Tag: neutrophils

Pituitary–Adrenal Axis and Peripheral Immune Cell Profile in Long COVID

Abstract:

In Long COVID, dysfunction in the pituitary–adrenal axis and alterations in immune cells and inflammatory status are warned against. We performed a prospective study in a cohort of 42 patients who suffered COVID-19 at least 6 months before attending the Long COVID unit at Althaia Hospital.
Based on Post-COVID Functional Status, 29 patients were diagnosed with Long COVID, while 13 were deemed as recovered. The hormones of the pituitary–adrenal axis, adrenocorticotropin stimulation test, and immune cell profiles and inflammatory markers were examined. Patients with Long COVID had significantly lower EuroQol and higher mMRC scores compared to the recovered individuals. Their symptoms included fatigue, myalgia, arthralgia, persistent coughing, a persistent sore throat, dyspnoea, a lack of concentration, and anxiety.
We observed the physiological levels of cortisol and adrenocorticotropin in individuals with or without Long COVID. The results of the adrenocorticotropin stimulation test were similar between both groups. The absolute number of neutrophils was lower in the Long COVID patients compared to recovered individuals (p < 0.05). The total count of B lymphocytes remained consistent, but Long COVID patients had a higher percentage of mature B cells compared to recovered participants (p < 0.05) and exhibited a higher percentage of circulating resident memory CD8+ T cells (p < 0.05) and Treg-expressing exonucleases (p < 0.05).
Our findings did not identify adrenal dysfunction related to Long COVID, nor an association between adrenal function and clinical symptoms. The data indicated a dysregulation in certain immune cells, pointing to immune activation. No overt hyperinflammation was observed in the Long COVID group.
Source: Alijotas-Reig J, Anunciacion-Llunell A, Esteve-Valverde E, Morales-Pérez S, Rivero-Santana S, Trapé J, González-García L, Ruiz D, Marques-Soares J, Miro-Mur F. Pituitary–Adrenal Axis and Peripheral Immune Cell Profile in Long COVID. Biomedicines. 2024; 12(3):581. https://doi.org/10.3390/biomedicines12030581 https://www.mdpi.com/2227-9059/12/3/581 (Full text)

Neutrophil degranulation, endothelial and metabolic dysfunction in unvaccinated long COVID patients

Abstract:

Background: Long COVID symptoms are widely diffused and have a poorly understood pathophysiology, with possible involvement of inflammatory cytokines.

Materials and methods: A prospective follow-up study involved 385 unvaccinated patients, started 1 month after SARS-CoV-2 infection and continued for up to 12 months. We compared circulating biomarkers of neutrophil degranulation, endothelial and metabolic dysfunction in subjects with long COVID symptoms and in asymptomatic post-COVID controls.

Results: The highest occurrence of symptoms (71%) was after 3 months from the infection, decreasing to 62.3% and 29.4% at 6 and 12 months, respectively. Compared to controls, long COVID patients had increased levels of the neutrophilic degranulation indices MMP-8 and MPO, of endothelial dysfunction indices L-selectin and P-selectin. Among indices of metabolic dysfunction, leptin levels were higher in long COVID patients than in controls.

Conclusion: In unvaccinated patients, symptoms may persist up to 1 year after acute COVID infection, with increased indices of neutrophil degranulation, endothelial and metabolic dysfunction. The clinical implications of specific inflammatory biomarkers require further attention, especially in individuals with fatigue and long COVID-linked cognitive dysfunctions.

Source: Di Ciaula A, Liberale L, Portincasa P, Khalil M, Galerati I, Farella I, Noto A, JohnBritto S, Moriero M, Michelauz C, Frè F, Olivero C, Bertolotto M, Montecucco F, Carbone F, Bonfrate L. Neutrophil degranulation, endothelial and metabolic dysfunction in unvaccinated long COVID patients. Eur J Clin Invest. 2024 Jan 16:e14155. doi: 10.1111/eci.14155. Epub ahead of print. PMID: 38226472. https://pubmed.ncbi.nlm.nih.gov/38226472/

Single-Cell RNA Sequencing Reveals Alterations in Patient Immune Cells with Pulmonary Long COVID-19 Complications

Abstract:

