In people With Rare Autoimmune Diseases, Risk Of Early Death Has Risen With COVID-19

Individuals with rare autoimmune rheumatic diseases (RAIRDs) die younger during the COVID-19 pandemic than they did before and also have higher all-cause mortality than the general population, a new U.S. study shows.

During the pandemic, people with an RAIRD have an increased risk of dying relative to before COVID-19 from age 35 onwards, while this heightened risk begins at age 55 for the general population, researchers report in Rheumatology.

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In addition, although women with RAIRDs typically face a lower risk of death than do men, this difference was turned on its head during the pandemic, according to Dr. Fiona Pearce of the University of Nottingham.

There's an urgent need to quantify how much of the increased risk of all-cause death is because of COVID-19 infection and how much is because of disruption to healthcare services, she and her colleagues say.

Drawing on a nationwide database, the researchers identified more than 168,000 people diagnosed with RAIRDs who were alive as of March 1. This cohort was 70% female, with a mean age of 61.

The most common RAIRDs were giant-cell arteritis (22%), systemic lupus erythematosus (22%), juvenile inflammatory arthritis (13%), unspecified arteritis (12%) and polymyositis (10%).

During March and April 2020, 1.1% of the overall cohort died of any cause, yielding an age-standardized mortality rate (ASMR) of 3,669 per 100,000 person-years. This was significantly higher than the ASMR for March and April over 2015-2019, which averaged 2,554 per 100,000.

In the whole population of England, the ASMR for March-April 2020 was 1,361 per 100,000 people, significantly lower than for individuals with RAIRDs and significantly greater than the general 2015-2019 ASMR, which averaged 983.3 per 100,000 person-years.

The March-April 2020 ASMR for males with RAIRDs was 4,025 and that for females was 4,242, compared with ASMRs in the general population of 1,626 and 1,150, respectively.

The group that saw the largest rise in their risk of all-cause death was women ages 35 and up. Depending on the specific age range, the absolute risk of all-cause death for someone with a RAIRD was similar to that of someone in the general population at least 10 years older.

Dr. Pearce told Reuters Health by email that the researchers are working to quantify how much of the increased risk of death they report is caused by COVID-19 itself, versus disruption to usual healthcare delivery, and also whether the death-rate disparities have worsened since the spring.

Dr. Nilanjana Bose of the Rheumatology Center of Houston, Texas, told Reuters Health by phone that the COVID-19 Rheumatology Global Alliance, which relies on physician-reported data, has not yet seen increased morbidity or mortality among patients with autoimmune rheumatic diseases in the United States.

As a result, she said, this study provides very important data, because "We don't really know much about how COVID affects our patients . . . Intuitively, it makes sense that any kind of infection is a problem for our patients."

Dr. Shailendra Singh, a rheumatologist with Unity Health, in Searcy, Arkansas, said people with autoimmune rheumatic diseases "are at similar risk of COVID infection as the general population, but are at significantly higher risk of experiencing complications including death."

This is so, he told Reuters Health by email, partly because the immune system in such patients is overactive, but is not as robust in fighting infection, even without immunosuppressive/modulatory medication. And when the immune system does mount a response to infection, it can cause "collateral damage" to the patient's body, which is why flares of autoimmune diseases are seen with infections.

Dr. Singh cautioned that patients with autoimmune rheumatic diseases who are immunosuppressed might not show typical COVID symptoms, such as fever, which could lead to delayed diagnosis and treatment. They might also present with a flare of their autoimmune disease as the only symptom.

It's very important for such patients to stay current with immunizations, such as for pneumonia and influenza and other immunizations as appropriate by age, he emphasized.

Neither Dr. Bose nor Dr. Singh was not involved in the new study.

—Scott Baltic

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