Een studie van Brenu en kollega's onder ME/CVS-patiënten en gezonde proefpersonen
bevestigt dat de cytotoxiciteit van NK-cellen van ME/CVS-patiënten sterk afgenomen is.
De onderzoekers onderzochten drie keer met halfjaarlijkse tussenpozen (T1, T2 en T3)
Het percentage CD56brightCD16- NK cellen was significant lager op moment T1 en T2.
De exacte rol van dit type NK-cellen is nog onduidelijk, maar de afname van CD56bright
CD16- NK cellen wordt door de auteurs in verband gebracht met
verlaagde IFNγ-productie.
De gestimuleerde cytokine-productie was, zowel bij patiënten als gezonde proefpersonen,
in de tijd gezien nogal grillig, dus het trekken van conclusies hierover bleek onmogelijk.
De auteurs stellen in hun conclusie dat verschillen in cytokine-aanmaak
tussen patiënten en andere proefpersonen mogelijk beter tot uitdrukking komen in de ongestimuleerde productie.
Uit sommige studies (voor een voorbeeld:
klik hier)
is gebleken dat de respons van de cytokine-productie
op stimulatie in ME/CVS duidelijk afwijkt van die bij gezonde mensen.
Longitudinal investigation of natural killer cells and cytokines
in chronic fatigue syndrome/myalgic encephalomyelitis.
Journal of Translational Medicine 2012, 10:88 doi:10.1186/1479-5876-10-88.
Brenu EW, van Driel ML, Staines DR, Ashton KJ, Hardcastle SL, Keane J,
Tajouri L, Peterson D, Ramos SB, Marshall-Gradisnik SM.
Abstract (provisional)
Background
Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME)
is an etiologically unexplained disorder
characterised by irregularities in various aspects of the immunological function.
Presently, it is unknown whether these immunological changes remain consistent over time.
This study investigates Natural Killer (NK) cell cytotoxic activity,
NK cell subsets (CD56brightCD16- and CD56dimCD16+) and cytokines,
over the course of a 12 month period in patients with CFS/ME.
Methods
The participants in the study comprised
65 (47.2+/-11.5 years) CFS/ME participants and
21 (45.2 +/-9.3 years) non-fatigued controls.
Flow cytometry protocols were used to assess NK subsets and NK cytotoxic activity
at various time points that included baseline (T1), 6 (T2) and 12 months (T3).
Cytokine secretions were measured
following mitogenic stimulation of peripheral blood mononuclear cells.
Results
NK cytotoxic activity was significantly decreased in the CFS/ME patients at T1, T2 and T3
compared to the non-fatigued group.
Additionally, in comparison to the non-fatigued controls,
the CFS/ME group had significantly lower numbers of CD56brightCD16- NK cells
at both T1 and T2.
Interestingly, following mitogenic stimulation, cytokine secretion revealed
significant increases in IL-10, IFN-gamma and TNF-alpha at T1 in the CFS/ME group.
A significant decrease was observed at T2 in the CFS/ME group for IL-10 and IL-17A
while at T3, IL-2 was increased in the CFS/ME group
in comparison to the non-fatigued controls.
Overall cytotoxic activity was significantly decreased at T3 compared to T1 and T2.
CD56brightCD16- NK cells were much lower at T2 compared to the T1 and T3.
IL-10 and IL-17A secretion was elevated at T2 in comparison to the T1 and T3.
Conclusion
These results confirm decreases in immune function in CFS/ME patients,
suggesting an increased susceptibility to viral and other infections.
Furthermore
NK cytotoxic activity may be a suitable biomarker for diagnosing CFS/ME
as it was consistently decreased during the course of the 12 months study.
Keywords
Chronic fatigue syndrome, Cytokines, Cytotoxic activity
http://www.translational-medicine.com/content/pdf/1479-5876-10-88.pdf
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