IgA nephropathy in a patient receiving infliximab for generalized pustular psoriasis

BACKGROUND: IgA nephropathy is the most common glomerulonephritis. Secondary IgA nephropathy complicated with systemic diseases, including psoriasis, is also often reported. Generalized pustular psoriasis is a form of psoriasis characterized by sterile pustules on reddened skin and fever. Infliximab, one of the first-line therapies for severe psoriasis, has also been reported to cause systemic vasculitis and IgA nephropathy. We herein report a case of IgA nephropathy activated during infliximab treatment for generalized pustular psoriasis. CASE PRESENTATION: A 28-year-old woman presented with episodic gross hematuria, increasing proteinuria, and renal dysfunction. She had been receiving anti-TNFα therapy with infliximab because of generalized pustular psoriasis for 3 years, but her skin symptoms worsened following withdrawal during pregnancy. After delivery, her skin symptoms improved with the resumption of infliximab, but clinical signs suggested glomerulonephritis, and renal biopsy showed active IgA nephropathy. Infliximab was discontinued, and the combination of corticosteroids, tonsillectomy, and secukinumab, an IL-17A inhibitor, improved both the skin symptoms and the glomerulonephritis. CONCLUSIONS: In our case, the activity of IgA nephropathy was exacerbated by anti-TNFα therapy but was improved by the combination of corticosteroids, tonsillectomy, and an IL-17A inhibitor against the original disease. Autoimmune diseases may underlie the development of secondary IgA nephropathy associated with anti-TNFα therapy, and so further studies are needed to better understand the association between molecular-targeted drugs and IgA nephropathy.