.001). Antibody avidity was lower in HIV-infected than healthy children (P<0.001). A direct correlation between anti-VZV IgG level and avidity was present in HIV-infected children (P=0.001), but not in healthy children. CONCLUSION: Failure to maintain anti-VZV IgG levels in HIV-infected children results from failure to reactivate memory responses. Further studies are required to investigate long-term protection and the potential benefits of immunization.

Antiretroviral therapy during pregnancy and premature birth: analysis of Swiss data.

BACKGROUND: There is an ongoing debate as to whether combined antiretroviral treatment (cART) during pregnancy is an independent risk factor for prematurity in HIV-1-infected women. OBJECTIVE: The aim of the study was to examine (1) crude effects of different ART regimens on prematurity, (2) the association between duration of cART and duration of pregnancy, and (3) the role of possibly confounding risk factors for prematurity. METHOD: We analysed data from 1180 pregnancies prospectively collected by the Swiss Mother and Child HIV Cohort Study (MoCHiV) and the Swiss HIV Cohort Study (SHCS). RESULTS: Odds ratios for prematurity in women receiving mono/dual therapy and cART were 1.8 [95% confidence interval (CI) 0.85-3.6] and 2.5 (95% CI 1.4-4.3) compared with women not receiving ART during pregnancy (P=0.004). In a subgroup of 365 pregnancies with comprehensive information on maternal clinical, demographic and lifestyle characteristics, there was no indication that maternal viral load, age, ethnicity or history of injecting drug use affected prematurity rates associated with the use of cART. Duration of cART before delivery was also not associated with duration of pregnancy. CONCLUSION: Our study indicates that confounding by maternal risk factors or duration of cART exposure is not a likely explanation for the effects of ART on prematurity in HIV-1-infected women.

High specificity of line-immunoassay based algorithms for recent HIV-1 infection independent of viral subtype and stage of disease.

BACKGROUND: Serologic testing algorithms for recent HIV seroconversion (STARHS) provide important information for HIV surveillance. We have shown that a patient's antibody reaction in a confirmatory line immunoassay (INNO-LIA HIV I/II Score, Innogenetics) provides information on the duration of infection. Here, we sought to further investigate the diagnostic specificity of various Inno-Lia algorithms and to identify factors affecting it. METHODS: Plasma samples of 714 selected patients of the Swiss HIV Cohort Study infected for longer than 12 months and representing all viral clades and stages of chronic HIV-1 infection were tested blindly by Inno-Lia and classified as either incident (up to 12 m) or older infection by 24 different algorithms. Of the total, 524 patients received HAART, 308 had HIV-1 RNA below 50 copies/mL, and 620 were infected by a HIV-1 non-B clade. Using logistic regression analysis we evaluated factors that might affect the specificity of these algorithms. RESULTS: HIV-1 RNA < 50 copies/mL was associated with significantly lower reactivity to all five HIV-1 antigens of the Inno-Lia and impaired specificity of most algorithms. Among 412 patients either untreated or with HIV-1 RNA ≥ 50 copies/mL despite HAART, the median specificity of the algorithms was 96.5% (range 92.0-100%). The only factor that significantly promoted false-incident results in this group was age, with false-incident results increasing by a few percent per additional year. HIV-1 clade, HIV-1 RNA, CD4 percentage, sex, disease stage, and testing modalities exhibited no significance. Results were similar among 190 untreated patients. CONCLUSIONS: The specificity of most Inno-Lia algorithms was high and not affected by HIV-1 variability, advanced disease and other factors promoting false-recent results in other STARHS. Specificity should be good in any group of untreated HIV-1 patients.

Swiss recommendations for the management of varicella zoster virus infections.

Infections with varicella zoster virus (VZV) are common viral infections associated with significant morbidity. Diagnosis and management are complex, particularly in immunocompromised patients and during pregnancy. The present recommendations have been established by a multidisciplinary panel of specialists and endorsed by numerous Swiss medical societies involved in the medical care of such patients (Appendix). The aim was to improve the care of affected patients and to reduce complications.

Frequent detection of HIV- and IgG-specific IgM and IgA antibodies in HIV-positive cord-blood sera: fine analysis by western blot.

