Outcome and predictors of kidney disease progression in Puerto Ricans with systemic lupus erythematosus initially presenting with mild renal involvement

Impact of baseline proteinuria level on long-term outcomes in lupus nephritis

OBJECTIVES

Proteinuria is a marker of lupus nephritis (LN) activity and damage. We aimed to explore the impact of baseline proteinuria level on long-term outcomes.

METHODS

We included 249 patients diagnosed with their first biopsy-proven LN. We divided patients based on baseline proteinuria into low-level (≤1 g/day, group 1; 62 patients), moderate-level (>1 and <3 g/day, group 2; 90 patients) and high-level proteinuria (≥3 g/day, group 3; 97 patients). Outcomes included complete proteinuria recovery (CPR) at 1 year, an adverse composite outcome (ESKD, a sustained ≥40% decline in eGFR, or death) and LN flares. Cox proportional hazard models were used to examine the association between baseline characteristics and long-term outcomes.

RESULTS

At baseline, the median [IQR] age was 33.2 [26.4, 42.4] years; median proteinuria level was 2.2 [1.0, 3.8] g/day. A total of 177 (71%) patients had proliferative lesions on biopsy; 59.7% in group 1, 78.9% in group 2 and 71.4% in group 3. The rate of achievement of CPR at 1 year was highest for group 1 and lowest for group 3. For long-term outcomes (median follow-up 8.4 years), the frequency of the adverse composite outcome was 27.4%, 26.7% and 48.5% in groups 1, 2 and 3, respectively; P = 0.003. The corresponding frequency of flares was 27.4%, 38.2% and 61.9%, respectively; P < 0.001. In the multivariable model for factors associated with long-term outcomes, there was no significant difference between groups 1 and 2; group 3 was associated with the worst prognosis.

CONCLUSIONS

Low-level proteinuria is commonly associated with proliferative LN and adverse long-term outcomes.

Measuring Disease Activity and Damage with Validated Metrics: A Systematic Review on Mortality and Damage in Systemic Lupus Erythematosus

Objective.

To identify the effect of disease activity and damage, measured by validated indices, on mortality and damage accrual, in order to inform upcoming Canadian systemic lupus erythematosus (SLE) recommendations.

Methods.

Following GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology to fill in evidence-to-decision tables to create recommendations for “minimal investigations needed to monitor SLE patients at baseline and subsequent visits,” a systematic literature review was performed. The effect of disease activity and damage, measured by validated metrics, on mortality and damage was systematically reviewed, with metaanalyses performed when available.

Results.

A title/abstract screen of 5599 articles identified 816 articles for full paper review, with 102 meeting inclusion criteria and 53 with extractable data. Thirty-three articles describing outcomes related to disease activity and 20 articles related to damage were identified. Mortality was associated with higher SLE Disease Activity Index-2000 scores in 6 studies (HR 1.14, 95% CI 1.06–1.22) and higher Systemic Lupus International Collaborating Clinics/ACR Damage Index scores in 6 studies (HR 1.53, 95% CI 1.28–1.83). Higher SLE Activity Measure scores were associated with increased risk of damage in 3 studies (OR 1.06, 95% CI 1.04–1.08). British Isles Lupus Assessment Group was associated with mortality in 1 study with HR of 1.15.

Conclusion.

Active SLE disease and damage are associated with and predict greater mortality and damage. The use of validated disease activity and damage metrics is important in the assessment of disease activity and damage and will inform upcoming Canadian recommendations for the assessment of SLE.

