[Interdisciplinary AWMF guideline for the treatment of primary antibody deficiencies]

BACKGROUND

Currently, management of antibody deficient patients differs significantly among caregivers. Evidence and consensus based (S3) guidelines for the treatment of primary antibody deficiencies were developed to improve the management of these patients.

METHODS

Based on a thorough analysis of current evidence (systematic literature search in PubMed; deadline November 2011) 14 recommendations were finalized during a consensus meeting in Frankfurt in November 2011 using structured consensus methods (nominal group technique). Experts were nominated by their scientific societies/patient initiatives (Tab. 1).

RESULTS

The guidelines focus on indication, practical issues and monitoring of immunoglobulin replacement therapy as well as on different routes of administration. Furthermore recommendations regarding supportive measures such as antiinfective therapy, vaccinations and physiotherapy are given. Combining literature evidence and experience of caregivers within this evidence and consensus based guidelines offers the chance to improve the quality of care for anti-body deficient patients.

Hereditary angioedema (HAE) in children and adolescents--a consensus on therapeutic strategies

Hereditary angioedema due to C1 inhibitor (C1 esterase inhibitor) deficiency (types I and II HAE-C1-INH) is a rare disease that usually presents during childhood or adolescence with intermittent episodes of potentially life-threatening angioedema. Diagnosis as early as possible is important to avoid ineffective therapies and to properly treat swelling attacks. At a consensus meeting in June 2011, pediatricians and dermatologists from Germany, Austria, and Switzerland reviewed the currently available literature, including published international consensus recommendations for HAE therapy across all age groups. Published recommendations cannot be unconditionally adopted for pediatric patients in German-speaking countries given the current approval status of HAE drugs. This article provides an overview and discusses drugs available for HAE therapy, their approval status, and study results obtained in adult and pediatric patients. Recommendations for developing appropriate treatment strategies in the management of HAE in pediatric patients in German-speaking countries are provided.Conclusion Currently, plasma-derived C1 inhibitor concentrate is considered the best available option for the treatment of acute HAE-C1-INH attacks in pediatric patients in German-speaking countries, as well as for short-term and long-term prophylaxis.

Hyperbilirubinemia and rapid fatal hepatic failure in severe combined immunodeficiency caused by adenosine deaminase deficiency (ADA-SCID)

Adenosin deaminase (ADA) deficiency is the cause for Severe Combined Immunodeficiency (SCID) in about 15% of patients with SCID, often presenting as T (-)B (-)NK (-)SCID. Treatment options for ADA-SCID are enzyme replacement, bone marrow transplantation or gene therapy. We here describe the first patient with ADA-SCID and fatal hepatic failure despite bone marrow transplantation from a 10/10 HLA identical related donor. As patients with ADA-SCID may be at yet underestimated increased risk for rapid hepatic failure we speculate whether hepatitis in ADA-SCID should lead to the immediate treatment with enzyme replacement by pegylated ADA.

A 12-year-old boy with multidrug-resistant human immunodeficiency virus type 1 successfully treated with HAART including ritonavir-boosted tipranavir oral solution and enfuvirtide

For intensively pretreated pediatric patients with human immunodeficiency virus type 1 (HIV-1) infection, the treatment options available are limited. We report the case of a highly treatment-experienced 12-year-old boy with multidrug-resistant HIV-1, who was successfully treated with highly active antiretroviral therapy (HAART) including ritonavir-boosted tipranavir oral solution, a novel non-peptic protease inhibitor, and enfuvirtide.

