Tag: cytokines

Overlapping Clinical Presentation of Long COVID and Postacute COVID-19 Vaccination Syndrome: Phenotypes, Severity, and Biomarkers

Abstract:

Background: Postacute sequelae of COVID-19 (PASC), also known as long COVID, and postacute COVID-19 vaccination syndrome (PACVS) present overlapping but distinct clinical challenges. We hypothesize that PASC and PACVS share clinical features but differ in symptom patterns and biomarker profiles. This study aims to identify differences in presentation and distinguish immunologic biomarkers relevant to general clinical practice.

Methods: This cross-sectional study analyzed 181 patients from a PASC clinic at Columbia University Irving Medical Center. Patients were divided into PASC with myalgic encephalomyelitis/chronic fatigue syndrome (MECFS), PASC without MECFS (LC), and PACVS groups. Prevalence and severity of self-reported symptoms, as well as immunologic abnormalities, were compared across groups.

Results: Fatigue was the most common symptom (Total: 88.95%; MECFS: 100.00%; PACVS: 92.86%; LC: 78.05%). The MECFS group generally reported more symptoms across all organ systems. The PACVS group reported higher rates of atypical chief complaints such as peripheral neuropathy (17.9%), tinnitus (7.1%), and rash (10.7%) compared to the other groups (P = <.01). Functional impairment was comparable between the MECFS and PACVS groups and less severe in the LC group. All groups had high rates of autoantibody positivity and cytokine elevation. The PACVS group showed significantly higher rates of anticardiolipin IgM (PACVS 42.9%, LC 11.6%; P = .02) and anti-U1-RNP (PACVS 21.4%, LC 2.3%; P = .04) positivity compared to the LC group.

Conclusions: PASC and PACVS share symptom overlap but exhibit distinct biomarker patterns, particularly elevated autoantibody levels in PACVS. These findings suggest autoimmune involvement, warranting further investigation for targeted therapies.

Source: Purpura L, Heisler T, Palmer S, Shah J, Graham A, Seo GY, Sturiza A, Javier X, Pinto G, Rosa A, Bosco J, Reis K, Sobieszczyk ME, Yin MT. Overlapping Clinical Presentation of Long COVID and Postacute COVID-19 Vaccination Syndrome: Phenotypes, Severity, and Biomarkers. Clin Infect Dis. 2026 Jan 9:ciaf624. doi: 10.1093/cid/ciaf624. Epub ahead of print. PMID: 41510565. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaf624/8417802 (Full text)

Cytokine profiles associated with persisting symptoms of post-acute sequelae of COVID-19

Abstract:

Background/aims: Post-acute sequelae of COVID-19 (PASC) are highly heterogeneous; therefore, the pathophysiological mechanisms for PASC remain unclear. In this study, we aimed to examine the immunologic aspects of various PASC symptoms.

Methods: We prospectively enrolled adults aged ≥ 18 years who were diagnosed with COVID-19 between August 2022 and September 2023. Blood samples were collected from all participants, who were interviewed using a questionnaire for PASC symptoms at least once between 1 and 6 months after the COVID-19 diagnosis. For immunological evaluation, plasma concentrations of SARS-CoV-2 spike subunit 1-specific IgG and 33 cytokines were measured using enzyme-linked immunosorbent assays and multiplex-based immunoassay, respectively.

Results: In total, 156 pairs of blood samples and symptom reports from 79 participants were eligible for analysis. The most frequent symptom was fatigue, followed by post exertional malaise, chronic cough, thirst, and brain fog. Gastrointestinal symptoms, chest pain, post exertional malaise, smell/taste change, fatigue, brain fog, abnormal movement, and palpitation were accompanied by significant increases in IL-10, VEGF, and inflammatory cytokines like MIP-1α, IL-1β, IL-6, IL-8, MIG, granzyme A, and CX3CL1 levels, while chronic cough, dizziness, dyspnea, and hair loss were not accompanied by significant differences in cytokine levels.

