Tissue biopsies with immunofluorescence
How direct immunofluorescence on kidney, skin and other tissue works, how to send it, and how to read the patterns that matter to an immunologist (linear, granular, pauci-immune, full house, IgA-dominant, C3-dominant), with worked kidney and skin examples and the errors that waste a biopsy.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Direct immunofluorescence (DIF) stains the patient's own tissue with fluorescent antibodies to IgG, IgA, IgM, C3, C1q, fibrinogen, and kappa and lambda light chains. It shows where immune reactants sit and in what pattern.
- Indirect IF is a serology test: the patient's serum on a substrate (ANA on HEp-2 cells, ANCA on neutrophils, pemphigoid on salt-split skin). This note covers tissue DIF.
- DIF is central to diagnosing glomerulonephritis, autoimmune blistering disease, cutaneous lupus and IgA vasculitis. Light microscopy and electron microscopy complete the picture.
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Sources
- KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases. Kidney International 2021;100(4S):S1-S276KDIGO, 2021, with 2024 lupus nephritis and ANCA vasculitis and 2025 IgA nephropathy updates
- Bose B, Carter SA, Abdy ME et al. CARI Guidelines commentary on the KDIGO clinical practice guideline for the management of glomerular diseases. Nephrology 2025;30(9):e70119AU/NZCARI Guidelines (Caring for Australians and New Zealanders with Kidney Impairment), 2025
- Bajema IM et al. Revision of the International Society of Nephrology/Renal Pathology Society classification for lupus nephritis. Kidney Int 2018;93:789-96ISN/RPS, 2018
- Pickering MC et al. C3 glomerulopathy: consensus report. Kidney Int 2013;84:1079-89Kidney International, 2013
- RCPA Manual: immunofluorescence of renal and skin biopsiesAU/NZRoyal College of Pathologists of Australasia, online edition, accessed November 2026
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Turnstile bot check on sign-in and signed-out feedback