Case Report: A rare case of biopsy-proven lupus nephritis complicated by Graves’ disease in a 39-year-old man

Hyperthyroidism and systemic lupus erythematosus (SLE) are both common diseases in internal medicine. Among them, Graves’ disease (GD) is the most frequent cause of hyperthyroidism, while lupus nephritis (LN) represents one of the most severe organ manifestations of SLE. Basic research suggests that GD and SLE may share overlapping genetic and immunological pathways; however, whether these shared mechanisms contribute to their clinical coexistence remains uncertain. Clinical studies or case reports on their coexistence are currently limited, and we cannot effectively manage cases of co-occurrence based on authoritative guidelines or expert consensus. In this study, we report a 39-year-old male patient with biopsy-proven ISN/RPS Class IV + V LN concomitant with GD. The patient was treated with a combination of glucocorticoids, mycophenolate mofetil, and hydroxychloroquine for LN, along with methimazole for GD, supplemented by symptomatic therapy including antihypertensive and heart rate controlling agents, etc. The patient demonstrated early clinical and laboratory improvement during follow-up, although the limited follow-up precluded assessment of an established renal response.