HIV-1-resistance-associated mutations after failure of first-line antiretroviral treatment among children in resource-poor regions: a systematic review

HIV-positive children are at high risk of drug resistance, which is of particular concern in settings where antiretroviral options are limited. In this Review we explore resistance rates and patterns among children in developing countries in whom antiretroviral treatment has failed. We did a systematic search of online databases and conference abstracts and included studies reporting HIV-1 drug resistance after failure of first-line paediatric regimens in children (<18 years) in resource-poor regions (Latin America, Africa, and Asia). We retrieved 1312 citations, of which 30 studies reporting outcomes in 3241 children were eligible. Viruses with resistance-associated mutations were isolated from 90% (95% CI 88-93%) of children. The prevalence of mutations associated with nucleoside reverse transcriptase inhibitors was 80%, with non-nucleoside reverse transcriptase inhibitors was 88%, and with protease inhibitors was 54%. Methods to prevent treatment failure, including adequate paediatric formulations and affordable salvage treatment options are urgently needed.

Improved general health of international adoptees, but immunization status still insufficient

We studied the demographic and clinical data from 495 adopted children seen between January 2002 and January 2007 to evaluate the medical condition and immunization status of international adoptees. The data of children from Chinese origin (53.5%) were compared to children arriving from other countries. Medical problems requiring treatment were present in 42.8% of the children. Parasitic gastrointestinal infection (22.0%) and skin abnormalities (22.4%) were diagnosed most often. Hepatitis B (1.2%) and tuberculosis (1%) were documented in some children; HIV, hepatitis C, and syphilis were not seen in any of the children. Antibody levels against diphtheria and tetanus were insufficient in about half of all children, particularly in those from China. In conclusion, most adoptive children had a good general health, with only a few having major medical problems. Many adoptive children had an inadequate immunization status.

Plasma vascular endothelial growth factor in severe sepsis

Vascular endothelial growth factor (VEGF) is a potent vascular permeability factor. The development of capillary leak is common in septic patients, and several sepsis-associated mediators may induce VEGF production. The potential role of VEGF during sepsis has not been studied to date. The aim of the study was first to assess whether circulating VEGF levels increase during sepsis, and second, to examine whether plasma VEGF levels are associated with disease severity. VEGF levels were measured in serial plasma samples of 18 patients with severe sepsis and in 40 healthy controls. VEGF levels were correlated to clinical signs and symptoms. VEGF levels were significantly elevated in sepsis patients compared with healthy controls (134 vs. 55 pg/mL; P <0.001). Serum albumin levels used as an indirect measure of vascular leak were decreased in septic patients. Increased plasma VEGF levels at study entry were correlated to severity of multiple organ dysfunction during the course of disease (Pearson correlation coefficient r=0.75; P=0.001). Moreover, maximum VEGF levels in nonsurvivors were significantly higher than those in survivors (P=0.018). These data show that plasma VEGF levels are elevated during severe sepsis. Furthermore, our data indicate that plasma VEGF levels are associated with disease severity and mortality. Further study of the potential role of VEGF in the development of sepsis-associated capillary leak is indicated.

[Persistent fever of unknown origin in two young infants caused by the atypical form of Kawasaki disease]

Two previously healthy infants, a boy and a girl aged 3 and 4 months, respectively, were admitted for fever of unknown origin with laboratory results indicating an inflammation. The boy presented with vomiting, pyuria, anaemia, and thrombocytosis. The girl presented with irritability, erythema and diarrhoea. All viral and bacterial cultures remained negative and supplementary radiology was unable to detect a focus of infection. The fever had persisted for at least 12 days in both cases before the diagnosis 'atypical Kawasaki disease' was considered. Cardiac echograms showed dilatation of the coronary arteries in both patients and confirmed the diagnosis. Immediate therapy with intravenous immunoglobulins and acetylsalicylic acid was given, whereupon the fever subsided within 24 hours; the further clinical course was uneventful. These cases illustrate the fact that atypical Kawasaki disease is often a late consideration, especially when the symptoms of the classical form are absent. This condition should be considered in every infant presenting with long-lasting unexplained fever.

