B cell dysfunction – American ME and CFS Society

Case-Control Study of Individuals With Small Fiber Neuropathy After COVID-19

Abstract:

Objectives: To report a case-control study of new-onset small fiber neuropathy (SFN) after COVID-19 with invasive cardiopulmonary exercise testing (iCPET). SFN is a critical objective finding in long COVID and amenable to treatment.

Methods: A retrospective chart review was conducted on patients seen in the NeuroCOVID Clinic at Yale who developed new-onset SFN after a documented COVID-19 illness. We collected demographics, symptoms, skin biopsy, iCPET testing, treatments, and clinical response to treatment or no intervention.

Results: Sixteen patients were diagnosed with SFN on skin biopsy (median age 47, 75% female, 75% White). 92% of patients reported postexertional malaise characteristic of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and 7 patients underwent iCPET, which demonstrated neurovascular dysregulation and dysautonomia consistent with ME/CFS. Nine patients underwent treatment with IVIG, and 7 were not treated with IVIG. The IVIG group experienced significant clinical response in their neuropathic symptoms (9/9) compared with those who did not receive IVIG (3/7; p = 0.02).

Discussion: Here, we present preliminary evidence that after COVID-19, SFN is responsive to treatment with IVIG and linked with neurovascular dysregulation and dysautonomia on iCPET. A larger clinical trial is indicated to further demonstrate the clinical utility of IVIG in treating postinfectious SFN.

Classification of evidence: This study provides Class III evidence. It is a retrospective cohort study.

Source: McAlpine L, Zubair AS, Joseph P, Spudich S. Case-Control Study of Individuals With Small Fiber Neuropathy After COVID-19. Neurol Neuroimmunol Neuroinflamm. 2024 May;11(3):e200244. doi: 10.1212/NXI.0000000000200244. Epub 2024 Apr 17. PMID: 38630952. https://www.neurology.org/doi/10.1212/NXI.0000000000200244 (Full text)

Haematological sequelae in the post-acute phase of symptomatic SARS-CoV-2 infection

Abstract:

Many patients surviving SARS-CoV-2 infection suffer from long-term symptoms (long COVID or post COVID) such as shortness of breath, fatigue, loss of taste or smell and cognitive deterioration. However, few data are available concerning blood cell counts and haematological parameters during the post-COVID period.

We analysed haematological data from 83 patients previously admitted to the internal medicine unit of our institution because of symptomatic SARS-CoV-2 infection; all data were obtained within 1-12 months from disease onset. A control group of 70 apparently healthy, age- and sex-matched COVID-19 negative individuals was assessed for comparison. Blood cell counts improved in the post-COVID period, but 81% of patients had persistent abnormalities, compared with 50% in the control group, p < 0.001.

Most common haematological findings included anaemia (40%), reduced lymphocyte (43%) or eosinophil counts (38%) and low IgM memory B cells and correlated with advanced age, number of chronic comorbidities, female gender, altered renal function, reduced baseline Hb and procalcitonin concentrations and increased RDW. Data on lymphocytes and IgM memory B cells show that impaired immune responses may persist for up to one year in the post-COVID period, possibly contributing to long-term symptoms, especially in female patients.

Source: Bergamaschi G, Barteselli C, Calabretta F, Lenti MV, Merli S, Rossi CM, Di Sabatino A. Haematological sequelae in the post-acute phase of symptomatic SARS-CoV-2 infection. Intern Emerg Med. 2024 Jan;19(1):125-133. doi: 10.1007/s11739-023-03459-6. Epub 2023 Nov 24. PMID: 38001354. https://pubmed.ncbi.nlm.nih.gov/38001354/

Long COVID manifests with T cell dysregulation, inflammation, and an uncoordinated adaptive immune response to SARS-CoV-2

Abstract:

Long COVID (LC), a type of post-acute sequelae of SARS-CoV-2 infection (PASC), occurs after at least 10% of SARS-CoV-2 infections, yet its etiology remains poorly understood. Here, we used multiple “omics” assays (CyTOF, RNAseq, Olink) and serology to deeply characterize both global and SARS-CoV-2-specific immunity from blood of individuals with clear LC and non-LC clinical trajectories, 8 months following infection and prior to receipt of any SARS-CoV-2 vaccine. Our analysis focused on deep phenotyping of T cells, which play important roles in immunity against SARS-CoV-2 yet may also contribute to COVID-19 pathogenesis.

