Reactive Arthritis After COVID-19 Infection

Investigation of recurrence of joint symptoms after COVID-19 in patients with rheumatoid arthritis: Cross-sectional study

Background

In this study, the relationship between involvement by COVID-19 and the recurrence of symptoms of rheumatoid arthritis (RA) was investigated.

Materials and Methods

This cross-sectional study was conducted on 112 patients with RA with and without a history of COVID-19. The severity and recurrence of RA symptoms were measured and recorded by the Disease Activity Score in 28 joints (DAS-28) index and clinical evaluations by a rheumatologist.

Results

The results showed that the recurrence of RA in patients with and without a history of COVID-19 had a statistically significant difference (P < 0.001). In addition, there was a statistically significant relationship between erythrocyte sedimentation rate, visual analogue scale (VAS), tender joint count, swollen joint count, and DAS-28 and the history of COVID-19 (P < 0.05).

Conclusion

The present study showed that infection with COVID-19 leads to the recurrence of joint symptoms in RA patients.

COVID-19 with Suspected Secondary Pyogenic Arthritis of the Hip: A Case Report and Literature Review

Introduction

COVID-19 may be associated with orthopedic symptoms, including myalgia and joint pain. There are reports of reactive arthritis and acute arthritis diagnosed after COVID-19; however, COVID-19-associated pyogenic arthritis has not been reported.

Case Report

We treated a young woman with secondary pyogenic hip arthritis that started after COVID-19. The patient was a 23-year-old woman who developed acute pain in the right hip 9 days after being diagnosed with COVID-19. Blood cultures revealed methicillin-sensitive Staphylococcus aureus and contrast-enhanced computed tomography revealed joint effusion in the right hip. Although the joint fluid culture results were negative, we suspected pyogenic arthritis of the hip joint and performed curettage and continuous irrigation of the right hip joint. Intraoperative histopathological examination of the synovial membrane revealed numerous neutrophils with segmental nuclei, consistent with a diagnosis of pyogenic arthritis.

Conclusion

To the best of our knowledge, this is the first report of probable secondary pyogenic hip arthritis in a patient with COVID-19.

Reactive arthritis following COVID-19: clinical case presentation and literature review

Reactive arthritis (ReA) is a clinical condition typically triggered by extra-articular bacterial infections and often associated with the presence of HLA-B27. While ReA has traditionally been associated with gastrointestinal and genitourinary infections, its pathogenesis involves immune and inflammatory responses that lead to joint affections. The emergence of COVID-19, caused by SARS-CoV-2, has prompted studies of plausible associations of the virus with ReA. We present a case of ReA in a patient who survived COVID-19 and presented with joint affections. The patient, a 31-year-old man, presented with lower limb joints pain. SARS-CoV-2 was confirmed by PCR testing during COVID-19-associated pneumonia. Following a thorough examination and exclusion of all ReA-associated infections, a diagnosis of ReA after COVID-19 was confirmed. In addition, this article encompasses a study of similar clinical cases of ReA following COVID-19 reported worldwide.

Reactive arthritis following COVID-19: cause for concern

Low-quality evidence suggests that COVID-19 may trigger reactive arthritis one to four weeks after the infection. Post COVID-19 reactive arthritis resolves within a few days, and no additional treatment is required. Established diagnostic or classification criteria for reactive arthritis are missing, and a deeper understanding of the immune mechanism related to COVID-19 prompt us to further investigate the immunopathogenic mechanisms capable of promoting or contrasting the development of specific rheumatic diseases. Caution should be exerted when managing post-infectious COVID-19 patient with arthralgia.

Reactive arthritis following COVID-19 current evidence, diagnosis, and management strategies

BACKGROUND

Immune-mediated conditions associated to Corona Virus Disease-19 (COVID-19) have been reported, including vasculitis, antiphospholipid antibody syndrome, myositis, and lupus. Emerging studies have reported the potential occurrence of reactive arthritis in patients previously infected with COVID-19. This systematic review summarised the current evidence on the occurrence of reactive arthritis in patients previously infected by COVID-19.