[Invasive infection with Moraxella catarrhalis in two children with lymphatic leukemia and granulocytopenia]

In two young children with leukaemia, a girl and a boy aged 5 and 4 years, respectively, an invasive infection due to Moraxella catarrhalis was diagnosed at the time of granulocytopenia. They were treated with antibiotics. The first child developed pneumonia and recovered, the other developed severe septic shock and died. M. catarrhalis is a Gram-negative diplococcus, frequently colonising the upper respiratory tract in young children. In childhood this pathogen mainly causes infections such as otitis media and sinusitis, while in adults it primarily causes laryngitis, bronchitis and pneumonia. Immunocompromised patients or patients with chronic cardiopulmonary disease have an increased risk of severe infections.

Endocrinologic and immunologic factors associated with recovery of growth in children with human immunodeficiency virus type 1 infection treated with protease inhibitors

INTRODUCTION

Growth failure is a common presenting sign in children with HIV disease and is a sensitive indicator of disease progression in children with AIDS. Highly active antiretroviral therapy (HAART) is associated with a significant decrease in viral load and a subsequent rise in CD4+ T cell counts in HIV-1-infected children and also with increased height and weight. The underlying mechanisms of catch-up growth during HAART are yet unknown.

METHODS

Height and weight measurements, blood sample analyses for HIV-1 RNA and peripheral blood CD4+ T cell counts were obtained twice within 1 month before the start of HAART and after 12, 24, 36 and 48 weeks of treatment. Serum concentrations of insulin-like growth factor I (IGF-1), IGFs complexed to specific, structurally homologous binding proteins (IGFBP-3), cortisol, free thyroxine and tumor necrosis factor alpha (TNF-alpha) were measured before the start of therapy and after 24 weeks. In addition serum IGF-1 and IGFBP-3 values were determined after 48 weeks.

RESULTS

Twenty-seven HIV-1-infected children with a median age of 5.5 years (range, 0.3 to 14.9 years) were included. Overall no significant changes in height and body mass index (BMI) z scores were observed. The median baseline plasma viral load of 68,800 copies/ml decreased to less than the detection limit of 500 copies/ml in 80% of the children after 48 weeks. TNF-alpha values were elevated (44 pg/ml) at baseline and decreased significantly to 37 pg/ml after 24 weeks. At baseline elevated TNF-alpha was observed in 78%, which decreased to 55% after 24 weeks. Baseline free thyroxine and cortisol values were normal and did not change during therapy. Baseline serum of IGF-1 and IGFBP-3 concentrations were normal, but IGF-1 tended to be lower than IGFBP-3. Both values increased significantly after the initiation of therapy. IGFBP-3 decreased after 48 weeks whereas IGF-1 stabilized. The increase in IGF-1 was significantly higher in children in whom the BMI and length (after correction for age and sex) increased the most.

CONCLUSION

Hypothyroidism and adrenal axis abnormalities are not associated with restoration of growth after the initiation of antiretroviral therapy in HIV-1-infected children. The combination of relatively high serum IGFBP-3 concentration and relatively lower serum IGF-1 suggests the presence of a growth hormone-resistant state. During treatment with a protease inhibitor-containing regimen, decreased serum IGFBP-3 and stabilization of IGF-1 after a significant initial increase suggest restoration of normal sensitivity to growth hormone and recovery to an anabolic condition.

Therapeutic immune reconstitution in HIV-1-infected children is independent of their age and pretreatment immune status

OBJECTIVE

To evaluate long-term immune reconstitution of children treated with highly active antiretroviral therapy (HAART).

METHODS

The long-term immunological response to HAART was studied in 71 HIV-1-infected children (aged 1 month to 18 years) in two prospective, open, uncontrolled national multicentre studies. Blood samples were taken before and after HAART was initiated, with a follow-up of 96 weeks, and peripheral CD4 and CD8 T cells plus naive and memory subsets were identified in whole blood samples. Relative cell counts were calculated in relation to the median of the age-specific reference.

RESULTS

The absolute CD4 cell count and percentage and the CD4 cell count as a percentage of normal increased significantly (P < 0.001) to medians of 939 x 106 cells/l (range, 10-3520), 32% (range, 1-50) and 84% (range, 1-161), respectively, after 48 weeks. This increase was predominantly owing to naive CD4 T cells. There was a correlation between the increase of absolute naive CD4 T cell counts and age. However, when CD4 T cell restoration was studied as percentage of normal values, the inverse correlation between the increase of naive CD4 T cell count and age was not observed. In addition, no difference in immunological reconstitution was observed at any time point between virological responders and non-responders.

