Diagnostic value of urinary light chain detection in essential hypertension renal injury

Objective To investigate the diagnostic value of urinary light chain detection in essential hypertension renal injury. Methods According to National Prevention and Treatment Guide of Hypertension (2005 Edition) and the diagnostic criteria of essential hypertension renal injury, patients'medical history and damage of target organs, we selected 60 patients with essential hypertension and divided them into two groups: 28 patients without renal injury and 32 patients with renal injury. Meanwhile, Thirty healthy individuals were included in a control group. Urinary proteins and light chains were detected by immuonephelometry and the activity of NAG was determined by liquid kinetic rate assay with MNP as substrate. The urinary light chains concentration of each group were compared and analyzed with those of Alb and α1-MG. Results The results of lamU in renal injury group [8. 89(3.84-33. 30) mg] were higher than those of non renal injury group [3. 84(3. 84-10. 4) mg] and control group [3.84(0. 00-3.84) mg]. There was statistically significant difference ( H = 37.97, P ＜ 0. 01 ). The levels of kapU in renal injury group [26. 65 (6. 97-62. 5 ) mg] were higher than those of non renal injury group [6. 97 (6. 97-23.7 )mg] and control group [6. 97(6. 97-7. 20) mg], which also had statistical significance (H =40. 09,P ＜0. 01 ). All the other results in renal injury group ( Alb, α1-MG, IgG, TRF and NAG) were higher than those of non renal injury group and control group ( H =21.02, 32. 65, 25.50, 30. 45 and 30. 57, P ＜0. 01 ). Correlation analysis showed that Alb levels were highly correlated with urinary IgG and TRF levels [Correlation coefficient (r) =0. 911, 0. 965, P ＜ 0. 01]. The levels of urinary light chain lamU and kapU were also highly correlated with α1-MG ( r = 0. 804, 0. 827, P ＜ 0. 01 ). However, There was no correlationship between NAG and α1MG levels (r=0. 398,P＞0. 05). Conclusion The urinary light chain lamU and kapU can be used as indicators for evaluation of renal injury in essential hypertension, especially renal tubular injury. Key words: Hypertension,renovascular;  Immunoglobulin λ chain;  Immunoglobulin κ chain; Urinalysis