Differences in innate cytokine responses between European and African children

Schistosomiasis in Gabon from 2000 to 2021 - A review

INTRODUCTION

Schistosomiasis is a public health issue of concern in Gabon, with the disease being reported from all regions of the country. The topic has been of interest for the local researchers and physicians for over two decades. The objective of this narrative review was to provide an overview of the research activities in the area from 2000 to early 2021.

METHODS

We performed a narrative literature review. The search strategy was designed to get a broad overview of the different research topics on schistosomiasis and the national control programme, and included grey literature.

RESULTS

A total of 159 articles was screened, and 42 were included into the review in addition to the grey literature. During the past two decades, the work on schistosomiasis originated from five out of the nine provinces of the country, with diverse aspects of the disease investigated; including immunology, epidemiology, diagnosis and treatment. Several studies investigated various aspects of schistosomiasis-related morbidity in the respective study populations. The body of work demonstrates that much effort was made to understand the details of the host immune response to schistosomiasis, and the immune profile changes induced in patients treated with praziquantel. Although some MDA campaigns were conducted in the country; little, however, is known on the epidemiological situation of the disease, particularly of its distribution within the population, as well as co-infections with other parasitic diseases also endemic in the area.

CONCLUSION

Progress has been made over the past two decades in the understanding of schistosomiasis in the country, including disease-related morbidity and its interaction with other parasitic infections, and the immunology and epidemiology of the disease. However, for optimising control of the disease, there is a need to fine-tune these findings with detailed local epidemiological and malacological data. We call for such studies to accomplish the knowledge of schistosomiasis in the country, particularly in areas of moderate or high endemicity, and recommend this approach to comparable schistosomiasis-endemic areas elsewhere.

A functional genomics approach in Tanzanian population identifies distinct genetic regulators of cytokine production compared to European population

Humans exhibit remarkable interindividual and interpopulation immune response variability upon microbial challenges. Cytokines play a vital role in regulating inflammation and immune responses, but dysregulation of cytokine responses has been implicated in different disease states. Host genetic factors were previously shown to significantly impact cytokine response heterogeneity mainly in European-based studies, but it is unclear whether these findings are transferable to non-European individuals. Here, we aimed to identify genetic variants modulating cytokine responses in healthy adults of East African ancestry from Tanzania. We leveraged both cytokine and genetic data and performed genome-wide cytokine quantitative trait loci (cQTLs) mapping. The results were compared with another cohort of healthy adults of Western European ancestry via direct overlap and functional enrichment analyses. We also performed meta-analyses to identify cQTLs with congruent effect direction in both populations. In the Tanzanians, cQTL mapping identified 80 independent suggestive loci and one genome-wide significant locus (TBC1D22A) at chromosome 22; SNP rs12169244 was associated with IL-1b release after Salmonella enteritidis stimulation. Remarkably, the identified cQTLs varied significantly when compared to the European cohort, and there was a very limited percentage of overlap (1.6% to 1.9%). We further observed ancestry-specific pathways regulating induced cytokine responses, and there was significant enrichment of the interferon pathway specifically in the Tanzanians. Furthermore, contrary to the Europeans, genetic variants in the TLR10-TLR1-TLR6 locus showed no effect on cytokine response. Our data reveal both ancestry-specific effects of genetic variants and pathways on cytokine response heterogeneity, hence arguing for the importance of initiatives to include diverse populations into genomics research.

Inflammatory cytokine responses in children with asymptomatic malaria infection living in rural, semi-urban and urban areas in south-eastern Gabon

