The effect of acupoint stimulation on T lymphocyte subsets and NK cells in cancer patients: A systematic review and meta-analysis

Abstract

IntroductionAcupoint stimulation (AS) is used in treating patients with cancer for a variety of indications and may affect the body's immune function. This systematic review aimed to investigate the effects of clinical AS on T-lymphocyte subsets and natural killer (NK) cells in patients with malignant tumors. MethodsA search was conducted for randomized controlled trials (RCT) published between 1.1.1990 and 10.2. 2020 in English, Chinese, Korean and Japanese databases. RCTs were included if the studies had: more than 30 participants, the control was placebo/usual care, AS was the primary intervention and a primary outcome of T-cell subgroup percentage or NK cell percentage was measured by peripheral blood flow cytometry. A random-effects model was applied where I2≥50%, as heterogeneity was high. For other cases, the fixed-effects model was applied. ResultsA total of 18 studies with 980 patients were included in the systematic review. The results showed that AS could significantly increase the number of CD4+ cells in the peripheral blood of all patients with cancer (chemotherapy group: mean difference (MD): 2.58; 95% CI: 0.09–5.08, I2 = 77%; and non-chemotherapy group: MD: 6.46; 95% CI: 2.12–10.80, I2 = 90%). In the non-chemotherapy group, AS could increase the number of CD3+ cells (MD: 9.34; 95% CI: 5.26–13.41, I2 = 84%), and NK cells (MD: 5.88; 95% CI: 0.90–10.86, I2 = 94%) in the peripheral blood. In addition, acupuncture could increase the number of CD3+ (MD: 12.21; 95% CI: 3.79 to 20.64, I2 = 91%), CD4+ (MD: 7.68; 95% CI: 0.31 to 15.04, I2= 88%) and CD8+ (MD: 2.55; 95% CI: 0.55 to 4.55, I2 = 0%) cells., while warm acupuncture could significantly increase the number of NK cells (MD: 2.58; 95% CI: 1.20–3.96, I2 = 0%). However, the incomplete record of the adverse effects, the difference in frequency and duration of AS and the low evidence level limited our conclusion. ConclusionAS increased the number of CD4+ cells in the peripheral blood and moderated other immune cells benefiting the immune system of patients with cancer. (PROSPERO ID is CRD42020167842).