COVID in Autoimmune Disease Patients: It’s Getting Better

Patients with autoimmune diseases were still getting COVID-19 like everyone else when the Omicron wave hit, but — also like everyone else — the worst outcomes had become far less frequent compared with the early months of the pandemic, at least in one major U.S. medical center’s experience.

Among 1,449 patients with systemic autoimmune rheumatic diseases treated at Boston’s Mass General Brigham Healthcare System, 15% of COVID cases treated during the Omicron wave (Dec. 17, 2021-Jan. 31, 2022) were severe, compared with a 46% severity rate in March-June 2020, according to the institution’s Jeffrey A. Sparks, MD, MMSc, and colleagues.

During those same periods, death rates fell from 8.8% to 2.0%, the group reported in Annals of the Rheumatic Diseases. And disproportionately more of those with severe outcomes were unvaccinated: 59.5% of non-severe cases were unvaccinated, as opposed to 78.4% of the severe cases.

“Severe” outcomes were defined as either hospitalization or death within 30 days of diagnosis.

Sparks and colleagues speculated that a combination of factors were likely responsible for the improved outcomes over time: more widely available testing, increases in hospital capacity, better therapies, “depletion of susceptible individuals,” altered virulence for the SARS-CoV-2 virus — and, of course, vaccines and other preventive measures.

Rheumatic disease patients have been considered at special risk during the pandemic because, in most cases, the treatment or the disease itself disrupts immune function. Drugs such as rituximab that deplete B-cells are a particular concern and are used in a variety of autoimmune conditions.

Sparks and colleagues found a death rate of 4.1% among their patients — who were being treated in the authors’ hospital system — as compared with just over 1% in the general population, suggesting that those worries had some validity. The majority of patients were on immunosuppressive therapy at the time of infection.

Still, of the 60 overall deaths, more than half occurred before vaccinations were widely available (Jan. 31, 2021).

On the negative side for patients’ future, the Omicron wave did result in many cases (401) coming to Mass General Brigham, which was more than in the earlier 10.5 months (295). Newer variants have circulated since, and more will likely develop.

Some changes in COVID-19 treatment over time that were evident in the data included the introduction of monoclonal antibody therapies, which were used in half of patients in late 2021, and a decline in use of remdesivir after a peak in early 2021. Resort to mechanical ventilation almost vanished, falling from 11.1% of cases early in the pandemic to 1.7% during Omicron.

How much of these trends can be attributed to vaccination versus improved treatments, though, remains unclear, the researchers acknowledged. However, the biggest drop in rates of severe outcomes occurred during the “early treatment” phase, July 2020 to January 2021, before vaccines reached the broader population.

Nevertheless, Sparks and colleagues emphasized the importance, if not the necessity, of vaccination.

“These findings suggest that while some patients with [systemic autoimmune diseases] on immunosuppressives may be at higher risk for breakthrough infection, vaccination provided important benefits for many of these patients if infected with SARS-CoV-2,” the researchers wrote.

Hospital admission rates fell by about two-thirds from early 2020, when 44.1% of patients were hospitalized. During the Omicron wave, the rate was just 14.5%.

Average age of COVID-19 patients declined gradually from 63.1 in the early weeks to 54.2 during Omicron. The racial makeup shifted, too, with white patients becoming a larger fraction (59% increasing to 74.6%).

Overall, about one-third of patients in the study had rheumatoid arthritis, 13% had lupus, and 15% had psoriatic or spondyloarthritis. Ten other diagnoses were recorded, along with “other” to account for the rest. The proportions didn’t change markedly over the study period.

Treatment patterns generally followed wider trends in healthcare, with a smattering of patients receiving convalescent plasma, and dexamethasone use rising and then falling as severe cases declined. One therapy tried and discarded was the interleukin-6 inhibitor tocilizumab (Actemra), given to 15 patients, almost all in the pandemic’s first 3 months.

Sparks and colleagues viewed the findings cautiously. “[S]ome patients with [autoimmune disease] continue to experience severe disease, especially those on immunosuppressives known to blunt the response to vaccine and infection, as well as those with other serious comorbidities. Additional studies are needed to refine risk mitigating strategies for patients at highest risk for severe outcomes,” the group wrote.