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IgA nephropathy; focal glomerulonephritis; Berger's disease

Also see IgA vasculitis Etiology: 1) increased mucosal IgA production 2) associated disorders* a) advanced chronic liver disease, cirrhosis b) celiac disease c) dermatitis herpetiformis d) ankylosing spondylitis e) Henoch Schonlein purpura (acute leukocytoclastic vasculitis) f) inflammatory bowel disease g) HIV1 infection [7] * may be associated with a systemic disorder Epidemiology: 1) most common glomerulonephropathy worldwide 2) frequently occurs in young males (2nd & 3rd decades) Pathology: 1) glomerulonephritis affecting a small proportion of glomeruli 2) mesangial proliferation 3) immunofluorescence shows IgA deposits in the glomerular mesangium 4) generally polymeric IgA1 originating in secretory mucosal system 5) partly due to aberrant or incomplete galactosylation of IgA1 molecules Genetics: - susceptibility to IgA neuropathy associated with defects in C1GALT1 gene Clinical manifestations: 1) variable manifestations from asymptomatic microscopic hematuria with or without proteinuria to rapidly progessive glomerulonephritis 2) an antecedent upper respiratory tract infection may be noted a) hematuria 1-2 days after a sore throat b) generally no latency between infection & acute kidney injury [3] 3) hematuria may be noted after vigorous physical exercise or trauma [7] 4) urine is usually brown rather than red - clots are unusual [7] 5) gross hematuria may occur synchronously with respiratory infection or gastrointestinal infection [3] 6) may occur as disease restricted to the kidney or as part of a syndrome (see etiology) 7) rapidly progessive glomerulonephritis may be associated with - acute renal failure, hypertension, edema, proteinuria, hematuria [3] Laboratory: 1) urinalysis a) hematuria (microscopic or macroscopic) b) erythrocyte casts c) proteinuria, including nephrotic syndrome, may be present 2) serum IgA is increased in 50% of patients - levels do NOT correlated with disease severity 3) serum complement levels are normal 4) complete blood count may show erythrocytosis 5) skin biopsy for IgA is NOT helpful 6) renal biopsy with immunofluorescence studies is diagnostic 7) monitor serum creatinine, urinalysis [3] Complications: - acute renal failure with macroscopic hematuria - acute tubular necrosis [3,4] Differential diagnosis: - postinfectious glomerulonephritis - IgA vasculitis Management: 1) control blood pressure (alone sufficient in most patients) 2) ACE inhibitors slow progression of renal disease; ARB if ACE inhibitor not tolerated [3] 3) omega-3 fatty acids (fish oil & perhaps flax-seed oil) slows progression of disease in high-risk patients 4) broad-spectrum antibiotics not useful 5) benefit of immunosuppressive agents is unclear a) benefit of corticosteroid for proteinuria is controversial [3] - progression of renal failure may be attenuated [11,14] - serious infections may occur, including fatalities [11,14] b) add alkylating agent to corticosteroid if renal insufficiency c) benefit/risk ratio unacceptable [9] 6) prevention - in adults age 19-64 years vaccination with both PCV13 & PPSV23 is indicated - with advanced kidney disease a 2nd dose of PPSV23 is recommended 5 years after the 1st [3] - annual influenza virus vaccine 7) prognosis is generally good a) poor prognostic signs: 1] heavy proteinuria - absence of proteinuria portends benign course managed conservatively [3] 2] hypertension 3] renal insufficiency b) 20% of patients may reach end-stage renal disease in 20 years 8) renal transplantation: a) disease often recurs b) generally not clinically significant

Related

acute leukocytoclastic vasculitis (Henoch-Schonlein purpura; IgA vasculitis)

General

mesangioproliferative glomerulonephritis

References

  1. Stedman's Medical Dictionary 26th ed, Williams & Wilkins, Baltimore, 1995
  2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 606
  3. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2009, 2012, 2015, 2018, 2021. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  4. Gutierrez E, Gonzalez E, Hernandez E. Factors that determine an incomplete recovery of renal function in macrohematuria-induced acute renal failure of IgA nephropathy. Clin J Am Soc Nephrol. 2007 Jan;2(1):51-7 PMID: 17699387
  5. Working Group of the International IgA Nephropathy Network and the Renal Pathology Society. The Oxford classification of IgA nephropathy: rationale, clinicopathological correlations, and classification. Kidney Int. 2009 Sep;76(5):534-45 PMID: 19571791
  6. Wikipedia: IgA nephropathy http://en.wikipedia.org/wiki/IgA_nephropathy
  7. Brake A, Batuman V Medscape: IgA Nephropathy http://emedicine.medscape.com/article/239927-overview
  8. Wyatt RJ, Julian BA IgA Nephropathy N Engl J Med 2013; 368:2402-2414. June 20, 2013 PMID: 23782179 http://www.nejm.org/doi/full/10.1056/NEJMra1206793
  9. Rauen T et al. Intensive supportive care plus immunosuppression in IgA nephropathy. N Engl J Med 2015 Dec 3; 373:2225. PMID: 26630142 http://www.nejm.org/doi/full/10.1056/NEJMoa1415463
  10. Roberts IS, Cook HT, Troyanov S et al for the Working Group of the International IgA Nephropathy Network and the Renal Pathology Society. The Oxford classification of IgA nephropathy: pathology definitions, correlations, and reproducibility. Kidney Int. 2009 Sep;76(5):546-56. PMID: 19571790 Free full text
  11. Lv J, Zhang H, Wong MG et al Effect of Oral Methylprednisolone on Clinical Outcomes in Patients With IgA NephropathyThe TESTING Randomized Clinical Trial. JAMA. 2017;318(5):432-442 PMID: 28763548 http://jamanetwork.com/journals/jama/article-abstract/2646717 - O'Shaughnessy MM, Lafayette RA. Corticosteroids for IgA Nephropathy: TESTING for Benefit, Discovering Harm. JAMA. 2017 Aug 1;318(5):429-431. No abstract available. PMID: 28763530 http://jamanetwork.com/journals/jama/article-abstract/2646698
  12. Feehally J. Immunosuppression in IgA Nephropathy: Guideline Medicine Versus Personalized Medicine. Semin Nephrol. 2017 Sep;37(5):464-477. Review. PMID: 28863793
  13. Lai KN, Tang SC, Schena FP et al IgA nephropathy. Nat Rev Dis Primers. 2016 Feb 11;2:16001. Review. PMID: 27189177
  14. Lv J, Wong MG, Hladunewich MA et al Effect of Oral Methylprednisolone on Decline in Kidney Function or Kidney Failure in Patients With IgA Nephropathy. The TESTING Randomized Clinical Trial. JAMA. 2022;327(19):1888-1898 PMID: 35579642 https://jamanetwork.com/journals/jama/fullarticle/2792252
  15. National Kidney Foundation. IgA Nephropathy http://www.kidney.org/atoz/content/iganeph
  16. IgA Nephropathy http://kidney.niddk.nih.gov/kudiseases/pubs/iganephropathy/index.htm