IL6 and juvenile polyposis syndrome: Meta-analysis suggested that, as shown in Fig. 5, serum IL-6 achieved a positive likelihood ratio of 6.2 (95%CI 4.3–9.0) and a negative likelihood ratio of 0.28 (95%CI 0.22–0.35) for detecting PJI; however, synovial fluid IL-6 achieved a positive likelihood ratio of 8.5 (95%CI 5.3–13.6) and a negative likelihood ratio of 0.15 (95%CI 0.08–0.29).