Correlation between hemoglobin and progression of renal function in patients with proliferative lupus nephritis / 中华肾脏病杂志

ABSTRACT

Objective:To explore the correlation between hemoglobin (Hb) and progression of renal function in patients with proliferative lupus nephritis (PLN).Methods:Data of biopsy-proven PLN patients from January 2010 to February 2019 in Department of Nephrology, the First Affiliated Hospital of Shenzhen University were retrospectively analyzed. The patients were divided into stable renal function group and renal function progression group according to changes of renal function including serum creatinine doubling/end-stage renal disease (ESRD) and the demographic, clinical, and pathological characteristics were compared between the two groups. Cox regression and smooth curve fitting of generalized additive model analysis were used to explore the correlation between Hb and progression of renal function.Results:A total of 87 patients were included in this study. The age was (34.97±11.95) years old and 79 cases (90.80%) were females. During follow-up of 19.0(6.5, 43.5) months, renal function of 15 patients (17.24%) progressed. Compared with stable renal function group, Hb level of patients in renal function progression group were lower ( t=3.887, P<0.001), and serum creatinine ( Z=-2.466, P=0.003) and uric acid ( t=-2.154, P=0.034) were higher. As to the pathological characteristics, the proportion of class lupus nephritis-IV, renal tubular atrophy and interstitial fibrosis in renal function progression group were higher than those in stable renal function group, but there was no statistical difference between the two groups (all P>0.05). Multivariate Cox regression analysis indicated that high Hb was an independent protective factor of renal function progression in PLN patients ( HR=0.893, 95% CI 0.836-0.954, P=0.001). The risk of progression to serum creatinine doubling/ESRD would decrease by 10.7% when Hb increased by 1 unit (g/L). Smooth curve fitting of generalized additive model analysis showed that Hb was linearly correlated with the risk of renal function progression ( P=0.100). Receiver operating characteristic curve indicated that the risk of doubling serum creatinine/ESRD in PLN patients would be relatively low when Hb level was above 77 g/L (area under the curve 0.788, best threshold 77 g/L, sensitivity 0.600, specificity 0.903). Conclusions:Hb is closely related to progression of renal function in patients with PLN. More attention and management of Hb levels in patients with PLN can play an important role in improving renal prognosis.