Cord-blood sera of 36 babies born to HIV-positive mothers in Switzerland were tested for immunoglobulin (Ig) M or IgA by HIV Western blot. IgM was found in 28, and IgA in 19 of unabsorbed sera. Preabsorption with immobilized protein A or G was used to remove IgG, which allowed differentiation between HIV-specific and IgG-specific IgM or IgA. Protein G proved superior and showed that 30% of 23 sera had HIV-specific IgM, while 48% had HIV-specific IgA. HIV-specific IgM and/or IgA was found in 13 out of 21 cases (62%); four out of 21 (19%) had both. HIV-specific IgM reacted most frequently with pol or env proteins, while HIV-specific IgA reacted more frequently with gag than pol; no IgA were directed against env proteins. IgG-specific IgM and IgA, mostly at gag bands, were present in 83 and 38%, respectively. Thus, a large percentage of children born to HIV-positive mothers have HIV-specific IgA and/or IgM which can be distinguished from IgG-specific IgA or IgM, which is also present in the majority of such children. Future studies will have to show whether these antibodies are of diagnostic relevance.

Evaluation of diagnostic tests for HIV infection in infants born to HIV-infected mothers in Switzerland.

Children born to HIV-infected women in Switzerland were tested every 3 months for HIV-reactive serum immunoglobulin (Ig) G, IgM and IgA antibodies by Western blot, viral antigen, virus replicating in T-lymphocyte cultures, and immunologic and clinical parameters. At birth, 27% were isolation-positive, 68% had IgM, 48% IgA and 10% circulating antigen. The proportion of IgM and IgA declined to about 18 and 27%, respectively, during the first 2 years. Detection of circulating antigen was less frequently positive than virus isolation in all age and disease groups. Clinical symptoms were only seen in infants or children who were or had been positive for IgM and/or IgA, but only 39% of children positive for these markers have developed disease so far. Clinical symptoms combined with signs of immunodeficiency were seen only in children who were isolation-positive or had evidence of HIV-reactive IgA or child-produced IgG. Absorption studies showed that Western blot-detected IgM and IgA antibodies were of two types: 42% were directed against various HIV proteins, while the rest represented rheumatoid-factor-like IgM or IgA binding to HIV-specific IgG. HIV-specific IgG antibodies were detected in all samples up to the age of 12 months and were still found in 83% of infants 13-18 months old. We observed weak HIV-specific IgG above the age of 15 months with no other signs of HIV infection, suggesting that the demonstration of antibodies in children beyond this age does not necessarily indicate HIV infection.

Prevention of vertical HIV transmission: additive protective effect of elective Cesarean section and zidovudine prophylaxis. Swiss Neonatal HIV Study Group.

OBJECTIVE: To study the effect of elective Cesarean section and zidovudine prophylaxis on vertical HIV transmission. DESIGN: Prospective study. SETTING: Obstetric and paediatric clinics in Switzerland. PARTICIPANTS: Children of mothers with HIV infection identified before or at delivery. INTERVENTIONS: Routine use of elective Cesarean section for HIV-infected parturients by some Swiss centres since 1985. National recommendation for zidovudine prophylaxis in mid-1994. MAIN OUTCOME MEASURE: HIV infection status of children. RESULTS: In a cohort of 494 children born at least 6 months before the analysis date, 67 out of 414 children with known infection status were found to be infected, giving an overall transmission rate of 16.2% [95% confidence interval (CI), 13.0-18.51. Elective Cesarean section with intact membranes and without previous labour was associated with a lower transmission rate of 6% [odds ratio (OR), 0.29; 95% CI, 0.12-0.70; P = 0.006 versus other delivery modes]. Transmission rate was intermediate after spontaneous delivery or non-elective Cesarean section (18%), and higher after obstetric interventions (27%; test for trend, P < 0.001). Since mid-1994, 78% of all women with registered pregnancies have received some form of zidovudine prophylaxis. Transmission rate was reduced from 17 to 7% after any zidovudine exposure (OR, 0.4; 95% CI, 0.11-1.41). Combined use of elective Cesarean section and zidovudine resulted in a 0% transmission rate (none out of 31), compared with 8% (seven out of 86) after elective Cesarean section without zidovudine, 17% (four out of 24) after zidovudine alone, and 20% (55 out of 271) after no intervention. CONCLUSIONS: Elective Cesarean section and zidovudine prophylaxis appear to have an additive effect in the prevention of vertical HIV transmission.

Antiretroviral therapies in pregnancy: maternal, fetal and neonatal effects. Swiss HIV Cohort Study, the Swiss Collaborative HIV and Pregnancy Study, and the Swiss Neonatal HIV Study.

