Novel Biomarkers for Lupus Nephritis in the "OMICS" Era

Lupus nephritis (LN) is severe renal comorbidity associated with systemic lupus erythematosus (SLE), a complex autoimmune disorder with high morbidity and mortality. Diagnosis and monitoring of LN patients still rely on renal biopsy, a procedure that exposes patients to a variety of risks and is not capable of providing longitudinally information about disease prognosis. In this review, we summarized current data of recent promising biomarkers developed in the precision medicine era, particularly under genomic, transcriptomic, proteomic, and metabolomic techniques. Genome-wide association studies have been evaluating the role of endogenous elements beyond the autoimmunity in LN. Transcriptomic methods, including single-cell sequencing, are potential tools in identifying inflammatory signatures, miRNAs, and gene expression. Proteomic measures, including anti-C1q antibodies, cytokines, TLRs, VCAM-1, NGAL osteopontin, angiostatin, have been considered helpful to provide a more profound comprehension of the disease pathogenic processes. Metabolomic approaches may identify several abnormal metabolite profiles related to the impairment of cellular functions. Together, these accurate, non-invasive, and moderate-cost propedeutic resources may be the novel tools for recognizing, distinguishing, and predicting LN progression and prognosis. Furthermore, omics evaluation may also predict responsiveness to treatment and, consequently, change the way we manage LN cases in the near future.