Conclusion: Symptoms classified into different categories based on the dysfunctional organs may share a common pathophysiology regarding elevation of certain cytokines. Although PASC symptoms are heterogeneous, our findings suggest that T-cell recruitment, thrombosis, and increased vascular permeability might contribute to various symptom clusters sharing common pathophysiological mechanisms.

Source: Kwon JS, Chang E, Jang HM, Kim JY, Kim W, Son JY, Cha J, Jang CY, Bae S, Jung J, Kim MJ, Chong YP, Lee SO, Choi SH, Kim YS, Kim SH. Cytokine profiles associated with persisting symptoms of post-acute sequelae of COVID-19. Korean J Intern Med. 2025 Jul;40(4):667-675. doi: 10.3904/kjim.2024.217. Epub 2025 Jul 1. PMID: 40635493. https://kjim.org/journal/view.php?doi=10.3904/kjim.2024.217 (Full text)

Immune Signatures in Post-Acute Sequelae of COVID-19 (PASC) and Myalgia/Chronic Fatigue Syndrome (ME/CFS): Insights from the Fecal Microbiome and Serum Cytokine Profiles

Abstract:

While there are many postulates for the etiology of post-viral chronic fatigue and other symptomatology, little is known. We draw on our past experience of these syndromes to devise means which can expose the primary players of this malady in terms of a panoply participating biomolecules and the state of the stool microbiome.
Using databases established from a large dataset of patients at risk of colorectal cancer who were followed longitudinally over 3 decades, and a smaller database dedicated to building a Long PASC cohort (Post-Acute Sequelae of COVID-19), we were able to ascertain factors that predisposed patients to (and resulted in) significant changes in various biomarkers, i.e., the stool microbiome and serum cytokine levels, which we verified by collecting stool and serum samples.
There were significant changes in the stool microbiome with an inversion from the usual Bacillota and Bacteroidota species. Serum cytokines showed significant differences in MIP-1β versus TARC (CC chemokine ligand 17) in patients with either PASC or COVID-19 (p < 0.02); IL10 versus IL-12p70a (p < 0.02); IL-1b versus IL-6 (p < 0.01); MCP1 versus TARC (p < 0.03); IL-8 versus TARC (p < 0.002); and Eotaxin3 versus TARC (p < 0.004) in PASC. Some changes were seen solely in COVID-19, including MDC versus MIP-1α (p < 0.01); TNF-α versus IL-1-β (p < 0.06); MCP4 versus TARC (p < 0.0001). We also show correlates with chronic fatigue where an etiology was not identified.
These findings in patients with positive criteria for PASC show profound changes in the microbiome and serum cytokine expression. Patients with chronic fatigue without clear viral etiologies also have common associations, including a history of tonsillectomy, which evokes a likely immune etiology.
Source: Tobi, M., Chaudhari, D., Ryan, E. P., Rossi, N. F., Koka, O., Baxter, B., Tipton, M., Dutt, T. S., Tobi, Y., McVicker, B., & Angoa-Perez, M. (2025). Immune Signatures in Post-Acute Sequelae of COVID-19 (PASC) and Myalgia/Chronic Fatigue Syndrome (ME/CFS): Insights from the Fecal Microbiome and Serum Cytokine Profiles. Biomolecules, 15(7), 928. https://doi.org/10.3390/biom15070928 https://www.mdpi.com/2218-273X/15/7/928 (Full text)

Brainstem Reduction and Deformation in the 4th Ventricle Cerebellar Peduncles in Long COVID Patients: Insights into Neuroinflammatory Sequelae and “Broken Bridge Syndrome”

Abstract:

Post-COVID Syndrome (PCS), also known as Long COVID, is characterized by persistent and often debilitating neurological sequelae, including fatigue, cognitive dysfunction, motor deficits, and autonomic dysregulation (Dani et al., 2021). This study investigates structural and functional alterations in the brainstem and cerebellar peduncles of individuals with PCS using diffusion tensor imaging (DTI) and volumetric analysis. Forty-four PCS patients (15 bedridden) and 14 healthy controls underwent neuroimaging. Volumetric analysis focused on 22 brainstem regions, including the superior cerebellar peduncle (SCP), middle cerebellar peduncle (MCP), periaqueductal gray (PAG), and midbrain reticular formation (mRt).