METHODS

This study was conducted according to the 2020 PRISMA guidelines. All the clinical investigations describing the occurrence of reactive arthritis following COVID-19 were accessed. In September 2022, the following databases were accessed: PubMed, Web of Science, Google Scholar, Embase. The generalities of the study were extracted: author, year and journal of publication, country of the main author, study design, sample size, mean age, number of women, main results of the study. The following data on COVID-19 severity and management were retrieved: type of treatment, hospitalization regimes (inpatient or outpatient), admission to the intensive care unit, need of mechanical ventilation, pharmacological management. The following data on reactive arthritis were collected: time elapsed between COVID-19 infection to the onset of reactive arthritis symptoms (days), pharmacological management, type of arthritis (mono- or bilateral, mono- or polyarticular), extra-articular manifestations, presence of tenosynovitis or enthesitis, synovial examination at microscopic polarised light, imaging (radiography, magnetic resonance, sonography), clinical examination, laboratory findings.

RESULTS

Data from 27 case reports (54 patients) were retrieved, with a mean age of 49.8 ± 14.5 years. 54% (29 of 54 patients) were women. The mean time span between COVID-19 infection and the occurrence of reactive arthritis symptoms was 22.3 ± 10.7 days. Between studies diagnosis and management of reactive arthritis were heterogeneous. Symptoms resolved within few days in all studies considered. At last follow-up, all patients were minimally symptomatic or asymptomatic, and no additional therapy or attentions were required by any patient.

CONCLUSION

Poor evidence suggests that COVID-19 could target the musculoskeletal system causing reactive arthritis at its post infectious stage. COVID-19 can act as a causative agent or as a trigger for development of reactive arthritis even without presence of antibodies of rheumatological disorders. Treating physicians should have a high index of suspicion while treating post infectious COVID-19 patient with arthralgia.

LEVEL OF EVIDENCE

Level IV, systematic review.

Does post-COVID reactive arthritis exist? Experience of a tertiary care centre with a review of the literature

Background

Rheumatological manifestations following COVID-19 are various, including Reactive Arthritis (ReA), which is a form of asymmetric oligoarthritis mainly involving the lower limbs, with or without extra-articular features. The current case series describes the clinical profile and treatment outcome of 23 patients with post-COVID-19 ReA.

Methods

A retrospective, observational study of patients with post-COVID-19 arthritis over one year was conducted at a tertiary care centre in India. Patients (n = 23) with either a positive polymerase chain reaction test for SARS-CoV2 or an anti-COVID-19 antibody test were included. Available demographic details, musculoskeletal symptoms, inflammatory markers, and treatment given were documented.

Results

Sixteen out of 23 patients were female. The mean age of the patients was 42.8 years. Nineteen patients had had symptomatic COVID-19 infection in the past. The duration between onset of COVID-19 symptoms and arthritis ranged from 5 to 52 days with a mean of 25.9 days. The knee was the most involved joint (16 out of 23 cases). Seven patients had inflammatory lower back pain and nine had enthesitis. Most patients were treated with non-steroidal anti-inflammatory drugs (NSAIDs) and steroids - either depot injection or a short oral course. Three patients required treatment with hydroxychloroquine and methotrexate which were eventually stopped. No relapse was reported in any of the patients.

Conclusion

On combining our data with 21 other case reports of ReA, a lower limb predominant, oligoarticular, asymmetric pattern of arthritis was seen with a female preponderance. The mean number of joints involved was 2.8. Axial symptoms and enthesitis were often coexistent. Treatment with NSAIDs and intra-articular steroids was effective. However, whether COVID-19 was the definitive aetiology of the arthritis is yet to be proven.

Reactive arthritis occurring after COVID-19 infection: a narrative review

PURPOSE

Reactive arthritis is acute aseptic arthritis occurring 1 to 4 weeks after a distant infection in a genetically predisposed individual. It may occur after COVID-19 infection. We summarize, in this article, the current findings of reactive arthritis following COVID-19 infection.

METHODS

A literature search has been performed from December 2019 to December 2021. We included case reports of reactive arthritis occurring after COVID-19 infection. We collected demographic, clinical, and paraclinical data.

RESULTS

A total of 22 articles were reviewed. There were 14 men and 11 women with a mean age of 44.96 + 17.47 years. Oligoarticular involvement of the lower limbs was the most frequent clinical presentation. The time between arthritis and COVID infection ranged from 6 to 48 days. The diagnosis was based on clinical and laboratory findings. The pharmacological management was based on non-steroidal anti-inflammatory drugs in 20 cases. Systemic or local steroid therapy was indicated in 13 patients. Sulfasalazine was indicated in two cases. Alleviation of symptoms and recovery were noted in 22 cases. The mean duration of the clinical resolution was 16 + 57 days.

