Population-based Study of 24 Autoimmune Diseases Carried Out in a Brazilian Microregion

Prevalence and burden of vitiligo in Africa, the Middle East and Latin America

Vitiligo is a common chronic autoimmune disorder characterized by skin and hair depigmentation that affects 0.5%-2.0% of the global population. Vitiligo is associated with diminished quality of life (QoL) and psychosocial burden. The burden of vitiligo may vary based on skin tone and cultural differences as well as geographical variations in disease awareness, societal stigma, healthcare systems and treatment options. Data on the burden and management of vitiligo in Africa, the Middle East and Latin America are scarce. Literature searches using terms covering vitiligo in Africa, the Middle East and Latin America were conducted using PubMed to identify relevant publications that focused on disease prevalence and burden, QoL and psychosocial impact and disease management between 2011 and 2021. Most of the reviewed studies were conducted in the Middle East, and most Latin American studies were from Brazil. Most studies involved small patient numbers and may not be generalizable. Reported prevalence of vitiligo ranged from 0.18% to 5.3% in Africa and the Middle East, and from 0.04% to 0.57% in Latin America. In several studies, prevalence was higher among female participants. Generally, non-segmental vitiligo was the dominant clinical variant identified and the age at onset varied widely across studies. Common comorbidities include autoimmune diseases such as Hashimoto's thyroiditis, alopecia areata and diabetes. Few treatment guidelines exist in these regions, with the exceptions of guidelines published by the Brazilian and Argentinian Societies of Dermatology. There is a clear unmet need for large epidemiological studies with uniform methodology to accurately ascertain the true prevalence of vitiligo in Africa, the Middle East and Latin America. Additional data on vitiligo burden and management in Africa and Latin America are also needed, along with local disease management guidelines that consider genetic variation, psychosocial burden and socioeconomic diversity in all 3 regions.

Epidemiology of the idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of systemic autoimmune diseases that affect the skeletal muscles and can also involve the skin, joints, lungs and heart. The epidemiology of IIM is obscured by changing classification criteria and the inherent shortcomings of case identification using healthcare record diagnostic coding. The incidence of IIM is estimated to range from 0.2 to 2 per 100,000 person-years, with prevalence from 2 to 25 per 100,000 people. Although the effects of age and gender on incidence are known, there is only sparse understanding of ethnic differences, particularly in indigenous populations. The incidence of IIM has reportedly increased in the twenty-first century, but whether this is a genuine increase is not yet known. Understanding of the genetic risk factors for different IIM subtypes has advanced considerably. Infections, medications, malignancy and geography are also commonly identified risk factors. Potentially, the COVID-19 pandemic has altered IIM incidence, although evidence of this occurrence is limited to case reports and small case series. Consideration of the current understanding of the epidemiology of IIM can highlight important areas of interest for future research into these rare diseases.

Global prevalence and epidemiological trends of Hashimoto's thyroiditis in adults: A systematic review and meta-analysis

Objective

Although Hashimoto's thyroiditis is associated with cardiovascular disease and malignancy, the global status of Hashimoto's thyroiditis is not well characterized across regions. Our objective was to evaluate the prevalence and trends of Hashimoto's thyroiditis in adults in regions with different economic income levels around the world.

Methods

For this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, Scopus, and Web of Science databases, and 48 random-effects representative studies from the inception to June 2022 were included without language restrictions to obtain the overall prevalence of Hashimoto's thyroiditis in adults worldwide. In addition, we stratified by time of publication, geographic region, economic level of the region of residence, gender, diagnostic method, etc.

Results

A total of 11,399 studies were retrieved, of which 48 met the research criteria: 20 from Europe, 16 from Asia, five from South America, three from North America, and three from Africa. Furthermore, there are two projects involving 19 countries and 22,680,155 participants. The prevalence of Hashimoto's thyroiditis was 7.5 (95%CI 5.7-9.6%), while in the low-middle-income group the prevalence was 11.4 (95%CI 2.5-25.2%). Similarly, the prevalence was 5.6 (95%Cl 3.9-7.4%) in the upper-middle-income group, and in the high-income group, the prevalence was 8.4 (95%Cl 5.6-11.8). The prevalence of Hashimoto's varied by geographic region: Africa (14.2 [95% CI 2.5-32.9%]), Oceania (11.0% [95% CI 7.8-14.7%]), South America and Europe 8.0, 7.8% (95% Cl 0.0-29.5%) in North America, and 5.8 (95% Cl 2.8-9.9%) in Asia. Although our investigator heterogeneity was high (I²), our results using a sensitivity analysis showed robustness and reliability of the findings. People living in low-middle-income areas are more likely to develop Hashimoto's thyroiditis, while the group in high-income areas are more likely to develop Hashimoto's thyroiditis than people in upper-middle-income areas, and women's risk is about four times higher than men's.