Significant volume reductions were observed in the SCP (p < .001, Hedges’ g = 3.31) and MCP (p < .001, Hedges’ g = 1.77), alongside decreased fractional anisotropy (FA) in the MCP, indicative of impaired white matter integrity. FA_Avg fractional anisotropy average tested by FreeSurfer Tracula, is an index of white matter integrity, reflecting axonal fiber density, axonal diameter and myelination. These neuroimaging findings correlated with clinical manifestations of motor incoordination, proprioceptive deficits, and autonomic instability. Furthermore, volume loss in the dorsal raphe (DR) and midbrain reticular formation suggests disruption of pain modulation and sleep-wake cycles, consistent with patient-reported symptoms.

Post-mortem studies provide supporting evidence for brainstem involvement in COVID-19. Radtke et al. (2024) reported activation of intracellular signaling pathways and release of immune mediators in brainstem regions of deceased COVID-19 patients, suggesting an attempt to inhibit viral spread. While viral genetic material was detectable, infected neurons were not observed. Matschke et al. (2020) found that microglial activation and cytotoxic T lymphocyte infiltration were predominantly localized to the brainstem and cerebellum, with limited involvement of the frontal lobe. This aligns with clinical observations implicating the brainstem in PCS pathophysiology. Cell-specific expression analysis of genes contributing to viral entry (ACE2, TMPRSS2, TPCN2, TMPRSS4, NRP1, CTSL) in the cerebral cortex showed their presence in neurons, glial cells, and endothelial cells, indicating the potential for SARS-CoV-2 infection of these cell types. Associations with autoimmune diseases with specific autoantibodies, including beta-2 and M-2 against G-protein coupled alpha-1, beta-1, beta-2 adrenoceptors against angiotensin II type 1 receptor or M1,2,3-mAChR, among others, voltage-gated calcium channels (VGCC) are known (Blitshteyn et al. 2015 and Wallukat and Schminke et al. 2014).

These findings support the “Broken Bridge Syndrome” hypothesis, positing that structural disconnections between the brainstem and cerebellum contribute to PCS symptomatology. Furthermore, we propose that chronic activation of the Extended Autonomic System (EAS), encompassing the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system, may perpetuate these symptoms (Goldstein, 2020). Perturbations in this system may relate to the elevation of toxic autoantibodies AABs (Beta-2 and M-2), specific epitopes of the COVID virus’s SPIKE protein and Cytokine storm of IL-1, IL-6, and IL-8 in their increased numbers (1,000->10,000)

Further research is warranted to elucidate the underlying neuroinflammatory mechanisms, EAS dysregulation, and potential therapeutic interventions for PCS

Source: Ziaja Peter Christof, Young Yvette Susanne, Stark Sadre-Chirazi Michael, Lindner Thomas, Zurék Grzegorz, Sedlacik Jan. Brainstem Reduction and Deformation in the 4th Ventricle Cerebellar Peduncles in Long COVID Patients: Insights into Neuroinflammatory Sequelae and “Broken Bridge Syndrome” medRxiv 2025.04.08.25325108; doi: https://doi.org/10.1101/2025.04.08.25325108 https://www.medrxiv.org/content/10.1101/2025.04.08.25325108v1.full-text (Full text)

Direct effects of prolonged TNF-α and IL-6 exposure on neural activity in human iPSC-derived neuron-astrocyte co-cultures

Abstract:

Cognitive impairment is one of the many symptoms reported by individuals suffering from long-COVID and other post-viral infection disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A common factor among these conditions is a sustained immune response and increased levels of inflammatory cytokines. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) are two such cytokines that are elevated in patients diagnosed with long-COVID and ME/CFS.

In this study, we characterized the changes in neural functionality, secreted cytokine profiles, and gene expression in co-cultures of human iPSC-derived neurons and primary astrocytes in response to prolonged exposure to TNF-α and IL-6. We found that exposure to TNF-α produced both a concentration-independent and concentration-dependent response in neural activity.