Since the emergence of the COVID-19 pandemic, the effects of SARS-CoV-2 have been extensively researched. While much is already known about the acute phase of the infection, increasing attention has turned to the prolonged symptoms experienced by a subset of individuals, commonly referred to as long COVID-19 patients. This study aims to delve deeper into the immune landscape of patients with prolonged symptoms by implementing single-cell mRNA analysis.
A 71-year-old COVID-19 patient presenting with persistent viral pneumonia was recruited, and peripheral blood samples were taken at 3 and 2 years post-acute infection onset. Patients and control peripheral blood mononuclear cells (PBMCs) were isolated and single-cell sequenced. Immune cell population identification was carried out using the ScType script.
Three months post-COVID-19 patients’ PBMCs contained a significantly larger immature neutrophil population compared to 2-year and control samples. However, the neutrophil balance shifted towards a more mature profile after 18 months. In addition, a notable increase in the CD8+ NKT-like cells could be observed in the 3-month patient sample as compared to the later one and control. The subsequent change in these cell populations over time may be an indicator of an ongoing failure to clear the SARS-CoV-2 infection and, thus, lead to chronic COVID-19 complications.
Source: Vaivode K, Saksis R, Litvina HD, Niedra H, Spriņģe ML, Krūmiņa U, Kloviņš J, Rovite V. Single-Cell RNA Sequencing Reveals Alterations in Patient Immune Cells with Pulmonary Long COVID-19 Complications. Current Issues in Molecular Biology. 2024; 46(1):461-468. https://doi.org/10.3390/cimb46010029 https://www.mdpi.com/1467-3045/46/1/29 (Full text)

Extensive acute and sustained changes to neutrophil proteomes post-SARS-CoV-2 infection

Abstract:

Background Neutrophils are important in the pathophysiology of COVID-19 but the molecular changes contributing to altered neutrophil phenotypes following SARS-CoV-2 infection are not fully understood. We used quantitative mass spectrometry-based proteomics to explore neutrophil phenotypes immediately following acute SARS-CoV-2 infection and during recovery.

Methods Prospective observational study of hospitalised patients with PCR-confirmed SARS-CoV-2 infection (May-December 2020). Patients were enrolled within 96 h of admission, with longitudinal sampling up to 29 days. Control groups comprised non-COVID-19 acute lower respiratory tract infection (LRTI) and age-matched non-infected controls. Neutrophils were isolated from peripheral blood and analysed by mass spectrometry. COVID-19 severity and recovery were defined using the WHO ordinal scale.

Results Neutrophil proteomes from 84 COVID-19 patients were compared to those from 91 LRTI and 42 control participants. 5800 neutrophil proteins were identified, with >1700 proteins significantly changed in neutrophils from COVID-19 patients compared to non-infected controls. Neutrophils from COVID-19 patients initially all demonstrated a strong interferon (IFN) signature but this signature rapidly declined in patients with severe disease. Severe disease was associated with increased abundance of proteins involved in metabolism, immunosuppression and pattern recognition, while delayed recovery from COVID-19 was associated with decreased granule components and reduced abundance of metabolic proteins, chemokine and leukotriene receptors, integrins and inhibitory receptors.

Conclusions SARS-CoV-2 infection results in the sustained presence of circulating neutrophils with distinct proteomes suggesting altered metabolic and immunosuppressive profiles and altered capacities to respond to migratory signals and cues from other immune cells, pathogens or cytokines.

Footnotes

This manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.

Source: Merete B Long, Andrew JM Howden, Holly R Keir, Christina M Rollings, Yan Hui Giam, Thomas Pembridge, Lilia Delgado, Hani Abo-Leyah, Amy F Lloyd, Gabriel Sollberger, Rebecca Hull, Amy Gilmour, Chloe Hughes, Benjamin JM New, Diane Cassidy, Amelia Shoemark, Hollian Richardson, Angus I Lamond, Doreen A Cantrell, James D Chalmers, Alejandro J Brenes. Extensive acute and sustained changes to neutrophil proteomes post-SARS-CoV-2 infection. European Respiratory Journal Jan 2023, 2300787; DOI: 10.1183/13993003.00787-2023 https://erj.ersjournals.com/content/early/2023/11/23/13993003.00787-2023 (Full text available as PDF file)

Neutrophil Extracellular Traps and Long COVID

Abstract:

Post-acute COVID-19 sequelae, commonly known as long COVID, encompasses a range of systemic symptoms experienced by a significant number of COVID-19 survivors. The underlying pathophysiology of long COVID has become a topic of intense research discussion. While chronic inflammation in long COVID has received considerable attention, the role of neutrophils, which are the most abundant of all immune cells and primary responders to inflammation, has been unfortunately overlooked, perhaps due to their short lifespan.