Apoptosis in T-lymphocyte subsets in human immunodeficiency virus-infected children measured immediately ex vivo and following in vitro activation

Phosphatidylserine molecules are translocated to the outer plasma membrane of lymphocytes undergoing apoptosis and can be detected by the binding of fluorochrome-conjugated annexin V. Using the annexin V assay, we examined CD4 and CD8 T cells from human immunodeficiency virus (HIV)-infected children for apoptosis upon isolation or following in vitro culture. Immediate ex vivo analysis or overnight culture showed significantly higher levels of apoptosis in CD8 cells than in CD4 cells. Following culture with the activating stimulus phytohemagglutinin or anti-CD3 monoclonal antibody, we observed an increase in the percentage of apoptotic CD4 cells, whereas there was no change in the rate of CD8 cell death. These results demonstrate that in HIV-infected children, CD8 apoptosis may occur at a greater rate than CD4 apoptosis in vivo; greater CD4 depletion may be observed due to more efficient mechanisms for peripheral lymphocyte replacement in the CD8 compartment. Furthermore, our data suggest that CD8 lymphocytes may be maximally activated in vivo, a condition which may lead to the exhaustion of CD8-mediated immunity. These findings clarify the differences between the CD4 and CD8 apoptotic responses to HIV.

Development of seasonal allergic rhinitis during the first 7 years of life

BACKGROUND

Against the background of the controversial discussion about an increase in allergic rhinitis in recent years, intraindividual longitudinal data is lacking for IgE-mediated seasonal allergic rhinitis (SAR). Little is known about the development of SAR in terms of prevalence and incidence rates from birth to school age.

OBJECTIVE

In a prospective birth cohort, we investigated the development of sensitization and symptoms of SAR. SAR should be defined with high specificity, and associated risk factors should be determined.

METHODS

Annual longitudinal data about seasonal allergic symptoms and sensitization was available for 587 children from birth to their seventh birthday. The definition of SAR was based on a combination of exposure-related symptoms and sensitization.

RESULTS

Up to 7 years of age, SAR developed in 15% of the children. Incidence and prevalence of symptoms and sensitization were low during early childhood (<2%) and increased steadily with age. Children in which SAR had already developed in the second year all were born in spring or early summer, resulting in at least two seasons of pollen exposure before manifestation of SAR. Risk factors assessed by multiple logistic regression analysis were male sex (odds ratio [OR] = 2.4), atopic mothers (OR = 2.6) and fathers (OR = 3.6) having allergic rhinitis themselves, first-born child (OR = 2.0), early sensitization to food (OR = 3.3), and atopic dermatitis (OR = 2.5), whereas early wheezing was not associated with SAR.

CONCLUSION

The development of SAR is characterized by a marked increase in prevalence and incidence after the second year of life. Our longitudinal data further indicate that in combination with the risk of allergic predisposition, at least 2 seasons of pollen allergen exposure are needed before allergic rhinitis becomes clinically manifest.

Association and linkage of atopic dermatitis with chromosome 13q12-14 and 5q31-33 markers

Atopic dermatitis is a chronic inflammatory skin disease that affects 10-20% of the population. Linkage of atopy, asthma, allergic rhinitis, and total serum IgE levels to several different chromosomal regions have been described extensively, but little is known about the genetic control of atopic dermatitis. We tested for the association and linkage between atopic dermatitis and five chromosomal regions: 5q31-33, 6p21.3, 12q15-24.1, 13q12-31, and 14q11.2/14q32.1-32.3. Marker analysis was performed in two Caucasian populations: (i) 192 unrelated German children with atopic dermatitis and 59 non-atopic children from a German birth cohort study (MAS'90), parental DNA was tested in 77 of 192 children with atopic dermatitis; (ii) 40 Swedish families with at least one family member with atopic dermatitis selected from the International Study of Asthma and Allergy in Children. Evidence for linkage and allelic association for atopic dermatitis was observed for markers on chromosome 13q12-14 and 5q31-33.

Glycyl-glutamine improves in vitro lymphocyte proliferation in AIDS patients

BACKGROUND

Glutamine (Gln) is a major nutrient for rapidly proliferating cells. Unlike glutamine itself, the dipeptide glycyl-glutamine as a source for Gln is stable in aqueous solutions ex vivo. In order to evaluate the possible therapeutic role of glycyl-glutamine on lymphocyte proliferation we investigated its influence on lymphocytes of AIDS patients and healthy controls under stimulation with different mitogens.