Long-term renal outcomes in a cohort of 1814 Chinese patients with biopsy-proven lupus nephritis

In the present study, we observed the renal outcomes in a cohort of 1814 Chinese patients with biopsy-proven lupus nephritis (LN) and evaluated the risk factors associated with poor renal prognosis. The 5 -, 10 -, 15 - and 20-year renal survival rates were 93.1%, 87.9%, 81.0% and 68.3%, respectively. Gender, LN duration, mean arterial pressure (MAP), proteinuria, serum creatinine, haemoglobin and pathological classification at the time of biopsy were independent risk factors for end-stage renal disease (ESRD). The long-term renal outcomes of patients with class II LN were unfavorable as opposed to those with class V. Additionally, the time-average proteinuria (TA-Pro) and the time-average mean arterial pressure (TA-MAP) during the follow-up were important risk factors for ESRD, with better predictive values than the baseline proteinuria and MAP. The results underscore the need for proteinuria and blood pressure control during follow-up in patients with LN; proteinuria levels should be controlled at least to < 1.0 g/24 h, and optimally to < 0.5 g/24 h; MAP should not exceed 96.5 mmHg. More attention should be paid to class II LN and emphasis should be placed on recurrence prevention of class II LN.

Time to Recovery from Proteinuria in Patients with Lupus Nephritis Receiving Standard Treatment

Objective.

The recovery time from abnormal levels of proteinuria with standard treatment in longitudinal studies of patients with systemic lupus erythematosus has not been well described. We aimed (1) to determine the recovery time from proteinuria in patients with lupus nephritis (LN) receiving standard treatment, and (2) to determine whether the initial level of proteinuria predicts time to improvement.

Methods.

We studied all patients with LN recorded in the database from 1970 until 2011. Proteinuria was defined as ≥ 0.5 g/24 h. Patients were grouped as follows: group 1 having 0.5–0.9 g/day, group 2 having 1–1.9 g/day, and group 3 having ≥ 2 g/day. Recovery from proteinuria was defined as proteinuria < 0.5 g/24 h. Time to recovery from proteinuria was studied with the Kaplan-Meier curves. Factors associated with proteinuria recovery were evaluated using proportional hazard models.

Results.

Among the 212 patients studied, 52% recovered from proteinuria within 2 years and an additional 22% recovered within 5 years, for a total of 74%. The level of proteinuria at baseline visit predicted the time to improvement. Patients with a higher level of proteinuria at baseline needed a longer time to normalize their proteinuria. Male sex, hypocomplementemia, high level of proteinuria at diagnosis of LN, and disease duration > 5 years at onset of LN each independently predicted late recovery of proteinuria and had an effect on the percentage of patients who recovered.

Conclusion.

The tempo of recovery from proteinuria in LN is slow and the level of proteinuria at baseline visit predicts the time to complete recovery.

Predictors of survival in Chinese patients with lupus nephritis

The current study was to determine the predictors of survival in 491 Chinese patients with lupus nephritis (LN). All patients were evaluated and consecutively followed up from 2003 to 2010. The female: male ratio was 9.5:1, with a median age of 31.1 ± 12 years. Forty-nine (10.0%) patients were lost to follow-up and 47 (10.3%) patients died. The overall cumulative probability of survival at 5, 10, 15 and 20 years by Kaplan-Meier analysis was 88%, 77%, 53% and 45%, respectively. The log-rank test showed that the probability of survival was significantly decreased in the late-onset patients (≥50 years) ( P = 0.036), patients with hypoproteinaemia (≤35 g/l) ( P = 0.014), patients with increased creatinine (≥1.5 mg/dl) ( P = 0.002) and patients with massive proteinuria (≥3.5 g/24 h) ( P = 0.009). However, the probability of survival was significantly higher in patients treated with hydroxychloroquine (HCQ) ( P = 0.003) than those not treated with it. Based on a multivariate model, increased creatinine (hazard ratio (HR) = 2.041; P = 0.017) and proteinuria ≥3.5 g/24hours (HR=1.716; P = 0.016) were independent risk factors. Glucocorticoid (HR = 0.457; P = 0.01) and HCQ (HR=0.197; P = 0.026) were independent protective factors. Our findings suggest that renal dysfunction and massive proteinuria are independent risk factors for mortality. HCQ could improve the survival of patients with LN.