Acute post strep GN - Diffuse proliferative glomerulonephritis

Question 1

etiology post strep GN ?

Answer 1

10–30 days following an acute infection:

most common cause :group A beta-hemolytic streptococci
inflaming the the mouth and tonsillitis, pharyngitis

Soft tissue infections : erysipelas : group A Streptococcus

non bullous impetigo : S. aureus or Group A streptococci

Question 2

clinical features of post strep GN ?

Answer 2

most commonly a throat infection or impetigo. While it can present with haematuria

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Nephritic syndrome :

Hematuria -, the onset of symptoms is typically around 1-3 weeks after the initial infectio

Hypertension: can lead to headaches

generalised Edema;

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influenza like symptoms

Question 3

diagnose post strep GN?

Answer 3

↑ Antistreptolysin-O titer (ASO) (particularly following streptococcal infection of the pharynx)

↑ Anti-DNase B antibody (ADB) titer (particularly following streptococcal infection of the soft tissue)

↓ C3 complement

Urinalysis: nephritic sediment (e.g., hematuria and RBC casts, mild proteinuria)

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Renal biopsy (not performed in most cases)
Indication: suspected rapidly progressive glomerulonephritis

Light microscopy:
Glomeruli are globally and diffusely enlarge
diffuse hypercellularity due to mesangial and endothelial cell increase
infiltration of monocytes and polymorphonuclear cells.
all of this block the capillary

IMMUNOFLUORESCENT FOR EVERY POST INFECTION : GRANULAR
GARLAND PATTERN, THE STARRY SKY PATTERN, AND THE MESANGIAL PATTERN

The starry sky pattern is an irregular, finely granular pattern with small C3 deposits on glomerular basement membrane This pattern is often seen in the early phase of the

The starry sky pattern may turn into the mesangial pattern, which is characterized by granular deposition of C3 with or without immunoglobulin G. - closely related to resolving

sometimes deposits are large and densely packed and aggregate into a garlandlike pattern. These correspond to the humps on the subepithelial side of the glomerular capillary wall seen with electron microscopy
These types of deposits may persist for months and may be associated with the persistence of proteinuria and the development of glomerulosclerosis

ELECTRON MICROSCOPY:
“HUMPS” = SUBEPITHELIAL IMMUNE COMPLEXES (BETWEEN EPITHELIAL CELLS AND THE GLOMERULAR BASEMENT MEMBRANE)