CONCLUSION

The diagnosis of reactive arthritis should be considered in patients with a new onset of arthritis following COVID-19 infection. Its mechanism is still unclear.

Does post-COVID reactive arthritis exist? Experience of a tertiary care centre with a review of the literature

BACKGROUND

Rheumatological manifestations following COVID-19 are various, including Reactive Arthritis (ReA), which is a form of asymmetric oligoarthritis mainly involving the lower limbs, with or without extra-articular features. The current case series describes the clinical profile and treatment outcome of 23 patients with post-COVID-19 ReA.

METHODS

A retrospective, observational study of patients with post-COVID-19 arthritis over one year was conducted at a tertiary care centre in India. Patients (n=23) with either a positive polymerase chain reaction test for SARS-CoV2 or an anti-COVID-19 antibody test were included. Available demographic details, musculoskeletal symptoms, inflammatory markers, and treatment given were documented.

RESULTS

Sixteen out of 23 patients were female. The mean age of the patients was 42.8 years. Nineteen patients had had symptomatic COVID-19 infection in the past. The duration between onset of COVID-19 symptoms and arthritis ranged from 5 to 52 days with a mean of 25.9 days. The knee was the most involved joint (16 out of 23 cases). Seven patients had inflammatory lower back pain and nine had enthesitis. Most patients were treated with non-steroidal anti-inflammatory drugs (NSAIDs) and steroids - either depot injection or a short oral course. Three patients required treatment with hydroxychloroquine and methotrexate which were eventually stopped. No relapse was reported in any of the patients.

CONCLUSION

On combining our data with 21 other case reports of ReA, a lower limb predominant, oligoarticular, asymmetric pattern of arthritis was seen with a female preponderance. The mean number of joints involved was 2.8. Axial symptoms and enthesitis were often coexistent. Treatment with NSAIDs and intra-articular steroids was effective. However, whether COVID-19 was the definitive aetiology of the arthritis is yet to be proven.

COVID-19-associated arthritis: an emerging new entity?

The current COVID-19 pandemic raises several clinical challenges. Cases of COVID-19-associated arthritis have been reported, and inconsistently described as either COVID-19 viral arthritis or COVID-19 reactive arthritis. We aimed to review all the reported cases of 'COVID-19-associated arthritis', which we propose, is a better term to define the entire spectrum of new-onset arthritis believed to be associated with SARS-CoV-2 infection. We performed a systematic literature review using MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews to search for articles published up to 13 December 2021. We included cohort studies, case series and case reports describing patients diagnosed with COVID-19 reactive or viral arthritis by a physician, irrespective of fulfilment of classification criteria. To identify relevant studies, medical subject headings and keywords related to 'COVID-19/SARS-CoV-2 infection' and 'reactive arthritis' were used. Our search retrieved 419 articles, of which 31 were included in the review. A total of 33 cases were reported in these 31 articles, the majority being adults (28/33=85%) with peripheral joint involvement (26/33=79%). Most of the patients responded well to treatment and the disease was self-limiting. These 33 case reports describe a possible causal relationship between exposure to SARS-CoV-2 and the onset of arthritis. However, since these cases were reported during a pandemic, other aetiologies cannot be fully excluded. The exact mechanism through which SARS-CoV-2 might trigger arthritis is not fully understood and robust epidemiological data to support a causal relationship are still lacking.

Rheumatoid arthritis and post-COVID-19 syndrome

In the third year of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2, COVID-19) pandemic doctors are encountering a new pathology – post-COVID-19 syndrome (PCS, long covid). Musculoskeletal manifestations are among the most common and may present as myalgia, arthralgia, or arthritis. Currently, there is no generally accepted definition of the disease, its duration, classification, or diagnostic criteria, and no single view on the “content” of musculoskeletal manifestations of PCS. We have enough descriptions of the debut of rheumatoid arthritis (RA) after SARS-CoV-2. That is a question: it is a coincidence, or COVID-19 may be a trigger factor of RA? We thought that SARS-CoV-2 infection may be a trigger factor for new rheumatic musculoskeletal diseases, including rheumatoid arthritis or COVID-19 can unmask previously undetected RA. The occurrence of arthritis may be a sign of PCS with transient character. So arthritis in the post covid period may induce problems in differential diagnosis of rheumatic diseases. 

