Sir, We conducted this study to describe the presence of comorbidities, frequency, and risk factors of hospitalization in a cohort of patients with immunoglobulin G4-related disease (IgG4-RD). Almost all patients had comorbidity (95.5%), the most common being diabetes mellitus, hypertension, allergy, concomitant autoimmune diseases, and osteoporosis. The hospitalized patients had higher CCI and RDCI scores and had more thrombotic events and biliary involvement, but less glandular involvement (Table 2). 2 TABLE Comparison of hospitalized and non-hospitalized patients. Sixteen patients had concurrent autoimmune/inflammatory conditions (two rheumatoid arthritis, two limited systemic sclerosis, and one patient each peripheral spondyloarthritis, granulomatosis with polyangiitis and microscopic polyangiitis), and 10 organ-specific autoimmune diseases. [Extracted from the article]