ABSTRACT
PURPOSE: The long-term symptoms of coronavirus disease 2019 (COVID-19), i.e., long COVID, have drawn research attention. Evaluating its subjective symptoms is difficult, and no established pathophysiology or treatment exists. Although there are several reports of long COVID classifications, there are no reports comparing classifications that include patient characteristics, such as autonomic dysfunction and work status. We aimed to classify patients into clusters based on their subjective symptoms during their first outpatient visit and evaluate their background for these clusters. METHODS: Included patients visited our outpatient clinic between January 18, 2021, and May 30, 2022. They were aged ≥ 15 years and confirmed to have SARS-CoV-2 infection and residual symptoms lasting at least 2 months post-infection. Patients were evaluated using a 3-point scale for 23 symptoms and classified into five clusters (1. fatigue only; 2. fatigue, dyspnea, chest pain, palpitations, and forgetfulness; 3. fatigue, headache, insomnia, anxiety, motivation loss, low mood, and forgetfulness; 4. hair loss; and 5. taste and smell disorders) using CLUSTER. For continuous variables, each cluster was compared using the Kruskal-Wallis test. Multiple comparison tests were performed using the Dunn's test for significant results. For nominal variables, a Chi-square test was performed; for significant results, a residual analysis was conducted with the adjusted residuals. RESULTS: Compared to patients in other cluster categories, those in cluster categories 2 and 3 had higher proportions of autonomic nervous system disorders and leaves of absence, respectively. CONCLUSIONS: Long COVID cluster classification provided an overall assessment of COVID-19. Different treatment strategies must be used based on physical and psychiatric symptoms and employment factors.
ABSTRACT
Coronavirus disease 2019 (COVID-19) is spreading worldwide; there is a need to address its sequelae known as Long COVID. This study evaluated postvaccination changes in symptoms and antibody titers in patients with Long COVID. Patients visiting the outpatient department specializing in Long COVID at our hospital were enrolled. Changes in symptoms were evaluated before and 14-21 days after first vaccination. Antibody titers were measured using ARCHITECT SARS-CoV-2 IgG II Quant at the same time. This study included 42 patients (median age: 45 years; 17 [40.5%] men). Median pre- and postvaccination antibody titers were 456 and 28,963 AU/ml, respectively. Postvaccination symptoms (fatigue, joint pain, and taste and olfactory abnormalities) were relieved, worsened, and unchanged in 7 (16.7%), 9 (21.4%), and 26 (61.9%) patients, respectively. Ratios of pre- and postvaccination antibody titers were 53, 40, and 174 in the unchanged, relief, and worsened groups, respectively. The worsened group had the significantly highest antibody titer ratio (p = 0.02). The higher increased rate of the antibody titer in the worsened group than in the nonworsened group suggests an excessive immune response to vaccination associated with worsening of sequelae. Although patients with Long COVID should be vaccinated, additional concerns should be addressed.