According to a Dutch prospective cohort study presented at the European Alliance of Associations for Rheumatology (EULAR) 2023 Annual Meeting, rheumatic disease is not considered a significant risk factor for long COVID. 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.
The study showed that 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 (WHO), compared with 13% of healthy individuals. 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.
Fatigue and loss of fitness were the most common long COVID symptoms reported by both iRD patients and controls. The duration of symptoms did not show a statistically significant difference. Kim Lauper, MD, University of Geneva, Switzerland, who chaired the session in which the study was presented, said that the data should be interpreted with caution.
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. 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.”
The cases of Omicron COVID-19 were identified during January 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.
In an editorial published in Lancet Rheumatology, Leonard H. Calabrese, Cleveland Clinic, Ohio, 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 […] It is crucial to include non-SARS-CoV-2 infected controls in all studies to further enhance our understanding.”
The study shows that while rheumatic disease is not considered a significant risk factor for long COVID, 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.
