Abstract 16323: Functional Autoantibody Analysis in Post-Acute Sequela of COVID-19 Patients With and Without Pots: A Case Control Study

Abstract

Introduction: Post-Acute Sequela of COVID-19 (PASC) occurs after recovery from the initial illness. Autonomic dysfunction (AD) may explain these findings. We have previously shown orthostatic intolerance (OI) on standard Italian protocol head-up tilt table in 23 of 24 prospectively studied subjects with PASC and no prior OI. Postural orthostatic tachycardia syndrome (POTS) was noted in 4 of the 23. POTS is associated with elevated levels of autoantibodies. There is a paucity of data evaluating autoantibody presence in subjects with PASC related POTS. Hypothesis: We hypothesized that individuals with PASC related POTS would demonstrate higher levels of certain autoantibodies than controls. Methods: We recruited healthy, COVID-19 PCR negative controls, all previously vaccinated for COVID, who were age and gender matched with the 4 previously identified PASC related POTS patients. Serum was tested for autoantibodies in both groups. Results: Mean ages for the PASC related POTS and control groups were 29 and 31 years, respectively. The PASC related POTS patients had higher levels of functional autoantibodies to several G-protein coupled receptors than controls. The median values for adrenergic A1, adrenergic B2, muscarinic M4, angiotensin 2 and endothelin receptors, comparing controls to PASC related POTS patients, were 10.4 vs 27.5, 14.9 vs 38.5, 7.8 vs 29.0, 12.2 vs 29.5 and 12.6 vs 31.7 Units/ml, respectively. The small size of the 2 groups precludes meaningful statistical testing, but the box plots in Figure 1 show consistent differences in the concentration of antibody receptors seen between the 2 groups. Conclusions: Functional autoantibodies to several G-protein coupled receptors were seen in higher amount in subjects with PASC related POTS compared to healthy controls. While this is a small, case-control study, it suggests a potential autoantibody mediated mechanism that may explain some of the AD seen in PASC patients with POTS.