Efficacy and Safety of Glycosides of Tripterygium wilfordii Combined with Renin-Angiotensin System in the Treatment of IgA Nephropathy: A Systematic Review and Meta-Analysis

BACKGROUND: IgA nephropathy (IgAN) is currently the most common primary glomerular disease, accounting for approximately 36.7% to 58.2% of primary glomerular disease in kidney biopsies in China. Definitive diagnosis depends on immunopathological examination of the kidney. The prognosis of this disease was generally considered to be good, but recent studies have found that about half of patients can progress to end-stage renal disease within 30 years of onset. Because the pathogenesis is unknown, there is no specific treatment. OBJECTIVE: To evaluate the efficacy and safety of glycosides of Tripterygium wilfordii (GTW) in combination with renin-angiotensin system (RAS) inhibitors for the treatment of IgAN. METHODS: Search Embase, Pubmed, Cochrane, CNKI, Web of Science, Wanfang, and VIP for all randomized controlled trials (RCTs) on treating IgAN with RASI from the self-built database to December 2021. Relevant data were searched and collected separately by two reviewers. The Cochrane risk of bias model was used for quality assessment, and RevMan 5.3 was used for data analysis. RESULTS: Thirteen Chinese publications with a total of 958 patients were finally included. There was no statistically significant difference in baseline information (including laboratory data and clinical parameters) between the two groups of patients. The urine protein quantification in both groups showed a significant decreasing trend as the treatment duration increased. At 3, 6, 9, and 12 months after treatment, urine protein was significantly lower than the baseline value in both the observation and control groups (P < 0.05). During the follow-up period, there was no statistical difference in blood creatinine (Scr) and eGFR values between the two groups compared with the baseline values (P > 0.05). Patients with CKD stage 2 achieved a higher remission rate compared with patients with CKD stage 3, with a statistically significant difference (P < 0.05), and the difference between the two groups was not significant for patients in the same stage. There was no statistically significant difference in the total effective rate between the two groups (P > 0.05). During the follow-up period, there was no statistically significant difference in urine protein quantification, Scr, and eGFR between the two groups. In terms of the incidence of adverse reactions, the observation group was less than the control group, and there was a significant difference between the two groups (P < 0.05). CONCLUSION: GTW combined with RASI is one of the safe and effective treatment modes for IgAN nephropathy. It can not only effectively reduce the excretion of urinary protein in patients and delay the progression of chronic kidney disease but also has less serious side effects and is well tolerated by patients, so it can be a new choice of therapeutic drugs for this group of patients.