Comparison of immunological status of African and European cord blood mononuclear cells.

The cellular aspects of the immunologic development of the fetus during pregnancy have been studied mainly in populations living in economically well developed countries, and there is no data concerning variation of the neonatal cellular immune system in geographically distinct areas with different environments. Here, we report a comparative immunologic marker analysis of the circulating mononuclear cell subsets in unstimulated cord blood of newborns from Gabon and Austria, assessing the activation and maturation status of T and B lymphocytes as well as antigen-presenting cells. Cells and markers hypothesized to be modulated by frequent exposure to microorganisms and parasites such as regulatory T cells and the expression of toll-like receptor 2 on antigen-presenting cells were also studied. We found marked differences in terms of expression of immunologic markers between the two populations, pointing to a comparatively enhanced maturation status of the neonatal immune system in general in the African setting. The observations suggest that environmental factors, including differential exposure to pathogens as well as nutritional differences, may have substantial impact on the development of the fetal immune system.

Pregnancy-associated malaria affects toll-like receptor ligand-induced cytokine responses in cord blood.

BACKGROUND: Pregnancy-associated malaria is known to modify fetal immunity. Most previous studies have been cross-sectional in nature and have focused on the priming of acquired immune responses in utero. In this context, the influence of the timing and/or duration of placental infection with Plasmodium falciparum are unknown, and changes to innate immune responses have not been studied extensively. METHODS: Pregnant women in Gabon, where P. falciparum infection is endemic, were followed up through monthly clinical and parasitological examinations from the second trimester to delivery. Cells of neonates born to mothers who had acquired P. falciparum infection

Increased prevalence of intestinal helminth infection during pregnancy in a Sub-Saharan African community.

Gestation is a unique physiologic state that carries with it several immunologic consequences and results in changing susceptibility to various diseases. In contrast to the well recognized excess vulnerability of primiparous women to Plasmodium falciparum infection in areas of high malaria transmission, it is not known whether pregnancy is associated with a higher prevalence of helminth infection. In Lambaréné, Gabon, 105 pregnant women were recruited and matched with non-gravid female controls. The prevalence of intestinal helminths was 66% (n=58) in the pregnant participants and 36% (n=32) in the non-pregnant controls (P<0.001). In multivariate analysis the pregnancy status was an independent risk factor for being infected with intestinal helminths (AOR and 95% CI: 3.0 [1.4-5.9]). These data show a previously undescribed susceptibility pattern of pregnant women to intestinal helminth infection in a sub-Saharan African community.

Microscopic and sub-microscopic Plasmodium falciparum infection, but not inflammation caused by infection, is associated with low birth weight.

Pregnancy-associated malaria is one of the leading causes of low birth weight in malaria endemic areas. In this study, 145 parturient women residing in areas endemic for Plasmodium falciparum in Lambaréné, Gabon, were recruited into the study after delivery, and the association of maternal P. falciparum infection, inflammatory response, and birth weight was studied. At delivery, 10% (15) of the mothers (12 were positive in both peripheral and placental blood smears, 1 was positive in peripheral blood only, and 2 were positive in placenta blood only) were positive for P. falciparum by microscopy and 23% (30) by real-time polymerase chain reaction (PCR). The level of C-reactive protein (CRP) was significantly elevated in microscopically P. falciparum-positive pregnant women (34 mg/L; 95% CI: 3-458) but not in those with sub-microscopic infections (6 mg/L; 95% CI: 1-40) compared with those free of P. falciparum infection (7 mg/L; 95% CI: 1-43). In a multivariate analysis, the presence of microscopic (adjusted OR = 28.6, 95% CI = 4.8-169.0) or sub-microscopic (adjusted OR = 13.2, 95% CI = 2.4-73.0) P. falciparum infection in pregnant women and age of mothers < 21 years (adjusted OR = 9.7 CI = 1.0-89.7), but not CRP levels, were independent predictors for low birth weight. This finding may have important operational implications and emphasizes the need for appropriate diagnostic methods in studies evaluating the outcome of pregnancy-associated malaria.

Effectiveness of quinine monotherapy for the treatment of Plasmodium falciparum infection in pregnant women in Lambaréné, Gabon.