CONCLUSIONS

Normalization of the CD4 cell counts in children treated with HAART is independent of age, indicating that children of all age groups can meet their CD4 T cell production demands. In general, it appears that children restore their CD4 T cell counts better and more rapidly than adults, even in a late stage of HIV-1 infection.

Pharmacokinetics of the protease inhibitor indinavir in human immunodeficiency virus type 1-infected children

The objective of this study was to evaluate the pharmacokinetics of indinavir in human immunodeficiency virus-infected children as part of a prospective, open, uncontrolled, multicenter study in The Netherlands. Human immunodeficiency virus type 1-infected children were monitored over 6 months of treatment with zidovudine (120 mg/m(2) every 8 h [q8h]), lamivudine (4 mg/kg of body weight q12h), and indinavir (33mg/kg of metabolic weight [MW] q8h). Four weeks after the start of treatment, the steady-state pharmacokinetics of indinavir were determined by high-pressure liquid chromatography. If patients had an indinavir area under the concentration-time curve (AUC) of below 10 or above 30 mg/liter. h, a dose increase or a dose reduction was made and pharmacokinetic measurements were repeated 4 weeks later. Nineteen patients started with the dose of 33 mg/kg of MW q8h. The median AUC (range) was 10.5 (2.8 to 51.0) mg/liter. h. The median AUC (range) in 17 children treated with 50 mg/kg of MW q8h was 20.6 (4.1 to 38.7) mg/liter. h. Finally, five patients had a dose increase to 67 mg/kg of MW q8h, resulting in a median AUC (range) of 36.6 (27.2 to 80.0) mg/liter. h. After 6 months of treatment, there were 11 children with an AUC of below 20 mg/liter. h, of whom 5 (45%) had a detectable viral load, while this was the case in none of the 11 children with an AUC of higher than 20 mg/liter. h. We conclude that the optimal dose of indinavir in children to obtain drug exposure similar to that observed in adult patients is 50 mg/kg of MW q8h, which approximates 600 mg/m(2) q8h. It would even be better to adjust the indinavir dose based on an AUC of greater than 20 mg/liter. h.

Neonatal sepsis by Campylobacter jejuni: genetically proven transmission from a household puppy

We report a case of neonatal Campylobacter jejuni sepsis in a 3-week-old infant who acquired the infection through transmission from a recently acquired household puppy. Genotyping of Campylobacter strains obtained from puppy and child resulted in highly homogeneous findings. This represents the first genetically proven C. jejuni dog-human transmission.

Vascular endothelial growth factor in bacterial meningitis: detection in cerebrospinal fluid and localization in postmortem brain

Vascular endothelial growth factor (VEGF) is a potent vascular permeability factor and a mediator of brain edema. To assess the role of VEGF during bacterial meningitis, VEGF was measured in cerebrospinal fluid (CSF) and blood of 37 patients with bacterial meningitis and 51 control patients, including 16 patients with viral meningitis. Circulating VEGF levels were similar in bacterial meningitis patients and control patients. VEGF(CSF) was detected in 11 (30%) of 37 of bacterial meningitis patients (range, <25-633 pg/mL) but in none of the control patients. The median VEGF index was 6.2 (range, 0.6-42), indicating intrathecal production. Median CSF cell counts, protein levels, and CSF: serum albumin ratios were higher for patients with detectable VEGF(CSF), although the difference was not statistically significant. VEGF immunoreactivity in autopsy brain specimens was found in the inflammatory infiltrate of patients with bacterial meningitis. These results indicate that inflammatory cells secrete VEGF during bacterial meningitis and that VEGF may contribute to blood-brain barrier disruption.

Streptococcus pneumoniae induces secretion of vascular endothelial growth factor by human neutrophils

Infection by pneumococci causes an acute inflammatory response associated with neutrophil influx, increased vascular permeability, and edema. Vascular endothelial growth factor (VEGF) is one of the most potent regulators of endothelial permeability. In vitro stimulation of neutrophils showed that pneumococci and purified pneumococcal cell wall induce VEGF secretion, independent of the presence of pneumolysin or polysaccharide capsule. The results of this study indicate VEGF is secreted in pneumococcal disease, suggesting a role as a mediator of increased vascular permeability.