Burst duration was significantly reduced within a few days of exposure regardless of concentration (1 pg/mL – 100 ng/mL) but returned to baseline after 7 days. Treatment with low concentrations of TNF-α (e.g., 1 and 25 pg/mL) did not lead to changes in the secreted cytokine profile or gene expression but still resulted in significant changes to electrophysiological features such as interspike interval and burst duration. Conversely, treatment with high concentrations of TNF-α (e.g., 10 and 100 ng/mL) led to reduced spiking activity, which may be correlated to changes in neural health, gene expression, and increases in inflammatory cytokine secretion (e.g., IL-1β, IL-4, and CXCL-10) that were observed at higher TNF-α concentrations.

Prolonged exposure to IL-6 led to changes in bursting features, with significant reduction in the number of spikes in bursts across a wide range of treatment concentrations (i.e., 1 pg/mL-10 ng/mL). In combination, the addition of IL-6 appears to counteract the changes to neural function induced by low concentrations of TNF-α, while at high concentrations of TNF-α the addition of IL-6 had little to no effect. Conversely, the changes to electrophysiological features induced by IL-6 were lost when the cultures were co-stimulated with TNF-α regardless of the concentration, suggesting that TNF-α may play a more pronounced role in altering neural function.

These results indicate that increased concentrations of key inflammatory cytokines associated with long-COVID can directly impact neural function and may be a component of the cognitive impairment associated with long-COVID and other post-viral infection disorders.

Source: Goshi N, Lam D, Bogguri C, George VK, Sebastian A, Cadena J, Leon NF, Hum NR, Weilhammer DR, Fischer NO, Enright HA. Direct effects of prolonged TNF-α and IL-6 exposure on neural activity in human iPSC-derived neuron-astrocyte co-cultures. Front Cell Neurosci. 2025 Feb 12;19:1512591. doi: 10.3389/fncel.2025.1512591. PMID: 40012566; PMCID: PMC11860967. https://pmc.ncbi.nlm.nih.gov/articles/PMC11860967/ (Full text)

Effect of Immunoadsorption on clinical presentation and immune alterations in COVID-19-induced and/or aggravated ME/CFS

Abstract:

Autoreactive antibodies (AAB) are currently being investigated as causative or aggravating factors during post-COVID. In this study we analyze the effect of immunoadsorption therapy on symptom improvement and the relationship with immunological parameters in post-COVID patients exhibiting symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) induced or aggravated by an SARS-CoV-2 infection. This observational study includes 12 post-COVID patients exhibiting a predominance of ME/CFS symptoms alongside increased concentrations of autonomic nervous system receptors (ANSR) autoantibodies and neurological impairments.

We found that following immunoadsorption therapy, the ANSR autoantibodies were nearly eliminated from the patients’ blood. The removal of IgG antibodies was accompanied by a decrease of pro-inflammatory cytokines including IL4, IL2, IL1β, TNF and IL17A serum levels, and a significant reduction of soluble spike protein. Notably, a strong positive correlation between pro-inflammatory cytokines and ASNR-AABs β1, β2, M3, and M4 was observed in spike protein-positive patients, whereas no such correlation was evident in spike protein-negative patients.

30 days post-immunoadsorption therapy, patients exhibited notable improvement in neuropsychological function and a modest but statistically significant amelioration of hand grip strength was observed. However, neither self-reported symptoms nor scores on ME/CFS questionnaires showed a significant improvement and a rebound of the removed proteins occurring within a month.

