Unravelling intracellular immune dysfunctions in chronic fatigue syndrome: interactions between protein kinase R activity, RNase L cleavage and elastase activity and their clinical relevance

This study examined possible interactions between immunological abnormalities and symptoms in CFS. Sixteen CFS patients filled in a battery of questionnaires, evaluating daily functioning, and underwent venous blood sampling, in order to analyse immunological abnormalities. Ribonuclease (RNase) L cleavage was associated with RNase L activity (r(s)=0.570; p=0.021), protein kinase R (PKR) (r(s)=0.716; p = 0. 002) and elastase activity (r(s) = 0. 500; p = 0. 049). RNase L activity was related to elastase (r(s)=0.547; p=0.028) and PKR activity (r(s)=0.625; p=0.010). RNase L activity (r(s)=0.535; p=0.033), elastase activity (r(s)=0.585; p=0.017) and RNase L cleavage (r(s)=0.521; p=0.038) correlated with daily functioning. This study suggests that in CFS patients an increase in elastase activity and subsequent RNase L cleavage is accompanied by increased activity of both the PKR and RNase L enzymes. RNase L and elastase activity are related to daily functioning, thus evidence supporting the clinical importance of these immune dysfunctions in CFS patients was provided