Following acute COVID-19, some patients develop a group of debilitating symptoms that include fatigue, orthostatic intolerance, difficulty with attention and concentration (often called brain fog), myalgias and disrupted sleep (1-8). The term Long COVID is used to describe the prolonged multisystem illness that occurs after acute infection with SARS-CoV-2. The frequency with which this syndrome occurs following acute COVID-19 ranges from 2-40% of cases (8, 9). Although individuals with more severe acute COVID-19 are more likely to develop Long COVID, it is prevalent in people who were mildly symptomatic or asymptomatic at the time of acute infection with SARS-CoV-2 (8, 10, 11).~Many people with Long COVID remain ill for many months. Currently there are thousands of people in the U.S. that have been suffering with Long COVID for the past three years since the onset of the COVID-19 pandemic in January 2020 (12). In a recent study, the Imperial College in London estimated that there are 2 million adults suffering from Long COVID in the UK (13). According to the US News, Long COVID has become the 'Pandemic After the Pandemic (14). There is evidence that diagnosis and treatment early in the course of illness improves the likelihood of recovery and sustained remission of post-infectious illness (15, 16).~A code U09.9 was added to ICD-10 in October 2021 to document post-acute sequela of COVID-19 after infection and Long COVID. The WHO published a Long COVID clinical case definition coincident with the ICD code that described the common symptoms of Long COVID including fatigue, shortness of breath, cognitive dysfunction but also others and these generally have an impact on everyday functioning (17). The signs and symptoms described in this case definition were also described in survey responses from an international cohort of more than 6,000 people with Long COVID (18). This study found that signs and symptoms that persisted more than 6 months of illness included fatigue, brain fog, post-exertional malaise, insomnia, joint and muscle pain, orthostatic intolerance, gastrointestinal symptoms, and sensorimotor symptoms including tremors and nerve pain. These symptoms are the same as those that define myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). ME/CFS is defined by the National Academy of Medicine as a substantial reduction or impairment in the ability to engage in pre-illness levels of activity (occupational, educational, social, or personal life) that lasts for more than 6 months and is accompanied by profound fatigue of new onset that is not a result of ongoing or unusual excessive exertion and is not alleviated by rest; post-exertional malaise (PEM) which is the worsening of symptoms after physical, mental, or emotional exertion that would not have caused a problem before the illness; unrefreshing sleep; and at least one of the following two additional manifestations must be present, cognitive impairment or orthostatic intolerance (18).~Oxaloacetate is an energy metabolite found in every cell of the human body. It holds a key place in the TCA cycle within the mitochondria, providing energy to the cells. It is also a critical early metabolite in gluconeogenesis, which provides glucose for the heart and brain during times of low glucose. In addition, oxaloacetate is found in the urea cycle (which converts toxic ammonia to urea), amino acid synthesis, and fatty acid synthesis. It is critical to human metabolism and proper cellular function, and it is central to energy production and use in the body.~A Proof of Concept trial showed significant fatigue benefit in Long COVID patients. This randomized, placebo controlled follow-on trial will determine whether oxaloacetate can reduce fatigue and improve other symptoms in patients with Long COVID who meet diagnostic criteria for ME/CFS.
Following acute COVID-19, some patients develop a group of debilitating symptoms that include fatigue, orthostatic intolerance, difficulty with attention and concentration (often called brain fog), myalgias and disrupted sleep. The term Long COVID is used to describe these symptoms after the initial viral infection has passed. These symptoms are the same as those that define myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).~A Proof of Concept trial showed significant fatigue benefit in Long COVID patients. This randomized, placebo controlled follow-on trial will determine whether oxaloacetate can reduce fatigue and improve other symptoms in patients with Long COVID who meet diagnostic criteria for ME/CFS.