Complete persistent remission of rheumatoid arthritis after COVID-19 infection - A rare case and literature review

A 55-year-old man was admitted to a hospital in Northeast India with fever, cough and breathlessness and was diagnosed with severe COVID-19 pneumonia. He was a known case of seropositive, erosive rheumatoid arthritis (RA) and was taking disease-modifying anti-rheumatic drugs (DMARDs). The patient was treated with remdesivir, heparin and a short course of corticosteroids for COVID-19 pneumonia. With the improvement of COVID-19 pneumonia, the patient also noticed a marked improvement in his joint symptoms despite not taking any DMARDs for RA. The temporal relationship between the time of disappearance of all signs and symptoms of RA within a few days after COVID-19 pneumonia and maintenance of RA remission for over one year of follow up to date suggests that COVID-19 likely caused the remission of RA. This case highlights the need for larger studies to understand the COVID-19 effects on RA remission and their potential link if any. However, the evidence of worse outcome with COVID-19 in immunosuppression which is common in RA cannot be overlooked.

Reactive arthritis before and after the onset of the COVID-19 pandemic

Most accepted definitions of reactive arthritis (ReA) consider it a type of spondyloarthritis (SpA) precipitated by a gut or urogenital infection. A wider definition considers any arthritis that occurs after a mucosal surface infection as ReA. There is limited consensus regarding a working definition, status of HLA-B27, or even classification criteria for ReA. This may also contribute to a lack of systemic studies or clinical trials for ReA, thereby reducing further treatment recommendations to expert opinions only. The emergence of post-COVID-19 ReA has brought the focus back on this enigmatic entity. Post-COVID-19 ReA can present at extremes of age, appears to affect both sexes equally and can have different presentations. Some present with small joint arthritis, others with SpA phenotype-either with peripheral or axial involvement, while a few have only tenosynovitis or dactylitis. The emergence of post-vaccination inflammatory arthritis hints at similar pathophysiology involved. There needs to be a global consensus on whether or not to include all such conditions under the umbrella of ReA. Doing so will enable studies on uniform groups on how infections precipitate arthritis and what predicts chronicity. These have implications beyond ReA and might be extrapolated to other inflammatory arthritides.

Key Points

• Classical reactive arthritis (ReA) has a spondyloarthritis phenotype and is preceded by symptomatic gut or urogenital infection

• The demonstration of antigen and nucleic acid sequences of pathogens in synovium has blurred the difference between invasive arthritis and reactive arthritis

• Post-COVID-19 ReA has a transient phenotype and can have different presentations. All reported cases are self-limiting

• The large amount of literature reporting post-COVID-19 ReA calls for introspection if the existing definitions of ReA need to be updated.

New-onset Polymyalgia Rheumatica Following the Administration of the Pfizer-BioNTech COVID-19 Vaccine

We herein report the case of an 80-year-old Japanese woman who presented to our hospital with bilateral pain in the shoulders and hips lasting for a month since 2 days after the second dose of the BNT162b2 COVID-19 vaccine. Her physical findings, laboratory data, and ultrasonographic findings of bilateral biceps tenosynovitis and lateral subacromial bursitis were consistent with a diagnosis of polymyalgia rheumatica (PMR). She was successfully treated with oral prednisolone 15 mg/day. Although a causal relationship could not be definitively confirmed, PMR should be considered as a differential diagnosis in cases of persistent myalgia after administration of the BNT162b2 vaccine.

Successful Use of Certolizumab Pegol for Refractory Psoriatic Arthritis Triggered by COVID-19 Infection

Recently, the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has spread worldwide. Although nearly all patients incur mild-to-moderate disease from this viral infection, some develop severe manifestations with a poor prognosis. COVID-19 can also induce autoimmune disease; several cases of arthritis following COVID-19 have been documented in the literature, such as reactive arthritis and chronic arthritis. We herein report a case of psoriatic arthritis triggered by COVID-19. Although the arthritis had been refractory to glucocorticoids and methotrexate, certolizumab pegol subsequently led to remission.

