CD20 – American ME and CFS Society

Abstract:

The chronic fatigue syndrome (CFS), formerly known as chronic Epstein-Barr virus syndrome, is a clinical state of some complexity and uncertain etiology. In order to characterize in a comprehensive manner the status of laboratory markers associated with cellular immune function in patients with this syndrome, 30 patients with clinically defined CFS were studied.

All of the subjects were found to have multiple abnormalities in these markers. The most consistent immunological abnormality detected among these patients, when compared with normal controls, was low natural killer (NK) cell cytotoxicity. The number of NK cells, as defined by reactivity with monoclonal antibody NKH.1 (CD56), was elevated, but the killing of K562 tumor cells per CD56 cell was significantly diminished.

Lymphoproliferative responses after stimulation with phytohemagglutinin and pokeweed mitogen were decreased in most patients when compared with those in normal controls, as was the production of gamma interferon following mitogen stimulation. Lymphocyte phenotypic marker analysis of peripheral blood lymphocytes showed that there were significant differences between patients with CFS and controls.

There was an increase in the percentage of suppressor-cytotoxic T lymphocytes, CD8, and a proportionally larger increase in the number of CD8 cells expressing the class II activation marker. Most patients had an elevated number of CD2 cells which expressed the activation marker CDw26. The numbers of CD4 cells and the helper subset of CD4+CD29+ cells in patients with CFS were not different from those in controls. There was, however, a significant decrease in the suppressor inducer subset of CD4+ CD45RA+ cells. The number of B cells, CD20 and CD21, were elevated, as were the numbers of a subset of B cells which coexpressed CD20 and CD5.

The patterns of immune marker abnormalities observed was compatible with a chronic viral reactivation syndrome.

Source: Klimas NG, Salvato FR, Morgan R, Fletcher MA. Immunologic abnormalities in chronic fatigue syndrome. J Clin Microbiol. 1990 Jun;28(6):1403-10. http://www.ncbi.nlm.nih.gov/pubmed/2166084

Note: You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC267940/

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]