MATERIAL AND METHODS

Lymphocytes were collected from 11 adult patients suffering from AIDS according to the CDC definition and from 7 adult healthy donors. Glutamine (Gln) and glycyl-glutamine (GlyGln), respectively, were added to cell cultures at concentrations between 0 and 1.0 mmol/l. ConA or SAC served as T or B cell mitogens, respectively. Plasma amino acid levels were determined.

RESULTS

Proliferation upon ConA-stimulation with GlyGln-supplementation was similar to Gln-supplementation and peaked dose dependently at 1.0 mmol/l. When SAC was used Gln seemed slightly superior to GlyGln with a peak at 0. 4 mmol/l but the results did not reach the level of statistical significance. An identical response pattern was demonstrated in HIV-patients, however at lower absolute proliferation rates. Normal values could not be restored. Overall, the use of either source of glutamine in equimolar concentrations did not result in major differences of proliferation. Glutamine and glycin plasma levels did not differ between HIV patients and controls.

CONCLUSION

GlyGln can be used as a substitute for Gln with regard to lymphocyte proliferation. Lymphocytes from AIDS patients show, as controls do, an enhanced proliferation under supplementation either glutamine source. Supplementation of GlyGln might enhance lymphocyte proliferation and thus improve immunity.

[Mollusca contagiosa in HIV-infected children receiving optimal antiretroviral therapy]

Two children with symptomatic HIV-infection suffered from extended mollusca contagiosa. Intensified antiretroviral therapy including a protease inhibitor, resulted in a decrease of HIV RNA plasma concentration and a dramatic increase of CD4 T cells. Mollusca contagiosa nearly completely disappeared. These cases demonstrated that newly generated CD4 T cells during sufficient antiretroviral treatment have functional abilities. Therefore, sufficient antiretroviral treatment should be offered to HIV infected children with extended mollusca contagiosa before surgical intervention is considered.

Treatment-resistant expansion of CD8+CD28-cells in pediatric HIV infection

There is a disease stage-dependent loss of CD28 expression on T cells in HIV-infected children. In this study, T cell recovery, in particular CD28 expression on T cells, was analyzed after initiation of highly active antiretroviral therapy in a group of eight mostly treatment-naive HIV-infected children. Plasma HIV-RNA levels were recorded, and numbers of CD4, CD8, CD4+CD28+, and CD8+CD28+ cells were determined by two-color flow cytometry. Values after 12 mo of therapy were compared with age-matched, seronegative control subjects. CD4 recovery to subnormal values was observed in all children. CD8+CD28+ cells recovered and were within the normal range after 12 mo of therapy (patients, 703 +/- 250 cells/microL; controls, 789 +/- 269 cells/microL), whereas CD8+CD28- cells (546 +/- 269 cells/microL) remained significantly expanded compared with age-matched controls (140 +/- 35 cells/microL). Expansions of CD8+CD28- cells persisted even in cases with long-term suppression of viral replication. Highly active antiretroviral therapy in HIV-infected children induces substantial but incomplete T cell recovery.

Diversity, functionality, and stability of the T cell repertoire derived in vivo from a single human T cell precursor

In this report, we have analyzed the human T cell repertoire derived in vivo from a single T cell precursor. A unique case of X-linked severe combined immunodeficiency in which a reverse mutation occurred in an early T cell precursor was analyzed to this end. It was determined that at least 1,000 T cell clones with unique T cell receptor-beta sequences were generated from this precursor. This diversity seems to be stable over time and provides protection from infections in vivo. A similar estimation was obtained in an in vitro murine model of T cell generation from a single cell precursor. Overall, our results document the large diversity potential of T cell precursors and provide a rationale for gene therapy of the block of T cell development.

[Polysaccharide specific humoral immunodeficiency in ectodermal dysplasia. Case report of a boy with two affected brothers]

We report a now three year old male patient with ectodermal dysplasia and a polysaccharide specific humoral immunodeficiency. Immunological investigations showed compromised production of IgA, IgM, and IgG2. Isohaemagglutinins still were not detectable at the age of three years. Repeated vaccination with polyvalent pneumococcal polysaccharide vaccine did not result in production of specific antibodies. Two brothers showed clinical signs of ectodermal dysplasia. The elder brother died from pneumococcal sepsis at the age of 3 years. The younger brother suffers from chronic inflammatory gastrointestinal disease with ulcerations in all parts of the gastrointestinal system. Thus, a possible association between polysaccharide specific humoral immunodeficiency and ectodermal dysplasia may be considered.

