Prognostic factors for treatment response in patients with lupus nephritis

Multicenter lupus register from Argentina, the RELESSAR database: Influence of ethnicity on disease phenotype

OBJECTIVE

The objective is to describe the main characteristics of patients with systemic lupus erythematosus (SLE) in Argentina and to examine the influence of ethnicity on the expression of the disease.

PATIENTS AND METHODS

RELESSAR is a multicentre register carried out by 106 researchers from 67 rheumatologic Argentine centres. It is a cross-sectional study of SLE (1982/1997 ACR) patients. RELESSAR electronic database includes demographic, cumulative SLE manifestations, SELENA-SLEDAI, SLICC-SDI, Katz's severity and Charlson's comorbidity indexes and treatment patterns.

RESULTS

We included 1,610 patients, 91.7% were female with a median age at diagnosis of 28.1 ± 12.8; 96.2% met ≥4 ACR 1982/97 criteria. Frequent manifestations were arthritis (83.5%), malar rash (79.5%), photosensitivity (75.3%), haematological (63.8%) and renal disease (47.4%), antinuclear antibodies (96%), anti-dsDNA (66.5%) and anti-Smith antibodies (29%). The mean Selena-SLEDAI score at last visit was 3.18 (SD 4.3) and mean SDI was 1 (SD 1.3). The accumulated treatments most frequently used were antimalarials (90.4%), corticosteroids (90%), azathioprine (31.8%), intravenous cyclophosphamide (30.2%), mycophenolate mofetil or mycophenolic acid (24.5%), methotrexate (19.3%), belimumab 5.3% and rituximab 5.1%. Refractory lupus was diagnosed in 9.3% of the cases. The main causes of death were lupus activity (25.0%), activity and concomitant infections (25.0%), infections (18.2%), vascular disease (13.6%) and cancer (4.5%). Mortality was associated with higher SLEDAI, Katz, damage indexes and comorbidities. Of the 1610 patients included, 44.6% were Caucasian, 44.5% Mestizo, 8.1% Amerindian and 1.2% Afro-Latin American. Mestizo patients had higher male representation, low socioeconomic status, more inadequate medical coverage, fewer formal years of education and shorter disease duration. Polyadenopathies and Raynaud's phenomenon were more frequent in Caucasians. In the logistic regression analysis higher damage index (OR 1.28, CI 95% 1.02-1.61, p = 0.03) remained associated to mestizo ethnicity.

CONCLUSIONS

This study represents the largest number of adult patients with SLE studied in Argentina. Caucasian patients were differentiated by having Raynaud's phenomenon and polyadenopathy more frequently, while patients of Mestizo origin had higher damage indexes.

Causes and predictors of mortality in biopsy-proven lupus nephritis: the Sarawak experience

Background

Lupus nephritis (LN) is a serious manifestation of systemic lupus erythematosus that can be fatal if left untreated. The causes and prognostic predictors of mortality in LN have been well studied in developed countries but evidence is lacking for developing countries. The objective of this study was to investigate the causes and predictors of mortality in a cohort of Malaysian patients with biopsy-proven LN.

Methods

We retrospectively studied all patients with biopsy-proven LN treated in Sarawak General Hospital during the period of 2000–15. Demographic data, clinical features and outcomes were collected. Cox regression analysis was carried out to determine the independent predictors of mortality.

Results

There was a total of 250 patients with 259 renal biopsies available for our analysis. Our patients were of multi-ethnic origins with a female predominance (90%). Their mean ± standard deviation age was 37.7 ± 12.8 years. The patients had a mean disease duration of 135.6 ± 81.9 months. Nephrotic syndrome was the most common presentation (29.6%) and acute renal failure was evident at initial presentation in 16% of patients. Class IV LN was the predominant biopsy class within the cohort (66.8%). The majority of patients achieved remission (81.2%) and had normal renal function (83.9%) at the last follow-up. The 5-, 10-, 15- and 20-year survival rates for our cohort were 93%, 88%, 82% and 77%, respectively. There were 37 deaths (14.8%), of which the main causes were: infection and flare (52.7%), infection alone (25.0%) and other causes (22.3%). Independent predictors of mortality in our cohort of LN patients were: the presence of acute kidney injury at presentation [hazard ratio (HR) 3.41; confidence interval (CI) 1.50–7.76], failure to achieve remission at 1-year post-induction therapy (HR 2.99; CI 1.35–6.65) and non-compliance with treatment (HR 1.89; CI 1.22–2.96). Age, ethnicity, class of LN and type of immunosuppressant used were not predictive of mortality.

Conclusions

Survival and renal outcomes in our LN cohort were comparable to most LN studies reported worldwide. Both flare and infection remained the main causes of death. The presence of acute renal failure at presentation, failure to achieve remission at 1 year post-treatment and non-compliance with treatment were independent prognostic predictors of mortality in LN.

Hypomethylation of interleukin 6 correlates with renal involvement in systemic lupus erythematosus

OBJECTIVE

To analyze peripheral blood interleukin 6 (IL-6) methylation status and its clinical significance in patients with systemic lupus erythematosus (SLE).

MATERIAL AND METHODS

Blood samples from 41 adult patients with SLE, and 20 healthy controls were collected. The methylation status of IL-6 was determined by methylation specific polymerase chain reaction (MSP). The IL-6 expression was detected by real-time PCR. Correlations between IL-6 methylation status and clinical features or laboratory findings in patients with SLE were investigated.

RESULTS

The methylation status and expression of IL-6 in peripheral blood could reflect the level in peripheral blood mononucleated cells (PBMCs) of SLE. Significantly positive correlation was found between IL-6 hypomethylation and renal disorder. Interleukin 6 hypomethylation was found negatively correlated with serum C3.

CONCLUSIONS

The detection of IL-6 methylation status in peripheral blood could reflect the status in PBMC with SLE. Interleukin 6 may play a role in renal disorder with SLE patients. Interleukin 6 could be considered as a new biomarker for predicting SLE flare.