The potential impact of autoimmune diseases family history in IgG4-Related Disease: a case control study

Abstract Objective: Autoimmune comorbidities may be associated with IgG4-Related Disease (IgG4-RD), here we aimed to determine the correlation of AID family history and IgG4-RD in a Chinese cohort. Methods: This case-control studyidentified 628 cases of IgG4-RD in Peking Union Medical College Hospital. Patients were classified into two groups, with AID family history group (AID-pos) and without AID family history group (AID-neg). We viewed the potential value of AID family history on IgG4-RD by comparing the differences between the two groups. In addition, Cox regression analysis estimated confidence intervals (CI) and hazard ratio (HR) for IgG4-RD risk. Results: 93 (14.8%) IgG4-RD patients had AID family history. Compared with AID-neg group, baseline data analysis revealed that AID-pos group patients had an earlier age of IgG4-RD onset (50.4 ± 14.8 vs. 54.2 ± 12.6, p=0.014*), a higher percentage of antinuclear antibody (ANA) positivity (38.9% vs 22.7%, p=0.0277*) and IgG4-related thyroiditis (10.9% vs 2.4%, p=0.001*), were prone to comorbid with other AID (16.1% vs 6.2%, p=0.0238*). Cox analysis found that younger age (HR 0.97 [95%CI 0.94-0.99], p=0.0384*) and higher proportions of baseline peripheral eosinophils (HR 1.1 [95%CI 1.02-1.2], p=0.0199*) increased the risk of unfavorable prognosis for AID-pos IgG4-RD patients. Conclusions: 14.8% of IgG4-RD patients had AID family history, with younger age of disease onset age and higher frequency of ANA positivity, indicating that IgG4-RD may share genetic background with other AID.