BACKGROUND: Therapies containing two reverse transcriptase inhibitors (RTI) with or without protease inhibitors are used with increasing frequency in pregnant HIV-infected women. OBJECTIVE: To assess the safety of antiretroviral therapy in pregnant women and their newborns. METHODS: All clinical events and laboratory abnormalities in pregnant women on RTI with or without protease inhibitors and in their newborns were collected through an observational study. RESULTS: A total of 37 HIV-infected pregnant women have given birth to 30 children (by 30 April 1998). All received RTI, which were combined with protease inhibitors in 16 cases. Twelve women became pregnant while on treatment. Drugs used were as follows: zidovudine (n = 33), lamivudine (n = 33), stavudine (n = 4), indinavir (n = 9), ritonavir (n = 4), nelfinavir (n = 2) and saquinavir (n = 2). Adverse events during pregnancy were anaemia (n = 15), elevation of transaminases (n = 4), nausea/vomiting (n = 4), glucose intolerance (n = 2), nephrolithiasis (n = 2), diarrhoea (n = 2), hypertension (n = 1), insulin-requiring diabetes (n = 1). Adverse events in neonates were prematurity (n = 10), anaemia (n = 8), cutaneous angioma (n = 2), cryptorchidism (n = 2), transient hepatitis (n = 1). Non-life-threatening intracerebral haemorrhage occurred in a premature baby (33 weeks gestation) exposed during fetal life to zidovudine-lamivudine-indinavir, and in a term baby exposed to stavudine-lamivudine-indinavir. Extrahepatic biliary atresia occurred in one newborn exposed to zidovudine-lamivudine-indinavir. Maternal viral load was below 400 copies/ml in 18 out of 30 patients who delivered. One case of mother-to-child HIV transmission was identified. CONCLUSIONS: In HIV-infected pregnant women treated with two RTI with or without protease inhibitors, one or more adverse events occurred in 29 out of 37 women and in 14 out of 30 babies. In newborns, frequent prematurity, one case of biliary malformation and one intracerebral haemorrhage in a term baby are of concern. These observations do not preclude combination therapies during pregnancy but emphasize the necessity to maintain updated registers on their safety.

Interventions to prevent vertical transmission of HIV-1: effect on viral detection rate in early infant samples.

OBJECTIVE: To determine whether mode of delivery or the use of maternal or neonatal antiretroviral prophylaxis influence the age when HIV-1 can first be detected in infected infants, particularly the probability of detection at birth. METHODS: In a collaboration between four multicentre studies, data on 422 HIV-1 infected infants who were assessed by HIV-1 DNA PCR or cell culture before 14 days of age were analysed. Weibull mixture models were used to estimate the cumulative proportion of infants with detectable levels of HIV-1 according to use of maternal/neonatal antiretroviral therapy (mainly zidovudine monotherapy) and mode of delivery. RESULTS: HIV-1 was detected in 162 infants (38%) when they were first tested, at a median age of 2 days. At birth, it was estimated that 36% [95% confidence interval (CI), 31-41%] of infants have levels of virus that can be detected by DNA PCR or cell culture. This percentage was not associated with either mode of delivery (35% for vaginal delivery versus 40% for cesarean section delivery; P = 0.4) or the use of maternal or neonatal antiretroviral prophylaxis. Among infants with undetectable levels of HIV-1 at birth, the median time to viral detectability was estimated to be 14.8 days (95% CI, 12.9-16.8 days). This time was increased by 15% (95% CI, -11 to 48%; P = 0.3) among infants who were exposed to antiretroviral therapy postnatally compared with infants who were not exposed. No effect was observed for mode of delivery. CONCLUSIONS: The outcome of an early virological test for HIV-1 is thought to be related directly to the timing of transmission and cesarean section delivery primarily reduces the risk of intrapartum transmission. The absence of an association between mode of delivery and viral detectability at birth was therefore unexpected. There was no evidence that foetal or neonatal exposure to prophylactic zidovudine delays substantially the diagnosis of infection, although this cannot be inferred for combination antiretroviral therapy.

IgG, IgM, and IgA response to HIV in infants born to HIV-1 infected mothers. Swiss Neonatal HIV Study Group.

Children born to HIV-1-positive mothers were prospectively tested for HIV-reactive IgG, IgM, and IgA by Western blot, in order to study the children's humoral immune response in the background of passively transferred maternal IgG. In infected infants, a response was first seen at 1-3 months for env-reactive IgM and IgA, as well as gag-reactive IgM and IgG. This was followed by production of IgG to env, IgA to pol and to gag p17 and p55 at 7-9 months, and IgG to pol at 10-12 months. IgG Western blot positivity by all interpretation guidelines in all infected infants was found by 10-12 months. Subsequently, only IgG to env and p24, and IgA to env were maintained in all, whereas IgG to pol and p17 disappeared again in a significant fraction. A considerable proportion of uninfected infants also produced gag-reactive antibodies: IgM at 1-3 months, followed by IgG, which persisted in 10-20% and were also found in children born to uninfected mothers. These antibodies were, however, present at lower titers than in infected infants and were apparently produced in response to agent(s) different from HIV. Maternal antibodies to env disappeared significantly faster in infected than uninfected infants. Traces of HIV-reactive IgG were present for up to 21 months in children who subsequently seroreverted completely.

