The impact of cytokine levels in young South African children with and without HIV-associated acute lower respiratory infections.

Altered host immune responses are considered to play a key role in the pathogenesis of acute lower respiratory infections (ALRI). The existing literature on cytokine responses in ALRI is largely focussed on adults from developed countries and there are few reports describing the role of cytokines in childhood ALRI, particularly in African or human immunodeficiency virus (HIV)-infected populations. To measure systemic cytokine levels in blood plasma from young South African children with and without ALRI and with and without HIV to determine associations between cytokine responses and disease status and respiratory viral identification. Blood plasma samples were collected from 106 hospitalized ALRI cases and 54 non-ALRI controls less than 2 years of age. HIV status was determined. Blood plasma concentrations of 19 cytokines, 7 chemokines, and 4 growth factors (epidermal growth factor, fibroblast growth factor-basic, hepatocyte growth factor, and vascular endothelial) were measured using The Human Cytokine 30-Plex Panel. Common respiratory viruses were identified by PCR. Mean cytokine concentrations for G-CSF, interferon (IFN)-γ, interleukin (IL)-5, and MCP-1 were significantly higher in ALRI cases than in nonrespiratory controls. Within the ALRI cases, several cytokines were higher in children with a virus compared with children without a virus. Mean cytokine concentrations for IFN-α, IFN-γ, IL-4, IL-5, IL-13, tumour necrosis factor-α, and MIP-1α were significantly lower in HIV-infected cases than in HIV-uninfected cases, while IP-10 and monokine induced by interferon-γ were significantly higher in HIV-infected cases than in HIV-uninfected cases. Certain cytokines are likely to play an important role in the host immune response to ALRI. HIV-infected children have impaired inflammatory responses to respiratory infections compared with HIV-uninfected children.

An investigation into biomarkers for the diagnosis of ABPA and aspergillus disease in cystic fibrosis.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease due to Aspergillus fumigatus (Af) which occurs in 10% of patients with cystic fibrosis (CF). ABPA is associated with increased morbidity and accelerated lung function decline; however, existing diagnostic criteria are nonspecific and diagnosis remains challenging. As ABPA is driven by Th2 inflammation, the aim of this study was to evaluate exhaled nitric oxide (FE NO ), eosinophilic cationic protein (ECP), peripheral eosinophil count, and bronchodilator response (BDR) in patients with CF. METHODS: A prospective observational cohort study of pediatric CF patients in a tertiary center. Patients had a clinical and serologic ABPA assessment, FENO , serum ECP, peripheral eosinophil count, and assessment of BDR. Patients were stratified into three groups; ABPA, Af sensitized (AFS), and non-ABPA non-Af-sensitized (non-AFS). RESULTS: A total of 62 patients were included in the study: 13% ABPA, 19% AFS, and 68% non-AFS. Mean FENO was higher in the ABPA group at 37.8 ppb compared to AFS 15.1 ppb (P = .05) and non-AFS 13.7 ppb (P = .04). Mean peripheral eosinophil count in ABPA group was also higher at 1000 cells/uL, compared to AFS 221 cells/uL (P = .03) and non-AFS 220 cells/uL (P = .03). Mean BDR in ABPA group was 13% compared to 5.5% in non-AFS (P = .01). Serum ECP was higher in patients with ABPA positive compared to the other groups, although this was not statistically significant. CONCLUSION: In children with cystic fibrosis, FENO and peripheral eosinophil counts are elevated in ABPA compared to those that are just sensitized to Aspergillus and may serve as useful diagnostic tests.

Respiratory viruses in young South African children with acute lower respiratory infections and interactions with HIV.

BACKGROUND: Human rhinovirus (RV) is the most common respiratory virus and has been associated with frequent and severe acute lower respiratory infections (ALRI). The prevalence of RV species among HIV-infected children in South Africa is unknown. OBJECTIVES: To describe the prevalence of respiratory viruses, including RV species, associated with HIV status and other clinical symptoms in children less than two years of age with and without ALRI in Pretoria, South Africa. STUDY DESIGN: Nasopharyngeal aspirates were collected from 105 hospitalized ALRI cases and 53 non-ALRI controls less than two years of age. HIV status was determined. Common respiratory viruses were identified by PCR, and RV species and genotypes were identified by semi-nested PCR, sequencing and phylogenetic tree analyses. RESULTS: Respiratory viruses were more common among ALRI cases than controls (83.8% vs. 69.2%; p=0.041). RV was the most commonly identified virus in cases with pneumonia (45.6%) or bronchiolitis (52.1%), regardless of HIV status, as well as in controls (39.6%). RV-A was identified in 26.7% of cases and 15.1% of controls while RV-C was identified in 21.0% of cases and 18.9% of controls. HIV-infected children were more likely to be diagnosed with pneumonia than bronchiolitis (p<0.01). RSV was not identified in any HIV-infected cases (n=15) compared with 30.6% of HIV-uninfected cases (n=85, p=0.013), and was identified more frequently in bronchiolitis than in pneumonia cases (43.8% vs. 12.3%; p<0.01). CONCLUSIONS: RV-A and RV-C are endemic in South African children and HIV infection may be protective against RSV and bronchiolitis.

The Relationship between Maternal Atopy and Childhood Asthma in Pretoria, South Africa.

Introduction. Asthma is the commonest chronic condition of children. Diagnosis of this condition remains difficult. Many surrogate markers are used, such as documenting evidence of atopy. Method. A random sample of asthmatic children and their mothers attending the Children's Chest and Allergy Clinic at Steve Biko Academic Hospital were enrolled. Children were classified as having atopic or nonatopic asthma. Mothers completed a questionnaire to uncover atopic features. Results. Along with their mothers, 64 children with atopic asthma and 36 with nonatopic asthma were studied. The proportion of children with atopic asthma does not differ for mothers with and without a positive SPT (P = 0.836), a history of asthma (P = 0.045), symptoms suggestive of an allergic disease (P = 1.000), or who were considered to be allergic (P = 0.806). The odds ratio of a child having atopic asthma when having a mother with a doctor diagnosed history of asthma is 4.76, but the sensitivity is low (21.9%). Conclusion. The data demonstrates that all maternal allergic or asthmatic associations are poor predictors of childhood atopic asthma. Despite the increased risk of atopic asthma in a child to a mother that has a doctor diagnosis of asthma (OR 4.76 P = 0.045), this is a poor predictor of atopic asthma (sensitivity 21.9%).