Investigators report on the implications of ethnicity and rheumatic diseases on South Korean patients with COVID-19.
New research from South Korea found that patients with rheumatic diseases were at an increased risk of testing positive for SARS-CoV-2, procuring severe COVID-19, and COVID-19-related death.
Researchers led by Professor Youn Ho Shin, MD, also found that patients who took a daily high-dose of a systemic corticosteroid (≥10 mg per day) had a greater risk of testing positive for the pandemic virus, while patients who took disease-modifying antirheumatic drugs (DMARDs) showed no increased risk.
South Korea was one of the first countries to be affected by COVID-19, with the first confirmed case being reported on January 20, 2020. Since June 8, 2021, there have been 114,637 confirmed cases in South Korea as well as 1974 deaths.
To their knowledge, no studies thus far have reported COVID-19 outcomes in patients with autoimmune inflammatory rheumatic diseases of Asian ethnicity.
Researchers wrote that the ethnicity of a COVID-19 patient would be impactful in terms of their experience dealing with the virus.
Shin and colleagues noted that patients with autoimmune inflammatory rheumatic diseases were at risk of developing COVID-19 due to lowered immunity and immune-modulating therapies.
In order to gauge how many South Korean residents with a rheumatic disease had COVID-19, the team utilized a South Korean nationwide cohort linked to general health examination records.
South Korean patients ages 20 and older who underwent SARS-CoV-2 RT-PCR testing between January 1 and May 30, 2020 were eligible for the study. General health examinations from the Korean National Health Insurance Service were also required.
The group was comprised of 133,609 patients, 3.3% of whom had a positive SARS-CoV-2 test. Additionally, 6.2% of all patients were also diagnosed with an autoimmune inflammatory rheumatic disease. A smaller percentage of patients suffered from a tissue disease (1.5%)
Autoimmune inflammatory rheumatic diseases such as inflammatory arthritis and connective tissue diseases) were defined by ICD-10 codes.
The dynamic between the COVID-19 virus and patient’s corticosteroid use was noted in the study. Much like DMARDs, corticosteroids were used by some patients to help mitigate symptoms and difficulties caused by their rheumatic disease.
While standard doses of corticosteroid were not associated with an increased change of testing positive for COVID-19, high doses of the steroid contributed to increased odds of a positive COVID-19 test.
However, DMARDs were not associated with any increased risk.
The study had limitations, such as a small sample size, skewed clinic-based data, selection bias, and insufficient confounding adjustment. Additionally, not all participants had a laboratory-confirmed case of COVID-19.
Despite this, Shin and colleagues considered the study a success, believing it to be the first fstudy to show that patients with inflammatory arthritis and connective tissue diseases are at increased risk of testing positive for SARS-CoV-2 independently. The study also found no association between connective tissue disease and COVID-19-related death, which they attribute to a small number of patients with the disease.
The findings also gave credence to a previous study which reported that Asian ethnicity compared with White ethnicity is associated with higher intensive care admission and COVID-19-related mortality rates.
“The reason for this adverse association of COVID-19 with Asian ethnicity might be due to higher angiotensin-converting enzyme (ACE) concentrations and lower androgen concentrations, which lead to increased ACE2 expression, cross-reactive
immunity—eg, due to past exposure to infections (eg, malaria), regional temperature, and humidity—which can affect virus survival and the host immune response,” the team wrote.
While Shin and colleagues had made important strides in topic of rheumatic diseases and COVID-19, they also advised researchers to incorporate the most recent date regarding the COVID-19 virus in future studies.
“Because we used the dataset that reflected the initial period of the pandemic in South Korea, caution should be exercised when generalising our results to the current situation,” the team wrote.
The study, “Autoimmune inflammatory rheumatic diseases and COVID-19 outcomes in South Korea: a nationwide cohort study,” was published online in The Lancet Rheumatology.