Risk factors associated with rhinitis, allergic conjunctivitis and eczema among schoolchildren in Uganda

Clarifying the effect of gut microbiota on allergic conjunctivitis risk is instrumental for predictive, preventive, and personalized medicine: a Mendelian randomization analysis

Background

Allergic conjunctivitis is an ocular immune disease which affects the conjunctiva, eyelids, and cornea. Growing evidence implicates the gut microbiota in balancing and modulating immunity response, and in the pathogenesis of allergic disease. As a result, gut microbial imbalance could be a useful indicator for allergic conjunctivitis. From the perspective of predictive, preventive, and personalized medicine (PPPM), clarifying the role of gut microbial imbalance in the development of allergic conjunctivitis could provide a window of opportunity for primary prediction, targeted prevention, and personalized treatment of the disease.

Working hypothesis and methodology

In our study, we hypothesized that individuals with microbial dysbiosis may be more susceptible to allergic conjunctivitis due to an increased inflammatory response. To verify the working hypothesis, our analysis selected genetic variants linked with gut microbiota features (N = 18,340) and allergic conjunctivitis (4513 cases, 649,376 controls) from genome-wide association studies. The inverse-variance weighted (IVW) estimate, Mendelian randomization (MR)-Egger, weighted median estimator, maximum likelihood estimator (MLE), and MR robust adjusted profile score (MR.RAPS) were employed to analyze the impact of gut microbiota on the risk of allergic conjunctivitis and identify allergic conjunctivitis-related gut microbes. Ultimately, these findings may enable the identification of individuals at risk of allergic conjunctivitis through screening of gut microbial imbalances, and allow for new targeted prevention and personalized treatment strategies.

Results

Genetic liability to Ruminococcaceae_UCG_002 (OR, 0.83; 95% CI, 0.70-0.99; P = 4.04×10^-2), Holdemanella (OR, 0.78; 95% CI, 0.64-0.96; P = 2.04×10^-2), Catenibacterium (OR, 0.69; 95% CI, 0.56-0.86; P = 1.09×10^-3), Senegalimassilia (OR, 0.71; 95% CI, 0.55-0.93; P = 1.23×10^-2) genus were associated with a low risk of allergic conjunctivitis with IVW. Besides, we found suggestive associations of a genetic-driven increase in the Oscillospira (OR, 1.41; 95% CI, 1.00-2.00; P = 4.63×10^-2) genus with a higher risk of allergic conjunctivitis. Moreover, MLE and MR.RAPS show consistent results with IVW after further validation and strengthened confidence in the true causal associations. No heterogeneity and pleiotropy was detected.

Conclusions

Our study suggests that gut microbiota may play a causal role in the development of allergic conjunctivitis and provides new insights into the microbiota-mediated mechanism of the disease. Gut microbiota may serve as a target for future predictive diagnostics, targeted prevention, and individualized therapy in allergic conjunctivitis, facilitating the transition from reactive medical services to PPPM in the management of the disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00321-9.

Effectiveness of calamine lotion as an adjunctive therapy to mometasone furoate ointment in the treatment of infant eczema: A retrospective study

This retrospective study investigated the effectiveness of calamine lotion (CL) as an adjunctive therapy to mometasone furoate ointment (MFO) in the treatment of infant eczema (IE). This retrospective study analyzed the electronic medical records of 50 IE infants. They were allocated to a treatment group or a control group, with 25 subjects in each group. All infants in both groups received MFO. In addition, infants in the treatment group underwent CL. The outcomes were effectiveness based on the eczema area and severity index, lesion area, and pruritus severity. We analyzed the outcomes before and after treatment. The results of this study showed that infants in the treatment group had more effective in effectiveness based on eczema area and severity index (P < .01), lesion area (P < .01), and pruritus severity (P = .01) than those in the control group. However, no medical records reported any adverse events in either group. The results of this study showed that CL added to MFO was more effective than MFO alone in the treatment of infants with IE.

Keratoconus in Africa: A systematic review and meta-analysis

PURPOSE

The aim of this review is to evaluate the prevalence of and factors associated with keratoconus in Africa.

METHOD

A systematic online literature search was conducted for articles on keratoconus in Africa. Meta-analysis was performed to estimate the prevalence of keratoconus in Africa. The Freeman-Tukey double arcsine transformation was used to minimize the effects of studies with extremely high or low prevalence estimates on the overall pooled estimates. Leave-one-out sensitivity analysis was used to assess the robustness of the pooled effects and potential outliers. Meta-regression was performed to explore associations between keratoconus, gender and age.