Genetic linkage of HLA-class II locus to mite-specific IgE immune responsiveness

BACKGROUND

IgE response to common inhalant allergens seems to be the major determinant of the development of atopic rhinitis and asthma but it has been difficult to demonstrate genetic control of the IgE response.

OBJECTIVE

To investigate genetic linkage between specific IgE reactions to purified aero-allergens (grass, birch, cat, mite) and the HLA-class II locus.

METHODS

DNA-based HLA-class II typing was performed for determination of DRB1, DQB1 and DPB1 alleles. Linkage was studied by the affected sibpair method and the extended transmission disequilibrium test in 100 children from 40 nuclear families selected from a homogeneous population in south-western Germany.

RESULTS

Significant linkage of mite-specific IgE response to HLA-DPB (P = 0.00001), HLA-DRB (0.02) and HLA-DQB (P = 0.001) was revealed by sibpair analysis of MHC class II alleles and confirmed by the extended transmission disequilibrium test for HLA-DRB (P = 0.01) and HLA-DPB (P = 0.04). No consistent significant linkage between the HLA-class II locus and IgE response to grass pollen, birch pollen, and cat dander could be demonstrated.

CONCLUSION

The findings are consistent with the existence of one or more genes in the HLA-class II region modifying the IgE immune response to common environmental allergens.

Natural course of sensitization to food and inhalant allergens during the first 6 years of life

BACKGROUND

Specific IgE antibody responses to alimentary and environmental allergens are one of the hallmarks of atopic diseases. The knowledge of the time course of allergic sensitization during early life may facilitate measures for preventive interventions.

OBJECTIVE

In a prospective birth cohort study (the Multicenter Allergy Study [MAS]) we investigated annual incidence and prevalence rates of sensitization to food and inhalant allergens during the first 6 years of life.

METHODS

For 216 children of a prospective birth cohort (MAS), a complete follow-up of specific IgE measurements to 9 food and inhalant allergens was available at 1, 2, 3, 5, and 6 years of age. On the basis of these measurements, sensitization rates were estimated for the reference population of 4082 children by weighted analysis.

RESULTS

Annual incidence rates of sensitization to food allergens decreased from 10% at 1 year of age to 3% at the 6 years of age. Incidences of sensitization to inhalant allergen, however, increased with age (from 1.5% at 1 year to 8% at 6 years). Point prevalences of allergic sensitization to at least 1 of the 9 tested allergens increased from 11% at 1 year up to 30% at 6 years. This increase was due to markedly increasing sensitization rates to inhalant allergens (1.5% to at least 1 inhalant allergen at 1 year and 26% at 6 years of age), whereas sensitization rates to food allergens remained stable during the first 6 years of life (10%).

CONCLUSION

The earliest serologic marker for atopic immunoreactivity in infancy is the presence of IgE antibodies to egg, followed by milk. The development of sensitization to inhalant allergens occurs mostly after infancy. Beyond the third birthday annual incidence and prevalence increase markedly with age. Rates for outdoor allergens are twice those for indoor allergens.

Serum IgE levels during the first 6 years of life

OBJECTIVE

Total serum IgE percentiles were derived for a population-based sample of 4082 white children from Germany by weighted analysis of measurements from the Multicenter Allergy Study cohort.

METHODS

The children of a prospective birth cohort were selected from a complete 1-year sample of newborns in 6 obstetric departments in 1990. Total IgE was determined at 1, 2, 3, 5, and 6 years of age in 1160 newborns of the cohort. By weighting these measurements for sex, atopic family history, and elevated cord blood IgE, total serum IgE percentiles were estimated for the original population-based sample of 4082 children.

