Clinical characteristics of IgG4-related disease patients with different serum IgG4 levels: A single-center retrospective study
Dong-Ge Han, Lei Long, Qin-Xue Pu, Lu-Gao Tian, Wei LiuObjective
Immunoglobulin G4-related disease is a rare autoimmune disorder, and serum immunoglobulin G4 (IgG4) levels vary among patients. This study aimed to systematically compare the clinical features of patients with immunoglobulin G4-related disease across different serum IgG4 levels to improve understanding of disease heterogeneity.
Methods
This retrospective observational study enrolled 77 patients with immunoglobulin G4-related disease admitted to Yichang Central People's Hospital from January 2019 to April 2025.
Results
Among the 77 patients with immunoglobulin G4-related disease, 13 (16.88%) had serum IgG4 levels ≤ the upper limit of normal (ULN), 19 (24.68%) had levels within the range of ULN <IgG4< 2 × ULN, 25 (32.47%) had levels within the range of 2 × ULN ≤IgG4 <5 × ULN, and 20 (25.97%) had serum IgG4 levels ≥5 × ULN. The incidence of multiorgan involvement was higher in patients with serum IgG4 levels ≥5 × ULN than in patients with serum IgG4 levels ≤ULN and those with 2 × ULN ≤IgG4 <5 × ULN (p = 0.007). Additionally, the prevalence of lymph node involvement was significantly higher in patients with serum IgG4 levels ≥5 × ULN than in those with 2 × ULN ≤IgG4 <5 × ULN (p = 0.013). Patients with serum IgG4 levels ≥5 × ULN had higher total protein (p = 0.007), globulin (p < 0.001), and immunoglobulin G (p < 0.001) levels than patients with serum IgG4 levels ≤ ULN and those with 2 × ULN ≤IgG4 <5 × ULN. They also had lower serum albumin levels than patients with 2 × ULN ≤IgG4 <5 × ULN (p
Conclusions
Patients with immunoglobulin G4-related disease may exhibit diverse clinical characteristics according to their serum IgG4 levels. Clinicians should consider variations in serum IgG4 levels when assessing and managing patients with immunoglobulin G4-related disease.