Nephritic and nephrotic syndromes Flashcards
What is the pathophysiology of Berger’s disease?
Due to IgA immune complex deposits in the mesangium of the nephrons. These complexes form elsewhere in the body and travel to the kidneys where they deposit.
What type of hypersensitivity is Berger’s disease? Why?
Type 3
As the immune complexes form elsewhere and travel to where they deposit (the kidneys) and cause destruction there.
Common presentations and features of a patient with IgA nephropathy?
Young male
Recurrent episodes of macroscopic (frank) haematuria
Is typically associated with URTI (a few days, a few weeks would be associated with post-streptococcal nephritis)
Often occurs in childhood
What would you see under a microscope when a patient has IgA nephropathy?
Immunofluorescence?
Mesangial proliferation (IgA immune complexes).
You would get a positive immunofluorescence for IgA and C3 (part of the complement system)
What is the difference between IgA nephropathy and post-streptococcal glomerulonephritis?
n1. Post-streptococcal glomerulonephritis is associated with LOW complement levels (In Berger’s –> these are elevated due to immune complex activation)
- The main symptom in post-streptococcal glomerulonephritis is PROTEINURIA (haematuria may also occur) but in IgA nephropathy, you have haematuria (and lower levels of proteinuria compared to Post-strep glomerulonephritis)
3.URTI usually triggers both but IgA —> develops after 1-2 days after URTI
Post streptococcal glomerulonephritis —> develops 1-2 weeks after URTI
What is the difference between nephritic and nephrotic syndrome?
Nephritic
Describes inflammation of the GBM (glomerular basement membrane)
Haematuria
Cola coloured urine
Oliguria
Proteinuria (less than 3g per 24 hours)–> not as much as in nephrotic syndrome
Fluid retention (oedema in peri-oribtal region,face and hands)
Pt may also have hypertension (either a history of it or currently has it)
Nephrotic
The basement membrane of the glomerulus becomes highly permeable. Allows proteins to pass through.
SIGNIFICANT proteinuria ( more than 3g per day/24hrs)
HYPOalbuminemia (<25g per litre)
Peripheral oedema
HYPERcholesterolaemia
What are the top causes of nephrotic syndrome in adults?
Membranous nephropathy
Focal segmental glomerulosclerosis
Most common cause of nephrotic syndrome in children?
Minimal change disease
What causes minimal change disease?
Most cases are idiopathic but a few minor cases can be due to DRUGS (rifampicin,NSAIDs) HODGKIN’S LYMPHOMA or THYMOMA, INFECTIOUS MONONUCLEOSIS
What is the pathophysiology of Minimal change disease?
T-cells in the blood reach the glomerulus and release cytokines that specifically destroy the foot processes of the podocytes (podocytes are found over the GBM(glomerular basement membrane))——> This process is called effacement.
So negatively charged proteins like albumin can pass through. But larger ones like immunoglobulins can’t. This is why there is highly selective proteinuria in minimal change disease.
Upon conducting a renal biopsy, what would be seen in a patient who has minimal change disease? light and electron microscopy
Light microscopy —> nothing
Electron microscopy —> fusion of podocytes and effacement of the foot processes (which are found at the bottom/foot of the podocytes)
What can cause membranous nephropathy and how serious is it?
Causes may be idiopathic (majority of cases) or secondary (e.g. due to SLE/hep B)
If this nephrotic syndrome is not managed medically, it can develop into end stage renal disease (ESRD)
Upon histologic view, what would you see if someone has membranous nephropathy?
IgG and complement deposits in the subepithelial space
THICKENED GBM
Upon electron micrsocopy, what would be seen in a person who has membranous nephropathy?
Spike and dome shape of the GBM matrix and effacement of the foot processes of the podocytes
What is seen on light microscopy when a pt has focal segmental glomerulosclerosis?
Focal and segmental sclerosis and hyalinosis