In this review, we discuss the emerging role of neutrophil extracellular traps (NETs) in the persistent inflammatory response observed in long COVID patients. We present early evidence linking the persistence of NETs to pulmonary fibrosis, cardiovascular abnormalities, and neurological dysfunction in long COVID.

Several uncertainties require investigation in future studies. These include the mechanisms by which SARS-CoV-2 brings about sustained neutrophil activation phenotypes after infection resolution; whether the heterogeneity of neutrophils seen in acute SARS-CoV-2 infection persists into the chronic phase; whether the presence of autoantibodies in long COVID can induce NETs and protect them from degradation; whether NETs exert differential, organ-specific effects; specifically which NET components contribute to organ-specific pathologies, such as pulmonary fibrosis; and whether senescent cells can escape clearance and drive NET formation in long COVID. Answering these questions may pave the way for the development of clinically applicable strategies targeting NETs, providing relief for this emerging health crisis.

Source: Shafqat, A., Omer, M., Albalkhi, I., Alabdul Razzak, G., Abdulkader, H., Abdul Rab, S., … & Yaqinuddin, A. Neutrophil Extracellular Traps and Long COVID. Frontiers in Immunology, 14, 1254310. https://www.frontiersin.org/articles/10.3389/fimmu.2023.1254310/abstract

Persistent immune and clotting dysfunction detected in saliva and blood plasma after COVID-19

Abstract:

A growing number of studies indicate that coronavirus disease 2019 (COVID-19) is associated with inflammatory sequelae, but molecular signatures governing the normal versus pathologic convalescence process have not been well-delineated. Here, we characterized global immune and proteome responses in matched plasma and saliva samples obtained from COVID-19 patients collected between 20 and 90 days after initial clinical symptoms resolved.

Convalescent subjects showed robust total IgA and IgG responses and positive antibody correlations in saliva and plasma samples. Shotgun proteomics revealed persistent inflammatory patterns in convalescent samples including dysfunction of salivary innate immune cells, such as neutrophil markers (e.g., myeloperoxidase), and clotting factors in plasma (e.g., fibrinogen), with positive correlations to acute COVID-19 disease severity. Saliva samples were characterized by higher concentrations of IgA, and proteomics showed altered myeloid-derived pathways that correlated positively with SARS-CoV-2 IgA levels.

Beyond plasma, our study positions saliva as a viable fluid to monitor normal and aberrant immune responses including vascular, inflammatory, and coagulation-related sequelae.

Source: Jang H, Choudhury S, Yu Y, Sievers BL, Gelbart T, Singh H, Rawlings SA, Proal A, Tan GS, Qian Y, Smith D, Freire M. Persistent immune and clotting dysfunction detected in saliva and blood plasma after COVID-19. Heliyon. 2023 Jul 4;9(7):e17958. doi: 10.1016/j.heliyon.2023.e17958. PMID: 37483779; PMCID: PMC10362241. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10362241/ (Full text)

Chronic inflammation, neutrophil activity, and autoreactivity splits long COVID

Abstract:

While immunologic correlates of COVID-19 have been widely reported, their associations with post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, understanding if specific disease features associate with discrete immune processes and therapeutic opportunities is important.

Here we profile patients in the recovery phase of COVID-19 via proteomics screening and machine learning to find signatures of ongoing antiviral B cell development, immune-mediated fibrosis, and markers of cell death in PASC patients but not in controls with uncomplicated recovery. Plasma and immune cell profiling further allow the stratification of PASC into inflammatory and non-inflammatory types.

Inflammatory PASC, identifiable through a refined set of 12 blood markers, displays evidence of ongoing neutrophil activity, B cell memory alterations, and building autoreactivity more than a year post COVID-19. Our work thus helps refine PASC categorization to aid in both therapeutic targeting and epidemiological investigation of PASC.

