Systematic Review of the Outcomes and Prognostic Factors of Patients With Systemic Lupus Erythematosus-Associated Thrombotic Microangiopathy

Introduction: Thrombotic microangiopathy (TMA) is a rare but severe complication of systemic lupus erythematosus (SLE); however, the overall patient and renal survival rates of patients with SLE-associated TMA (SLE-TMA) remain controversial. This study aimed to evaluate the prognosis of and identify potential prognostic factors in patients with SLE-TMA. Methods: Literature search was performed in MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trial, CINAHL, PsycINFO, Scopus, CNKI, and Sinomed for studies published before December 2023. Studies that encompassed no less than 5 patients with SLE-TMA and followed well-recognized diagnostic criteria were included, whereas studies with a median follow-up < 6 months or that provided incomplete outcomes were excluded. Results: Fourteen eligible studies encompassing a total of 446 patients with SLE-TMA were included in the meta-analysis. The pooled 1-, 3-, and 5-year patient survival rates were 83% (95% confidence interval [CI]: 0.65-0.96), 81% (95% CI: 0.59-0.96), and 77% (95% CI: 0.52-0.95), respectively. The pooled 1-, 3-, and 5-year renal survival rates were 85% (95% CI: 0.81-0.89), 75% (95% CI: 0.63-0.85), and 56% (95% CI: 0.31-0.79). The pooled 1-, 3-, and 5-year renal relative risks in patients with SLE-TMA compared with patients with SLE without TMA were 4.01 (95% CI: 2.10-7.65), 2.53 (95% CI: 1.83-3.51), and 2.58 (95% CI: 2.01-3.29). Univariate Cox regression indicated that high baseline serum creatinine (SCr) levels, high renal chronicity index and acute hemodialysis were independent prognostic factors of renal survival. Conclusion: Patients with SLE-TMA exhibit lower long-term patient and renal survival rates. High baseline SCr levels, high renal chronicity index or a need for acute hemodialysis at baseline are associated with poorer renal outcomes.