RESULTS

IgE levels increased by age (P <.0001). We found statistically significant higher total IgE values in boys than in girls at each age (P <.05). Within the group of atopic children, this sex difference was not statistically significant.

CONCLUSION

Our estimates of total serum IgE levels for a large population-based sample were lower than most values previously reported. We suggest that for both clinical and epidemiologic and genetic studies, IgE values should be expressed with percentiles.

Exposure to environmental tobacco smoke during the first five years of life-results of a prospective birth cohort study

Objective: To exanine links between environmental tobacco smoke (ETS)-exposure and urnary cotinine excretion during the first five years of life.

Design: Prospective birth cohiort study

Patients: 307 children from the Genran Multicenter Atopy Study (MAS-90)

Measurements and results: ETS-exposure was investigated by questionnaires about the parental smoking habits at home and by analysis of urinary cotinine exacetion by the children at 1 year, 4 years and 5 years of age (capillary gas-chromatography).

Results: From age 1 year to age 5 five years, the proportion of children growig up in smoker households remiained nearly constant (42%). However, 17% of the initial smoker households changed to non smoker households and vice versa. Within the smoker housholds the percentage of smoldng mothers increased from 19.9% to 25.7% and the percentage of smoking fathers decreased from 29.7% to 20.7%. 77% of the mothers and 60% of the fathers smoldng in the households when the child was 1 year old smoked continuously until children were 5 years old. The daily number of cigarettes smoked in the smoker households remained nearly constant (mean value: 6 cig/day).

Urnary cotinine excretion of the ETS-exposed children was found to peak at 1 year of age, decreasing significantly to 5 years of age (p = 0.02). From age 1 year to age 5 years there was a significant correlation between the urinary cotinine excretion of the children and the number of daily cigarettes smoked in the households (p < 0.01). At age 1 year, cotinine excretion was further influenced by the season of the year, the size of domestic apartment and the presence of an atopic mother. At age 5 years, cotinine excretion of the children living in smoker households and attending a kindergarten was significantly lower than that of children living in smoker households but not attending a kindergarten (< O.000 1).

Conclusion: Our results show that ETS-exposure passes through a peak during infancy. This suggests, that the reduced association between ETS-exposure and respiratory symptoms in children after age 2 years reported by earlier studies is due to an agedependent reduction of the ETS-exposure.

Preliminary experiences with ritonavir in children with advanced HIV infection

The aim of this study was to obtain information on the feasibility (tolerance, safety) of antiretroviral combination therapy, including ritonavir, in children. In eight children (median age 8.9 years; range 3 to 13 years) with advanced HIV disease (median CD4+ lymphocyte count at baseline, 80 cells/microliter; range 0 to 280 cells/ microliter), drug combinations including ritonavir (approximately 300 mg/m2 b.i.d.) were administered. In seven children, previous therapy using a combination of at least two nucleoside reverse transcriptase inhibitors (NRTI) had failed. Four patients had ritonavir added to an already existing regimen of two NRTI; two patients had one NRTI replaced by a new one; and in two patients two new NRTI were initiated. The number of CD4 T cells, plasma HIV RNA concentration, CBC and blood chemistry profile were monitored. Medication had to be discontinued in two children because of severe nausea and vomiting. In the remaining six children, ritonavir was tolerated and treatment was maintained for at least 6 months. The number of CD4 cells increased in five of six patients. The median number of CD4 cells increased from 66 +/- 110 cells/microliter at baseline to 92 +/- 99 cells/microliter, 161 +/- 88 cells/microliter, and 252 +/- 25 cells/microliter after 1, 3 and 6 months of therapy, respectively. The plasma HIV RNA concentration decreased below the detection limit of 500 copies/ml in three children. In the remaining children a maximum reduction of 0.8, 1.0 and 1.8 log10 was observed. In one child the HIV RNA concentration reincreased after 6 months by 0.7 log10 above the nadir. Antiretroviral combinations including ritonavir were tolerated by six of eight children and produced substantial benefits with respect to increased numbers of CD4 cells and a decline in plasma viral RNA concentration. It can be concluded that the administration of ritonavir is possible in a significant proportion of HIV-infected children, and leads to improvement of the CD4 cell count and viral load.

