renal essay - glomerulonephritis Flashcards
What is glomerulonephritis?
A host-immune response to pathogenic or self antigens which results in immunoglobulins and T cells causing immune deposits in the glomerulus.
What are the 3 classes of antigen implicated in glomerulonephritis?
Exogenous bacterial/viral products, exogenous self-circulating products, endogenous glomerular components (in situ)
What are the 4 possible locations of immune deposits in the glomerulus in glomerulonephritis?
Subepithelial, subendothelial, mesangial, basement membrane
When and why does post-streptococcal glomerulonephritis arise?
Appears 1-4 weeks after a skin/pharyngeal infection with a nephritogenic strain of group A Beta-haemolytic streptococci.
Which demographic is most prone to post-streptococcal glomerulonephritis?
Children - however they have the best clinical outcomes
Where in the glomerulus are immune deposits found in post-streptococcal glomerulonephritis?
Subendothelial location - deposits found in the basement membrane
What syndrome does post-streptococcal glomerulonephritis present with?
Nephritic syndrome
What are the symptoms of post-streptococcal glomerulonephritis?
Nephritic symptoms - oliguria, gross haematuria, mild proteinuria, mild-moderate hypertension
What does serology show in post-streptococcal glomerulonephritis?
Elevated anti-strep antibodies, low serum C3 due to consumption of complement components
What is the histological morphology in post-streptococcal glomerulonephritis?
Enlarged, hypercellular glomerulus, obliterated capillary lumens, cellular proliferation and leukocyte infiltration (neutrophils)
What does immunofluuresence microscopy show in post-streptococcal glomerulonephritis?
Granular deposition of IgG, IgM and C3 in capillary walls
What is the most common cause of membranous nephropathy?
Auto-immunity to PLA2R receptors on podocytes
What is the pathophysiology of membranous nephropathy?
C5b-C9 MAC mediated autoimmunity to PLA2R receptors on podocytes, resulting in the release of proteolytic enzymes that break down foot processes damaging the filtration barrier.
Where in the glomerulus are immune complexes deposited in membranous nephropathy?
IgG complexes in subepithelial location, then are incorporated into the basement membrane
Why is there no inflammatory cell recruitment and cellular proliferation seen in membranous nephropathy, despite it being an immunological pathology?
Complement C5a and C3a molecules at the podocytes are unable to activate and recruit inflammatory cells as they are not on the capillary side of the basement membrane
What syndrome does membranous nephropathy present with?
Nephrotic syndrome
What are the signs and symptoms of membranous nephropathy?
symptoms of nephrotic syndrome: massive proteinuria, hypoalbuminaemia, generalised oedema, hyperlipidaemia
What types of oedema may be observed in a patient with a nephrotic syndrome?
Pulmonary oedema (orthopnoea, PND), pleural effusion, oedema of lower legs/sacrum
Why do nephrotic syndromes cause hyperlipidaemia?
There is increased hepatic lipogenesis as a non-specific response to the falling oncotic pressure secondary to low albumin
What is the histological morphology of membranous nephropathy?
Thickened basement membranes with a spiked appearance
What are the findings of a immunofluoresence microscopy in membranous nephropathy?
Granular IgG deposits
What syndrome does rapidly progressive glomerulonephritis present with?
acute Nephritic syndrome
