Active monitoring of adverse drug reactions in children. Italian Paediatric Pharmacosurveillance Multicenter Group

An active monitoring system of adverse drug reactions (ADR) in children was developed through a network of family paediatricians. The reported Incidence of ADRs was 15.1 per 1000 children.

Variable use of therapeutic interventions for children with human immunodeficiency virus type 1 infection in Europe

Although a range of antiretroviral drugs are available for use in children, the appropriate paediatric regimen remains unclear. In a survey to investigate policies and practices relating to the therapeutic management of children infected by the human immunodeficiency virus (HIV), a postal questionnaire was sent to a named paediatrician in 70 major HIV centres in 13 European countries in early 1998. A total of 64 paediatricians (91%) responded. Pneumocystis carinii pneumonia prophylaxis was found to be routine in all centres, although considerable variation existed regarding the time of starting and stopping therapy. Prophylaxis for fungal infections and recurrent bacterial infections was common, with cytomegalovirus prophylaxis being less frequent. Although most centres (89%) used all five currently available nucleoside analogues (ziduvodine, lamivudine, stavudine, didanosine, zalcitabine), there was considerable variability regarding the availability of protease inhibitors. Most respondents delayed initiation of antiretroviral therapy until evidence of disease progression was apparent. The initial prescription of 38% of clinicians was triple therapy and that of 57% prescribed double therapy. Policies varied regarding the modification to regimens in response to disease progression and emergence of side effects and drug resistance. Clinical practice was informed by a number of sources, including centre-specific and national guidelines. Most respondents affirmed the need for European guidelines.

CONCLUSION

Approaches to the therapeutic management of paediatric human immunodeficiency virus infection differ across Europe.

HIV: mother to child transmission, current knowledge and on-going studies

It is estimated that approximately 6000 women of childbearing age, mostly living in the developing world, acquire HIV infection every day. Taking into account that approximately 98% of HIV infected children have acquired HIV from the mother, during pregnancy, at delivery or through breastfeeding, therefore, prevention of mother-to-child transmission (MTCT) is a major health priority. Several studies have showed how MTCT of HIV may be prevented using antiretrovirals. Results from a study conducted in Thailand have also recently showed how a short oral zidovudine course during pregnancy and labor may reduce the risk of HIV transmission by approximately 50%. These findings represent a major challenge for the International Health Agencies and Organizations that will have the major obligation to provide HIV tests, counseling and antiviral drugs in settings with high HIV prevalence.

Care of human immunodeficiency virus-infected children in developing countries. International Working Group on Mother-to-Child Transmission of HIV

CONTEXT

There is urgent need to strengthen the area of pediatric HIV/AIDS care in developing countries. Clinical research in this area is also scarce.

METHODOLOGY

A literature review and a postal survey were used to obtain updated information on mortality, morbidity and current standards of care of children born to HIV-infected mothers in developing countries. A 2-day workshop was organized to review the available data and to identify the key areas where clinical research should be conducted.

MAIN FINDINGS

Rates of mortality and morbidity were very different from one study to another but generally higher than in industrialized countries. Prognostic studies for HIV-1-infected children in developing countries were not available. Based on the report of 14 teams from 11 countries, specific protocols for HIV-infected children with persistent diarrhea or severe malnutrition were documented in fewer than one-half of the cases. Secondary antimicrobial prophylaxis after interstitial pneumonia or recurrent infections was still infrequent, as primary prophylaxis of opportunistic infections. The following list of clinical research priorities was identified by the workshop participants: primary prophylaxis of opportunistic and bacterial infections; case management of persistent diarrhea; reassessment of the performance of p24 antigen for diagnostic and prognosis use; studies on the etiology of pulmonary infections; long term observational pediatric cohorts; current weaning practices and duration of breast-feeding; counseling and HIV testing of children and families; prevention of HIV sexual transmission in children and adolescents.

