Ribonuclease-L (RNase-L) is one of the key proteins induced in response to a viral infection. Once activated, the RNase-L destroys viral RNA (stopping the infectious process) and at the same time triggers the removal of the infected cell by inducing programmed cell death (apoptosis). Normally this enzyme is “turned off” after the infection has resolved. With continual stimulation from chronic infections, there can be an induction of an abnormal RNase-L that no longer appropriately “turns off”, resulting in destruction of the body’s own RNA.

Normal RNase-L protein has a molecular weight (MW) of 80 kDa and is activated by binding a small effector molecule known as 2-5A. In the immune cells of chronic fatigue syndrome patients, RNase-L is cleaved by the action of proteases. Once cleaved, the lower molecular weight (LMW) species of RNase-L lack the regulatory functions to control them and as a result, cellular RNA is cleaved at an abnormally accelerated rate, hindering cellular function and disrupting cellular ion flow, accounting for many of the typical symptoms of chronic fatigue syndrome. This abnormal RNase-L can be tested at Redlabs USA (no affiliation).