Cytokines are soluble mediators of the immune response, and their evolution influences the disease outcome. Gaining knowledge on cytokines has become important, as they can constitute biomarkers allowing the diagnosis of malaria and preventing severe forms of the disease. Here, we investigated 10 cytokines and their circulating levels in asymptomatic Gabonese children with Plasmodium falciparum infection living in urban, semi-urban and rural areas. Blood samples were collected from 273 schoolchildren (153 uninfected and 120 infected) aged 6 to 192 months. Hematological parameters were determined and P. falciparum diagnosis was performed using a rapid diagnosis test, microscopy and nested polymerase chain reaction (PCR). Plasma pro- [interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-12p70, IL-17A and IL-22] and anti-inflammatory [IL-10, IL-4, IL-13 and transforming growth factor (TGF)-β] cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA) and compared between asymptomatic-infected and uninfected children. Results revealed that without distinction of area, IL-10 and IL-6 levels were higher in infected compared to uninfected children; however, the pro- and anti-inflammatory ratios (IL-6/IL-10 and TNF-α/IL-10) were similar. Furthermore, with area distinction significantly elevated levels of IL-10 in these asymptomatic children were always accompanied by either significantly low or high levels of a proinflammatory cytokine. Also, comparison between asymptomatic-infected children from the three areas showed significantly lower IL-17A, IL-22 and TGF-β levels in urban area compared to semi-urban and rural areas. These results suggest that asymptomatic malaria infections induce significantly high inflammatory cytokine levels without modifying the balanced between pro- and anti-inflammatory cytokines and underline the higher exposure to infections of children in rural areas.

Activity of the Toll-like receptor ligands in children with high and low socioeconomic backgrounds

BACKGROUND

Adjuvants are essential in the induction of immunity by vaccines and interact with receptors, including the Toll-like receptors (TLRs). Responsiveness of these receptors differs between and within populations, which impacts vaccine effectiveness.

OBJECTIVE

Here we examine how the innate cytokine response towards TLR ligands differs between high and low socioeconomic status (SES) school-aged children from Makassar, Indonesia.

METHODS

We stimulated whole blood from children, of which 27 attended a high SES school and 27 children a low SES school, with ligands for TLR-2/1, -2/6, -3, -4, -5, -7, -9 and measured pro- (TNF) and anti-inflammatory (IL-10) cytokines released.

RESULTS

In the low SES there is an increased pro-inflammatory response after 24 h stimulation with TLR-2/1 ligand Pam3 and TLR-4 ligand LPS compared to the high SES. Comparison of the response to LPS after 24 h versus 72 h stimulation revealed that the pro-inflammatory response in the low SES after 24 h shifts to an anti-inflammatory response, whereas in the high SES the initial anti-inflammatory response shifts to a strong pro-inflammatory response after 72 h stimulation.

CONCLUSION

We observed differences in the TLR-mediated innate immune response between children attending low and high SES schools, which can have important implications for vaccine development.

Population differences in vaccine responses (POPVAC): scientific rationale and cross-cutting analyses for three linked, randomised controlled trials assessing the role, reversibility and mediators of immunomodulation by chronic infections in the tropics

INTRODUCTION

Vaccine-specific immune responses vary between populations and are often impaired in low income, rural settings. Drivers of these differences are not fully elucidated, hampering identification of strategies for optimising vaccine effectiveness. We hypothesise that urban-rural (and regional and international) differences in vaccine responses are mediated to an important extent by differential exposure to chronic infections, particularly parasitic infections.

METHODS AND ANALYSIS

Three related trials sharing core elements of study design and procedures (allowing comparison of outcomes across the trials) will test the effects of (1) individually randomised intervention against schistosomiasis (trial A) and malaria (trial B), and (2) Bacillus Calmette-Guérin (BCG) revaccination (trial C), on a common set of vaccine responses. We will enrol adolescents from Ugandan schools in rural high-schistosomiasis (trial A) and rural high-malaria (trial B) settings and from an established urban birth cohort (trial C). All participants will receive BCG on day '0'; yellow fever, oral typhoid and human papilloma virus (HPV) vaccines at week 4; and HPV and tetanus/diphtheria booster vaccine at week 28. Primary outcomes are BCG-specific IFN-γ responses (8 weeks after BCG) and for other vaccines, antibody responses to key vaccine antigens at 4 weeks after immunisation. Secondary analyses will determine effects of interventions on correlates of protective immunity, vaccine response waning, priming versus boosting immunisations, and parasite infection status and intensity. Overarching analyses will compare outcomes between the three trial settings. Sample archives will offer opportunities for exploratory evaluation of the role of immunological and 'trans-kingdom' mediators in parasite modulation of vaccine-specific responses.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from relevant Ugandan and UK ethics committees. Results will be shared with Uganda Ministry of Health, relevant district councils, community leaders and study participants. Further dissemination will be done through conference proceedings and publications.

