Elevated serum uric acid is associated with renal arteriolopathy and predict poor outcome in patients with lupus nephritis.

OBJECTIVES: Increased serum uric acid (SUA) levels are well known to be concomitant of cardiovascular and kidney diseases, and have been proposed to be implicated in the development of arteriolar damage. The aim of the present study was to assess the association between SUA levels, renal damage and its implication for outcome in patients with lupus nephritis (LN). METHODS: This retrospective study included 194 cases with biopsy proven LN at the Affiliated Hospital of Qingdao University between January 2013 and June 2021. We reviewed clinical, laboratory and histologic data of patients and analysed the correlation between SUA levels, renal damage and the primary outcome (death or ESRD). Biopsy-proven arteriolar damage was defined by the presence of arteriolar hyalinosis and/or intimal thickening. RESULTS: Compared to LN patients without hyperuricemia, LN patients with hyperuricaemia presented with higher BP, hyperlipidaemia, lower eGFR, lower haemoglobin, lower serum albumin, worse renal arteriolar damage and proteinuria, and also higher SLEDAI score, activity index and chronicity index (p<0.05). At logistic regression analysis, SUA was independently related to the presence of arteriolar damage. For each 100 µmol/L increase in SUA levels the risk for arteriolar damage raised by 53.8% (hazard ratio [HR] =1.538; 95% CI: 1.147-2.063; p=0.004) after adjustment for haemoglobin, serum creatinine and erythrocyte sedimentation rate. Cox regression analysis showed that female (HR=3.180; 95% CI: 1.216-8.313; p=0.018), white blood cell count (HR=1.111; 95% CI: 1.027-1.202; p=0.009), SUA (HR=1.100; 95% CI: 1.023-1.253; p=0.035), serum creatinine (HR=1.800; 95% CI: 1.348-2.404; p<0.001), and renal arteriolar damage (HR=3.117; 95% CI: 1.022-9.511; p=0.046) was significantly associated with development of ESRD or death in patients with LN after adjustment for several potential confounding factors. Furthermore, for each 100 µmol/L increase in SUA levels, the risk of ESRD or death increased by 10%. CONCLUSIONS: SUA levels are directly associated with renal arteriolar damage and poor prognosis in LN patients. Hyperuricaemia is an important predictor for poor prognosis in patients with LN.

Changes of miR-155 expression in serum of uremic patients before and after treatment and risk factors analysis.

The aim of the present study was to investigate the changes of miR-155 expression in the serum of uremic patients before and after treatment and analyze the risk factors of efficacy. A total of 116 uremic patients admitted to the People's Hospital of Chengyang (Qingdao, China) were enrolled in the study as the uremia group, and were treated by hemodialysis combined with hemoperfusion, and 127 healthy subjects who underwent health examination during the same period were selected as the normal group. Reverse transcription quantitative PCR was used to detect the serum miR-155 levels of all the subjects in the two groups before treatment and those of uremia patients after treatment. The changes of clinically related indicators and inflammatory factors in uremic patients before and after treatment and their correlation with miR-155 were investigated. The risk factors affecting the efficacy of treatment were analyzed. Serum miR-155 levels in the uremia group were higher than those in the normal group (P<0.001); the miR-155 level in patients after treatment was significantly lower than that before treatment (P<0.001), and it was positively correlated with efficacy (r=0.6873, P<0.05). The serum miR-155 level in the invalid group was higher than that in the effective group, and the sensitivity and specificity of miR-155 for predicting the efficacy before treatment were 64.71 and 87.88%, respectively. After treatment, the sensitivity and specificity of miR-155 for evaluating the efficacy were 76.47 and 88.89%, respectively. Clinically related indicators and inflammatory factor levels in uremic patients decreased significantly after treatment, and the expression levels before and after treatment were significantly correlated with miR-155. Clinically related indicators, inflammatory factors and miR-155 were all risk factors affecting efficacy. The expression level of miR-155 in serum was significantly upregulated. Findings of this study suggest that monitoring miR-155 may reflect the efficacy and inflammatory state effectively.