Source: Anft M, Wiemers L, Rosiewicz KS, Doevelaar A, Skrzypczyk S, Kurek J, Kaliszczyk S, Seidel M, Stervbo U, Seibert FS, Westhoff TH, Babel N. Effect of Immunoadsorption on clinical presentation and immune alterations in COVID-19-induced and/or aggravated ME/CFS. Mol Ther. 2025 Jan 9:S1525-0016(25)00011-5. doi: 10.1016/j.ymthe.2025.01.007. Epub ahead of print. PMID: 39797400. https://www.cell.com/molecular-therapy-family/molecular-therapy/pdf/S1525-0016(25)00011-5.pdf (Full text) https://pubmed.ncbi.nlm.nih.gov/39797400/ (Abstract)

Longitudinal Cytokine and Multi-Modal Health Data of an Extremely Severe ME/CFS Patient with HSD Reveals Insights into Immunopathology, and Disease Severity

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) presents significant challenges in patient care due to its intricate multisystem nature, comorbidities, and global prevalence. To address these complexities, we employed a comprehensive approach, integrating longitudinal cytokine profiling with extensive clinical, health, textual, pharmaceutical, and nutraceutical data, and performed personalized analyses using AI.

Focusing on an exceptionally severe ME/CFS patient with hypermobility spectrum disorder (HSD) and marginal symptom improvements, our study highlights the dynamic nature of symptoms, severity, triggers, and modifying factors. As part of this study, we introduced an updated platform and two applications, ME-CFSTrackerApp, and LexiTime, facilitating real-time symptom tracking and enhancing physician-patient communication.

Our longitudinal cytokine profiling underscores the significance of Th2-type cytokines and synergistic activities between mast cells and eosinophils, leading to skewing of Th1 toward Th2 immune responses in ME/CFS pathogenesis, especially in cognitive impairment and sensorial intolerance. This suggests a potentially shared underlying mechanism with major comorbidities.

Additionally, our data reveal potential roles of BCL6 and TP53 pathways in ME/CFS etiology and emphasize the importance of investigating low-dose drugs with partial agonist activity in ME/CFS treatment. Our analyses underscore the patient-centered care approach for better healthcare management.

Source: Fereshteh Jahanbani1, Justin C. Sing, Rajan D. Maynard, Shaghayegh Jahanbani, Janet Dafoe, Whitney Dafoe, Nathan Jones, Kelvin J. Wallace, Azuravesta Rastan, Hannes Rost, Holden Maecker, Michael P. Snyder, Ronald W. Davis. Longitudinal Cytokine and Multi-Modal Health Data of an Extremely Severe ME/CFS Patient with HSD Reveals Insights into Immunopathology, and Disease Severity. Front. Immunol. Sec. Autoimmune and Autoinflammatory Disorders: Autoinflammatory Disorders. Volume 15 – 2024 | doi: 10.3389/fimmu.2024.1369295 https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1369295/abstract

Sex differences in symptomatology and immune profiles of Long COVID

Abstract:

Strong sex differences in the frequencies and manifestations of Long COVID (LC) have been reported with females significantly more likely than males to present with LC after acute SARS-CoV-2 infection1-7. However, whether immunological traits underlying LC differ between sexes, and whether such differences explain the differential manifestations of LC symptomology is currently unknown.

Here, we performed sex-based multi-dimensional immune-endocrine profiling of 165 individuals8 with and without LC in an exploratory, cross-sectional study to identify key immunological traits underlying biological sex differences in LC.

We found that female and male participants with LC experienced different sets of symptoms, and distinct patterns of organ system involvement, with female participants suffering from a higher symptom burden. Machine learning approaches identified differential sets of immune features that characterized LC in females and males. Males with LC had decreased frequencies of monocyte and DC populations, elevated NK cells, and plasma cytokines including IL-8 and TGF-β-family members.

Females with LC had increased frequencies of exhausted T cells, cytokine-secreting T cells, higher antibody reactivity to latent herpes viruses including EBV, HSV-2, and CMV, and lower testosterone levels than their control female counterparts. Testosterone levels were significantly associated with lower symptom burden in LC participants over sex designation.

These findings suggest distinct immunological processes of LC in females and males and illuminate the crucial role of immune-endocrine dysregulation in sex-specific pathology.