CD28 expression in pediatric human immunodeficiency virus infection

Increased apoptosis of lymphocytes represents a key event of immune destruction in HIV infection. In this study it was investigated at which stage of the disease and in which T lymphocyte subpopulation (CD4+ or CD8+) protection against apoptosis may be lost as measured by decreased CD28 expression. In 26 HIV-infected and 20 healthy children, as well as 10 infants exposed to HIV, expression of CD28 and the apoptosis-related marker CD95 was studied by fluorescence-activated cell sorting analysis. According to established Centers for Disease Control and Prevention definitions, children were divided into three immunologic categories. In the CD8 population, patients in category 1 already showed a markedly decreased mean CD28 (36.2%+/-16.1 SD) and increased CD95 expression (48.8+/-24.1%), compared with the age-matched control group (67.7+/-14.4%, 15.8+/-8.9%). In the CD4 population, mean CD28 and CD95 expression was not altered in category 1 patients. Of the exposed children, the child with the lowest CD28 expression on CD8 cells was determined later to be infected with HIV. Significant immunophenotypical alterations are observed in early stage pediatric HIV infection, which may indicate an early loss of protection against apoptosis in the CD8+ T cell population.

Reverse mutations--spontaneous amelioration or cure of inherited disorders?

Some recent publications indicate that inherited disorders can ameliorate or possibly disappear if mutations responsible for the disease revert to normal. This review tries to summarize our current knowledge about reverse mutations as this information may be of special interest for attempts at somatic gene therapy.

Atopic dermatitis in early infancy predicts allergic airway disease at 5 years

BACKGROUND

Screening tests for atopy risk in newborns have a low predictive value. If early atopic symptoms and signs could be used as predictors for the next expected atopic disorder then secondary prevention could be employed. The aim of this study was to evaluate the capacity of early atopic dermatitis to predict aeroallergen sensitization and the manifestation of respiratory atopic disorders at 5 years of age.

METHODS

1314 children of a German prospective birth cohort study MAS-90 were followed from birth up to 5 years of age. Atopic dermatitis, asthma and rhinoconjunctivitis were diagnosed from symptoms and signs at physical examinations and by interviews of the parents. Blood was drawn at 1, 2, 3, and 5 years of age. Aeroallergen sensitization was diagnosed by a specific IgE value of at least 0.35 kU/L (CAP class > or = 1) against any of five respiratory allergens (mite, cat, dog, birch, grass).

RESULTS

Atopic dermatitis in the first 3 months was a risk factor for aeroallergen sensitization at 5 years. The risk increased with a positive family history for atopic diseases. Seventy-seven per cent of children with two atopic parents and early atopic dermatitis were sensitized against aeroallergens at 5 years, i.e. could have been predicted in early infancy without any laboratory tests. Although these risk factors were also significantly associated with the manifestation of allergic airway disease, the positive predictive value for this outcome at age 5 years was not yet as high, i.e. 50%.

CONCLUSION

Infants with very early signs of atopic dermatitis and a positive family history are candidates for early intervention measures against respiratory allergies.

Cord blood-IgE as risk factor and predictor for atopic diseases

BACKGROUND

Cord blood-IgE as risk factor or predictor for atopic diseases in infants has been discussed in a large number of papers with contradictory results. Our aim was to evaluate cord blood-IgE as risk factor and predictor for atopic dermatitis, recurrent wheezing and sensitization with emphasis on a clear-cut distinction between risk factor and predictor.

METHODS

A cohort of 1314 newborns was recruited in six German obstetric departments and followed-up for 5 years. Four hundred and ninety-nine infants (38%) were considered to be at high risk with at least two atopic family members and/or a cord blood-IgE value above the threshold of 0.9 kU/L. At follow-up visits, parents filled in a questionnaire, the infants were clinically examined, and blood samples were taken.