Clinical and virologic response to combination treatment with indinavir, zidovudine, and lamivudine in children with human immunodeficiency virus-1 infection: a multicenter study in the Netherlands. On behalf of the Dutch Study Group for Children with HIV-1 infections

OBJECTIVE

To evaluate the clinical, immunologic, and virologic response to indinavir, zidovudine, and lamivudine in children with human immunodeficiency virus-1 (HIV-1) infection.

STUDY DESIGN

Twenty-eight HIV-1-infected children (3 months to 16 years of age) with or without prior treatment with reverse-transcriptase inhibitors and a HIV-1 RNA >5000 copies/mL and/or a CD4 cell count less than the lower limit of the age-specific reference value were treated with indinavir, zidovudine, and lamivudine. Pharmacokinetics of indinavir were determined in each child.

RESULTS

The combination treatment was well tolerated in the majority of patients. Clinical improvement was seen in all patients. After 6 months of therapy, 70% of the patients had an HIV-1 RNA load below 500 copies/mL, whereas 48% of the children had a viral load below 40 copies/mL. Relative CD4 cell counts in relation to the lower limit of the age-specific reference value increased significantly from a median value of 79% at baseline to 106% after 6 months of therapy. The doses of indinavir necessary to achieve area under the curve values comparable to adult values varied from 1250 mg/m(2)/d to 2450 mg/m(2)/d.

CONCLUSIONS

Highly active antiretroviral therapy consisting of indinavir, zidovudine, and lamivudine in children reduced HIV-1 RNA to less than 500 copies/mL in 70% of the children within 6 months. Improved CD4 cell counts were observed in most patients, as was a better clinical condition (no invasive or opportunistic infections, increased weight gain). Side effects of the triple therapy were mild. Highly active antiretroviral therapy can be used as successfully in children as in adults.

Resistance to both complement activation and phagocytosis in type 3 pneumococci is mediated by the binding of complement regulatory protein factor H

To study the role of surface-associated proteins in the virulence of Streptococcus pneumoniae, we used two serotype 3 strains, ATCC 6303 and WU2, and two PspA-negative mutants of WU2, an encapsulated one, JY1123 (Caps(+)/PspA(-)), and an unencapsulated one, DW3.8 (Caps(-)/PspA(-)). ATCC 6303 and WU2 were highly virulent in mice, while the virulence of JY1123 was slightly decreased (50% lethal doses [LD(50)s], 24, 6, and 147 CFU/mouse, respectively); DW3.8 was avirulent (LD(50), 2 x 10(8) CFU). In vitro, ATCC 6303, WU2, and JY1123 (Caps(+)/PspA(-)) strongly resisted complement activation and complement-dependent opsonophagocytosis, whereas DW3.8 (Caps(-)/PspA(-)) was easily phagocytized in fresh serum. Trypsin treatment of ATCC 6303, WU2, and JY1123 (Caps(+)/PspA(-)) resulted in enhanced complement activation and complement-dependent opsonophagocytosis. Trypsin had no deleterious effect on the polysaccharide capsule. In addition, trypsin pretreatment of ATCC 6303 strongly reduced virulence upon intraperitoneal challenge in mice. This indicated that surface proteins play a role in the resistance to complement activation and opsonophagocytosis and contribute to the virulence of type 3 pneumococci. In subsequent experiments, we could show that the modulation of complement activation was associated with surface components that bind complement regulator factor H; binding is trypsin sensitive and independent of prior complement activation. Immunoblotting of cell wall proteins of the virulent strain ATCC 6303 with anti-human factor H antibody revealed three factor H-binding proteins of 88, 150, and 196 kDa. Immunogold electron microscopy showed a close association of factor H-binding components with the outer surface of the cell wall. The role of these factor H-binding surface proteins in the virulence of pneumococci is interesting and warrants further investigation.