Visual development in preterm and full-term infants: a prospective masked study.

PURPOSE: To compare development of visual acuity and binocular vision in preterm and full-term infants in a prospective study that used testers masked to subject's gestational age. METHODS: Seventy-nine healthy full-term infants, mean gestational age 40 weeks, and 18 low-risk preterm infants, mean gestational age 33 weeks, were examined biweekly between the 44th and 54th weeks of postmenstrual age. Ocular alignment, convergence, fusion, grating acuity, and onset of optokinetic nystagmus (OKN) were assessed at each examination. RESULTS: The mean postnatal ages of onset of ocular alignment, convergence, fusion, grating acuity to 1.6 cycles per degree, and OKN from temporal to nasal and nasal to temporal were, respectively, 5, 7, 7, 11, 6, and 9 weeks for the full-term and 12, 13, 14, 18, 13, and 16 weeks for the preterm infants. The mean postmenstrual ages of onset for the corresponding parameters were 46, 48, 48, 51, 46, and 50 weeks for full-term and 46, 47, 48, 52, 47, and 49 weeks for preterm infants. The onset of all parameters was earlier in full-term infants than in preterm infants of the same postnatal age (P < or = 0.0001). However, no differences were found when the parameters were compared at postmenstrual ages. CONCLUSIONS: Additional visual experience of preterm infants does not influence development of visual acuity or binocular vision during the first months of life as measured from the time of conception.

The application of in-situ hybridisation and immuno-cytochemistry to problem resolution in drug development.

Localization of specific mRNA and protein molecules within cells and tissues can provide important information on the effects of a drug within a biological test system and help elucidate mechanisms of drug-induced toxicity and organ dysfunction. The most widely used techniques for measuring the cellular and tissue distribution of mRNA and protein are in-situ hybridization (ISH) and immunocytochemistry (ICC), respectively. These can be applied alongside quantitative measurements to provide an integrated picture of gene expression. In some cases, for example when the gene expression of interest is confined to a small subset of cells within a tissue, histochemical techniques may be the preferred method of analysis.

Pancreatic and nephrotoxicity of immunomodulator compounds.

Increasing clinical experience of FK 506 in transplantation therapy has revealed a number of potentially restrictive adverse effects associated with its use. The mechanisms of action underlying 2 prominent toxic effects of FK 506, namely diabetogenesis and renal dysfunction, were investigated. A simple model system based on the effect of FK 506 on isolated rat pancreatic islets was utilised to study the relationship between inhibition of insulin biosynthesis, inhibition of interleukin 2 (IL-2) activation and FK binding protein (FKBP-12) binding of FK 506 and a number of FK 506 analogues. Results indicate that the action of these compounds on inhibition of insulin biosynthesis (and by implication, diabetogenesis) may be related to their immunosuppressive potential. Observations on the FK 506-induced release of endothelin-1 from isolated rat kidney mesangial cells suggest that this cell may be an important target associated with the nephrotoxic potential of the drug, and that this action may be mediated via the FKBP.

The development of the circulating blood volume of the chick embryo.

The circulating blood volume of the chick embryo was determined from the 4th up to the 18th day of hatching. In contrast to former studies, there was employed a radioisotope dilution method with albumin-bound I131. The findings are in close correspondence to those of the earlier studies. The blood volume does not display an entirely perfect curve of exponential growth, i.e., the doubling time increases steadily. The blood volume attains a peak value between the 16th and 18th day and decreases somewhat toward the end of the hatching period. There has been postulated a reduction of total red cell volume and hemoglobin caused by the involution of the extraembryonic circulatory system. The destruction of the erythrocytes seems to take place in the endodermal epithelium of the proximal yolk sac, where an accumulation of iron could be demonstrated on the 19th and 20th days.

The measurement of serum unsaturated iron-binding capacity in the presence of iron-dextran.

The standard colorimetric methods most often used for the measurement of serum unsaturated iron binding capacity (UIBC) are subject to gross interference by iron dextran. This paper describes a brief evaluation of an alternative radiometric assay for serum UIBC, based on a commercially available kit method, but incorporating a modification to the manufacturer's protocol. The effects of iron dextran on the assay were determined.

Detection and cellular localization of stress-induced 72 kD heat shock protein in cultured Swiss 3T3 mouse fibroblasts.