Evolution of human immunodeficiency virus type 1 in perinatally infected infants with rapid and slow progression to disease

We addressed the relationship between the origin and evolution of human immunodeficiency virus type 1 (HIV-1) variants and disease outcome in perinatally infected infants by studying the V3 regions of viral variants in samples obtained from five transmitting mothers at delivery and obtained sequentially over the first year of life from their infected infants, two of whom (rapid progressors) rapidly progressed to having AIDS. Phylogenetic analyses disclosed that the V3 sequences from each mother-infant pair clustered together and were clearly distinct from those of the other pairs. Within each pair, the child's sequences formed a monophyletic group, indicating that a single variant initiated the infection in both rapid and slow progressors. Plasma HIV-1 RNA levels increased in all five infants during their first months of life and then declined within the first semester of life only in the three slow progressors. V3 variability increased over time in all infants, but no differences in the pattern of V3 evolution in terms of potential viral phenotype were observed. The numbers of synonymous and nonsynonymous substitutions varied during the first semester of life regardless of viral load, CD4+-cell count, and disease progression. Conversely, during the second semester of life the rate of nonsynonymous substitutions was higher than that of synonymous substitutions in the slow progressors but not in the rapid progressors, thus suggesting a stronger host selective pressure in the former. In view of the proposal that V3 genetic evolution is driven mainly by host immune constraints, these findings suggest that while the immune response to V3 might contribute to regulating viral levels after the first semester of life, it is unlikely to play a determinant role in the initial viral decline soon after birth.

Persistence of antibody responses to Haemophilus influenzae type b polysaccharide conjugate vaccine in children with vertically acquired human immunodeficiency virus infection

BACKGROUND

Recurrent bacterial sepsis is common in pediatric HIV infection and immunization against Haemophilus influenzae type b (Hib) is recommended. Long term persistence of anti-Hib antibody and the need for, or timing of, a booster dose has not been adequately studied.

METHODS

Immunogenicity during a 12-month period following immunization with Hib-tetanus conjugate vaccine (ACT-HIB; Merieux) was evaluated in 48 vertically HIV-infected children and 36 uninfected children, born to HIV-positive mothers. A titer of anti-Hib polysaccharide antibody of > or = 0.15 microgram/ml was considered to indicate short term and > or = 1 microgram/ml long term protection.

RESULTS

At 1 month postvaccination 36 (100%) uninfected and 42 (88%) HIV-infected children achieved titers of > or = 1 microgram/ml. However, by 1 year titers had dropped below this value in 18 (43%) infected compared with only 4 (11%) uninfected children (chi square, 9.7; P = 0.002). Although the rate of fall of antibody titer was greater in uninfected than in infected children, this was no longer the case after adjustment for the 1-month postimmunization titer. The rate of antibody titer decline was not significantly related to HIV disease status or to either the age-related CD4 count at the time of immunization or the change in age-adjusted CD4 count during the 12 months after immunization.

CONCLUSIONS

Not only was the initial antibody response to Hib conjugate vaccine decreased in children with HIV infection and AIDS but also 1 year later only 57% of the initial responders had persisting titers above the level associated with long term protection. The need for reimmunization of children with HIV infection against Hib requires further evaluation.

Intracranial hypertension and cryptococcal meningitis in a girl with AIDS

A girl with HIV infection acquired at birth by blood transfusion, was admitted at the age of 10 years for diplopia, vomiting, headache and papilledema. CT scan was negative. A lumbar puncture revealed clear CSF, protein 0.40 g/l, glucose 2 mmol/l, 5 mononuclear cells/mm3. The Indian ink preparation and the latex agglutination antigen test were positive for Cryptococcus n. Treatment with amphotericin B and flucytosine was started. After 10 days, since the in vitro susceptibility testing of the isolates showed resistence to both drugs, fluconazolo (400 mg/day) was started. Acetazolamide, furosemide and spironolactone were then added to the antifungal therapy for the persistence of severe intracranial hypertension. Diuretics were maintained for 10 weeks. The patient returned to school two and half months after the admission to the hospital. After 19 months, she is doing well and she is on maintenance of fluconazole (200 mg/day). We hypothesized that the increased intracranial pressure would be due to an impaired CSF reabsorption probably as a consequence of a direct cryptococcal infiltration of the villi.

Detection of virus in vertically exposed HIV-antibody-negative children

BACKGROUND

HIV-infected mothers can transmit their infection to their children in utero or at delivery (vertical transmission). There have been cases of children who were reported as acquiring infection vertically and later clearing the infection. We report the frequency of this phenomenon in a European cohort study.

METHODS

In four centres of the European Collaborative Study of children born to HIV-infected mothers, 299 children became HIV-antibody-negative and 264 of these had been followed up with virus culture and PCR for viral DNA at least once.

FINDINGS

Nine of the 264 children were positive by virus culture or PCR, and subsequently seroreverted. Two of the nine tested virus-positive after they became antibody-negative. Six cases were virus-positive early in life and became negative thereafter, which is consistent with clearance of infection. The pattern was less clear in the other three. The nine cases had had their last virus test at age 16-101 months. All nine children had been bottlefed only. Eight had been delivered vaginally. The children had no HIV-related symptoms and received no anti-HIV treatments. Based on only those children who had two or more positive virological tests, we estimate that 2.7% (6/219) cleared or "tolerated" the virus.