[Team care: a necessity for a child with HIV infection]

In four children, a boy aged 2.5 years, a girl of 4, her brother of 7 years and a girl aged 10 months, HIV infection was diagnosed. Since 1996 HIV-infected children in the Netherlands are treated with a combination of two nucleoside analogs and a protease-inhibitor. This therapy improves the quality of life, increases the life expectancy of HIV-infected children and is generally well tolerated. However, the current combination therapy is complex and puts a burden on the child and the family. Therefore, long term compliance will be difficult. Moreover, the majority of the families have extremely difficult social circumstances which interfere with an optimal medical treatment for the child. The parents of three of the children were refugees from African countries. Intensive support of the family by a team of health care and social workers is usually necessary to make antiretroviral combination therapy possible. Care directed at the individual needs of the child and family is crucial to help this vulnerable group of children and families in our society.

[Vertical HIV-I-transmission. II. HIV-diagnosis in a child]

In newborn children from HIV-infected women early establishment of HIV infection is of importance for optimal therapy of HIV-infected children and avoidance of unnecessary medication in uninfected children. A more than 95% reliable diagnosis of HIV infection can now be obtained at the age of four weeks by polymerase chain reaction (PCR) technology. Before this age a positive PCR result is relevant since it necessitates additional investigation such as measuring anti-HIV drug resistance and may lead to modification of anti-HIV treatment. Prophylaxis against Pneumocystis carinii is not needed if HIV infection can not be demonstrated by PCR after the age of four weeks.

[Pertussis in young infants]

Four infants, three girls aged 4 weeks, 2.5 months and 3 months, and a boy aged 2 months, were hospitalized because of severe respiratory distress. Apnoea spells with bradycardia and hypoxia were seen in two of the patients, one showing convulsions as well, and bronchopneumonia in the other two, of whom one eventually died. All suffered from pertussis. During outbreaks of pertussis, infants less than 6 months of age are at highest risk for severe disease. In this age group, however, the clinical signs of pertussis are often atypical. Classical symptoms such as paroxysms of cough and loud whoops may be absent while feeding problems, apnoea, cyanosis and bradycardia may be present. For infants younger than 6 months with signs indicating pertussis hospitalization is indicated. In the current vaccination schedule in the Netherlands infants are vaccinated at 3, 4, 5 and 11 months of age. Starting in 1999 the first vaccination will be administered at the age of 2 months.

Early recovery of CD4+ T lymphocytes in children on highly active antiretroviral therapy. Dutch study group for children with HIV infections

INTRODUCTION

Regeneration of CD4+ T lymphocytes has been shown to be thymus-dependent in bone marrow transplant recipients and after intensive chemotherapy. The rate of CD4+ T cell regeneration is correlated positively with enlargement of the thymus, as shown on radiographs, and higher rates of CD4+ T lymphocyte regeneration were observed in children as compared with adults, consistent with thymic function diminishing with age. We hypothesized that in HIV infected patients CD4+ T cell recovery during highly active antiretroviral therapy (HAART) may also be thymus dependent. Therefore, repopulation of naive (CD45RA+), memory (CD45RO+) and total CD4+ T lymphocytes and total CD8+ T lymphocytes in peripheral blood was assessed in 13 HIV infected children during the initial 3 months of HAART.

RESULTS

Significantly higher recovery rates of naive, memory and total CD4+ T cells were observed in children below the age of 3 years as compared with older children. Kinetics of total CD8+ T cells showed no relation to age. Moreover, recovery rates of naive CD4+ T cells in patients below 3 years of age were 10-40 fold higher as compared with previously reported naive CD4+ T cell recovery rates in adults on HAART.

CONCLUSIONS

High recovery rates of naive, memory and total CD4+ T cells can be achieved in children below 3 years of age. Changes in CD8 counts did not correlate with age. These results indicate that regeneration of CD4+ T cells during HAART may be a thymus-dependent process.

[Invasive streptococcal infection as a complication of chickenpox]

Two girls aged 11 months and 6 years, presented with an invasive group A streptococcal (GAS) infection during the course of primary varicella. The infant had severe cellulitis of the left arm and leg, fever and bacteraemia. She developed osteomyelitis of ulna and tibia. The 6-year-old girl had a fever > 38.5 degrees C, hypotension, an acute respiratory distress syndrome, liver function abnormalities, and positive cultures of blood and joints. Her clinical picture was compatible with a GAS-associated toxic shock syndrome. If during the course of primary varicella persistent fever, secondary fever or pain in one or more extremities occurs, invasive bacterial infection by GAS or Staphylococcus aureus should be considered, even in the absence of skin infection or cellulitis.

