The role of socioeconomic status in the susceptibility to develop systemic lupus erythematosus in Mexican patients

Major Histocompatibility Complex Class I and II Allele Frequencies and Disease Associations in Mexicans: A Systematic Review and Meta-Analysis

BACKGROUND

The major histocompatibility complex (MHC) plays a crucial role in immune responses and is associated with disease susceptibility. This study systematically reviews MHC class I and class II allele frequencies and their associations with diseases in the Mexican population from 1979 to 2023.

METHODS

A systematic review following PRISMA guidelines was conducted. Reports were obtained from the Allele Frequency Net Database and PubMed using keywords related to HLA and Mexican populations. A total of 776 reports were screened, and 214 were retained for final analysis. Seventy-six studies comprising allele frequency data from over 20,000 individuals across Mexican states and indigenous communities were analyzed. In addition, over 138 articles were examined to identify alleles associated with various diseases.

RESULTS

The analysis identified 117 alleles whose frequencies varied regionally within Mexico. While DPA1*01, DPB1*04:01, and DQA1*03 were predominant, DRB1*04, DQB1*03, and DQA1*05 were also prominent but variable. Certain alleles, such as A*02, B*35, C*04, and C*07, were relatively common in the population. Numerous disease correlations were uncovered, such as B*27's strong association with spondyloarthropathies. DRB1*15:01 and DRB1*04 conferred an increase in multiple sclerosis, while DRB1*04 may protect against some skin diseases.

CONCLUSION

This review improves the understanding of MHC allele frequencies and disease associations in Mexicans, highlighting genetic diversity. The findings lay the groundwork for future research on genetic predispositions and health outcomes, aiding healthcare strategies in this diverse population. Further studies are needed to address data gaps and refine genetic profiles for targeted medical applications.

HLA-DRB1 and HLA-DQB1 genes in patients diagnosed with systemic lupus erythematosus in Guatemala

Systemic lupus erythematosus (SLE) is an autoimmune disorder that impacts connective tissue and can affect various organs and systems within the body. One important aspect of this disease is the role of the human leukocyte antigen (HLA) system, a protein complex that plays a role in the immune response. Specifically, the HLA-DRB1 and HLA-DQB1 genes have been implicated in the development of SLE. In order to better understand this relationship in the Guatemalan population, a study was conducted with the objective of characterizing the allelic and haplotype profiles of the HLA-DQB1 and HLA-DRB1 loci in 50 patients diagnosed with SLE who were receiving treatment at a hospital in Guatemala. Allele and haplotype frequencies were determined and compared to 127 healthy Guatemalan subjects as a control group. The results of the analysis showed a reduction in the frequencies of HLA-DQB1*03 and HLA-DRB1*14 in SLE patients, which could suggest a protective effect on the development of the disease. In contrast, a risk association was found between HLA-DRB1*07, HLA-DRB1*08, HLA-DQB1*02 and HLA-DQB1*06 in SLE patients. Finally, we observed an additional protective associated of haplotype HLA-DRB1*04∼DQB1*03 with SLE patients, while haplotypes HLA-DRB1*07∼DQB1*02 and DRB1*08-DQB1*06 showed a risk association.

Health inequalities and social determinants of health: The role of syndemics in rheumatic disease

A syndemic is the co-existence of two or more health problems (including both social and biological features) that adversely influence each other with negative consequences on disease outcomes and perpetuation of inequalities. The syndemic approach can be applied to better understand the course of rheumatic musculoskeletal diseases (RMD) involving the study of adverse biological pathways and social determinants of health (SDH) all under the same framework. Identifying if a syndemic exists within RMDs may include investigating the synergic interactions between comorbidity (e.g., diabetes, obesity, chronic kidney diseases) and the concomitant of other adverse conditions (e.g., drug non-adherence, substance abuse), along with SDHs such as low household income, unemployment, low education, limited access to health care, as well as racial/ethnic discrimination. For decades, the understanding of RMDs progression has been based on causality, rather than investigating the kaleidoscopic web of connections that can potentially influence a disease course. The co-existence of health burdens in vulnerable populations, including those with RMD, specifically in certain socioeconomic groups, calls for new ways and strategies of thinking to improve our understanding of risk factors and co-morbidities to offer tailored interventions for clinical medicine and public health policy.

Advances in the Pathogenesis and Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a genetically predisposed, female-predominant disease, characterized by multiple organ damage, that in its most severe forms can be life-threatening. The pathogenesis of SLE is complex and involves cells of both innate and adaptive immunity. The distinguishing feature of SLE is the production of autoantibodies, with the formation of immune complexes that precipitate at the vascular level, causing organ damage. Although progress in understanding the pathogenesis of SLE has been slower than in other rheumatic diseases, new knowledge has recently led to the development of effective targeted therapies, that hold out hope for personalized therapy. However, the new drugs available to date are still an adjunct to conventional therapy, which is known to be toxic in the short and long term. The purpose of this review is to summarize recent advances in understanding the pathogenesis of the disease and discuss the results obtained from the use of new targeted drugs, with a look at future therapies that may be used in the absence of the current standard of care or may even cure this serious systemic autoimmune disease.

