Immunology

NK-cell function in ME/CFS—conflicting results?

Most previous studies on Natural Killer (NK) cell function had shown reduced function in CFS patients. However, two studies presented at the Ottawa conference came to two different conclusions. One study confirmed impaired NK cell function in CFS/ME patients which may be related to alterations in cytokines and reduced immune function in patients with CFS (EW Brenu). The other study found that NK cell function was higher in patients while they were acutely ill and during a period of time following the active infection (B Katz).

Dr. Komaroff thought this was quite feasible because if a viral infection is believed to trigger this illness, which applies to many but not all cases, then NK cell function could increase during the initial phase of infection and remain relatively stable, for a while, immediately after an infection. But when patients become chronically ill and NK cells are repeatedly activated to protect the body against viruses and other pathogens, this could lead to an exhaustion of NK cell function response (i.e., what is commonly seen in full-blown, persistent CFS).