TRIAL REGISTRATION NUMBERS

ISRCTN60517191, ISRCTN62041885, ISRCTN10482904.

Kawasaki Disease and Clinical Outcome Disparities Among Black Children

OBJECTIVE

To determine whether Black children with Kawasaki disease exhibit disparities in prevalence, sequelae, and response to intravenous gamma globulin (IVIG) treatment.

STUDY DESIGN

International Classification of Diseases codes were used to identify children with Kawasaki disease admitted to a tertiary center in the southeastern US. Subjects diagnosed and treated according to American Heart Association criteria were included. Demographic, laboratory, clinical, and echocardiographic data from the electronic medical record (2000-2015) were compared between Blacks and Whites.

RESULTS

Data from 369 subjects (52% Whites and 48% Blacks) were included in our analysis. No significant differences related to timely admission, IVIG treatment, or coronary artery (CA) abnormalities during hospitalization were observed. Blacks showed lower IVIG response rates than Whites for patients administered IVIG within 10 days of fever onset (86.6% vs 95.6%; P = .007). Blacks received more ancillary drugs (9.6% vs 2.6%; P = .003), and endured longer hospitalizations (mean, 5 ± 3.9 days vs 3.4 ± 2.2 days; P = .001). Blacks presented with higher C-reactive protein level and erythrocyte sedimentation rate and lower hemoglobin, albumin, and sodium levels. Blacks had a higher proportion of persistent CA abnormalities than Whites at second follow-up echocardiogram (14.5% vs 6.3%; P = .03), and at third follow-up echocardiogram (21.2% vs 6.9%; P = .01).

CONCLUSIONS

Compared with White children, Black children with Kawasaki disease had higher IVIG refractory prevalence, more severe inflammation, more ancillary treatments, and longer hospitalizations. Despite no racial differences in time to diagnosis or initial treatment, there was greater CA abnormality persistence among Black children at follow-up.

Paracoccidioimycosis and white individuals: Susceptibility and biogeographic aspects in an important endemic area in Brazil

Paracoccidioidomycosis (PCM) is a neglected mycosis most commonly occurring in Latin America. The etiologic agents are thermo dimorphic fungi of the genus Paracoccidioides, and cause an important granulomatous response in affected tissues. The Botucatu Medical School, from São Paulo State University (UNESP), is a PCM study pole, located in São Paulo State Midwest region, which is classified as a hyperendemic area in the Southeast region in Brazil. This study aimed to perform a retrospective epidemiological, geographical, and clinical analysis by the information available in medical records. It was listed as socio-demographic data along with clinical characteristics from patients diagnosed and treated during a 10-year period in Botucatu, totaling 177 patients with Paracoccidioidomycosis confirmed by the histopathological test. It was observed that the main clinical presentation was the chronic type (76,3%), most commonly identified in white male individuals over the age of 29 years old, smokers, and alcoholics, providing evidences for the first time that white individuals were more affected by the disease, in comparison to non-white individuals that may be more resistant to infection. This data opens new avenues for study within ancestry, resistance and susceptibility in paracoccidioidomycosis.

The conundrum of human immune system "senescence"

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Biomarkers of human immunosenescence are discussed.

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Longitudinal studies are essential.

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Associations of immune markers in older adults with clinical outcome are context-dependent.

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There are no universal biomarkers of human immunosenescence.

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There are common age-associated changes to peripheral immune markers in humans.

