MILAN – presented at the annual European Congress of Rheumatology.
Although more patients with inflammatory rheumatic diseases (iRD) report symptoms resembling long COVID, the data suggest that many of these symptoms can be attributed to the underlying rheumatic disease. “Overall, we find the data quite reassuring,” said Laura Boekel, Amsterdam Rheumatology and Immunology Center, Amsterdam University Medical Center.
The results were also published in The Lancet Rheumatology.
The risk of developing long COVID after infection with the Omicron variant appeared to be higher in patients with iRD, with 21% meeting the criteria set by the World Health Organization, compared with 13% of healthy individuals (odds ratio, 1.58; P = .037). Fatigue and loss of fitness were the most common long COVID symptoms reported by both iRD patients and controls. However, the difference in risk decreased after accounting for factors that are significantly associated with an increased risk for long COVID, such as body mass index and the severity of the acute COVID-19 infection (adjusted OR, 1.46; P = .081). The duration of symptoms did not show a statistically significant difference.
Kim Lauper, MD, University of Geneva, who chaired the session in which Ms. Boekel reported the study, said in an interview that the data should be interpreted with caution. “The data demonstrate that rheumatic disease itself is not a risk factor for long COVID. However, patients with rheumatic diseases are at a higher risk of severe disease, which in turn increases the likelihood of long COVID. Therefore, as a population, these patients are more susceptible to long COVID overall.”
Moreover, irrespective of their previous COVID-19 infection status, iRD patients often exhibit symptoms similar to those of long COVID even without a prior COVID-19 infection. (There was no history of COVID-19 in 21% of iRD patients vs. 11% of controls.) This suggests that some of the reported long COVID symptoms may actually be clinical manifestations of the underlying rheumatic disease, thereby complicating the diagnosis of long COVID in this population. The study employed the WHO definition of long COVID, which includes persistent symptoms lasting at least 8 weeks, beginning within 3 months of a confirmed SARS-CoV-2 infection, and that cannot be attributed to an alternative diagnosis. However, the data presented in Milan indicate that the WHO definition “is not well suited for patients with iRD due to significant overlap in symptoms and features,” Ms. Boekel concluded.
The cases of Omicron COVID-19 were identified during Jan. 1–April 25, 2022, among iRD patients recruited from the Amsterdam Rheumatology and Immunology Center. The population with confirmed SARS-CoV-2 Omicron infection during this period was monitored for long COVID. The total number of patients included in the study consisted of 77 iRD patients and 23 healthy controls. When asked about the potential risk of selection bias in the survey, Ms. Boekel stated that only approximately 8% of participants declined to respond, and the nonresponders were comparable with the respondents. She concluded that “the risk of selection bias is minimal.”
In an editorial published in The Lancet Rheumatology, Leonard H. Calabrese, DO, Cleveland Clinic, provided his insights on the findings. He emphasized that, “at present, long COVID remains an important reality that significantly impacts the lives of millions of individuals, yet it remains incompletely defined. ... These limitations in defining cases should not in any way undermine the experiences of those suffering from long COVID. Instead, they should serve as a reminder that, at this stage of the pandemic, we unfortunately still lack validated classification criteria for long COVID. It is crucial to include non–SARS-CoV-2–infected controls in all studies to further enhance our understanding.”
Ms. Boekel and coauthors, as well as Dr. Lauper and Dr. Calabrese, reported no relevant financial relationships.
A version of this article originally appeared on Medscape.com.