Renal Flashcards
How much HCO3- is filtered by the kidneys daily?
A lot: 4000mM and it is all essentially reabsorbed.
Describe the equation in which carbonic anhydrase relates to HCO3- in the body.
H20 + CO2 — H2CO3 — H+ + HCO-
How is anion gap calculated?
AG = Na+ + K+ - Cl- - HCO3-
With respect to the kidney, how does it handle glucose, inulin and PAH (para-amino hippurate)?
Normal kidneys:
Glucose: completely reabsorbed
Inulin: NOT reabsorbed and NOT secreted
PAH: completely secrete
Inulin - stays IN
PAH - PISSES off
Describe the renal reabsorption of HCO3-
Renal regulation of HCO3-
- Reabsorption in PT (carbonic anhydrase)
- Reabsorption in DT via excretion of H2PO4-
- Reabsorption in DT via excretion of NH4+
What is the histology of membranous glomerulonephritis?
Immune-complexes localised to subepithelial aspect of capillary loop (i.e. between outer aspect of BM and podocyte/epithelium)
True/False: membranous glomerulonephritis is an Ab-mediated disease.
True.
What age-group is membranous glomerulonephritis more likely to occur?
Adults - older than 30yrs.
25% of membranous glomerulonephritis is secondary to another disorder, give 4 common associations.
- SLE and other connective tissue disorders
- Drugs (NSAIDs, gold, penicillamine)
- Infections (Hep B, syphilis, malaria, leprosy, shistosomaiasis)
- Cancer (carcinoma, leukaemia, NHLs)
True/False: membranous glomerulonephritis tends to cause nephritic syndrome.
False.
Membranous glomerulonephritis accounts for up to 50% of adult cases of nephrotic syndrome. Most have insidious heavy proteinuria +/- microscopic haematuria.
Patient is noted to have haematuria, AKI and positive anti-glomerular basement membrane (anti-GBM) antibody on blood test.
Diagnosis?
Treatment?
Goodpasture’s syndrome - autoimmune disease with Abs against type IV collagen.
Prompt treatment required to prevent rapid descent to ESKD.
Treat with plasmapheresis and immunosuppression (prednisone + cyclophosphamide)
In simple terms compare the histopathology of nephrotic and nephritic syndromes.
What is found in the urine?
Nephrotic:
podocyte injury and sclerosis
UA = proteinuria
Nephritic:
glomerular proliferation and inflammation
UA = RBC casts
Give 4 conditions that cause predominantly nephrotic syndrome.
Minimal change nephropathy (MCN) Membranous nephropathy (MN) Focal segmental glomerulosclerosis (FSGS) Diabetic nephropathy (DM)
Give 7 conditions that cause predominantly nephritic syndrome (use mnemomic)
PIG WAIL: Post infectious GN IgA nephropathy Goodpasture's Wegner's Alport Idiotpathic Crescentic GN Lupus Nephritis
Give 3 conditions that cause a ‘mixed’ picture of nephrotic and nephritic syndrome.
- SLE
- Membranoproliferative GN (MPGN)
- IgA nephropathy