Supplement 1 to Volume XXXIV (2026) of Rheumatology (Bulgaria) compiles the scientific abstracts presented at the National Conference with International Participation, "Summer Rheumatology Days 2026".
The issue features clinical research and insights structured across dedicated plenary sessions. Key thematic areas encompass advanced diagnostic and therapeutic strategies in osteoporosis, inflammatory joint diseases, musculoskeletal ultrasound, and systemic connective tissue diseases. Notable highlights include clinical updates on sequential therapy of osteoporosis, cardiovascular risk evaluation, and innovative targeted interventions such as CAR T-cell and bispecific T-cell engager therapies. Additionally, a dedicated section presents complex clinical case reports from young rheumatologists exploring rare manifestations and challenging differential diagnoses.