Pregnant women participating in a longitudinal immuno-epidemiologic survey in Lambaréné, Gabon, and presenting with Plasmodium falciparum parasitemia at monthly blood smear examinations were offered treatment with oral 7-day quinine monotherapy according to national health guidelines. A total of 50 pregnant women were offered 7-day oral quinine sulfate 10 mg/kg thrice daily. Clinical examinations and laboratory tests were performed on Days 28 and 56 to assess the effectiveness of this standard regimen. By Day 28, the effectiveness of the 7-day quinine regimen was 60% (95% confidence interval: 46-72%). We conclude that a 7-day course of quinine has a poor effectiveness and that alternative treatment regimens for malaria in pregnant women should be assessed.

Production of interleukin 10 and transforming growth factor beta in concomitant allergy and autoimmunity.

BACKGROUND: The immunologic relationship between T(H)1-type autoimmune disorders and T(H)2-type allergic disorders and the role of T-cell regulation in humans is as yet unclear. The regulatory cytokine production capacity of individuals with concomitant allergy and T(H)1-type autoimmunity may provide insight into the role of T-cell regulation in both disorders. OBJECTIVES: To examine the production capacity of interleukin 10 (IL-10) and transforming growth factor beta (TGF-beta), 2 regulatory cytokines, in individuals with concomitant allergic rhinitis and T(H)1-type autoimmune diagnoses and to compare that capacity with that in individuals with allergic rhinitis only and individuals with neither diagnosis. METHODS: Seventeen case subjects and 17 age-, sex-, and ethnicity-matched controls with allergic rhinitis only were recruited from an allergy clinic. Fourteen matched controls with neither diagnosis were recruited from the general population. Peripheral blood mononuclear cells were obtained and cultured with and without mitogen stimulation (lipopolysaccharide and phytohemagglutinin). Cytokine levels from culture supernatants were measured by enzyme-linked immunosorbent assay. RESULTS: Cases with allergic rhinitis and autoimmune diseases had significantly lower unstimulated day 3 IL-10 levels compared with controls with allergic rhinitis only (P = .05) and significantly lower stimulated day 5 TGF-beta levels compared with controls with neither diagnosis (P = .02). Cases had consistently lower regulatory capacity compared with both control groups, as measured by an additive index using IL-10 and TGF-beta levels. CONCLUSION: Individuals with concomitant allergic rhinitis and T(H)1-type autoimmune disorders have a lower regulatory cytokine production capacity than individuals with allergic rhinitis only and those with neither diagnosis.

Shared breastfeeding in central Africa.

In this study, shared breastfeeding is described asa novel risk factor for vertical HIV transmission. This cross-sectional survey conducted in the central African country Gabon found that 40% of lactating mothers also breastfed other children than their own, and as many children were additionally breastfed by other women. Shared breastfeeding is increasing the exposure to potentially infectious individuals and has therefore to be considered in breastfeeding recommendations.

ISAAC-based asthma and atopic symptoms among Ha Noi school children.

Childhood asthma and atopy prevalence patterns in the developing world are only beginning to be defined. No such information exists for Vietnam. Estimates would assist in anticipating health service needs as well as add to the growing database on global patterns of atopy. To estimate the prevalence of atopic symptoms in school children in Ha Noi, Vietnam, a cross-sectional survey was conducted of children aged 5- to 11-years-old in two schools using the parent self-administered International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The response rate was 66.4% (969 responses). The overall prevalence of selected symptoms were: 'ever wheezed' 24.9%, 'wheezed in past 12 months' 14.9%, 'ever had asthma' 12.1%, 'doctor-diagnosed asthma' 13.9%, 'ever experienced allergic rhinitis (AR) symptoms' 34.9%, 'AR-conjunctivitis symptoms in past 12 months' 10.7%, 'ever had hay fever' 7.8%, 'doctor-diagnosed hay fever' 11.2%, 'ever had eczema' 3.3% and 'doctor-diagnosed eczema' 3.2%. Kappa statistics demonstrated high within symptom category consistency for 'ever had asthma/doctor-diagnosed asthma' (0.728) and 'ever had eczema/doctor-diagnosed eczema' (0.906). Age and gender adjusted odds ratios (OR) were also consistently significant across wheeze and allergic rhinitis symptom categories [highest OR = 10.10 (95% CI 6.23-16.35) between allergic rhinoconjunctivitis and wheeze in past 12 months]. There is a high prevalence of ISAAC-based symptoms in school children in Ha Noi, Vietnam, often above global averages. The high level of association between atopic symptoms suggests some degree of reliability and validity. Childhood atopy symptom prevalence in Vietnam is more similar to that in developed countries rather than developing countries.