New Onset of Autoimmune Diseases Following COVID-19 Diagnosis

There is growing evidence that coronavirus disease 2019 (COVID-19) can lead to a dysregulation of the immune system with the development of autoimmune phenomena. The consequence of this immune dysregulation ranges from the production of autoantibodies to the onset of rheumatic autoimmune disease. In this context, we conducted a systematic review to analyze the current data regarding the new-onset systemic and rheumatic autoimmune diseases in COVID-19 patients. A literature search in PubMed and Scopus databases from December 2019 to September 2021 identified 99 patients that fulfilled the specific diagnostic/classification criteria and/or nomenclature for each rheumatic autoimmune disease. The main diseases reported were vasculitis and arthritis. Idiopathic inflammatory myopathies, systemic lupus erythematosus, and sarcoidosis were also reported in a limited number of patients, as well as isolated cases of systemic sclerosis and adult-onset Still's disease. These findings highlight the potential spectrum of systemic and rheumatic autoimmune diseases that could be precipitated by SARS-CoV-2 infection. Complementary studies are needed to discern the link between the SARS-CoV-2 and new onset-rheumatic diseases so that this knowledge can be used in early diagnosis and the most suitable management.

Reactive arthritis after COVID-19: a case-based review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 19 (COVID-19) pandemic, which is deeply affecting the whole world. In this new case for the scientific world, scientists are investigating the etiopathogenesis of viral infection-induced damage and have started to focus on the short and long-term immune system effects and alterations after SARS-CoV-2 infection. The case is here reported of a 53-year-old female patient with acute monoarthritis after SARS-CoV-2 infection, who responded adequately to 150 mg/day diclofenac treatment, and the available case reports are comprehensively reviewed. With the focus on arthritis after SARS-CoV2 infection, which emerges as a new pathological condition associated with COVID-19, it was aimed to examine the possible immunological mechanisms of post-COVID-19 arthritis based on the current data on SARS-CoV-2 and the known pathogenetic background of viral arthritis.

Post-COVID-19 Arthritis and Sacroiliitis: Natural History with Longitudinal Magnetic Resonance Imaging Study in Two Cases and Review of the Literature

Severe acute respiratory coronavirus-2 syndrome (SARS-CoV-2) is a well-known pandemic infectious disease caused by an RNA virus belonging to the coronaviridae family. The most important involvement during the acute phase of infection concerns the respiratory tract and may be fatal. However, COVID-19 may become a systemic disease with a wide spectrum of manifestations. Herein, we report the natural history of sacroiliac inflammatory involvement in two females who developed COVID-19 infection with mild flu-like symptoms. After the infection they reported inflammatory back pain, with magnetic resonance imaging (MRI) studies showing typical aspects of sacroiliitis. Symptoms improved with NSAIDs therapy over the following months while MRI remained positive. A literature review was performed on this emerging topic. To our knowledge, this is the first MRI longitudinal study of post-COVID-19 sacroiliitis with almost one year of follow-up. Predisposing factors for the development of articular involvement are unclear but a long-lasting persistence of the virus, demonstrated by nasopharyngeal swab, may enhance the probability of altering the immune system in a favourable background.

[Post-Corona-Virus-Disease‑19 arthritis. Manifestation under the clinical picture of a reactive arthritis]

A total of 13 case reports of reactive arthritis reported in the literature in connection with coronavirus disease 2019 (COVID‑19) are reviewed. Men were affected more frequently than women. The arthritis was manifested 4-44 days after the infection or the occurrence of the COVID‑19 symptoms. Acute arthritis was monoarticular or oligoarticular. Only 1 out of 7 patients examined was human-leucocyte-antigen(HLA)-B27 positive. A direct viral infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could not be detected in the synovial fluid and was not investigated in the synovial membrane. The arthritis was successfully treated with nonsteroidal anti-inflammatory drugs and/or intra-articular or systemic corticosteroids. The pathogenesis of post-COVID‑19 reactive arthritis is unknown.