[Poor results of treatment of echinococcosis with albendazole in 7 patients]

OBJECTIVE

To assess the effect of treatment of echinococcal disease with albendazole, a drug recently licensed in the Netherlands for this treatment.

SETTING

The University Hospital Utrecht and the Wilhelmina Children's Hospital, Utrecht.

DESIGN

Follow-up study.

METHOD

Clinical symptoms, serology and size and morphology of cysts of all patients (n = 7) treated with albendazole with a therapeutical dose (10 mg/kg for adults and 6 mg/kg for children in two daily doses during three cycles of 28 days) were monitored for at least one year.

RESULTS

Two patients improved, two patients did not show any change, and the condition of three patients deteriorated.

CONCLUSION

The efficacy of albendazole treatment with this regimen for hydatid disease is disappointing. If patients are treated with albendazole, the total dose administered to adults should be more than 80 g.

Deficiencies in opsonic defense to pneumococci in the human newborn despite adequate levels of complement and specific IgG antibodies

We studied the major determinants of opsonophagocytosis against Streptococcus pneumoniae serotypes 14 and 19 in paired cord/maternal sera from 27 healthy term and 24 preterm infants in an attempt to gain more insight in the susceptibility of newborns to pneumococcal infection. For both pneumococcal serotypes studied, opsonic activity in neonatal sera varied greatly, but was moderately to profoundly deficient when compared to paired maternal sera, both in preterm (34.5 and 34.9% of the activity in maternal serum, for serotypes 14 and 19, respectively, p less than 0.001 for both) and in term serum (43.5 and 52.7% of the activity in maternal serum, for serotypes 14 and 19, respectively, p less than 0.001 for both). The opsonic deficiency in preterm sera could be ascribed to a diminished level of the major opsonins for pneumococci, i.e. complement factor C3 deposited on the bacterial surface (69.5 and 66.2% of C3 deposition in maternal serum on serotypes 14 and 19, respectively, p less than 0.01 for both) and specific anticapsular IgG antibodies (48.5 and 14.1% of maternal levels for serotypes 14 and 19, respectively, p less than 0.001 for both). However, the opsonic defect in serum from term infants could not be explained in a similar way, because C3 deposition and specific anticapsular IgG levels were equal to the values found in the paired maternal sera. Therefore, we conclude that the opsonic defect in newborn serum for pneumococci cannot be solely explained by a deficiency in the major opsonins for these bacteria. A dysfunction in these opsonins seems to be a more likely explanation for the observed opsonic defect in the neonate.

Pneumococcal septicemia in the newborn. A report on seven cases and a review of the literature

This report summarizes the essential findings of seven cases of pneumococcal septicemia in the newborn and compares the data with those reported in the literature. It is emphasized that pneumococcal septicemia is a rare but highly lethal disease of the newborn. The clinical course strongly resembles early onset group B streptococcal disease. Epidemiological data suggest that the majority of infants are colonized near birth. Analogous to group B streptococcal sepsis, it seems rational to administer penicillin prophylaxis during labor to women with S. pneumoniae isolated from their genital tract to prevent vertical transmission and neonatal pneumococcal septicemia.

[Cephalosporins: microbiological and pharmacokinetic properties, application to pediatrics]

Many cephalosporins are presently available for clinical use. Although the cephalosporins are excellent antimicrobial agents for many infectious diseases in childhood, they have not replaced the older antibiotic regiments. In fact they offer the pediatrician a broader range of choices in treatment. This article gives a review on microbiological and pharmacokinetic properties of cephalosporins and an indication for the use of cephalosporins in pediatric therapy.

[Typhoid fever in childhood]

Typhoid fever is an uncommon disease in the Netherlands. Acquisition occurs mainly during holidays in an endemic area. The history of three children, admitted in the summer of 1985, will be discussed, in one of them the disease had a complicated course. A short review of the literature is given, especially regarding pathogenesis, diagnosis and treatment. Cultures of blood, faeces and bone-marrow are essential for diagnosis. Bone marrow culture remains the most effective method for recovery of the causative agent, especially in children who previously were treated with antibiotics. Chloramphenicol still is the drug of choice in treatment. Vaccination with the oral typhoid vaccine of children who intend to visit an endemic area is recommended.