Double Glomerulonephritis in a Patient with Ankylosing Spondylitis Treated with Biologic Agent: Extrarticolar Involvement or Anti-Tumor Necrosis Factor Alpha Injury? A Case-Based Review

Secondary IgA Nephropathy and IgA-Associated Nephropathy: A Systematic Review of Case Reports

Primary (pIgAN), secondary IgA nephropathy (sIgAN), and IgA-associated nephropathy can be distinguished. While pIgAN has been thoroughly studied, information about the etiology of sIgAN remains scarce. As concerns sIgAN, several studies suggest that different etiologic factors play a role and ultimately lead to a pathophysiologic process similar to that of pIgAN. In this article, we review a vast number of cases in order to determine the novel putative underlying diseases of sIgAN. Moreover, updates on the common pathophysiology of primary disorders and sIgAN are presented. We identified liver, gastrointestinal, oncological, dermatological, autoimmune, and respiratory diseases, as well as infectious, iatrogenic, and environmental factors, as triggers of sIgAN. As novel biological therapies for listed underlying diseases emerge, we suggest implementing drug-induced sIgAN as a new significant category. Clinicians should acknowledge the possibility of sIgAN progression in patients treated with TNF-α inhibitors, IL-12/IL-23-inhibitors, immune checkpoint inhibitors, CTLA-4, oral anticoagulants, thioureylene derivatives, and anti-vascular endothelial growth factor drugs.

Glomerulonephritis in Two Patients with SpA Treated with TNF-α Blockers and a Review of the Literature

Renal failure or acute/chronic kidney damage may present as a clinical manifestation of rheumatic diseases. In addition treatment with DMARDs or biologic drugs may induce nephrotoxicity. In this case-based review, we present two patients with SpA under anti-TNF-α treatment admitted to our hospital because of renal failure and proteinuria. We review previously published yet isolated cases of TNF-α blocker-induced glomerular disease in patients with SpA. Renal manifestations are occasionally seen in patients with ankylosing spondylitis and psoriatic arthritis with IgA nephropathy being the most common of them. Anti-TNF-α agents although reportedly used for the treatment of glomerular nephropathy as a disease manifestation, they have been considered responsible for provoking renal damage in some cases. A diagnostic approach for patients with SpA treated with anti-TNF-α agents presenting with renal manifestations is proposed herein.