COVID-19 and the clinical course of rheumatic manifestations

The manifestations of COVID-19 have been evolving over time. Various post-COVID-19 syndromes are being recognised. Various viruses have been implicated in the pathogenesis of autoimmune diseases, and we expect a similar outcome with the severe acute respiratory syndrome-associated coronavirus-2 (SARS-CoV-2). The SARS-CoV-2 virus penetrates various tissues and organs and has a predisposition to lead to endotheliitis that may cause vascular manifestations including thrombosis. SARS-CoV-2 has been shown to activate Toll-like receptors and the complement system. It perpetuates NETosis and leads to autoantibody formation. These predispose to systemic autoimmunity. Both reactive arthritis and connective tissue disorders such as lupus and inflammatory myositis have been reported after COVID-19. Other reported autoimmune disorders include haemolytic anaemia, immune thrombocytopenia, cutaneous vasculitis, and Guillain Barré-like acute demyelinating disorders. The multi-system inflammatory syndrome in children and its adult counterpart are another post-COVID-19 entity that presents as an admixture of Kawasaki disease and staphylococcal toxic shock syndrome. Patients with preexisting rheumatic diseases may flare during the SARS-CoV-2 infection. They may develop novel autoimmune features also. The immune-suppressants used during the acute COVID-19 illness may confound the outcomes whereas comorbidities present in patients with rheumatic diseases may mask them. There is an urgent need to follow-up patients recovering from COVID and monitor autoantibody production in the context of rheumatic manifestations. Key Points • COVID-19 is associated with both innate and acquired immune reactions and production of various autoantibodies. • Various immune-mediated manifestations such as arthritis, myositis, haemolytic anaemia, thrombocytopenia, and acute demyelination may develop after COVID-19. • Longitudinal cohort data are warranted to describe, predict, and test prevent various rheumatic manifestations in post-COVID-19 subjects.

Incomplete Systemic Recovery and Metabolic Phenoreversion in Post-Acute-Phase Nonhospitalized COVID-19 Patients: Implications for Assessment of Post-Acute COVID-19 Syndrome

We present a multivariate metabotyping approach to assess the functional recovery of nonhospitalized COVID-19 patients and the possible biochemical sequelae of "Post-Acute COVID-19 Syndrome", colloquially known as long-COVID. Blood samples were taken from patients ca. 3 months after acute COVID-19 infection with further assessment of symptoms at 6 months. Some 57% of the patients had one or more persistent symptoms including respiratory-related symptoms like cough, dyspnea, and rhinorrhea or other nonrespiratory symptoms including chronic fatigue, anosmia, myalgia, or joint pain. Plasma samples were quantitatively analyzed for lipoproteins, glycoproteins, amino acids, biogenic amines, and tryptophan pathway intermediates using Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. Metabolic data for the follow-up patients (n = 27) were compared with controls (n = 41) and hospitalized severe acute respiratory syndrome SARS-CoV-2 positive patients (n = 18, with multiple time-points). Univariate and multivariate statistics revealed variable patterns of functional recovery with many patients exhibiting residual COVID-19 biomarker signatures. Several parameters were persistently perturbed, e.g., elevated taurine (p = 3.6 × 10-3 versus controls) and reduced glutamine/glutamate ratio (p = 6.95 × 10-8 versus controls), indicative of possible liver and muscle damage and a high energy demand linked to more generalized tissue repair or immune function. Some parameters showed near-complete normalization, e.g., the plasma apolipoprotein B100/A1 ratio was similar to that of healthy controls but significantly lower (p = 4.2 × 10-3) than post-acute COVID-19 patients, reflecting partial reversion of the metabolic phenotype (phenoreversion) toward the healthy metabolic state. Plasma neopterin was normalized in all follow-up patients, indicative of a reduction in the adaptive immune activity that has been previously detected in active SARS-CoV-2 infection. Other systemic inflammatory biomarkers such as GlycA and the kynurenine/tryptophan ratio remained elevated in some, but not all, patients. Correlation analysis, principal component analysis (PCA), and orthogonal-partial least-squares discriminant analysis (O-PLS-DA) showed that the follow-up patients were, as a group, metabolically distinct from controls and partially comapped with the acute-phase patients. Significant systematic metabolic differences between asymptomatic and symptomatic follow-up patients were also observed for multiple metabolites. The overall metabolic variance of the symptomatic patients was significantly greater than that of nonsymptomatic patients for multiple parameters (χ2p = 0.014). Thus, asymptomatic follow-up patients including those with post-acute COVID-19 Syndrome displayed a spectrum of multiple persistent biochemical pathophysiology, suggesting that the metabolic phenotyping approach may be deployed for multisystem functional assessment of individual post-acute COVID-19 patients.