There is a great deal of debate on the question of whether or not we know what ageing is (Ref. Cohen et al., 2020). Here, we consider what we believe to be the especially confused and confusing case of the ageing of the human immune system, commonly referred to as “immunosenescence”. But what exactly is meant by this term? It has been used loosely in the literature, resulting in a certain degree of confusion as to its definition and implications. Here, we argue that only those differences in immune parameters between younger and older adults that are associated in some definitive manner with detrimental health outcomes and/or impaired survival prospects should be classed as indicators of immunosenescence in the strictest sense of the word, and that in humans we know remarkably little about their identity. Such biomarkers of immunosenescence may nonetheless indicate beneficial effects in other contexts, consistent with the notion of antagonistic pleiotropy. Identifying what could be true immunosenescence in this respect requires examining: (1) what appears to correlate with age, though generality across human populations is not yet confirmed; (2) what clearly is part of a suite of canonical changes in the immune system that happen with age; (3) which subset of those changes accelerates rather than slows aging; and (4) all changes, potentially population-specific, that accelerate agig. This remains an immense challenge. These questions acquire an added urgency in the current SARS-CoV-2 pandemic, given the clearly greater susceptibility of older adults to COVID-19.

Epidemiology of Schistosomiasis and Soil-Transmitted Helminth Coinfections among Schoolchildren Living in Lambaréné, Gabon

Schistosomiasis is a parasitic infection highly prevalent in Central Africa where it is co-endemic with many other parasitic infections, including soil-transmitted helminths (STHs). For its optimal control, there is a need of descriptive epidemiological data for each endemic region. The objective of the present study was to determine the epidemiological situation around schistosomiasis in Lambaréné, Gabon. A cross-sectional study was conducted among schoolchildren. One urine sample per day was collected on three consecutive days for the diagnosis of schistosomiasis using a urine filtration technique. One stool sample was collected for the detection of Schistosoma spp. and STH spp. eggs using the Kato-Katz technique, and for larvae, using the coproculture technique. A total of 614 schoolchildren were included in the analysis. The overall prevalence of schistosomiasis and STH infections was 26% (159/614) and 15% (70/473), respectively. Human-freshwater contact was the main risk factor for schistosomiasis in the area (relative risk (RR) = 2.96 [2.20-4.00], P < 0.001). Hematuria (RR = 5.53 [4.30-7.10], P < 0.001) and proteinuria (RR = 2.12 [1.63-2.75], P < 0.001) as well as infection with Trichuris trichiura (RR = 1.86 [1.33-2.61], P = 0.002) and Ascaris lumbricoides (RR = 1.96 [1.19-3.21], P = 0.039) were associated with an increased risk of schistosomiasis. Trichuris trichiura was the highest prevalent STH species in the area. Our study reports a moderate prevalence for schistosomiasis with human-water contact as the main risk factor, whereas the prevalence of STH infections appears to be low. Our results stress the need for the implementation of WHO recommendations for schistosomiasis control.

Platelet and hemoglobin count at diagnosis are associated with survival in African American and Caucasian patients with colorectal cancer

BACKGROUND

African Americans (AAs) compared to Caucasian Americans (CAs) with colorectal cancer (CRC) have lower stage-specific survival. CRC patients often present with several hematopathologies (such as thrombocytosis, thrombocytopenia, anemia) at diagnosis, which is associated with poorer survival. However, whether these measures impact the racial disparity in survival is not known.

METHODS

The study population was composed of 581 histologically confirmed CRCs at the Medical University of South Carolina (393 CA, 188 AA) diagnosed between 01/01/2000 and 06/30/2013. We used Cox proportional hazards regression to estimate the association between thrombocytosis, thrombocytopenia, or anemia at diagnosis and risk of death by race. This analysis was adjusted for age, sex, stage and first-line treatment.

RESULTS

In all patients combined, thrombocytosis, thrombocytopenia, and anemia (vs. the normal ranges) were associated with significantly higher risks of death. In the race-specific analyses, AAs (HR 2.51 [95 % CI: 1.52-4.15]) vs. CAs (HR 1.15 [95 % CI: 0.75-1.75]) with thrombocytosis compared to normal had a higher risk of death (p for difference = 0.03).

CONCLUSIONS

Abnormal thrombocyte and hemoglobin levels at diagnosis were associated with poorer survival. AAs compared to CAs with elevated platelets at diagnosis had a higher risk of death. Our study is the first to examine the role of race, hematologic measures at diagnosis, and risk of death in colorectal cancer patients. These results suggest that the racial differences in the immune response may contribute to the racial disparity in survival.

