Objective: To determine if circulating autoantibodies (autoAbs) and T-helper cell cytokines correlate with a different class of lupus nephritis (LN), including class III/IV, compared to class V and other manifestations of systemic lupus erythematosus (SLE).
Methods: All patients (N=62) met the SLE classification criteria of the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) or Systemic Lupus International Collaborating Clinics (SLICC) classification criteria. Demographic, clinical data, and serologic manifestations included anti-DNA, anti-Smith (Anti-Sm), C3, and C4 were included. Plasma levels of interferon gamma (IFNɣ), interleukin 17 (IL-17), interleukin 10 (IL-10) isotype-specific (IgG) anti-DNA, anti-Ro/SSA (SSA), and anti-Sm were measured using enzyme-linked immunosorbent assay (ELISA).
Results: The most common manifestations by history were arthritis in 61% (N=38), photosensitivity rash in 53% (N=33), LN in 44% (N=27), and oral/nasal ulcer in 31% (N=19) SLE patients. AutoAbs (anti-DNA, anti-SSA, and anti-Sm), IFNɣ, and IL-17, but not IL-10, were significantly elevated in SLE patients compared to healthy controls. There were elevated plasma levels of anti-DNA (p = 0.0101) and anti-Sm (p = 0.0499) in patients with a history of LN compared to patients without LN. In contrast, plasma levels of anti-Sm were decreased in patients who had a history of acute mucocutaneous manifestations, including photosensitivity rash and/or malar rash (p = 0.0152). Among the three cytokines that were analyzed, IL-10 was significantly elevated in patients with a history of LN compared to patients without LN (p = 0.0216). IL-17 was positively correlated with anti-SSA (p = 0.0130) and was significantly higher in patients with discoid rash (p = 0.0238) and history of class V LN (p = 0.0055). IFNɣ was positively correlated with anti-DNA (p = 0.0355) and anti-SSA (p = 0.0402).
Conclusion: This cross-sectional study supports the role of different T-helper cell cytokines that may be associated with the development of different autoAbs in influencing the diversity of SLE clinical manifestations. The results suggests that elevated IFNɣ and IL-17 are more generalized features in SLE patients. In contrast, higher levels of IL-10 were observed in patients with a history of LN. This provide insights into the pathogenic mechanisms of LN that can help guide future diagnosis and therapies.