TNF and kidney failure: Patients who developed renal failure had significantly elevated levels of IL-21 (p=0.006) and IL-23 (p=0.002), while those having liver involvement had significantly elevated levels of IL-21 (p=0.001), IL-23 (p=0.001), and TNF-α (p=0.008) compared to the healthy controls (Tables 2 and 3).