Our findings demonstrate that individuals with LC exhibit systemic inflammation and immune dysregulation. This is evidenced by global differences in T cell subset distribution in ways that imply ongoing immune responses, as well as by sex-specific perturbations in cytolytic subsets. Individuals with LC harbored increased frequencies of CD4+ T cells poised to migrate to inflamed tissues, and exhausted SARS-CoV-2-specific CD8+ T cells. They also harbored significantly higher levels of SARS-CoV-2 antibodies, and in contrast to non-LC individuals, exhibited a mis-coordination between their SARS-CoV-2-specific T and B cell responses.

Collectively, our data suggest that proper crosstalk between the humoral and cellular arms of adaptive immunity has broken down in LC, and that this, perhaps in the context of persistent virus, leads to the immune dysregulation, inflammation, and clinical symptoms associated with this debilitating condition.

Source: Kailin Yin, Michael J. Peluso, Reuben Thomas, Min Gyoung Shin, Jason Neidleman, Xiaoyu Luo, Rebecca Hoh, Khamal Anglin, Beatrice Huang, Urania Argueta, Monica Lopez, Daisy Valdivieso, Kofi Asare, Rania Ibrahim, Ludger Ständker, Scott Lu, Sarah A. Goldberg, Sulggi A. Lee, Kara L. Lynch, J. Daniel Kelly, Jeffrey N. Martin, Jan Münch, Steven G. Deeks, Timothy J. Henrich, Nadia R. Roan. Long COVID manifests with T cell dysregulation, inflammation, and an uncoordinated adaptive immune response to SARS-CoV-2. bioRxiv 2023.02.09.527892; doi: https://doi.org/10.1101/2023.02.09.527892 https://www.biorxiv.org/content/10.1101/2023.02.09.527892v1.full (Full text)

Comparative Analysis of Extracellular Vesicles in Patients with Severe and Mild Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis, or chronic fatigue syndrome (ME/CFS) is a serious disease whose cause has yet to be identified. Objective markers of the disease are also not well understood and would serve as important tools in diagnosis and management.

One potential biomarker or transmitter of immune signals in ME/CFS is the extracellular vesicle (EV) compartment. These small, membrane bound particles have been shown to play a key role in intercellular signaling. Our laboratory has focused on methods of detection of EVS in clinical samples. In this study we explored whether the prevalence of EVs in the plasma of participants with mild or severe ME/CFS differed from the plasma of healthy control participants. By staining for multiple cell surface molecules, plasma EVs could be fingerprinted as to their cell of origin.

Our study revealed a significant correlation between severe ME/CSF and levels of EVs bearing the B cell marker CD19 and the platelet marker CD41a, though these changes were not significant after correction for multiple comparisons. These findings point to potential dysregulation of B cell and platelet activation or homeostasis in ME/CFS, which warrants validation in a replication cohort and further exploration of potential mechanisms underlying the association.

Source: Bonilla H, Hampton D, Marques de Menezes EG, Deng X, Montoya JG, Anderson J, Norris PJ. Comparative Analysis of Extracellular Vesicles in Patients with Severe and Mild Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Immunol. 2022 Mar 4;13:841910. doi: 10.3389/fimmu.2022.841910. PMID: 35309313; PMCID: PMC8931328. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8931328/ (Full text)

Role of adaptive and innate immune cells in chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

Perturbations in immune processes are a hallmark of a number of autoimmune and inflammatory disorders. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is an inflammatory disorder with possible autoimmune correlates, characterized by reduced NK cell activity, elevations in regulatory T cells (Tregs) and dysregulation in cytokine levels. The purpose of this article is to examine innate and adaptive immune cell phenotypes and functional characteristics that have not been previously examined in CFS/ME patients.

Thirty patients with CFS/ME and 25 non-fatigued controls were recruited for this study. Whole blood samples were collected from all participants for the assessment of cell phenotypes, functional properties, receptors, adhesion molecules, antigens and intracellular proteins using flow cytometric protocols. The cells investigated included NK cells, dendritic cells, neutrophils, B cells, T cells, γδT cells and Tregs.

Significant changes were observed in B-cell subsets, Tregs, CD4(+)CD73(+)CD39(+) T cells, cytotoxic activity, granzyme B, neutrophil antigens, TNF-α and IFN-γ in the CFS/ME patients in comparison with the non-fatigued controls. Alterations in B cells, Tregs, NK cells and neutrophils suggest significant impairments in immune regulation in CFS/ME and these may have similarities to a number of autoimmune disorders.

