Tag: NK cells

The chronic fatigue syndrome: definition, current studies and lessons for fibromyalgia research

Abstract:

Chronic fatigue syndrome (CFS) is characterized by chronic, debilitating fatigue lasting greater than 6 months. Frequent chronic and recurrent findings include fever, pharyngitis, myalgias, adenopathy, arthralgias, difficulties in cognition and disorders of mood. In the majority of patients, the illness starts suddenly with an acute, “flu-like” illness.

The following laboratory abnormalities are seen with some frequency, although none are seen in all patients: lymphocytosis, atypical lymphocytosis, monocytosis, elevation of hepatocellular enzymes, low levels of antinuclear antibodies, varying levels of antithyroid antibodies, partial hypergammaglobulinemia, elevated CD4:CD8 ratio, decreased cytolytic activity of natural killer cells, and low levels of immune complexes. Clinical and serologic studies suggest an association of CFS with all of the human herpesviruses, particularly Epstein-Barr virus (EBV) and the recently discovered human B lymphotropic virus (HBLV) or human herpesvirus 6; neither EBV nor HBLV has yet been shown to play a causal role in the illness.

Preliminary evidence suggests that many of these features of CFS also are seen in patients with fibromyalgia.

 

Source: Komaroff AL, Goldenberg D. The chronic fatigue syndrome: definition, current studies and lessons for fibromyalgia research. J Rheumatol Suppl. 1989 Nov;19:23-7. http://www.ncbi.nlm.nih.gov/pubmed/2691680

 

Phenotypic and functional deficiency of natural killer cells in patients with chronic fatigue syndrome

Abstract:

Natural killer (NK)3 cells are large granular lymphocytes that appear to play a significant role in the host’s defense against viral infection. We performed an extensive phenotypic and functional characterization of NK cells on 41 patients with the chronic fatigue syndrome (CFS), or “chronic active Epstein-Barr virus infection” syndrome, and on 23 age- and sex-matched asymptomatic control subjects in an attempt to further characterize this illness.

These studies demonstrated that a majority of patients with CFS have low numbers of NKH1+T3- lymphocytes, a population that represents the great majority of NK cells in normal individuals. CFS patients had normal numbers of NKH1+T3+ lymphocytes, a population that represents a relatively small fraction of NK cells in normal individuals.

When tested for cytotoxicity against a variety of different target cells, patients with CFS consistently demonstrated low levels of killing. After activation of cytolytic activity with recombinant interleukin 2, patients were able to display increased killing against K562 but most patients remained unable to lyse Epstein-Barr virus-infected B cell targets. Additional cytotoxicity experiments were carried out utilizing anti-T3 monoclonal antibody to block killing by NKH1+T3+ cells.

These experiments indicated that the NK cell that appears to be responsible for much of the functional activity remaining in patients with CFS belongs to the NKH1+T3+ subset, which under normal circumstances represents only approximately 20% of the NK cell population.

 

Source: Caligiuri M, Murray C, Buchwald D, Levine H, Cheney P, Peterson D, Komaroff AL, Ritz J. Phenotypic and functional deficiency of natural killer cells in patients with chronic fatigue syndrome. J Immunol. 1987 Nov 15;139(10):3306-13. http://www.ncbi.nlm.nih.gov/pubmed/2824604