Paeds · nephrology-urology-fluids-and-electrolytes
IgA nephropathy and IgA vasculitis nephritis
Also known as IgA nephropathy · Berger disease · IgA vasculitis · Henoch-Schonlein purpura · IgA vasculitis nephritis
Fellowship guide to IgA nephropathy and IgA vasculitis nephritis: the most common primary glomerulonephritis worldwide, defined by dominant mesangial IgA deposition and classified by the Oxford MEST-C score; IgA vasculitis as the most common childhood vasculitis whose renal lesion is histologically identical; the shared multi-hit pathogenesis centred on galactose-deficient IgA1; the distinction of synpharyngitic haematuria from post-infectious glomerulonephritis by normal C3 and a short latency; and the treatment ladder from ACE inhibitor or ARB supportive care to corticosteroids, targeted-release budesonide, and immunosuppression for crescentic disease.
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Target exams
Red flags
- A child or adolescent with macroscopic haematuria and a reduced estimated GFR, hypertension, or significant proteinuria
- Rapidly progressive glomerulonephritis with over 50 percent crescents on biopsy requiring urgent immunosuppression
- IgA vasculitis with severe abdominal pain, melaena, or signs of intussusception
- Nephrotic-range proteinuria or nephritic syndrome from IgA vasculitis nephritis
- Macroscopic haematuria with a palpable purpuric rash over the lower limbs and buttocks in a young child
- Sustained proteinuria over 1 g per day despite supportive care, marking high risk of progression
Life stages
Care settings
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- Recognises IgA nephropathy and IgA vasculitis nephritis and distinguishes synpharyngitic haematuria from post-infectious glomerulonephritis
- Initiates supportive care with ACE inhibitor or ARB and refers for renal biopsy when indicated
- Identifies the IgA vasculitis tetrad and screens for renal involvement
- Applies the Oxford MEST-C classification and International IgA Nephropathy Prediction Tool to risk-stratify progression
- Justifies disease-specific therapy selection against the TESTING and NefIgArd evidence
- Manages rapidly progressive crescentic IgA disease and post-transplant recurrence
- Definition and classification of IgA nephropathy and IgA vasculitis nephritis
- Role of the multi-hit pathogenesis and normal C3 in distinguishing IgA disease from post-infectious glomerulonephritis
- Principles of supportive care and when to involve nephrology
- Recognises a child with significant proteinuria or rapidly progressive IgA disease and escalates appropriately
- Communicates the chronic, relapsing nature and need for lifelong nephrology follow-up to families
- Counsels on the risks and benefits of corticosteroids versus steroid-sparing therapy
- Level 1: Recognition of synpharyngitic haematuria and the IgA vasculitis tetrad
- Level 2: Initiation of supportive care with ACE inhibition and interpretation of Oxford MEST-C
- Level 3: Selection of disease-specific therapy and coordination of long-term renal surveillance
- IgA nephropathy as the most common primary glomerulonephritis and the multi-hit pathogenesis
- Oxford MEST-C score and the prognostic weight of the T and C scores
- EULAR/PRINTO/PRES classification of IgA vasculitis and the ISKDC crescent grading of nephritis
- Assessment and initial management of a child with macroscopic haematuria after a viral illness
- Interpretation of renal biopsy showing dominant mesangial IgA deposition with normal C3
- Structured explanation of supportive care and the rationale for disease-specific therapy
- Recognition and supportive management of IgA nephropathy and IgA vasculitis nephritis
- Oxford MEST-C classification and risk stratification using the prediction tool
- Corticosteroid and budesonide therapy with attention to infectious risk and prophylaxis
- Recognition of IgA nephropathy and IgA vasculitis as causes of haematuria and proteinuria in children