Source: Brenu EW, Huth TK, Hardcastle SL, Fuller K, Kaur M, Johnston S, Ramos SB, Staines DR, Marshall-Gradisnik SM. Role of adaptive and innate immune cells in chronic fatigue syndrome/myalgic encephalomyelitis. Int Immunol. 2014 Apr;26(4):233-42. doi: 10.1093/intimm/dxt068. Epub 2013 Dec 16. http://intimm.oxfordjournals.org/content/26/4/233.long (Full article)

Altered functional B cell subset populations in patients with chronic fatigue syndrome compared to healthy controls

Abstract:

Chronic fatigue syndrome (CFS) is a heterogeneous disorder of unknown aetiology characterized by disabling fatigue, headaches, sleep disturbance and several other symptoms. The onset of CFS may follow a viral infection or period of stress. Patients with CFS do not have hypogammaglobulinaemia, predisposition to recurrent bacterial infections or symptoms of autoimmunity.

To date, defects in B cell numbers or function have not been shown in the literature. However, treatment with anti-B cell therapy using Rituximab has recently shown benefit to CFS patients. We therefore postulated that patients with CFS had a subtle humoral immune dysfunction, and performed extended B cell immunophenotyping.

We undertook a detailed characterization of the proportions of the different B cell subsets in 33 patients with CFS fulfilling the Canadian and Fukada criteria for CFS and compared these with 24 age- and gender-matched healthy controls (HC). CFS patients had greater numbers of naive B cells as a percentage of lymphocytes: 6·3 versus 3·9% in HC (P = 0·034), greater numbers of naive B cells as a percentage of B cells: 65 versus 47% in controls (P = 0·003), greater numbers of transitional B cells: 1·8 versus 0·8% in controls (P = 0·025) and reduced numbers of plasmablasts: 0·5 versus 0·9% in controls (P = 0·013). While the cause of these changes is unclear, we speculate whether they may suggest a subtle tendency to autoimmunity.

Source: Bradley AS, Ford B, Bansal AS. Altered functional B cell subset populations in patients with chronic fatigue syndrome compared to healthy controls. Clin Exp Immunol. 2013 Apr;172(1):73-80. doi: 10.1111/cei.12043. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3719933/ (Full article)

Evidence of inflammatory immune signaling in chronic fatigue syndrome: A pilot study of gene expression in peripheral blood

Abstract:

BACKGROUND: Genomic profiling of peripheral blood reveals altered immunity in chronic fatigue syndrome (CFS) however interpretation remains challenging without immune demographic context. The object of this work is to identify modulation of specific immune functional components and restructuring of co-expression networks characteristic of CFS using the quantitative genomics of peripheral blood.

METHODS: Gene sets were constructed a priori for CD4+ T cells, CD8+ T cells, CD19+ B cells, CD14+ monocytes and CD16+ neutrophils from published data. A group of 111 women were classified using empiric case definition (U.S. Centers for Disease Control and Prevention) and unsupervised latent cluster analysis (LCA). Microarray profiles of peripheral blood were analyzed for expression of leukocyte-specific gene sets and characteristic changes in co-expression identified from topological evaluation of linear correlation networks.

RESULTS: Median expression for a set of 6 genes preferentially up-regulated in CD19+ B cells was significantly lower in CFS (p = 0.01) due mainly to PTPRK and TSPAN3 expression. Although no other gene set was differentially expressed at p < 0.05, patterns of co-expression in each group differed markedly. Significant co-expression of CD14+ monocyte with CD16+ neutrophil (p = 0.01) and CD19+ B cell sets (p = 0.00) characterized CFS and fatigue phenotype groups. Also in CFS was a significant negative correlation between CD8+ and both CD19+ up-regulated (p = 0.02) and NK gene sets (p = 0.08). These patterns were absent in controls.

CONCLUSION: Dissection of blood microarray profiles points to B cell dysfunction with coordinated immune activation supporting persistent inflammation and antibody-mediated NK cell modulation of T cell activity. This has clinical implications as the CD19+ genes identified could provide robust and biologically meaningful basis for the early detection and unambiguous phenotyping of CFS.

Source: Aspler AL, Bolshin C, Vernon SD, Broderick G. Evidence of inflammatory immune signaling in chronic fatigue syndrome: A pilot study of gene expression in peripheral blood. Behav Brain Funct. 2008 Sep 26;4:44. doi: 10.1186/1744-9081-4-44. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569951/ (Full article)