Severity of arterial and/or arteriolar sclerosis in IgA nephropathy and the effects of renin-angiotensin system inhibitors on its prognosis

Clinicopathological characteristics, risk factors and prognostic value of intrarenal vascular lesions in IgA nephropathy

BACKGROUND

The aim was to study clinicopathological characteristics, risk factors and renal outcome in IgA nephropathy (IgAN) patients with vascular lesions.

METHODS

We enrolled a Chinese cohort with 458 biopsy-confirmed primary IgAN patients for a retrospective analysis. They were divided into three groups according to vascular lesions: no vascular lesions (n = 239), arterio-/arteriolosclerosis (n = 181) and microangiopathic lesions (n = 38). The clinicopathological features and renal outcome were recorded. In univariate and multivariate models, association between vascular lesions and renal outcome and vascular lesions associated clinical factors were analyzed.

RESULTS

Patients with vascular lesions presented worse clinical characteristics with regard to blood pressure and kidney function, and segmental glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis (T1/2) and lymphocytes and monocytes infiltration were more common. Furthermore, older age, hyperuricemia, proteinuria, global glomerulosclerosis and endocapillary hypercellularity (E1) were more severe in patients with simple arterio-/arteriolosclerosis. By multivariate logistic regression, age, MAP and eGFR were significantly associated with vascular lesions. Vascular lesions, especially arterio-/arteriolosclerosis, were significantly associated with poorer renal survival in IgAN patients, and renal survival was similar whether patients with arterio-/arteriolosclerosis received immunosuppressive therapy. In addition to eGFR, arterio-/arteriolosclerosis, along with arterial intimal fibrosis, was an independent predictor for renal survival in multivariate Cox analyses.

CONCLUSION

IgAN patients with vascular lesions, especially with arterio-/arteriolosclerosis, presented more severe clinicopathological features. Renal function, blood pressure and age contributed to distinguishing patients with vascular lesions. Arterio-/arteriolosclerosis lesions were associated with poorer renal survival.

Correlation Analysis between Intrarenal Small Artery Intimal Thickening and Clinicopathological Features and Prognosis in Primary Membranous Nephropathy Patients

BACKGROUND

Primary membranous nephropathy (PMN) is the most common pathological type of nephrotic syndrome in adults. Intrarenal small artery intimal thickening can be observed in most renal biopsies. The purpose of this study was to investigate the association between intrarenal small artery intimal thickening and clinicopathological features and prognosis in PMN patients.

METHODS

Data were continuously collected from patients who were diagnosed with PMN in Shenzhen Second People's Hospital (The First Affiliated Hospital of Shenzhen University) from 2008 to 2021 for a retrospective cohort study. Regression analysis and survival analysis were used to analyze the relationship between intrarenal small artery intimal thickening and renal prognosis in PMN patients.

RESULTS

300 PMN patients were enrolled in this study, including 165 patients (55%) with intrarenal small artery intimal thickening. Patients with intimal thickening were older, with higher BMI, systolic blood pressure and diastolic blood pressure, serum uric acid, a higher proportion of hypertension, acute kidney injury, nephrotic syndrome, more urine protein, and lower eGFR. Multivariate Cox regression analysis showed that after adjusting for age, gender, hypertension, BMI, urine protein, eGFR, and the use of ACEI/ARB and hormone immunosuppressants, intimal thickening was a risk factor for renal prognosis in PMN patients (HR = 3.68, 95% CI 1.36-9.96, p < 0.05). Kaplan-Meier survival curve analysis showed that the incidence of reaching the renal composite outcome was higher in the intimal thickening group (p < 0.05).

CONCLUSION

The prognosis of PMN patients with intrarenal small artery intimal thickening is worse, so early intervention is very important for these patients.

Clinical significance of intrarenal vascular lesions in non-hypertensive patients with IgA nephropathy

BACKGROUND

The clinical significance of intrarenal vascular lesions has not been elucidated in primary IgA nephropathy (IgAN), especially in non-hypertensive subjects.

METHODS

From January 2003 to December 2020, data of 3435 patients with biopsy-proven IgAN were reviewed. Two hundred-forty non-hypertensive patients who met the criteria for IgAN and had intrarenal vascular lesions (IgAN-vas) were selected. The control cohort was constructed with 1:1 matched cases of non-hypertensive IgAN patients without vascular lesions according to age, gender, estimated glomerular filtration rate (eGFR) and follow-up time.

RESULTS

The IgAN-vas cohort had significantly higher serum uric acid levels than the control IgAN cohort (P < 0.05); glomerulosclerosis was more common in IgAN-vas patients. Moreover, cluster analysis indicated that the serum uric acid level was associated with serum creatinine (s-Cr) levels in IgAN-vas while it was associated with serum lactate dehydrogenase (LDH) levels in control cases with IgAN. Both Kaplan-Meier analysis and generalized linear mixed-effects models revealed that the prognosis of the IgAN-vas cohort was significantly worse than that of the IgAN cohort after > 5 years of follow-up. Intimal thickening was an independent risk factor associated with reaching the endpoint (eGFR decrease ≥ 30% from the baseline or reaching end-stage renal disease [ESRD] or death).

CONCLUSIONS

The prognosis of non-hypertensive patients with IgAN-vas was worse than that of matched individuals with IgAN. The clinicopathologic manifestation of IgAN-vas was more severe, and included a higher proportion of glomerulosclerosis, and a higher serum uric acid level correlated with renal function impairment.