- Initiation of ACE inhibition and urgent nephrology referral
- Family communication on diagnosis, prognosis, and long-term follow-up
- Canadian approach to IgA nephropathy and IgA vasculitis nephritis classification and management
- Risk stratification with the Oxford score and prediction tool in children
- Long-term renal surveillance after IgA vasculitis and IgA nephropathy recovery
Overview & Definition
A teenager who notices dark, smoky urine the morning after a sore throat, or a five-year-old who arrives with a purpuric rash on the shins and blood in the urine, both have the same underlying problem: immune complexes built from a defective antibody called IgA are settling in the filtering surface of the kidney and injuring it. When that process is confined to the kidney it is called IgA nephropathy, the most common primary glomerulonephritis in the world. When the same IgA complexes also land in the skin, gut, and joints it is called IgA vasculitis (the modern name for Henoch-Schonlein purpura), and when it scars the kidney it is called IgA vasculitis nephritis. The renal lesion in the two conditions is histologically identical. [8]
The link between the two is the central teaching point. Both are driven by a faulty IgA molecule whose sugar chains are incomplete — galactose-deficient IgA1 (Gd-IgA1). The body makes antibodies against this abnormal molecule, the resulting immune complexes circulate, and they lodge wherever they can, above all in the glomerular mesangium. Whether the child presents with isolated kidney disease or with a full systemic vasculitis depends on where those complexes deposit, not on a different mechanism. [11]
References11ShowHide
- [1]Cattran DC, Coppo R, Cook HT, et al. The Oxford classification of IgA nephropathy: rationale, clinicopathological correlations, and classification. Kidney Int, 2009.PMID 19571791
- [2]Trimarchi H, Barratt J, Cattran DC, Cook HT, Coppo R, Haas M, et al Oxford Classification of IgA nephropathy 2016: an update from the IgA Nephropathy Classification Working Group. Kidney Int, 2017.PMID 28341274
- [3]Haas M, Verhave JC, Liu ZH, Alpers CE, Barratt J, Becker JU, et al A Multicenter Study of the Predictive Value of Crescents in IgA Nephropathy. J Am Soc Nephrol, 2017.PMID 27612994
- [4]Lv J, Xu D, Perkovic V, Ma X, Johnson DW, Woodward M, et al Corticosteroid therapy in IgA nephropathy. J Am Soc Nephrol, 2012.PMID 22539830
- [5]Barratt J, Lafayette R, Kristensen J, Stone A, Cattran D, Floege J, et al Results from part A of the multi-center, double-blind, randomized, placebo-controlled NefIgArd trial, which evaluated targeted-release formulation of budesonide for the treatment of primary immunoglobulin A nephropathy. Kidney Int, 2023.PMID 36270561
- [6]Ozen S, Pistorio A, Iusan SM, Bakkaloglu A, Herlin T, Brik R, et al EULAR/PRINTO/PRES criteria for Henoch-Schonlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria. Ann Rheum Dis, 2010.PMID 20413568
- [7]Barbour SJ, Coppo R, Er L, Pillebout E, Russo ML, Alpers CE, et al Histologic and Clinical Factors Associated with Kidney Outcomes in IgA Vasculitis Nephritis. Clin J Am Soc Nephrol, 2024.PMID 38261310
- [8]Floege J, Barratt J, Cook HT, Noronha IL, Reich HN, Suzuki Y, et al Executive summary of the KDIGO 2025 Clinical Practice Guideline for the Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV). Kidney Int, 2025.PMID 40975525
- [9]Zhang Y, Hu YT, Lv JC, Zhang H Corticosteroids in the treatment of IgA nephropathy: lessons from the TESTING trial. Pediatr Nephrol, 2023.PMID 36881171
- [10]Barbour SJ, Coppo R, Er L, Russo ML, Liu ZH, Ding J, et al Application of the updated International IgA Nephropathy Prediction Tool in children one or two years post-biopsy. Kidney Int, 2024.PMID 39094695
- [11]Suzuki H, Moldoveanu Z, Julian BA, Wyatt RJ, Novak J Autoantibodies Specific for Galactose-Deficient IgA1 in IgA Vasculitis With Nephritis. Kidney Int Rep, 2019.PMID 31844808