When lupus nephritis "runs" high blood pressure, what are the harms?

Lupus nephritis (LN) is one of the most serious and common complications of systemic lupus erythematosus.

At present, with the application of immunosuppressive agents, the therapeutic effect of LN has improved, but the prognosis of patients is still not ideal.

About 20%-25% of LN patients progress to end-stage renal disease 10 years after diagnosis.

Factors related to poor kidney prognosis include age, genetic characteristics, high serum creatinine, high blood pressure and severe infections.

Among them, the prognostic value of hypertension to LN is controversial.

To this end, Chinese scholars have carried out a retrospective cohort study to determine the prevalence of hypertension in LN patients in China, and analyze the clinical and histological characteristics of LN patients with hypertension.
The main purpose is to determine whether hypertension is LN.
Independent risk factors for patient death and adverse renal outcome.

The results were recently published online in the journal J Hum Hypertens.
(IF: 2.
26).

Study Design The study included patients with LN who were admitted to the First Affiliated Hospital of Sun Yat-sen University between 1996 and 2011, aged ≥14 years, and confirmed by biopsy.

The patients were divided into hypertension group and normal blood pressure group.

Hypertension is defined as: three consecutive measurements of systolic blood pressure>140mmHg and/or diastolic blood pressure>90mmHg, or taking antihypertensive drugs.

End-stage renal disease (ESRD) is defined as the glomerular filtration rate <15mL/min/1.
73m2, or the need for dialysis/kidney transplantation to maintain.

Study endpoints: 1) death from any cause; 2) occurrence of ESRD; 3) doubling of serum creatinine level.

The correlation of each factor was evaluated with the mean ± standard deviation, hazard ratio (HR) and 95% confidence interval (CI).

Research results The study included 1406 patients with LN, including 764 patients with hypertension (53.
1%), mostly women (82.
9%), and the ratio of male to female was about 1.
0:4.
8.

Compared with the normal blood pressure group, the incidence of acute kidney injury and advanced chronic kidney disease in the hypertensive group was significantly increased, and the scores of the main pathological parameters of the patients and the chronic index were also significantly increased.
High (all P<0.
001).

At the same time, the serum creatinine, urea nitrogen, total urine protein, triglycerides, cholesterol, low-density lipoprotein cholesterol and serum uric acid levels of patients in the hypertension group were significantly higher than those in the normal blood pressure group (all P<0.
001).

In addition, compared with the normal blood pressure group, the glomerular filtration rate, hemoglobin, and serum albumin levels of the hypertension group were significantly lower (all P<0.
001).

The pathological changes of LN patients with hypertension are more severe in histology.
Compared with the normal blood pressure group, the hypertension group is more prone to glomerulosclerosis, thickening of renal capillary loops, crescent formation, and more severe endothelial cell proliferation.
(P all ≤0.
002).

Compared with the normal blood pressure group, the renal tubule atrophy and renal interstitial inflammatory cell infiltration were more serious in the hypertension group, the incidence of interstitial fibrosis was higher, and microthrombosis was more common (all P≤0.
001).

The survival time of LN patients with hypertension was shorter.
The median follow-up time of the study was 52 months.
A total of 871 patients were included for survival analysis.

The data showed that compared with the normal blood pressure group, the survival time of patients in the hypertension group was significantly reduced at the three endpoints (P<0.
05).

It can be seen that hypertension is related to the poor clinical and renal prognosis of LN patients.

Considering the above three endpoints, the study also found that systolic blood pressure <126mmHg, diastolic blood pressure 77~83mmHg, and mean arterial pressure maintained at 87~108mmHg are the best blood pressure levels to reduce the risk.

Hypertension can be used as a predictor of adverse outcomes for LN patients.
After adjusting for factors such as age and gender, data analysis shows that hypertension is the death of LN patients (HR=1.
12; 95%CI: 1.
15–2.
57, P=0.
009).
Independent predictors of ESRD (HR=1.
73, 95%CI: 1.
07–2.
81, P=0.
026) and doubling of serum creatinine (HR=1.
67; 95%CI: 1.
10–2.
53, P=0.
017).

Research conclusions Among the LN patients included in the study, the incidence of hypertension was as high as 53.
1%.

Studies have found that patients with LN and hypertension have more severe renal damage and pathological changes.

At the same time, hypertension is an independent risk factor for poor prognosis such as death, end-stage renal disease and doubling of serum creatinine in patients with LN.

Therefore, when patients with systemic lupus erythematosus have renal disease, blood pressure monitoring should be an important clinical strategy.

Data show that systolic blood pressure <126mmHg, diastolic blood pressure 77~83mmHg, and average arterial pressure maintained at 87~108mmHg are the best blood pressure levels to reduce the risk of adverse events in LN patients, which provides guidance for the clinical treatment of such patients.

References: Rong R, Wen Q, Wang Y, et al.
Prognostic significance of hypertension at the onset of lupus nephritis in Chinese patients: prevalence and clinical outcomes[J].
J Hum Hypertens.
2021 Mar 8.
doi: 10.
1038/s41371 -021-00492-w.
Epub ahead of print.