Heterogeneity of Genetic Admixture Determines SLE Susceptibility in Mexican

Systemic Lupus Erythematosus (SLE) is an autoimmune inflammatory disorder for which Major Histocompatibility Complex (MHC) genes are well identified as risk factors. SLE patients present different clinical phenotypes, which are partly explained by admixture patterns variation among Mexicans. Population genetic has insight into the high genetic variability of Mexicans, mainly described through HLA gene studies with anthropological and biomedical importance. A prospective, case-control study was performed. In this study, we recruited 146 SLE patients, and 234 healthy individuals were included as a control group; both groups were admixed Mexicans from Mexico City. The HLA typing methods were based on Next Generation Sequencing and Sequence-Based Typing (SBT). The data analysis was performed with population genetic programs and statistical packages. The admixture estimations based on HLA-B and -DRB1 revealed that SLE patients have a higher Southwestern European ancestry proportion (48 ± 8%) than healthy individuals (30 ± 7%). In contrast, Mexican Native American components are diminished in SLE patients (44 ± 1%) and augmented in Healthy individuals (63 ± 4%). HLA alleles and haplotypes' frequency analysis found variants previously described in SLE patients from Mexico City. Moreover, a conserved extended haplotype that confers risk to develop SLE was found, the HLA-A^∗29:02∼C^∗16:01∼B^∗44:03∼DRB1^∗07:01∼DQB1^∗02:02, pC = 0.02, OR = 1.41. Consistent with the admixture estimations, the origin of all risk alleles and haplotypes found in this study are European, while the protection alleles are Mexican Native American. The analysis of genetic distances supported that the SLE patient group is closer to the Southwestern European parental populace and farthest from Mexican Native Americans than healthy individuals. Heterogeneity of genetic admixture determines SLE susceptibility and protection in Mexicans. HLA sequencing is helpful to determine susceptibility alleles and haplotypes restricted to some populations.

Mayan alleles of the HLA-DRB1 major histocompatibility complex might contribute to the genetic susceptibility to systemic lupus erythematosus in Mexican patients from Tapachula, Chiapas

INTRODUCTION

Systemic lupus erythematosus (SLE) is the prototypic autoimmune disease that disrupts numerous immunity mechanisms with the potential to exert damage to any organ or tissue. Its etiology remains uncertain; however, genetic and environmental factors that differ between populations strongly influence its development. Among the physiopathogenic factors, the genetic ones predominate, notably the major histocompatibility complex (MHC) loci. A high degree of ethnical admixture makes Mexican Mestizos a thoroughly genetically heterogeneous population. Therefore, this study aimed to identify the MHC polymorphisms associated with SLE development in Mexican Mestizos from Southern Mexico and compare them with patients from Mexico City.

METHOD

A transversal study in SLE patients from Tapachula, Chiapas, was conducted. DNA typing of human leukocyte antigens (HLA) classes I and II was performed using single specific primers (SSP). Admixture analysis was performed using the population genetics LEADMIX software.

RESULTS

The frequencies of HLA-DRB1*16 and HLA-DQB1*05 were found to have a tendency towards increase in SLE patients, compared to ethnically matched healthy controls. The allele HLA-DRB1*03 seemed to be less associated with SLE in this group of Mexican Mestizos, opposed to other more Caucasian populations. Admixture analysis showed a higher Mayan genetic component in these patients from Chiapas.

CONCLUSIONS

The genetic susceptibility for SLE differed in two populations of Mexican Mestizos with dissimilar ethnic ancestries. Autochthonous Amerindian alleles, and not the more widely known Caucasian alleles, might be associated with the susceptibility to SLE in Mexican Mestizos from Tapachula, Chiapas. Key Points • Autochthonous Amerindian alleles, such as HLA-DRB1*16, had a tendency to be increased in SLE patients, compared to healthy controls. • SLE susceptibility alleles vary considerably among regions in Mexico, according to the distribution of the indigenous groups. • Ethnic admixture is a key determinant in the genetic susceptibility of SLE.

The COVID-19 Pandemic and Ethics in Mexico Through a Gender Lens

In Mexico, significant ethical and social issues have been raised by the COVID-19 pandemic. Some of the most pressing issues are the extent of restrictive measures, the reciprocal duties to healthcare workers, the allocation of scarce resources, and the need for research. While policy and ethical frameworks are being developed to face these problems, the gender perspective has been largely overlooked in most of the issues at stake. Domestic violence is the most prevalent form of violence against women, which can be exacerbated during a pandemic: stress and economic uncertainty are triggers for abuse, and confinement limits access to support networks. Confinement also exacerbates the unfair distribution of unpaid labor, which is disproportionately assigned to women and girls, and highlights inequality in the overall labor market. Lack of security measures has resulted in attacks towards health workers, particularly female nurses, due to fear of contamination. Finally, resource results in lack of access to other health necessities, including sexual and reproductive health services. Research across all disciplines to face-and to learn from-this crisis should be done through a gender lens, because understanding the realities of women is essential to understand the pandemic's true effects in Mexico and the world.