INTERPRETATION

The detection of virus or viral DNA in "uninfected" children born to HIV-infected mothers was rare and was not associated with clinical disease or immunological abnormalities. The timing of samples will affect the documentation of clearance since, in uninfected children of HIV-positive mothers who cleared the virus, viraemia was intermittent. Current paediatric opinion is to inform parents of children who serorevert that the child is not HIV-infected.

Dynamics of viral replication in infants with vertically acquired human immunodeficiency virus type 1 infection

About one-third of vertically HIV-1 infected infants develop AIDS within the first months of life; the remainder show slower disease progression. We investigated the relationship between the pattern of HIV-1 replication early in life and disease outcome in eleven infected infants sequentially studied from birth. Viral load in cells and plasma was measured by highly sensitive competitive PCR-based methods. Although all infants showed an increase in the indices of viral replication within their first weeks of life, three distinct patterns emerged: (a) a rapid increase in plasma viral RNA and cell-associated proviral DNA during the first 4-6 wk, reaching high steady state levels (> 1,000 HIV-1 copies/10(5) PBMC and > 1,000,000 RNA copies/ml plasma) within 2-3 mo of age; (b) a similar initial rapid increase in viral load, followed by a 2.5-50-fold decline in viral levels; (c) a significantly lower (> 10-fold) viral increase during the first 4-6 wk of age. All infants displaying the first pattern developed early AIDS, while infants with slower clinical progression exhibited the second or third pattern. These findings demonstrate that the pattern of viral replication and clearance in the first 2-3 mo of life is strictly correlated with, and predictive of disease evolution in vertically infected infants.

Use of polymerase chain reaction and quantitative antibody tests in children born to human immunodeficiency virus-1-infected mothers

The diagnosis of human immunodeficiency virus (HIV) infection in children born to HIV-infected mothers is complicated by the presence of passively acquired maternal antibodies, and exclusion of infection in these infants remains problematic. The use of genome detection by polymerase chain reaction (PCR) amplification and the quantification of anti-HIV-1 antibodies were examined as methods for early diagnosis. Blood samples were taken from 84 non-breast-fed infants of HIV-infected mothers in five Italian and Spanish centres, a subgroup of children enrolled in the European Collaborative Study (ECS) for whom clinical and immunological information has been documented from birth. Whole blood was added to glycigel cryopreservative, stored, and tested in the United Kingdom by a nested PCR method. Antibody to HIV-1 was detected and quantified by titration using a gelatin particle agglutination test. PCR sensitivity and specificity were assessed. Twenty-one of the 84 children tested were infected. The estimated PCR sensitivity ranged from 0% (95% CI 0-26%) on day 1, 57% (19-85) on day 7, to 63% (33-92) on day 30. The negative predictive value of PCR ranged from 85% (83-88) on day 0 to 98% (94-100) at 3 months of age. On average, the level of maternal antibody halved every 33 days (31-36.5) in uninfected children. Between 6 and 9 months of age, increases in antibody titres in infected children were not more informative than absolute levels. These findings suggest that antibody measurement may supplement genomic diagnosis and that this collection method provides an alternative to the use of dried blood spots.

Pharmacokinetics of zidovudine and dideoxyinosine alone and in combination in children with HIV infection

The pharmacokinetics of zidovudine (ZDV) and dideoxyinosine (ddI) were investigated following administration alone and in combination to children with symptomatic HIV disease. The children were studied on three separate occasions and received ZDV 200 mg m-2, ddI 100 mg m2 or a combination of ZDV 200 mg m-2 plus ddI 100 mg m-2. The administration of ddI did not significantly alter ZDV pharmacokinetics. The area under the curve (AUC) was 14.2 +/- 4.9 and 15.8 +/- 7.2 mumol l-1 h and elimination half-life (t1/2, z) was 1.4 +/- 0.4 and 1.2 +/- 0.2 h in the absence and presence of ddI respectively. The peak concentration (Cmax), time to peak (tmax) and apparent oral clearance (CL/F) were also unchanged. The administration of ZDV had no significant effect on ddI Cmax, tmax, t1/2,z, or CL/F, however the AUC was reduced by 19% (5.9 +/- 2.9 to 4.8 +/- 2.7 mumol l-1 h; P < 0.05). This study suggests that ZDV and ddI may be co-administered to children with symptomatic HIV disease without concern of a clinically relevant pharmacokinetic drug interaction.