Conclusions

Global Hashimoto's thyroiditis patients are about four times as many as males, and there are discrepancies in the regions with different economic levels. In low-middle-income areas with a higher prevalence of Hashimoto's thyroiditis, especially countries in Africa, therefore local health departments should take strategic measures to prevent, detect, and treat Hashimoto's thyroiditis. At the same time, the hidden medical burden other diseases caused by Hashimoto's thyroiditis should also be done well.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD 42022339839.

Global epidemiology of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease that predominantly affects the joints. The prevalence of RA varies globally, with generally a higher prevalence in industrialized countries, which may be explained by exposures to environmental risk factors, but also by genetic factors, differing demographics and under-reporting in other parts of the world. Over the past three decades, strong trends of the declining severity of RA probably reflect changes in treatment paradigms and overall better management of the disease. Other trends include increasing RA prevalence. Common risk factors for RA include both modifiable lifestyle-associated variables and non-modifiable features, such as genetics and sex. A better understanding of the natural history of RA, and of the factors that contribute to the development of RA in specific populations, might lead to the introduction of specific prevention strategies for this debilitating disease.

The burden of illness of rheumatoid arthritis in Latin America-A systematic literature review

Rheumatoid arthritis (RA) is a chronic autoimmune disease which, when left untreated, may result in the destruction of multiple joints and damage a wide variety of body systems, including the skin, eyes, lungs, heart, and blood vessels. The objective of this study was to conduct a systematic review of disease burden for RA in Argentina, Brazil, Colombia, Mexico, and Venezuela. PubMed/Medline, Embase, and Web of Science were searched for publications in English, Spanish, or Portuguese from 2008 through June 2018. A total of 1700 records were retrieved and 36 articles were included. The estimated prevalence of RA for these countries ranged from 0.15% (Colombia) to 2.8% (Mexico). The Global Burden of Disease initiative 2019 estimated that RA accounted for 0.13% of world disability-adjusted life-years. For Latin America, these figures were higher: Argentina 0.16%, Brazil 0.16%, Colombia 0.21%, Mexico 0.30%, and Venezuela 0.24%. RA has a negative impact on physical, mental, and emotional well-being as shown by substantially lower scores on measures of quality of life (SF-36) compared with the general population. The annual direct cost in Mexico was estimated at US$3599 per person. For patients with severe RA in Brazil these costs were approximately US$10 000. Data from other studied countries were similar. Though evidence of the full cost and impact of RA in Latin American countries is scarce and additional studies are needed, the burden of RA in these regions is significant and comparable to other parts the world.

Environmental and individual factors associated with protection and predisposition to autoimmune diseases

OBJECTIVE

This study aimed to correlate possible predisposing and protective factors involved with autoimmune diseases (ADs) in a Brazilian microregion.

METHODS

This case-control study recorded 362 cases of ADs prevalent in the Águas Formosas microregion, state of Minas Gerais, Brazil, between January and December 2016, through the application of a questionnaire. Overall, 724 controls were randomly selected according to gender and age. Logistic regression was used to calculate the adjusted odds ratio (OR), confidence interval, and P-value to compare the strength of association between the variables of interest assessed.

RESULTS

Individuals with Graves' disease (OR: 11.9977), followed by rheumatoid arthritis (RA), psoriasis, lupus, Hashimoto's thyroiditis (HT), and vitiligo, were strongly associated with the risk of developing the disease after the hepatitis B vaccine. Having consumed cow milk before 6 months of life was a factor associated only with psoriasis (OR: 0.3321) and RA (OR: 0.2880). Type 1 diabetes patients were associated only with surgical procedures (OR: 0.1160), just as physical and psychological traumas were associated only with vitiligo (OR: 5.9848). Contact with chemicals was more related to vitiligo (OR: 0.7142), RA, psoriasis, lupus, and thyroiditis. Physical exercise was the most significant protective factor for vitiligo (OR: 0.4904), followed by HT, RA, psoriasis, and lupus; and the consumption of filtered water with candles was a protective factor for vitiligo (OR: 0.3325).

CONCLUSION

The associations suggest that predisposing and protective factors for ADs play a pivotal role in their onset, enabling health management, control, and intervention of this population.