IgA Nephropathy: Core Curriculum 2021

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease worldwide. The diagnostic histologic hallmark is dominant or codominant IgA staining on kidney biopsy; however, patients may present with various clinical syndromes ranging from asymptomatic abnormalities noted on urinalysis to rapidly progressive glomerulonephritis. Given substantial heterogeneity in the clinical course of disease, online risk calculators are available that may assist in prognostication and inform discussions with patients. Comprehensive supportive treatment is central in the initial therapy of IgAN; the additive benefit of currently available immunosuppressive agents remains an area of controversy. Although proteinuria is attenuated by the use of corticosteroids, the long-term benefits have been questioned, and the use of corticosteroids is associated with severe adverse effects, notably infection. Recent advances in our understanding of mucosal immunity and the role of the complement system in IgAN pathogenesis are leading to development of novel therapeutic options, which are being evaluated in ongoing clinical trials. In this installment of the AJKD Core Curriculum in Nephrology, IgAN pathogenesis, clinical manifestations, histology, prediction tools, and treatment are reviewed, and case examples are presented to illustrate the approach to the management of patients with IgAN. Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease worldwide. The diagnostic histologic hallmark is dominant or codominant IgA staining on kidney biopsy; however, patients may present with various clinical syndromes ranging from asymptomatic abnormalities noted on urinalysis to rapidly progressive glomerulonephritis. Given substantial heterogeneity in the clinical course of disease, online risk calculators are available that may assist in prognostication and inform discussions with patients. Comprehensive supportive treatment is central in the initial therapy of IgAN; the additive benefit of currently available immunosuppressive agents remains an area of controversy. Although proteinuria is attenuated by the use of corticosteroids, the long-term benefits have been questioned, and the use of corticosteroids is associated with severe adverse effects, notably infection. Recent advances in our understanding of mucosal immunity and the role of the complement system in IgAN pathogenesis are leading to development of novel therapeutic options, which are being evaluated in ongoing clinical trials. In this installment of the AJKD Core Curriculum in Nephrology, IgAN pathogenesis, clinical manifestations, histology, prediction tools, and treatment are reviewed, and case examples are presented to illustrate the approach to the management of patients with IgAN. FEATURE EDITOR:Asghar RastegarADVISORY BOARDUrsula C. BrewsterMichael ChoiAnn O’HareBiff F. PalmerThe Core Curriculum aims to give trainees in nephrology a strong knowledge base in core topics in the specialty by providing an overview of the topic and citing key references, including the foundational literature that led to current clinical approaches. FEATURE EDITOR: Asghar Rastegar ADVISORY BOARD Ursula C. Brewster Michael Choi Ann O’Hare Biff F. Palmer The Core Curriculum aims to give trainees in nephrology a strong knowledge base in core topics in the specialty by providing an overview of the topic and citing key references, including the foundational literature that led to current clinical approaches.