Characterization of biological variation of peripheral blood immune cytome in an Indian cohort

Immune parameters show characteristic normal baseline levels and variance in the population. We characterised the degree of inter-individual and within-individual variation over one-year time period in 33 immune cell subsets by flow cytometry in peripheral blood mononuclear cells from 43 healthy young adult volunteers. Our analysis revealed that immune subsets that showed low variability between individuals also showed low short-term fluctuations within-individuals, as well as concordance in siblings. However, when baseline levels and degree of fluctuation were considered together, individuals failed to cluster into discreet groups. Together, the data reveal complex inter-relationships between immune subsets in individuals, and provide insights into the observed heterogeneity between individuals and between multiple immune subsets.

[Research advances in the pathogenesis of familial Kawasaki disease]

Kawasaki disease has become the leading cause of acquired heart disease in children in North America and Japan. The incidence rate of Kawasaki disease varies significantly across regions and races. The first-degree relatives of patients with Kawasaki disease have a significantly higher risk of this disease than the general population. This article reviews the onset of familial Kawasaki disease and possible pathogenesis.

Tumor-Infiltrating Lymphocytes and Colorectal Cancer Survival in African American and Caucasian Patients

Background: Compared with Caucasian Americans (CAs), African Americans (AAs) with colorectal cancer have poorer survival, especially younger-age patients. A robust lymphocytic reaction within colorectal cancers is strongly associated with better survival, but whether immune response impacts the disparity in colorectal cancer survival is unknown.Methods: The study population was comprised of 211 histologically confirmed colorectal cancers at the Medical University of South Carolina (Charleston, SC; 159 CAs and 52 AAs) diagnosed between Jan 01, 2000, and June 30, 2013. We constructed a lymphocyte score based on blinded pathologic assessment of the four different types of lymphocytic reactions. Cox proportional hazards regression was used to evaluate the association between the lymphocyte score and risk of death by race.Results: Colorectal cancers in AAs (vs. CAs) had a stronger lymphocytic reaction at diagnosis. A high lymphocyte score (vs. the lowest) was associated with better survival in AAs [HR 0.19; 95% confidence interval (CI), 0.04-0.99] and CAs (HR 0.47; 95% CI, 0.15-1.45). AAs with no lymphocytic reaction (vs. other categories) had poor survival HR 4.48 (1.58-12.7) whereas no difference was observed in CAs. The risk of death in AAs (vs. CA) was more pronounced in younger patients (HR 2.92; 95% CI, 1.18-7.22) compared with older (HR 1.20; 95% CI, 0.54-2.67), especially those with lymphocytic poor colorectal cancers.Conclusions: The lymphocytic reaction in tumor impacted the racial disparity in survival.Impact: Our results confirm the importance of the lymphocytic score on survival and highlight the need to fully characterize the immune environment of colorectal cancers by race. Cancer Epidemiol Biomarkers Prev; 27(7); 755-61. ©2018 AACR.

The causes and consequences of variation in human cytokine production in health

Cytokines are important cell-signaling molecules that activate and modulate immune responses. Major factors influencing cytokine variation in healthy individuals are host genetics, non-heritable factors and the microbiome. Genetic variation accounts for a significant part of heterogeneity in cytokine production by peripheral blood mononuclear cells. Variation in cytokines such as IL-6 and IL-6Ra is strongly influenced by heritability, suggesting an evolutionarily pressure for their genetic regulation that potentially contributes to differences in immune responsiveness between human populations. Non-heritable factors, including age, body weight and environmental variables such as seasonality, drive variation in baseline cytokine levels. Age further affects pathogen-induced lymphocyte-derived cytokine responses, whereas seasonality affects monocyte-derived cytokine production in response to influenza virus, Coxiella burnetti or Cryptococcus neoformans. Another influential factor that shapes the immune system is the human microbiome. Microbes and microbial products (e.g. short-chain fatty acids and tryptophan metabolites) possess strong immunomodulatory effects, induce regulatory T cells and lead to the diversification of B cells and the production of specific antibodies. In particular, differential TNFα and IFNγ production is associated with the gut microbiome. Understanding causes of variation in the healthy human immune system can reveal factors that lead to aberrant cytokine production in immune-related disorders.

