Correlation of tumor necrosis factor alpha and interleukin 6 with hypertensive renal damage

BACKGROUND: Many efforts have been made to investigate the role played by cytokines in the development of hypertension. But few reports exist on the association between cytokines and hypertensive renal damage. This study was to observe the changes of the serum levels of cytokines, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) in patients with hypertensive renal damage, whereby to study the correlation of TNF-alpha and IL-6 with the hypertensive renal damage. METHODS: According to their urinary albumin excretion rate (UAER), 102 patients with essential hypertension were divided into three groups: normoalbuminuria hypertensive group (n = 37), microalbuminuria hypertensive group (n = 36), and proteinuric hypertensive group (n = 29). Serum TNF-alpha and IL-6 of all subjects were measured with radioimmune assay. Thirty age- and gender-matched normotensive persons were selected as normotensive control group. RESULTS: Serum levels of TNF-alpha and IL-6 were significantly higher in patients with essential hypertension than those in normotensive control group (p < 0.5). Serum levels of TNF-alpha and IL-6 increased in proportion to UAER. The statistical significance was present among groups (p < 0.05). Both TNF-alpha and IL-6 were found to have a positive correlation with UAER (r = 0.79, p < 0.01; r = 0.75, p < 0.01), but not with the levels of blood pressure (BP). CONCLUSIONS: TNF-alpha and IL-6 are remarkably increased in hypertensive patients and may play an important role in the pathogenesis and the development of hypertensive renal damage.