RESULTS

Twelve studies were included in the review; 5 from Egypt, 2 from South Africa, 2 from Kenya, 1 from Sudan, 1 from Ghana and 1 from Nigeria. Two studies were conducted in allergic conjunctivitis patients, 4 in keratoconus patients, 1 in contact lens service seekers, 1 in pre-LASIK patients, 1 in refractive patients and 1 in a student population. Eight studies were included in the meta-analysis. The overall prevalence estimate of keratoconus in Africa was 7.9% (95% CI: 2.5%-16.0%). The prevalence of keratoconus among males and females in Africa was estimated to be 9.3% (95% CI: 2.5%-19.5%) and 5.8% (95% CI: 1.5%-12.7%) respectively. The estimated prevalence of unilateral and bilateral keratoconus was 2.6% (95% CI: 0.4%-6.5%) and 5.8% (95% CI: 1.6%-12.3%), respectively. The estimated prevalence of mild keratoconus was 2.2% (95% CI: 0.7%-4.7%), moderate keratoconus was 3.5% (95% CI: 0.0%-11.8%) and severe keratoconus was 4.0% (95% CI: 0.0%-19.6%). There was no significant association between gender and the prevalence of keratoconus in Africa (p = 0.63), and age and the prevalence of keratoconus in Africa (p = 0.78).

CONCLUSION

The estimated prevalence of keratoconus reported here is higher than prevalence values reported in other meta-analyses or different geographical locations. This is mainly because studies included in this meta-analysis were either conducted on a cohort at high risk of keratoconus or a population with high possibility of finding keratoconus patients. There is a dearth of well-designed population-based studies on keratoconus in Africa, resulting in a lack of epidemiological information. This highlights the urgent need for research on keratoconus in Africa.

Prevalence and Risk Factors of Asthma in Preschool Children in Shanghai, China: A Cross-Sectional Study

BACKGROUND

Previous studies have shown the increasing prevalence of childhood asthma around the world as well as in China. Nevertheless, little is known about the epidemiology of asthma in preschool children. Thus, the present study investigated the prevalence and severity of asthma in Shanghai, China, and identified related risk factors for asthma in children at the age of 3-6.

METHODS

Information was obtained through the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Risk factor analysis was carried out using univariate and multivariate logistic regression. The odds ratio (OR)/adjusted odds ratio (aOR) and the 95% confidence interval (CI) were determined.

RESULTS

A total of 6,183 children (3,165 boys and 3,018 girls) covering 12 communities were included in our study, with an average age of 4.2 ± 0.7 years. The prevalence of ever asthma, current asthma, and physician-diagnosed asthma was 16.0, 11.2, and 5.3%, respectively. Parental allergic history, including rhinitis and asthma, was significantly associated with asthma symptoms. The strongest association with current asthma was paternal asthma (aOR = 5.91, 95% CI 3.87-9.01), and maternal asthma had the second strongest association with current asthma (3.85; 2.40-6.17). Among personal factors, allergic rhinitis history, eczema history, food allergy history, and antibiotic use in the first year of life were significantly associated with current asthma (aOR = 1.89, 95% CI 1.52-2.34; aOR = 1.34, 95% CI 1.09-1.64; aOR = 1.68, 95% CI 1.37-2.06; aOR = 1.53, 95% CI 1.25-1.87, respectively). More than once paracetamol use per year and per month were associated with current asthma in a dose-response manner. Additionally, female sex was an independent protective factor for ever asthma (0.82; 0.70-0.96). Among environmental factors, dampness or mildew at home was an independent risk factor for ever asthma (1.50; 1.15-1.97) and current asthma (1.63; 1.21-2.19). Floor heating system was significantly associated with ever asthma (1.57; 1.25-1.98) and current asthma (1.36; 1.04-1.78). Furthermore, dampness or mildew, infrequent house cleaning, and truck traffic in residential streets were significantly associated with asthma symptoms only in old communities, while paracetamol use in the first year of life and flooring materials were significant factors only in new communities.

CONCLUSION

The prevalence of asthma has increased among preschool children in Shanghai over the past three decades. The identified risk factors indicated the combined effects of genetic, personal, and environmental factors on asthma symptoms. Differentiated strategies should be taken for preventing asthma in old and new communities.