Increased subsequent risk of myasthenia gravis in children with allergic diseases

The Association Between Asthma and Risk of Myasthenia Gravis: A Systematic Review and Meta-analysis

PURPOSE

This study aimed to investigate the association between asthma and risk of myasthenia gravis (MG) using the method of systematic review and meta-analysis.

METHODS

Potentially eligible studies were identified from Medline and EMBASE databases from inception to July 2020 using search strategy that comprised terms for "Asthma" and "Myasthenia Gravis". Eligible cohort study must consist of one cohort of individuals with asthma and another cohort of individuals without asthma. Then, the study must report relative risk (RR) with 95% confidence intervals (95% CIs) of incident MG between the groups. Eligible case-control studies must include cases with MG and controls without MG. Then, the study must explore their history of asthma. Odds ratio (OR) with 95% CIs of the association between asthma status and MG must be reported. Point estimates with standard errors were retrieved from each study and were combined together using the generic inverse variance method.

RESULTS

A total of 6,835 articles were identified. After two rounds of independent review by five investigators, two cohort studies and three case-control studies met the eligibility criteria and were included into the meta-analysis. Pooled analysis showed that asthma was significantly associated with risk of MG with the pooled risk ratio of 1.38 (95% CI 1.02-1.86). Funnel plot was symmetric, which was not suggestive of publication bias.

CONCLUSION

The current study found a significant association between asthma and increased risk of MG.

Incidence and Ocular Features of Pediatric Myasthenias

PURPOSE

To report the incidence, demographics, and ocular findings of children with myasthenia.

DESIGN

Retrospective cohort study.

METHODS

The medical records of all children (<19 years) examined at Mayo Clinic with any form of myasthenia from January 1 1966, through December 31, 2015, were retrospectively reviewed.

RESULTS

A total of 364 children were evaluated during the study period, of which 6 children were residents of the Olmsted County at the time of their diagnosis, yielding an annual age- and sex-adjusted incidence of 0.35 per 100 000 <19 years, or 1 in 285 714 <19 years. The incidence of juvenile myasthenia gravis (JMG) and congenital myasthenic syndrome (CMS) was 0.12 and 0.23 per 100 000, respectively. Of the 364 study children, 217 (59.6%) had JMG, 141 (38.7%) had CMS, and 6 (1.7%) had Lambert-Eaton syndrome, diagnosed at a median age of 13.5, 5.1, and 12.6 years, respectively. A majority of the JMG and CMS patients had ocular involvement (90.3% and 85.1%, respectively), including ptosis and ocular movement deficits. Among children with at least 1 year of follow-up (JMG; median, 7.1 years, CMS; median, 7.0 years), improvement was seen in 88.8% of JMG patients (complete remission in 31.3%) and in 58.3% of CMS patients.

CONCLUSION

Although relatively rare, myasthenia gravis in children has 2 predominant forms, CMS and JMG, both of which commonly have ocular involvement. Improvement is more likely in children with the juvenile form.

Neonatal jaundice and risks of childhood allergic diseases: a population-based cohort study

BACKGROUND

Only a few studies have systemically analyzed the association between neonatal jaundice and childhood-onset allergic diseases.

METHODS

From 2000 to 2007, 27,693 neonates with newly diagnosed neonatal jaundice and 55,367 matched nonneonatal jaundice cohorts were identified. The incidences and hazard ratios (HRs) of five allergic diseases, namely allergic conjunctivitis (AC), allergic rhinitis (AR), atopic dermatitis (AD), asthma, and urticaria, by the end of 2008 were calculated.

RESULTS

The incidence density and HRs of the five allergic diseases were greater in the neonatal jaundice cohort than in the nonneonatal jaundice cohort, and the HRs declined modestly with age. The HRs for AR (HR = 2.51, 95% confidence interval (CI) = 2.43-2.59) and AD (HR = 2.51, 95% CI = 2.40-2.62) were the highest, and that for urticaria was the lowest (HR = 2.06, 95% CI = 1.94-2.19). The HRs of allergic diseases were substantially greater for boys and those requiring phototherapy. The HRs of the allergic diseases, except urticaria (HR = 2.49, 95% CI = 1.57-3.97), were not significantly different between the neonatal jaundice regardless of whether the patients received exchange transfusion.

CONCLUSION

Neonatal jaundice is associated with the development of allergic diseases in early childhood.

Higher risk of myasthenia gravis in patients with thyroid and allergic diseases: a national population-based study

The aim of this study was to determine the risk of myasthenia gravis (MG) in patients with allergic or autoimmune thyroid disease in a large cohort representing 99% of the population in Taiwan. Data from the Taiwan National Health Insurance Database were used to conduct retrospective analyses. The study comprised 1689 adult patients with MG who were 4-fold frequency matched to those without MG by sex, age, and assigned the same index year. Multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals for the association between allergic or autoimmune thyroid disease and MG. An increased subsequent risk of MG was observed in the patients with allergic conjunctivitis (AC), allergic rhinitis, Hashimoto thyroiditis, and Graves disease. The adjusted odds ratios (aORs) were 1.93 (1.71-2.18), 1.26 (1.09-1.45), 2.87 (1.18-6.97), and 3.97 (2.71-5.83), respectively. The aORs increased from 1.63 (1.43-1.85) in a patient with only 1 allergic or autoimmune thyroid disease to 2.09 (1.75-2.49) in a patient with 2 thyroid or allergic diseases to 2.82 (2.19-3.64) in a patient with ≥3 thyroid or allergic diseases. MG was associated with the cumulative effect of concurrent allergic and autoimmune thyroid disease with combined AC and Hashimoto thyroiditis representing the highest risk (aOR = 15.62 [2.88-87.71]). This population-based case-control study demonstrates the association between allergic or autoimmune thyroid disease and the risk of MG. The highest risk of subsequent MG was associated with combined AC and Hashimoto thyroiditis.