Postnatal Innate Immune Development: From Birth to Adulthood

It is well established that adaptive immune responses are deficient in early life, contributing to increased mortality and morbidity. The developmental trajectories of different components of innate immunity are only recently being explored. Individual molecules, cells, or pathways of innate recognition and signaling, within different compartments/anatomical sites, demonstrate variable maturation patterns. Despite some discrepancies among published data, valuable information is emerging, showing that the developmental pattern of cytokine responses during early life is age and toll-like receptor specific, and may be modified by genetic and environmental factors. Interestingly, specific environmental exposures have been linked both to innate function modifications and the occurrence of chronic inflammatory disorders, such as respiratory allergies. As these conditions are on the rise, our knowledge on innate immune development and its modulating factors needs to be expanded. Improved understanding of the sequence of events associated with disease onset and persistence will lead toward meaningful interventions. This review describes the state-of-the-art on normal postnatal innate immune ontogeny and highlights research areas that are currently explored or should be further addressed.

Lack of broad functional differences in immunity in fully vaccinated vs. unvaccinated children

BACKGROUND

Concerns have been raised that with an increase in the number of vaccines administered early in life, immune development could be altered, leading to either increased or decreased immune reactivity.

METHODS

We investigated the impact of vaccination on immune status, contrasting the immune response to general, nonantigen-specific stimuli in a cohort of entirely unvaccinated vs. fully vaccinated children at 3-5 y of age. Innate immunity was assessed by quantifying bulk and cell-type-specific cytokine production in response to stimulation with pathogen associated microbial patterns. Adaptive immune status was characterized by assessing lymphocyte proliferation and cytokine production in response to generic T cell stimuli.

RESULTS

Our investigations failed to reveal a broadly evident alteration of either innate or adaptive immunity in vaccinated children. Equivalently robust innate and adaptive responses to pathogen associated microbial patterns and generic T cell stimulants were observed in both groups.

CONCLUSION

Although our sample size was small, our data suggest that standard childhood vaccinations do not lead to long-lasting gross alterations of the immune system.

Whole genome sequencing of an African American family highlights toll like receptor 6 variants in Kawasaki disease susceptibility

Kawasaki disease (KD) is the most common acquired pediatric heart disease. We analyzed Whole Genome Sequences (WGS) from a 6-member African American family in which KD affected two of four children. We sought rare, potentially causative genotypes by sequentially applying the following WGS filters: sequence quality scores, inheritance model (recessive homozygous and compound heterozygous), predicted deleteriousness, allele frequency, genes in KD-associated pathways or with significant associations in published KD genome-wide association studies (GWAS), and with differential expression in KD blood transcriptomes. Biologically plausible genotypes were identified in twelve variants in six genes in the two affected children. The affected siblings were compound heterozygous for the rare variants p.Leu194Pro and p.Arg247Lys in Toll-like receptor 6 (TLR6), which affect TLR6 signaling. The affected children were also homozygous for three common, linked (r² = 1) intronic single nucleotide variants (SNVs) in TLR6 (rs56245262, rs56083757 and rs7669329), that have previously shown association with KD in cohorts of European descent. Using transcriptome data from pre-treatment whole blood of KD subjects (n = 146), expression quantitative trait loci (eQTL) analyses were performed. Subjects homozygous for the intronic risk allele (A allele of TLR6 rs56245262) had differential expression of Interleukin-6 (IL-6) as a function of genotype (p = 0.0007) and a higher erythrocyte sedimentation rate at diagnosis. TLR6 plays an important role in pathogen-associated molecular pattern recognition, and sequence variations may affect binding affinities that in turn influence KD susceptibility. This integrative genomic approach illustrates how the analysis of WGS in multiplex families with a complex genetic disease allows examination of both the common disease–common variant and common disease–rare variant hypotheses.