Onset of clinical signs in children with HIV-1 perinatal infection. Italian Register for HIV Infection in Children

OBJECTIVE

To investigate the timing of onset of each clinical sign in infants and children with HIV-1 perinatal infection.

DESIGN AND METHODS

A total of 200 HIV-1-infected children followed-up from birth were studied. Failure and conditional probabilities were estimated by the Kaplan-Meier product-limit method. Cox proportional hazard analysis was used to evaluate independently associated factors. Results of 934 seroreverters were used to calculate reference values of CD4+ cell counts and predictivity of early signs.

RESULTS

Median age at the onset of any sign was 5.2 months (range, 0.03-56 months). The probability of remaining asymptomatic was 19% [95% confidence interval (CI), 14-25.1] at 12 months and 6.1% (95% CI, 2.6-11.7) at 5 years. Lymphadenopathy (69.5%), splenomegaly (62.4%) and hepatomegaly (58.4%) were the most common signs in the first year of life. Peculiar to the first year of life (compared with subsequent ages) was the onset of primary HIV-1 hepatitis and diarrhoea (rate ratios, 23.3 and 15.2, respectively). When CD4+ cell counts in the asymptomatic stage (age, 2 months; range, 0.03-5.9 months) were below rather than above the fifth percentile in seroreverters, onset of signs was earlier [3 range, 0.03-19) versus 5 (range, 0.03-56) months]. Children manifesting signs before the 5.2-month breakpoint had a lower survival rate [74% (range, 65.9-82%) at 12 months and 45% (range, 32.9-57%) at 5 years] than children manifesting signs later [98% (range, 92.2-100%) at 12 months and 74% (range, 60.3-87.7%) at 5 years]. Children whose birthweight was < or = 2400 g had an earlier onset (24 months; range, 1-57 months) of severe conditions than children with higher birthweight (71 months; range, 1-71 months). Development of lymphadenopathy or hepatosplenomegaly within 3 months of life were reliable indicators of infection.

CONCLUSIONS

This study describes the sequence of onset of signs in perinatal HIV-1 infection. Infection is shown to progress faster than in adults and in a different manner. Low birthweight, early decreased CD4+ cell counts, and early onset of signs are predictive of rapid progression.

Viral phenotype and host-cell susceptibility to HIV-1 infection as risk factors for mother-to-child HIV-1 transmission

OBJECTIVE

To investigate the role of maternal HIV-1 isolate phenotype and a child's cell susceptibility/resistance to viral infection in mother-to-child HIV-1 transmission.

PATIENTS AND METHODS

Forty-nine women were studied at the time of delivery. Primary isolates, obtained by culturing patient peripheral blood mononuclear cells (PBMC) with PBMC from healthy donors, were characterized for tropism and syncytium-inducing capability in monocyte-derived macrophages (MDM), peripheral blood lymphocytes (PBL), and in the MT-2 and MOLT-3 T-cell lines.

RESULTS

Seven women transmitted HIV-1 to their children. Primary isolates were obtained from six and 28 transmitting and non-transmitting mothers, respectively. All primary isolates from transmitting mothers and their infants but only 50% of those from non-transmitting mothers replicated in MDM, regardless of their replication capacity in T-cell lines. PBL and MDM cells from six uninfected children were exposed to the corresponding maternal isolates. Polymerase chain reaction analysis of HIV-1 DNA in cells and p24 antigen assay in culture supernatants disclosed that two PBL and five MDM cultures were resistant to viral infection; two other PBL cultures, although HIV-1-infected, were negative for p24 production. Depletion of CD8+ cells only partially restored productive infection in CD4+ cell cultures. Moreover, all six PBL but only one MDM cultures were productively infected by an isolate obtained from a transmitting mother, thus suggesting that MDM resistance to HIV-1 infection is not viral isolate-restricted.

CONCLUSIONS

Our findings strongly suggest that mother-to-child HIV-1 transmission is influenced by both monocyte-macrophage tropism of the maternal isolate and susceptibility of the child's target cells, in particular monocyte-macrophages, to HIV-1 infection.

