Intermittent and graded exercise effects on NK cell degranulation markers LAMP‐1/LAMP‐2 and CD8+CD38+ in chronic fatigue syndrome/myalgic encephalomyelitis

There is substantial evidence of immune system dysfunction in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) but little is understood of exercise training effects on lymphocyte function in this illness. This study investigated whether graded and intermittent exercise improved CD8+ lymphocyte activation and natural killer cell degranulation markers compared to no exercise. Twenty-four chronic fatigue syndrome (CFS) patients (50.2 ± 10 year) were randomized to graded exercise (GE), intermittent exercise (IE) or usual care (UC) groups; a control group (CTL) of 18 matched sedentary non-CFS/ME participants were included for immunological variable comparisons. Main outcome measures were pre- and postintervention expression of CD3+ CD8+ CD38+ and CD3CD16+ 56+ CD107a+ (LAMP-1) CD107b+ (LAMP-2) and aerobic exercise capacity. The postintervention percentage of NK cells expressing LAMP-1 and -2 was significantly higher in IE compared to UC, and higher in GE compared to UC and CTL. LAMP-1 and LAMP-2 expression (absolute numbers and percent positive) increased significantly pre-to-postintervention for both GE and IE. Preintervention, the absolute number of CD8+ CD38+ cells was significantly lower in CTL compared to UC and IE. There were no significant pre- to postintervention changes in CD8+ CD38+ expression for any group. Aerobic exercise capacity was signifi- cantly improved by GE and IE. Twelve weeks of GE and IE increased the expression of NK cell activation and degranulation markers, suggesting enhanced immunosurveillance. Low-intensity exercise may also reduce CD8+ CD38+ expression, a marker of inflammation. Both GE and IE improved exercise capacity without worsening CFS/ME symptoms, and more robust trials of these exercise modalities are warranted.