Comparison of Human Neonatal and Adult Blood Leukocyte Subset Composition Phenotypes

The human peripheral leukocyte subset composition depends on genotype variation and pre-natal and post-natal environmental influence diversity. We quantified this composition in adults and neonates, and compared the median values and dispersal ranges of various subsets in them. We confirmed higher frequencies of monocytes and regulatory T cells (Tregs), similar frequencies of neutrophils, and lower frequencies of CD8 T cells, NKT cells, B1 B cells and gamma-delta T cells in neonatal umbilical cord blood. Unlike previous reports, we found higher frequencies of eosinophils and B cells, higher CD4:CD8 ratios, lower frequencies of T cells and iNKT cells, and similar frequencies of CD4 T cells and NK cells in neonates. We characterized monocyte subsets and dendritic cell (DC) subsets in far greater detail than previously reported, using recently described surface markers and gating strategies and observed that neonates had lower frequencies of patrolling monocytes and lower myeloid dendritic cell (mDC):plasmacytoid DC (pDC) ratios. Our data contribute to South Asian reference values for these parameters. We found that dispersal ranges differ between different leukocyte subsets, suggesting differential determination of variation. Further, some subsets were more dispersed in adults than in neonates suggesting influences of postnatal sources of variation, while some show the opposite pattern suggesting influences of developmental process variation. Together, these data and analyses provide interesting biological possibilities for future exploration.

Race and 30-Day Morbidity in Pediatric Urologic Surgery

BACKGROUND AND OBJECTIVE

Quality improvement in surgery involves identifying patients at high risk for postoperative complications. We sought to assess the impact of race and procedure type on 30-day surgical morbidity in pediatric urology.

METHODS

The National Surgical Quality Improvement Program-Pediatrics (NSQIP-P) is a prospective registry of surgical cases from 50 and 56 pediatric hospitals in 2012 and 2013, respectively. We performed a cohort study of children followed in NSQIP-P who underwent urologic surgery. Forty unique operations were stratified into 6 clinically related procedure groups: ureteral, testicular, renal, urinary diversion, penile and urethral, or bladder procedures. Outcomes were 3 different composite measures of 30-day morbidity. Primary predictors were patient race and procedural group. Multivariate logistic regression was used to identify associations between race, procedure type, and postoperative morbidity.

RESULTS

Of 114 395 patients in the NSQIP-P cohort, 11 791 underwent pediatric urologic procedures. Overall 30-day complication rate was 5.9% and was higher in bladder and urinary diversion procedures. On multivariate analyses, non-Hispanic black compared with non-Hispanic white children had higher odds of 30-day overall complications (odds ratio 1.34; 95% confidence interval, 1.03-1.74) and 30-day hospital-acquired infection (odds ratio 1.54; 95% confidence interval, 1.08-2.20). Bladder and urinary diversion procedures relative to testicular procedures had significantly higher odds of surgical morbidity across all composite outcome measures.

CONCLUSIONS

Black race and bladder and urinary diversion operations were significantly associated with 30-day surgical morbidity. Future efforts should identify processes of care that decrease postoperative morbidity among children.

Childhood allergies and asthma: New insights on environmental exposures and local immunity at the lung barrier

While certain bacteria and respiratory viruses promote local inflammation and disease onset, a more diverse colonization of the different species in the (gut) microbiome may be linked to more regulatory responses and protection against asthma and allergies. These processes are also influenced in part by food intake, both targeting the composition of the gut microbiome and influencing the immune system via metabolites. Early life environmental microbial exposure also contributes to protection against asthma and allergy and is linked with an early activation of the innate immune system and the development of regulatory immune responses. Although greater mechanistic insight is needed, it is tempting to speculate that part of the environmental effect can be explained by modulation of the microbiome composition at mucosal surfaces, epithelial barrier function and/or local immunity. A review of the latest studies is provided.