Cellular expression of the 72 kD heat shock protein (72 kD hsp) is increased following exposure to a wide range of physical and chemical stimuli and may be useful as a marker of cell toxicity. The primary objective of this work was to develop a cytochemical method suitable for the detection and cellular localization of stress-inducible 72 kD hsp mRNA and protein in cell cultures. Swiss 3T3 mouse fibroblasts, grown on multi-chamber glass slides, were transiently exposed to an elevated incubation temperature or various chemical agents and cellular 72 kD hsp expression visualized using immunocytochemical and in situ hybridization detection methods. Expression of 72 kD hsp was found to be dependent on the applied stimulus and recovery time. The combined culture system and cytochemical assay for 72 kD hsp provides a convenient method for studying cellular responses to a variety of toxins.

Provision of supplementary fluids to breast fed infants and later breast feeding success.

It has been shown that altering hospital policies in a way to avoid interference of routine prescriptions with initiation of breast feeding and to provide active encouragement to mothers and personnel can result in significant benefit for later breast feeding success. It is less clear, however, which of the elements of a promotional programme such as UNICEF/WHO's "ten steps to successful breast feeding" are absolutely essential and which can be adapted to local cultural habits. We performed an open randomized multicenter study in Switzerland to evaluate, whether restriction of supplementary fluids for breast fed infants in the first week of life and strict avoidance of artificial teats and pacifiers affects later breast feeding success. Follow up to 6 months was ensured by mailed questionnaires. 602 mother infant pairs were enrolled. Of 294 infants in the intervention group 39% were excluded from the final analysis because of protocol violations, mainly maternal request for the use of pacifiers or bottles. Though the number of dextrin maltose supplements during the first two days (1.7 vs. 2.2 on day 1, 2.2 vs. 2.6 on day 2) and the percentage of infants receiving any supplement (85% vs. 96.6%) was significantly smaller in the intervention group, the difference was disappointingly small. The prevalence of breast feeding was 100% vs. 99% at day 5, 88% vs. 88% at 2 months, 75% vs. 71% at 4 months and 57% vs. 55% at 6 months, none of the differences being significant. We conclude that rigorous adherence to all of the ten steps may encounter obstinate resistance from cultural habits even in a population highly favourable to breast feeding. An improvement in adherence does not necessarily lead to better breast feeding success. The results of the few comparable studies in the literature show also that cultural practices during the first months of life may influence profoundly the long term effects of interventions during the first days of life.

[Therapy in unfavorable prognosis. Ethical dilemma in the treatment of newborn infants with severe abnormalities]. / Therapie bei ungünstiger Prognose. Das ethische Dilemma in der Behandlung von Neugeborenen mit schweren Fehlbildungen.

The doctor treating a baby destined to be handicapped with certainty has to find a way between the two extremes of overtreatment and selective medicine. Medico-ethical directives cannot replace personal commitment in this process. The observation of the jargon used in team discussions can reveal tendencies to one or the other extreme position. An attitude is proposed that tries to balance the gain in joy of life, in possibilities for human relations and in experience of life, the start or pursuit of a therapeutic measure possibly allows against the pain, discomfort and deprivation it inevitably entails.

Molecular epidemiology of the nasal colonization by methicillin-susceptible Staphylococcus aureus in Swiss children.

Nasal carriage of Staphylococcus aureus contributes to an increased risk of developing an infection with the same bacterial strain. Genetic regulatory elements and toxin-expressing genes are virulence factors associated with the pathogenic potential of S. aureus. We undertook an extensive molecular characterization of methicillin-susceptible S. aureus (MSSA) carried by children. MSSA were recovered from the nostrils of children. The presence of Panton-Valentine leukocidin (PVL), exfoliatins A and B (exfoA and exfoB), and the toxic-shock staphylococcal toxin (TSST-1) and agr group typing were determined by quantitative PCR. A multiple-locus variable-number of tandem repeat analysis (MLVA) assay was also performed for genotyping. Five hundred and seventy-two strains of MSSA were analysed. Overall, 30% were positive for toxin-expressing genes: 29% contained one toxin and 1.6% two toxins. The most commonly detected toxin gene was tst, which was present in 145 (25%) strains. The TSST-1 gene was significantly associated with the agr group 3 (OR 56.8, 95% CI 32.0-100.8). MLVA analysis revealed a large diversity of genetic content and no clonal relationship was demonstrated among the analysed MSSA strains. Multilocus sequence typing confirmed this observation of diversity and identified ST45 as a frequent colonizer. This broad diversity in MSSA carriage strains suggests a limited selection pressure in our geographical area.