ABSTRACT
Introduction: Long COVID is the overarching name for a wide variety of disorders that may follow the diagnosis of acute SARS-COVID-19 infection and persist for weeks to many months. Nearly every organ system may be affected. Methods: We report nine patients suffering with Long COVID for 101 to 547 days. All exhibited significant perturbations of their immune systems, but only one was known to be immunodeficient prior to the studies directed at evaluating them for possible treatment. Neurological and cardiac symptoms were most common. Based on this data and other evidence suggesting autoimmune reactivity, we planned to treat them for 3 months with long-term high-dose immunoglobulin therapy. If there was evidence of benefit at 3 months, the regimen was continued. Results: The patients' ages ranged from 34 to 79 years-with five male and four female patients, respectively. All nine patients exhibited significant immune perturbations prior to treatment. One patient declined this treatment, and insurance support was not approved for two others. The other six have been treated, and all have had a significant to remarkable clinical benefit. Conclusion: Long-term high-dose immunoglobulin therapy is an effective therapeutic option for treating patients with Long COVID.