Tag: B cell

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.

© 2012 British Society for Immunology.

 

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)

 

Extended B-cell phenotype in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A cross-sectional study

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a heterogeneous condition of unknown etiology characterized by multiple symptoms including fatigue, post-exertional malaise and cognitive impairment, lasting for at least 6 months.

Recently, two clinical trials of B-cell depletion therapy with rituximab (anti-CD20) reported convincing improvement in symptoms. A possible but undefined role for B-cells has therefore been proposed. Studies of the relative percentages of B-cell subsets in patients with ME/CFS have not revealed any reproducible differences from healthy controls (HC).

In order to explore whether more subtle alterations in B-cell subsets related to B-cell differentiation exist in ME/CFS patients we used flow cytometry to immunophenotype CD19+ B-cells. The panel utilized IgD, CD27 and CD38 (classical B-cell subsets) together with additional markers. A total of 38 patients fulfilling Canadian, Centre for Disease Control, and Fukuda ME/CFS criteria and 32 age/sex-matched HC were included.

We found no difference in percentages of classical subsets between ME/CFS patients and HC. However, we observed an increase in frequency (p<0.01) and expression (MFI; p=0.03) of CD24 on total B-cells, confined to IgD+ subsets. Within memory subsets, a higher frequency of CD21+CD38- B-cells (>20%) was associated with the presence of ME/CFS (Odds ratio: 3.47 (1.15-10.46); p=0.03) compared with HC and there was a negative correlation with disease duration.

In conclusion, we identified possible changes in B-cell phenotype in patients with ME/CFS. These may reflect altered B-cell function and if confirmed in other patient cohorts, could provide a platform for studies based on clinical course or responsiveness to rituximab-therapy.

 

Source: Fane Mensah, Amolak Bansal, Saul Berkovitz, Arti Sharma, Venkat Reddy, Maria J. Leandro and Geraldine Cambridge. Extended B-cell phenotype in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A cross-sectional study. Clin Exp Immunol. 2015 Dec 8. doi: 10.1111/cei.12749. [Epub ahead of print]