Concurrent hepatitis B infection and IgA nephropathy in a patient with a history of malignant melanoma

IgA nephropathy (IgAN) is an immune complex-mediated glomerulonephritis characterized by the deposition of IgA-dominant immune complexes in the mesangium, leading to mesangial proliferation and subsequent renal injury. Clinically, IgAN often manifests as episodic macroscopic hematuria following upper respiratory tract or gastrointestinal infections. Disease progression is variable, with 20–50% of patients advancing to end-stage renal disease within 10–20 years of diagnosis. Although IgAN is primarily idiopathic, it may also occur secondary to systemic conditions such as Henoch-Schönlein purpura, HIV infection, toxoplasmosis, ankylosing spondylitis, and liver cirrhosis. Less commonly, IgAN can be associated with hepatitis B virus (HBV) infection or manifest as a paraneoplastic phenomenon. Here, we report a unique case of clinical presentation and successful treatment of concurrent HBV infection and IgAN in a patient with a history of malignant melanoma. To our knowledge, this is the first documented case in which these three conditions (IgAN, HBV infection, and malignant melanoma) coexist in a single patient.