Toll-Like Receptors: Ligands, Cell-Based Models, and Readouts for Receptor Action

This chapter details Toll-like receptors (TLRs) and the tools available to study their biology in vitro. Key parameters to consider before exploring TLR action such as receptor localization, signaling pathways, nature of ligands and cellular expression are introduced. Cellular models (i.e., host cells and readouts) based on the use of cell lines, primary cells, or whole blood are presented. The use of modified TLRs to circumvent some technical problems is also discussed.

Immunomodulatory activity of pidotimod administered with standard antibiotic therapy in children hospitalized for community-acquired pneumonia

BACKGROUND

Several attempts to improve immune function in young children have been made and encouraging results have been collected with pidotimod (PDT), a synthetic dipeptide molecule that seems to have immunomodulatory activity on both innate and adaptive responses. Until now, the effects of PDT on the immune system have only been studied in vivo after long-term administration to evaluate whether its immunomodulatory activity might prevent the development of infections. This study was planned to evaluate the immunomodulatory activity of PDT administered together with standard antibiotic therapy in children hospitalized for community-acquired pneumonia (CAP).

METHODS

A total of 20 children hospitalized for community-acquired pneumonia (CAP) were randomized at a 1:1 ratio to receive either standard antibiotics plus pidotimod (PDT) or standard antibiotics alone to evaluate the immunomodulatory activity of PDT. Blood samples for the evaluation of immunological parameters were drawn at the time of recruitment (T0) (i.e., before therapy administration), at T3 and T5 (i.e., 3 and 5 days after the initiation of therapy) as well as at T21 (i.e., 7 days after the therapy ended).

RESULTS

Following pneumococcal polysaccharide stimulation, the percentage of dendritic cells (DCs) expressing activation and costimulatory molecules was significantly higher in children receiving PDT plus antibiotics than in the controls. A significant increase in tumor necrosis factor-α and/or interleukin-12 secretion and expression of toll like receptor 2 was observed in PDT-treated children compared with controls; this was followed by an increased release of proinflammatory cytokines by monocytes. In the PDT-treated group, mRNA expression of antimicrobial peptides and genes involved in the inflammatory response were also augmented in comparison with the controls.

CONCLUSIONS

These results demonstrate, for the first time, that PDT administered together with standard antibiotics is associated with a favorable persistent immunomodulatory effect in children with CAP.

Cytokine and chemokine profile of the innate and adaptive immune response of Schistosoma haematobium and Plasmodium falciparum single and co-infected school-aged children from an endemic area of Lambaréné, Gabon

BACKGROUND

Helminths and malaria are among the most prevalent infectious diseases in the world. They both occur in tropical area where they often affect the same populations. There are studies suggesting an effect of helminths on malariometric indices. For example, malaria attacks as well as disease severity has been shown to be influenced by a concurrent chronic helminth infection. However, there are also studies that show no effect of concurrent helminth infections on malarial outcomes. To start addressing this issue, the effect of chronic Schistosoma haematobium infection on both the innate and adaptive immune response of Plasmodium falciparum-infected subjects was assessed in an area endemic for both these infections in Gabon.

METHOD

Subjects infected with S. haematobium and or P. falciparum, as well as a control group with neither of these infections, were recruited. For innate immune response, heparinized blood was obtained and cultured for 24 hours with a panel of TLR ligands. For adaptive immune response, PBMC was isolated and stimulated with SEB for 72 hours. Cytokines and chemokines were measured in supernatants using a multiplex beads array immunoassay. Principal Component analysis was used to assess pattern of cytokine and chemokine responses representing the innate and adaptive components of the immune system.

RESULTS

Overall it was observed that the presence of P. falciparum infection was marked by an increase in innate and adaptive immune responsiveness while S. haematobium infection was characterized by an increased chemokine profile, with at the same time, lower pro inflammatory markers. When the study subjects were split into single infected and co-infected groups no effect of S. haematobium on the immune response of P. falciparum infected subjects was observed, neither for the innate nor for the adaptive component of the immune response.

CONCLUSION

This study provides original information on the cellular immune response of S. haematobium and/or P. falciparum in infected subjects. It rules out an effect of S. haematobium on the cytokine profile of subjects co-infected with P. falciparum.