A Review of Lupus Nephritis

Lupus nephritis (LN) is one of the most common severe organ manifestations of systemic lupus erythematosus (SLE). LN is associated with significant morbidity and mortality in SLE patients, as up to 20% of patients progress to end-stage renal disease (ESRD). The clinical manifestations of LN are variable, ranging from asymptomatic proteinuria to a myriad of manifestations associated with nephritic and nephrotic syndromes and ESRD. It is therefore important to screen all SLE patients for LN.

Urinalysis is a useful screening test in LN. Quantification of proteinuria can be performed with either a urine protein-to-creatinine ratio or 24-h urine sample collection for protein. Renal biopsy remains the gold standard for diagnosis of LN. Traditional serum biomarkers used to monitor SLE and LN disease activity and flares include anti-double-stranded DNA antibodies and complement components 3 and 4. Other nonconventional biomarkers found to correlate with LN include anti-C1q and surrogate markers of type 1 interferon regulatory genes (INF gene signature). Potential urinary biomarkers for LN include monocyte chemoattractant protein 1, neutrophil gelatinase-associated lipocalin, tumor necrosis factor-like inducer of apoptosis, and vascular cell adhesion molecule 1.

Although studies have shown promising results for the use of alternative biomarkers, these require validation in prospective studies to support their use. Renal remission rates in patients receiving standard of care therapy for induction and maintenance treatment of LN remain low. This has prompted further research in newer therapeutic targets in LN ,which have shown promising results.