This document provides an overview of rapidly progressive glomerulonephritis (RPGN) for medical students. It defines RPGN as a clinical syndrome characterized by rapid loss of renal function within 3 months. RPGN can be classified into 3 types based on pathogenesis and immunofluorescence patterns. Type I involves anti-GBM antibodies. Type II features immune complex deposition. Type III, also called pauci-immune RPGN, features neutrophil activation in response to ANCA but no immune complex deposition or anti-GBM antibodies. The diagnosis of RPGN relies on renal biopsy identifying crescents on microscopy along with urine and serum analysis.

1. Renal Pathology
for medical students
Rapidly Progressive
Glomerulonephritis
Professor Wadie M Y Elmadhoun, MBBS, MSc.,MD
E-mail: wadie2222@yahoo.com
Kidney Pathology – RPGN – Prof. Wadie 1

2. Presentation outlines
1. Intended Learning outcomes (ILOs).
2. Rapidly Progressive Glomerulonephritis
(RPGN): definition, pathogenesis and clinical
course.
3. Types of RPGN: Type I, Type II, Type III.
5. Quiz.
6. Further learning resources.
Kidney Pathology – RPGN – Prof. Wadie
2

3. Intended Learning outcomes (ILOs)
• By the end of this session, the learner should be
able to:
1. Explain what is meant by Rapidly Progress GN,
discuss its nature, clarify its clinical course,
causes and pathogenesis.
2. Differentiate between the various types of
RPGN.
Kidney Pathology –RPGN – Prof. Wadie
3

4. Definition of the Rapidly Progressive
Glomerulonephritis (RPGN)
• A clinical syndrome characterized by:
• Rapid loss of renal function: more than 50%
decline of GFR within 3 months.
• Crescent-shaped scars in most glomeruli,
• If not treated, will progress to acute renal
failure and death within months.
Kidney Pathology – RPGN – Prof. Wadie 4

5. Crescents in 2 glomeruli
Kidney Pathology – RPGN – Prof. Wadie 5

6. Crescent shape in glomerulus
Kidney Pathology – RPGN – Prof. Wadie 6

7. Crescent in RPGC
Kidney Pathology – RPGN – Prof. Wadie 7

8. Overview of RPGN/Crescentic GN
• RPGN is a clinical definition, NOT a specific
pathologic GN.
• Also known as “CRESCENTIC GN”
• It is caused by either
immunological damage to
glomeruli or associated with anti-
neutrophil cytoplasmic antibody
(ANCA). Kidney Pathology – RPGN – Prof. Wadie 8

9. Rapidly Progressive Glomerulonephritis
(Crescentic GN)
• Type I: anti-GBM antibodies.
• Type II :immune complex
deposition in GBM.
• Type III : No remarkable immune damage,
associated with anti-neutrophil cytoplasmic
antibody (ANCA).
Kidney Pathology – RPGN – Prof. Wadie

10. Signs and symptoms
• Most types of RPGN are characterized by:
• severe and rapid loss of kidney function
• with marked hematuria; red blood cell casts in
the urine; and proteinuria
• Some patients also experience hypertension
and edema.
• Severe disease is characterized by oliguria or
anuria.
Kidney Pathology – RPGN – Prof. Wadie

11. Two urine samples showing gross and microscopic
hematuria: in RPGN
Kidney Pathology – RPGN – Prof. Wadie
11

12. CLASSIFICATION
• Crescentic glomerulonephritis (CrGN)
• RPGN can be classified into three types, based
upon the pathogenesis and
immunofluorescence patterns:
Kidney Pathology – RPGN – Prof. Wadie 12

13. 1. Type I CrGN
• also called anti-GBM antibody Crescentic GN: is
characterized by the presence of autoantibodies
directed against type IV collagen in the (GBM).
• Some cases are associated with antibodies
directed against the basement membrane of lung
alveoli, producing Goodpasture syndrome.
• Type I accounts for less than 20% of RPGN.
• Plasma exchange or plasma-pheresis benefit
patients with type I CrGN, but not types II or III.
Kidney Pathology – RPGN – Prof. Wadie 13

14. Anti-GBM Antibody, type I RPGN
(Linear immunoflourescence in Type I CrGN)
Kidney Pathology – RPGN – Prof. Wadie 14

15. 2. Type II CrGN
• Characterized by deposition of immune
complexes in glomerular tissues. (Granular IF)
• Any immune complex disease—including SLE,
acute proliferative glomerulonephritis,
Henoch–Schönlein purpura, and IgA
nephropathy may progress to RPGN.
• Type II RPGN accounts for about 40% of cases
Kidney Pathology – RPGN – Prof. Wadie 15

16. Granular IF
Kidney Pathology – RPGN – Prof. Wadie 16

17. Granular pattern
17

18. RPGN type II: secondary to IgA nephropathy
Kidney Pathology – RPGN – Prof. Wadie 18

19. 3. Type III CrGN
• Also known as pauci-immune RPGN, and features
neither immune complex deposition nor anti-GBM
antibodies.
• Instead, the glomeruli are damaged perhaps
through the activation of neutrophils in response to
ANCA.
• Type III RPGN may be (primary, or idiopathic) or
associated with a systemic disease (secondary) to
ANCA-associated vasculitis such as granulomatosis
with polyangiitis.
• Type III RPGN accounts for more than 40% of RPGN
Kidney Pathology – RPGN – Prof. Wadie 19

20. Diagnosis of RPGN
• Impaired kidney function in an individual who has
had the condition for fewer than three months is
characteristic of RPGN.
1. Renal biopsy: is the most important
investigation. Crescents are identified on
microscopy + linear or granular pattern in
immunofluorescence.
2. Raised serum creatinine and urea.
3. Urine examination: oliguria or anuria, hematuria
and proteinuria.
Kidney Pathology – RPGN – Prof. Wadie 20

21. Renal biopsy showing a crescent
Kidney Pathology – RPGN – Prof. Wadie 21

22. Diagnosis
• Serum analysis often aids in the diagnosis of a
specific underlying disease.
1. The presence of anti-glomerular basement
membrane (GBM) antibodies suggests type I
RPGN.
2. Antinuclear antibodies (ANA) may support a
diagnosis of systemic lupus erythematosus and
type II RPGN;
3. Type III is associated with anti-neutrophil
cytoplasmic antibodies (ANCA)-positive serum.
Kidney Pathology – RPGN – Prof. Wadie 22

23. 23

24. Kidney Pathology – RPGN – Prof. Wadie 24

25. ASSIGNMENT
•You are asked to revise
the next slide carefully,
then write a two-page
essay about its topic.
Kidney Pathology – RPGN – Prof. Wadie
25

26. Kidney Pathology – RPGN – Prof. Wadie 26

27. Quiz 1: what is the pathological change
seen in this microphotograph?
Kidney Pathology – RPGN – Prof. Wadie
27
Answer: crescents.

28. Further sites for learning
• https://en.wikipedia.org/wiki/Rapidly_progres
sive_glomerulonephritis
• https://webpath.med.utah.edu/RENAHTML/R
ENALIDX.html#9
Kidney Pathology – RPGN – Prof. Wadie 28

29. Enjoy the scene
of this crescent.
Thanks
Kidney Pathology – Nephritic Syndrome – Prof. Wadie 29