IgG glycosylation profiling of systemic lupus erythematosus using lectin microarray

Area of Science:

• Immunology
• Glycobiology
• Rheumatology

Background:

• Research on immunoglobulin G (IgG) glycosylation in systemic lupus erythematosus (SLE) is limited, particularly concerning variations across SLE subtypes.
• Understanding these changes is crucial for elucidating SLE pathogenesis and identifying potential diagnostic markers.

Purpose of the Study:

• To characterize the serum IgG glycosylation profile in patients with SLE.
• To investigate potential diagnostic value of identified glycosylation alterations in SLE and its subtypes.

Main Methods:

• Lectin microarrays analyzed serum IgG glycosylation in 194 SLE patients, 100 disease controls, and 100 healthy controls.
• Differences were validated using lectin blotting, and diagnostic potential was assessed via Receiver Operating Characteristic (ROC) analysis for SLE and its subgroups.

Main Results:

• SLE patients showed significantly increased Galβ3GalNAc and decreased levels of core fucose, high mannose, GlcNAc, GalNAc, and Galβ4GlcNAc compared to controls.
• Elevated GalNAc and galactose patterns were observed in neuropsychiatric SLE (NPSLE) compared to SLE without major organ involvement (WMOI).
• ROC analysis indicated PNA levels could help differentiate SLE from primary Sjögren's syndrome (pSS).

Conclusions:

• Patients with SLE display unique alterations in serum IgG glycosylation.
• Aberrant Galβ3GalNAc, galactose, and GalNAc glycosylation patterns show potential diagnostic value for SLE and NPSLE.
• These abnormal IgG glycans offer new insights into SLE pathogenesis and progression.