RESUMEN
BACKGROUND: The aim of this study is to investigate the impact of arginine on immune function and postoperative complications in colorectal cancer (CRC) patients. METHODS: We conducted a comprehensive search to identify eligible RCTs in various databases, such as PubMed, Cochrane Library, EMBASE, Web of Science, MEDLINE, China National Knowledge Infrastructure (CNKI), Wanfang, VIP Medicine Information System (VIP), and Chinese Biomedical Database (CBM). This study aimed to examine IgA, IgG, and IgM levels as well as CD4+ and CD8+ counts as well as the CD4+/CD8+ ratio. Anastomotic leaking, length of stay (LOS), and surgical site infection (SSI) were included as secondary outcomes. Stata (StataCorp, version 14.0) was utilized for data analysis. To ensure the results were reliable, we used meta-regression, sensitivity analysis, and publication bias analysis. RESULTS: A total of 24 publications (including 1883 patients) out of 681 that were retrieved fulfilled the inclusion criteria. The arginine group showed notable improvements in humoral immunity, with gains in IgA (SMD=0.45, 95% CI: 0.30-0.60), IgG (SMD=0.80, 95% CI: 0.64-0.96), and IgM (SMD=0.66, 95% CI: 0.39-0.93). With regards to cellular immunity, the arginine group exhibited a substantial increase in the CD4+ T cell count (SMD = 1.03, 95% CI: 0.67-1.38) compared to the control group. However, the CD4+/CD8+ ratio decreased significantly (SMD=1.37, 95% CI: 0.88-1.86) in the same arginine group, indicating a change in the balance between these two cell types. Additionally, the CD8+ T cell count showed a notable decrease (SMD=-0.70, 95% CI: -1.09 to -0.32) in the arginine group when compared to the control group. Anastomotic leakage was also considerably lower in the arginine group (SMD=-0.05, 95% CI: -0.08 to -0.02), the rate of SSIs was lower (RR = -0.02, 95% CI: -0.05-0), and the length of time patients spent in the hospital was shorter (SMD=-0.15, 95% CI: -0.38 to -0.08). CONCLUSIONS: After radiation treatment for CRC, arginine improves immune function and decreases the risk of infection problems. TRIAL REGISTRATION: Registration with PROSPERO for this meta-analysis is number CRD42024520509.