Tag: Natural killer cells

The neurological significance of abnormal natural killer cell activity in chronic toxigenic mold exposures

Abstract:

Toxigenic mold activities produce metabolites that are either broad-spectrum antibiotics or mycotoxins that are cytotoxic. Indoor environmental exposure to these toxigenic molds leads to adverse health conditions with the main outcome measure of frequent neuroimmunologic and behavioral consequences. One of the immune system disorders found in patients presenting with toxigenic mold exposure is an abnormal natural killer cell activity.

This paper presents an overview of the neurological significance of abnormal natural killer cell (NKC) activity in chronic toxigenic mold exposure. A comprehensive review of the literature was carried out to evaluate and assess the conditions under which the immune system could be dysfunctionally interfered with leading to abnormal NKC activity and the involvement of mycotoxins in these processes. The functions, mechanism, the factors that influence NKC activities, and the roles of mycotoxins in NKCs were cited wherever necessary.

The major presentations are headache, general debilitating pains, nose bleeding, fevers with body temperatures up to 40 degrees C (104 degrees F), cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, vertigo/dizziness, and in some cases, seizures. Although sleep is commonly considered a restorative process that is important for the proper functioning of the immune system, it could be disturbed by mycotoxins. Most likely, mycotoxins exert some rigorous effects on the circadian rhythmic processes resulting in sleep deprivation to which an acute and transient increase in NKC activity is observed. Depression, psychological stress, tissue injuries, malignancies, carcinogenesis, chronic fatigue syndrome, and experimental allergic encephalomyelitis could be induced at very low physiological concentrations by mycotoxin-induced NKC activity.

In the light of this review, it is concluded that chronic exposures to toxigenic mold could lead to abnormal NKC activity with a wide range of neurological consequences, some of which were headache, general debilitating pains, fever, cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, and seizures.

 

Source: Anyanwu E, Campbell AW, Jones J, Ehiri JE, Akpan AI. The neurological significance of abnormal natural killer cell activity in chronic toxigenic mold exposures. ScientificWorldJournal. 2003 Nov 13;3:1128-37. http://www.hindawi.com/journals/tswj/2003/307098/abs/

 

The prognosis after multidisciplinary treatment for patients with postinfectious chronic fatigue syndrome and noninfectious chronic fatigue syndrome

Abstract:

The prognosis after multidisciplinary treatment for patients with postinfectious chronic fatigue syndrome (CFS, n = 9) and noninfectious CFS (n = 9) was clarified. After treatment, natural killer (NK) cell activity increased in the postinfectious CFS group but did not recover to within normal range in the noninfectious CFS group. In the postinfectious CFS group, physical and mental symptoms improved, and 8 patients returned to work. In the noninfectious CFS group, symptoms did not improve, and only 3 patients returned to work. The prognosis of postinfectious CFS group was better than that of noninfectious CFS group. Classification of CFS patients into postinfectious and noninfectious groups is useful for choosing the appropriate treatment in order to obtain better prognosis.

 

Source: Masuda A, Nakayama T, Yamanaka T, Koga Y, Tei C. The prognosis after multidisciplinary treatment for patients with postinfectious chronic fatigue syndrome and noninfectious chronic fatigue syndrome. J Behav Med. 2002 Oct;25(5):487-97. http://www.ncbi.nlm.nih.gov/pubmed/12442563

 

Natural killer cells and the post viral fatigue syndrome

Abstract:

60 patients were referred with a diagnosis of post viral fatigue syndrome (PVFS), but only 50 fulfilled strict criteria for this illness. Many lymphocyte subpopulations were normal, but there was a spectrum of natural killer (NK) cell results: 20/50 (40%) were raised; 8/50 (16%) were low;, 5/50 (10%) were low initially but normal on repeat testing; 17/50 (34%) were normal.

When patients were categorised on their NK cell results, there were significant differences in the two groups with raised or low NK cells compared to the “Not PVFS” group: the CD8 cells were increased (p less than 0.001, p less than 0.02) and the CD4/CD8 ratio was reduced (p less than 0.05) but the CD4 cells were normal.

Clinical data showed that the “Not PVFS” group were older, with less severe illness, less muscle pain and less virological evidence of infection. It is postulated that patients have low NK cells initially and then progress to normal or raised levels dependent on factors such as stress, other infections and behaviour.

 

Source: Ho-Yen DO, Billington RW, Urquhart J. Natural killer cells and the post viral fatigue syndrome. Scand J Infect Dis. 1991;23(6):711-6. http://www.ncbi.nlm.nih.gov/pubmed/1815333

 

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