RESULTS

With regard to early onset atopic dermatitis up to 12 months we found that the odds ratios at the cord blood-IgE cut-off points of 0.70 kU/L and 1.25 kU/L with values of 0.53 and 0.32, respectively, were smaller than one (i.e. protective factors) and highly statistically significant. No significant association was found between elevated cord blood-IgE and recurrent wheezing. There was a strong positive association between elevated cord blood-IgE levels and sensitization at 12 months, but even in this case the predictive performance was rather poor: a maximum positive predictive value of 42% was attained with a cut-off point of 3.0 kU/L, but the sensitivity was only 10%.

CONCLUSION

We conclude that even when elevated cord blood-IgE levels are identified as a strong risk factor for sensitization, their poor predictive performance may make them useless as a basis for preventive measures.

Pilot study of zidovudine-lamivudine combination therapy in vertically HIV-infected antiretroviral-naive children

OBJECTIVE

To examine tolerance and efficacy of a zidovudine plus lamivudine combination in HIV-infected children without previous exposure to antiretroviral drugs.

METHODS

Thirteen vertically infected children (aged 4 months to 10 years) were treated with zidovudine (approximately 100 mg/m2 three times daily) and lamivudine (4 mg/kg twice daily). CD4 T-cell count, plasma HIV RNA concentration, complete blood count and blood chemistry profile were monitored before treatment and at months 1, 3 and 6.

RESULTS

In general, treatment was well tolerated. One child developed slight neutropenia in the presence of antineutrophil antibodies. CD4 cell count increased from 851+/-621 x 10(6)/l at baseline to 1073+/-945 x 10(6)/l at month 3 (P < 0.05) and to 1133+/-728 x 10(6)/l at month 6 (P = 0.01). CD4+ cell count increased in 10 patients after 3 months and in 11 patients treated for 6 months. One child showed a continuous decrease of CD4 cells despite treatment. Before treatment the plasma HIV RNA concentration was elevated in nine children (> 4.0 log10 copies/ml) and decreased in all of them: by month 1, the mean reduction was -1.16 log10 copies/ml; by month 3, -1.38 log10 copies/ml; and by month 6, -1.53 log10 copies/ml compared with baseline. However, one child showed steadily increasing viral load from 2.7 log10 copies/ml to a maximum of 4.52 log10 copies/ml, surprisingly in association with increasing numbers of CD4 cells. This child was switched to a new combination regimen after 6 months of treatment. Plasma HIV RNA levels below limit of detection were reached in six patients: after 1 month of treatment in one patient, after 3 months in five patients, and after 6 months in six patients. There was a mean reduction of viral load from 4.56 log10+/-4.63 log10 copies/ml (n = 13) to 3.8 log10+/-3.9 log10 copies/ml (P < 0.05; n = 9) after 1 month, to 3.67 log10+/-3.88 log10 copies/ml (P < 0.01; n = 13) after 3 months, and to 3.64 log10+/-3.95 log10 copies/ml after 6 months of treatment (P < 0.001; n = 13).

CONCLUSIONS

This pilot study demonstrates the feasibility of zidovudine-lamivudine combination in children not previously exposed to antiretroviral drugs. This promising combination should therefore be evaluated in larger trials.

Antimicrobial functions of human monocytes depend on concentration of glutamine in vitro

We investigated the impact of different concentrations of glycyl glutamine on antimicrobial functions of human monocytes in vitro. Generation of suproxide anion, phagocytosis and killing capacity were measured as an expression of antimicrobial activity after an incubation period of 38 h at glycyl glutamine concentrations of 0.0, 0.4, and 2.0 mmol/l respectively. For each of the tests, significantly higher results were obtained with concentrations of glycyl glutamine of 0.4 mmol/l as compared to 0.0 mmol/l (p < 0.01). Further increases of superoxide anion production (p < 0.05) and killing capacity (p = 0.053) were observed when glycyl glutamine concentration in the culture medium was raised to 2.0 mmol/l. Variation of glycyl glutamine concentrations in vitro significantly affects antimicrobial functions of human monocytes.