Antibody responses to Haemophilus influenzae type b and Streptococcus pneumoniae vaccines in children with human immunodeficiency virus infection

Antibody responses to Haemophilus influenzae type b (Hib) conjugate (ActHIB; Pasteur Merieux) and pneumococcal (Pneumovax II; Morson) vaccines were measured in 56 infected children (VI) and 44 uninfected children (U) older than 18 months of age, born to human immunodeficiency virus-positive mothers. Preimmunization, 21% U and 20% VI had protective concentrations of anti-Hib polysaccharide antibodies. Postimmunization, 100% U and 86% VI achieved protective titers (P = 0.008). The geometric mean increase in anti-Hib polysaccharide antibody was 7.6 (95% confidence interval, 3.5 to 16.3; P = 0.0001) times higher in U than in VI children after adjusting for age and ethnicity. Sixty-one percent U compared to 54% VI showed a 2-fold increase in antibody levels to at least one of the four pneumococcal vaccine serotypes (3, 6, 19, 23) measured (P = 0.4). For both vaccines there was a significant trend toward poorer responses in children with acquired immunodeficiency syndrome but no correlation with age adjusted CD4 counts. These data suggest that human immunodeficiency virus-infected children should be immunized with these polysaccharide vaccines early in the course of their disease.

Paediatric AIDS: a new child abuse

In relation to youth rights, a new view has been created in recent decades that is included in the fundamental law of the child: the recognition of the right to education and the chance to develop a mature personality capable of creativity and liberty. Because of HIV infection it is very important to pay particular attention to the rights of the seropositive child and children born to seropositive mothers, which may be hampered not only in developing countries but also in the industrial world. HIV-affected children and their families are becoming abused and at high risk of becoming abused and this encroaches upon youth rights. As a consequence, in 1991 the Italian Society of Paediatrics issued a "Charter for the rights of seropositive children", which became an important document for all health care and social workers who deal with HIV-affected children. In this paper, we also consider the impact of HIV infection on the three main rights of children: the right to live, the rights of security and the rights of socialization.

The use of antibiotics in the treatment and prevention of infection in HIV-infected children

Children with HIV infection have an unusual susceptibility to bacterial infection, related to several immune abnormalities. Selection of initial antibiotic therapy must be individualized in these children. Patients with community-acquired disease are most likely to have infection by polysaccharide-encapsulated bacterial organism, most commonly Streptococcus pneumoniae and less frequently by Haemophilus influenzae type b. If it is possible to treat the patients at home, the use of amoxicillin-clavulanic acid might be appropriate. Other authors propose management with parenteral ceftriaxone because of the better compliance and the malabsorption. In hospitalized patients, concern for Gram-negative enteric pathogens other than polysaccharide-encapsulated organisms requires initial therapy with a third-generation cephalosporine in combination with an aminoglycoside. Trimethoprim-sulfamethizole is the most common drug used in HIV-infected children because it is recommended for the initial therapy and for prophylaxis of pneumocystis carinii pneumonia, which occurs in as many as 42% of these children.

Replication and tropism of human immunodeficiency virus type 1 as predictors of disease outcome in infants with vertically acquired infection

In a series of 97 infants born to mothers who were seropositive for human immunodeficiency virus type 1 (HIV-1), 18 were identified as infected within the first 60 days of life on the basis of viral culture and polymerase chain reaction findings. We studied viral burden in vivo by quantitative polymerase chain reaction and the in vitro replication pattern of the HIV-1 infecting strain by culturing patient cells with normal phytohemagglutinin-stimulated peripheral blood mononuclear cells. According to the lag phase before p24 antigen detection and the level of p24 production on peripheral blood mononuclear cells, HIV-1 isolates from these patients were classified as rapid/high (R/H), slow/high (S/H), and slow/low (S/L). The pattern of HIV-1 replication in vitro was significantly associated with the viral burden in vivo; the range of HIV-1 copies per 10(5) peripheral blood mononuclear cells was 10 to 38, 44 to 314, and 360 to 947 in children with isolates of the S/L, S/H, and R/H types, respectively. Viral tropism was assessed by culturing patient cells under end-point dilution conditions with either CD4+ T-lymphocytes or monocyte-derived macrophages. We found that children with S/L isolates harbored mainly monocytotropic variants; all infants with S/H or R/H isolates had T-lymphotropic variants and, in 7 of 11 cases, monocytotropic or amphitropic variants. All children with R/H isolates had HIV-related symptoms by the age of 4 months, and five had acquired immunodeficiency syndrome by the age of 1 year. At 1 year of age, four and no infants with S/H or S/L isolates, respectively, had HIV-1-related symptoms (p < 0.001), and none had acquired immunodeficiency syndrome (p = 0.006).