Source: Julio Silva, Takehiro Takahashi, Jamie Wood, Peiwen Lu, Sasha Tabachnikova, Jeffrey Gehlhausen, Kerrie Greene, Bornali Bhattacharjee, Valter Silva Monteiro, Carolina Lucas, Rahul Dhodapkar, Laura Tabacof, Mario Pena-Hernandez, Kathy Kamath, Tianyang Mao, Dayna Mccarthy, Ruslan Medzhitov, David van Dijk, Harlan Krumholz, Leying Guan, David Putrino, Akiko Iwasaki. Sex differences in symptomatology and immune profiles of Long COVID. medRxiv 2024.02.29.24303568; doi: https://doi.org/10.1101/2024.02.29.24303568 https://www.medrxiv.org/content/10.1101/2024.02.29.24303568v1 (Full study available as PDF file)

Spontaneous, persistent, T cell-dependent IFN-γ release in patients who progress to Long Covid

Abstract:

After acute infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a proportion of patients experience persistent symptoms beyond 12 weeks, termed Long Covid. Understanding the mechanisms that cause this debilitating disease and identifying biomarkers for diagnostic, therapeutic, and monitoring purposes are urgently required.

We detected persistently high levels of interferon-γ (IFN-γ) from peripheral blood mononuclear cells of patients with Long Covid using highly sensitive FluoroSpot assays. This IFN-γ release was seen in the absence of ex vivo peptide stimulation and remains persistently elevated in patients with Long Covid, unlike the resolution seen in patients recovering from acute SARS-CoV-2 infection. The IFN-γ release was CD8+ T cell-mediated and dependent on antigen presentation by CD14+ cells.

Longitudinal follow-up of our study cohort showed that symptom improvement and resolution correlated with a decrease in IFN-γ production to baseline levels. Our study highlights a potential mechanism underlying Long Covid, enabling the search for biomarkers and therapeutics in patients with Long Covid.

Source: Krishna BA, Lim EY, Metaxaki M, Jackson S, Mactavous L; NIHR BioResource; Lyons PA, Doffinger R, Bradley JR, Smith KGC, Sinclair J, Matheson NJ, Lehner PJ, Sithole N, Wills MR. Spontaneous, persistent, T cell-dependent IFN-γ release in patients who progress to Long Covid. Sci Adv. 2024 Feb 23;10(8):eadi9379. doi: 10.1126/sciadv.adi9379. Epub 2024 Feb 21. PMID: 38381822; PMCID: PMC10881041. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10881041/ (Full text)

Long COVID Diagnostic with Differentiation from Chronic Lyme Disease using Machine Learning and Cytokine Hubs

Abstract:

The absence of a diagnostic for long COVID (LC) or post-acute sequelae of COVID-19 (PASC) has profound implications for research and potential therapeutics. Further, symptom-based identification of patients with long-term COVID-19 lacks the specificity to serve as a diagnostic because of the overlap of symptoms with other chronic inflammatory conditions like chronic Lymedisease (CLD), myalgic encephalomyelitis-chronic fatigue syndrome (ME-CFS), and others. Here, we report a machine-learning approach to long COVID diagnosis using cytokine hubs that are also capable of differentiating long COVID from chronic Lyme.

We constructed three tree-based classifiers: decision tree, random forest, and gradient-boosting machine (GBM) and compared their diagnostic capabilities. A 223 patient dataset was partitioned into training (178 patients) and evaluation (45 patients) sets. The GBM model was selected based on performance (89% Sensitivity and 96% Specificity for LC) with no evidence of overfitting.

We tested the GBM on a random dataset of 124 individuals (106 PASC and 18 Lyme), resulting in high sensitivity (97%) and specificity 90% for LC). A Lyme Index composed of two features ((TNF-alpha +IL-4)/(IFN-gamma + IL-2) and (TNF-alpha *IL-4)/(IFN-gamma + IL-2 + CCL3) was constructed as a confirmatory algorithm to discriminate between LC and CLD.

Source: Bruce Patterson, Jose Guevara-Coto, Javier Mora et al. Long COVID Diagnostic with Differentiation from Chronic Lyme Disease using Machine Learning and Cytokine Hubs, 18 January 2024, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3873244/v1] https://www.researchsquare.com/article/rs-3873244/v1 (Full text)