Source: Woodruff MC, Bonham KS, Anam FA, Walker TA, Faliti CE, Ishii Y, Kaminski CY, Ruunstrom MC, Cooper KR, Truong AD, Dixit AN, Han JE, Ramonell RP, Haddad NS, Rudolph ME, Yalavarthi S, Betin V, Natoli T, Navaz S, Jenks SA, Zuo Y, Knight JS, Khosroshahi A, Lee FE, Sanz I. Chronic inflammation, neutrophil activity, and autoreactivity splits long COVID. Nat Commun. 2023 Jul 14;14(1):4201. doi: 10.1038/s41467-023-40012-7. PMID: 37452024; PMCID: PMC10349085. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10349085/ (Full text)

Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia

Abstract:

Fibromyalgia is a debilitating widespread chronic pain syndrome that occurs in 2 to 4% of the population. The prevailing view that fibromyalgia results from central nervous system dysfunction has recently been challenged with data showing changes in peripheral nervous system activity.

Using a mouse model of chronic widespread pain through hyperalgesic priming of muscle, we show that neutrophils invade sensory ganglia and confer mechanical hypersensitivity on recipient mice, while adoptive transfer of immunoglobulin, serum, lymphocytes, or monocytes has no effect on pain behavior.

Neutrophil depletion abolishes the establishment of chronic widespread pain in mice. Neutrophils from patients with fibromyalgia also confer pain on mice. A link between neutrophil-derived mediators and peripheral nerve sensitization is already established. Our observations suggest approaches for targeting fibromyalgia pain via mechanisms that cause altered neutrophil activity and interactions with sensory neurons.

Source: Caxaria S, Bharde S, Fuller AM, Evans R, Thomas B, Celik P, Dell’Accio F, Yona S, Gilroy D, Voisin MB, Wood JN, Sikandar S. Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia. Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2211631120. doi: 10.1073/pnas.2211631120. Epub 2023 Apr 18. PMID: 37071676. https://www.pnas.org/doi/10.1073/pnas.2211631120 (Full text)

NETosis induction reflects COVID-19 severity and Long COVID: insights from a two-center patient cohort study in Israel

Abstract:

Background: COVID-19 severity and its late complications continue to be poorly understood. Neutrophil extracellular traps (NETs) form in acute COVID-19, likely contributing to morbidity and mortality. This study evaluated immunothrombosis markers in a comprehensive cohort of acute and recovered COVID-19 patients, including the association of NETs with LongCOVID.

Methods: One-hundred-seventy-seven patients were recruited from clinical cohorts at two Israeli centers: acute COVID-19 (mild/moderate, severe/critical), convalescent COVID-19 (recovered and Long COVID), along with 54 non-COVID controls. Plasma was examined for markers of platelet activation, coagulation, and NETs. Ex vivo NETosis induction capability was evaluated after neutrophil incubation with patient plasma.

Results: Soluble P-selectin, Factor VIII, von Willebrand factor, and platelet factor 4 were significantly elevated in COVID-19 patients versus controls. Myeloperoxidase (MPO)-DNA complex levels were increased only in severe COVID-19 and did not differentiate between COVID-19 severities or correlate with thrombotic markers. NETosis induction levels strongly correlated with illness severity/duration, platelet activation markers, and coagulation factors, and were significantly reduced upon dexamethasone treatment and recovery. Long COVID patients maintained higher NETosis induction, but not NET fragments, compared to recovered convalescent patients.

Conclusions: Increased NETosis induction can be detected in Long COVID patients. NETosis induction appears to be a more sensitive NET measurement than MPO-DNA levels in COVID-19, differentiating between disease severity and Long COVID patients. Ongoing NETosis induction capability in Long COVID may provide insights into pathogenesis and serve as a surrogate marker for persistent pathology. This study emphasizes the need to explore neutrophil-targeted therapies in acute and chronic COVID-19.

Source: Krinsky N, Sizikov S, Nissim S, Dror A, Sas A, Prinz H, Pri-Or E, Perek S, Raz-Pasteur A, Lejbkowicz I, Cohen-Matsliah SI, Almog R, Chen N, Kurd R, Jarjou’i A, Rokach A, Ben-Chetrit E, Schroeder A, Caulin AF, Yost CC, Schiffman JD, Goldfeder M, Martinod K. NETosis induction reflects COVID-19 severity and Long COVID: insights from a two-center patient cohort study in Israel. J Thromb Haemost. 2023 Apr 11:S1538-7836(23)00274-X. doi: 10.1016/j.jtha.2023.02.033. Epub ahead of print. PMID: 37054916; PMCID: PMC10088279. https://www.jthjournal.org/article/S1538-7836(23)00274-X/fulltext (Full text available as PDF file)