Ulinastatin and/or thymosin α1 for severe sepsis: A systematic review and meta-analysis

Ulinastatin (UTI) and thymosin α1 (Tα1) have been investigated for their immunoregulatory properties in patients with severe sepsis. However, it is unclear whether immunomodulatory therapy using UTI combined with Tα1 (UCT), UTI alone (UA), or Tα1 alone (TA) improves the disease outcome. The objective of this study was to analyze the effectiveness of UCT, UA, and TA for the treatment of severe sepsis.

PubMed, EMBASE, and Cochrane Library databases were investigated from inception to September 2015. Randomized controlled trials (RCTs) examining the treatment of patients with severe sepsis by UCT, UA, and TA were defined as eligible. Data were analyzed using Review Manager 5.3, and the RCTs were evaluated by the Cochrane Handbook 5.1.0. The quality of the evidence was evaluated according to the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

Ten articles and 12 studies were included in this systematic review and meta-analysis. The primary outcome measures indicated that UCT was associated with significantly lower 28-day mortality (risk ratio [RR], 0.67; 95% confidence interval [CI], 0.57-0.80; p < 0.00001; n = 915; GRADE rating, moderate) and 90-day mortality (RR, 0.75; 95% CI, 0.61-0.93; p = 0.009; n = 547; GRADE rating, moderate); UA was associated with no significant difference in the 28-day mortality (RR, 0.60; 95% CI, 0.30-1.20; p = 0.15; n = 182; GRADE rating, low), and there was no report on 90-day mortality; TA was associated with significantly lower 28-day mortality (RR, 0.72; 95% CI, 0.55-0.93; p = 0.01; n = 494; GRADE rating, low), but there was no significant difference in the 90-day mortality (RR, 0.84; 95% CI, 0.54-1.31; p = 0.45; n = 91; GRADE rating, very low). In the secondary outcome measures, there was obvious heterogeneity in the length of the intensive care unit stay and that of the mechanical ventilation, length of the antibiotics and vasopressor use, and 28-day Acute Physiology and Chronic Health Evaluation II (APACHE II) scores.

Treatment of severe sepsis with UCT reduced both the 28-day and the 90-day mortality, whereas treatment with TA reduced only the 28-day mortality. The effects of UCT, UA, and TA on intensive care unit stay, mechanical ventilation, antibiotics and vasopressor use, and 28-day APACHE II scores of septic patients are still unclear. Additional high-quality RCTs are needed to define clearly the guidelines for the treatment of severe sepsis.

Systematic review, level IV.