[Changes in serum IL-22 level in patients with hypertensive renal damage and its clinical significance].

ABSTRACT

OBJECTIVE: To observe the changes in serum interleukin-22 (IL-22) level and its correlation with other clinical indexes in patients with essential hypertension and hypertensive renal damage, and to investigate its effects and clinical significance.
 Methods: A total of 97 essential hypertension (EH) patients and 40 healthy control were enrolled in this study. The EH patients were divided into a simple hypertension (SH) group (n=45) and a hypertensive renal damage (HRD) group (n=52) according to 24 h urinary protein (24 h-UPRO) level. Basic clinical data were collected; serum IL-22 level was detected by enzyme-linked immunosorbent assay (ELISA); the proportion of Th22 cells in peripheral blood was evaluated by flow cytometry (FCM); and serum high sensitivity C-reactive protein (hs-CRP) concentration was measured by immune turbidimetry. Correlation analysis was applied between serum IL-22 level and other indexes.
 Results: Serum IL-22 level and Th22 cell proportion in patients with hypertension were significantly higher than those in the healthy controls (all P<0.01). Compared with the SH group, serum IL-22 level and Th22 cell proportion were significantly elevated in the HRD group (P<0.01, P<0.05, respectively). Bivariate linear correlation analysis revealed that serum IL-22 level was positively correlated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hsCRP (r=0.367, P<0.01; r=0.402, P<0.01; r=0.329, P<0.05); there was also a positive correlation between serum IL-22 concentration and Th22 cell proportion (r=0.478, P<0.01) in the SH group. Serum IL-22 level was positively correlated with 24 h-UPRO level (r=0.318, P<0.05) in the HRD group.
 Conclusion: Serum IL-22 level and peripheral blood Th22 cells are significantly increased in the HRD group compared with the SH group. Serum IL-22 level is closely correlated with extent of hypertensive renal damage, indicating that serum IL-22 level may involve in the pathogenesis of hypertensive renal damage.