Serum uric acid level is correlated with the clinical, pathological progression and prognosis of IgA nephropathy: an observational retrospective pilot-study

Abstract

Objectives This study was aimed to assess the relationship between serum uric acid (SUA) level and the clinical, pathological phenotype of IgA nephropathy (IgAN), and to determine the role of SUA level in the progression and prognosis of IgAN. Methods A total of 208 patients with IgAN were included in this study, and were classified into the normo-uricemia group and hyperuricemia group according to the SUA level. The clinical data at baseline, IgAN Oxford classification scores (MEST-C scoring system), and other pathological features were collected and further analyzed. All patients were followed up and the prognosis was assessed using Kaplan-Meier survival curves. GraphPad Prism 7.0 and SPSS 23.0 were used for statistical analyses. Results In clinical indicators, patients with hyperuricemia had the significantly higher proportion of males to females, mean arterial pressure, the levels of total cholesterol, triglyceride, Scr, BUN, 24 hour-urine protein, C3, and C4, the lower levels of high-density lipoprotein cholesterol and eGFR than those without (p < 0.05). In terms of pathological characteristics, the tubular atrophy/interstitial fibrosis scores, vascular injury scores, and glomerular sclerosis percentage were significantly higher in patients with hyperuricemia compared with those without (p < 0.01). There was no significant difference in the scores of mesangial hypercellularity, endocapillary hypercellularity, focal segmental glomerulosclerosis, as well as crescents between the two groups (p > 0.05). As for the depositions of immune complexes deposition in IgAN, the hyperuricemia group had less deposition of immunoglobulin G and FRA than the normo-uricemia group (p < 0.05), while the deposition of immunoglobulin A, immunoglobulin M, and complement C3 in the two groups showed no statistical difference. The survival curve suggested that patients in the hyperuricemia group have significantly poorer renal outcome than those in the normo-uricemia group (p = 0.0147). Results also revealed that the SUA level is a valuable predictor of renal outcome in patients with IgAN. The optimal cutoff value was 361.1 µmol/L (AUC = 0.76 ± 0.08167) and 614 µmol/L (AUC = 0.5728 ± 0.2029) for female and male, respectively. Conclusions The level of SUA is associated with renal function level and pathological severity of IgAN, and maybe a prognostic indicator of IgAN.

A high value of fibrinogen in immunoglobulin A nephropathy patients is associated with a worse renal tubular atrophy/interstitial fibrosis score

“…Hyperuricemia may cause changes in renal structure through different biological mechanisms, such as endothelial dysfunction, glomerulosclerosis, and tubulointerstitial renal damage, which eventually lead to an irreversible decline in kidney function 23‐26 . Recent studies also have shown that hyperuricemia patients had higher T scores than normal uricemia patients 27 . The HUA leads to tubular atrophy/interstitial fibrosis might be illuminated by the following mechanisms.…”

“… 23 , 24 , 25 , 26 Recent studies also have shown that hyperuricemia patients had higher T scores than normal uricemia patients. 27 The HUA leads to tubular atrophy/interstitial fibrosis might be illuminated by the following mechanisms. Urate crystals sedimentate in the renal tubules can directly block or damage the renal tubules and also form uric acid renal stones to damage the kidney, which makes for renal tubular atrophy and interstitial fibrosis.…”

Is serum hemoglobin level an independent prognostic factor for IgA nephropathy?: a systematic review and meta-analysis of observational cohort studies

“…Through full-text reviews, two conference abstracts, two duplicated data-contained articles, and two articles without enough data to estimate the HR were removed from the remaining 15 articles. Finally, we included nine studies with 10,006 patients [ 10 , 14–18 , 23–25 ] ( Figure 1 ).…”

“…In Table 1 , among the nine studies, eight were performed in Asian countries: China, Korea, and Japan [ 10 , 14–16 , 18 , 23–25 ], and one was performed in Western countries (Turkey) [ 17 ]. Six of the nine studies estimated the correlation between the decreasing Hb in serum and kidney disease progression in IgAN [ 14–18 , 23 ], in which the HR was calculated using continuous variables relative to 1 g/dL.…”

Established the first clinical prediction model regarding the risk of hyperuricemia in IgA nephropathy

“…Similarly, Scr indicator was not included in the model too. In the previous literatures [3,20], Scr index was included in the original form. In order to explain the relationship between Scr level and hyperuricemia more conveniently, we transformed the original numerical variable into a categorical variable.…”