From: Potential Biomarkers in Systemic Lupus Erythematosus
| Candidate biomarkers | Utility in SLE | Notes |
|---|---|---|
| Immune cell subsets | ||
| CD4+ T lymphocytes | ||
| T helper 1 cells | disease activity | mucocutaneous involvement and lupus nephritis (LN) |
| T helper 2 cells | disease activity | produce interferon (IFN)-γ |
| T helper 17 cells | disease activity | main source of interleukin (IL)-17; LN |
| Follicular helper T cells | disease activity | debates on which one is authentically flare-correlated |
| Peripheral helper T cells | ||
| Regulatory helper T cells | disease activity | defective regulation; LN |
| Age-associated T helper cells | disease activity | |
| CD8+ T lymphocytes | disease activity | |
| Double-negative T cells | disease activity | important source of IL-17 |
| Plasmacytoid dendritic cells | disease activity | produce type I IFNs |
| B lymphocytes | disease activity | B cell-targeted therapy and chimeric antigen receptor (CAR) T therapy |
| Autoantibodies | ||
| Antibodies to double-stranded DNA (anti-dsDNA) | diagnosis | diagnostic criteria |
| disease activity | LN | |
| Antibodies to Smith antigen (anti-Sm) | diagnosis | diagnostic criteria; low sensitivity |
| disease activity | LN | |
| Antibodies to ribosomal proteins (anti-RibP) | diagnosis | low sensitivity |
| disease activity | central nervous system (CNS) lupus | |
| Antibodies to small nuclear ribonucleoprotein (anti-snRNP) | disease activity | CNS lupus |
| Antiphospholipid antibody (aPL) | disease activity | CNS lupus (?) |
| Cytokines and chemokines | ||
| BAFF/APRIL system: | ||
| B cell-activating factor (BAFF), A proliferation-inducing ligand (APRIL), B cell maturation antigen (BCMA) | disease activity | cardiovascular involvement and LN |
| Type I IFNs: IFN-α, IFN-β, IFN-ω | disease activity | LN |
| Type II IFNs: IFN-γ | disease activity | |
| Surrogate IFN-regulated markers: | ||
| Interferon γ-inducible protein 10 (IP-10), Galectin 9 (Gal-9), Sialic acid binding Ig-like lectin 1 (SIGLEC1) | diagnosis (SIGLEC1 only) | better for excluding SLE in suspected cases |
| disease activity | lack of adequate and convincing evidence | |
| Interleukin-1 families: | ||
| IL-1Receptor antagonist (IL-1Ra), IL-18, IL-36α, IL-36γ, IL-1R2, soluble IL-1R4, Soluble suppression of tumorigenicity 2 protein (sST2) | diagnosis (IL-1Ra only) | |
| disease activity | not specific to organ | |
| IL-6 | disease activity | not specific to organ |
| IL-17 | disease activity | LN |
| IL-23 | disease activity | LN |
| Complement system | ||
| C3, C4, CH50 | diagnosis | diagnostic criteria |
| disease activity | unstable correlation | |
| C3a | disease activity | thrombophilia |
| C3dg | diagnosis | |
