Renal medecine Flashcards
The cause fro low calcium and elevated PTH in kidney disease and teatment?
CKD the kidneys struggle to convert vitamin D to its active form 1,25-dihydroxyvitamin D. Given that vitamin D helps absorb calcium from the intestine without its active metabolite that can’t happen. The parathryoid gland starts to secre PTH in excess to compensate one possible treatment for such patients is alfacalcidol the active form of vitamin D to be given as supplementation.
- Alfacalcidol ( active Vit D supplement)
- parathyroidectomy
- Cinacalcet - PTH antagonist for patients with hyperparathyoidism who are on dialysis and not fit for surgery
Assosiations of retroperitoneal fibrosis ?
- Riedel’s thyroiditis
- previous radiotherapy
- sarcoidosis
- inflammatory abdominal aortic aneurysm
- drugs: methysergide
- Infection : TB and S. Pallidum
Liddle’s syndrome ?
- hypokalaemia with hypertension, metabolic alkalosis, hypoaldesteronism
- Due to mutation in the ubiquitin gene - ENaC gain of function mtuation - that channel acts to increase the uptake of sodium in exchange for potassium and H+. Increase sodium uptake results in increased water retention, hence hypertension.
Bartter’s syndrome ?
- Hypokalaemia without hypertension, metabolic alkalosis
- Defect in the Na+K+2CL co-transporter in the ascending loop of Henle - > think of this disease as having too much loop diuretic.
Gitelman’s syndrome
- hypokalaemia without hypertension, metabolic alkalosis, hypercalcaemia and hypomagnesemia, hypocalciuria
-autosomal recessive disorder affecting the function of Na-Cl symporter in the distal convoluted tubule - > similarly to where thiazide diuretics act therefore as having too much thiazides. - decreased sodium re-absorption leads to hypovolaemia which in turn triggers renin production leading to hypoaldosteronism without hypertension.
- Potassium and magnesium replacement + potassium sparing diuretics where needed.
Features of ADPKD?
- Acute loin pain /haematuria - due to cyst haemorrhage or infection.
- Loin pain due to increase renal size
- subarachnoid haemorrhage due to berry aneurysm ( 8%) rupture
- Hypertension
- Renal stone
- Liver cysts ( 70%) - may cause hepatomegaly
- Mitral valve prolapse, mitral/tricuspid incompetence, aortic root dilation, aortic dissection
- Cysts in other organs - pancreas, spleen, rarely : thyroid, oesophagus, ovary
Diagnostic criteria ?
- Two cysts unilateral or bilateral if patient is under 30
- Two cysts bilaterally if 30 to 59
- 4 cysts bilaterally if age over 60 years
Easiest way to diagnose Gitelman’s syndrome or Barrter’s syndrome?
- Urinary chloride levels over 40mmol are diagnostic
Kidney disease : Improving global outcomes organisation recommends the following patient with ADPKD to be screened for cerebral aneurysms?
- FH of intracerebral aneurysms or subarachnoid haemorrhage
- Personal history of previous ICA rupture
- Patients with high risk profession e.g airplane pilot
- Patients anxiety
What type of amyloidosis is assosiated with long term dialysis and why?
- Beta 2 microglobulin amyloidosis - >5 years of dyalisis
- Occurs due to the fact that normal dyalisis filtration membranes e.g cellulose acetate dyalisis membrane, can’t filter out large molecules therefore there is accumulation to beta 2 microglobulin.
- Treatment is moving on to polyacrylnitrile or polysulphone dyalysis membrane ( high flux dialysis membranes ), or of course renal transplant
- Manifistations : Carpal tunnel syndrome, tenosynovitis, scapulohumeral arthropathy, bony cysts and pathological fractures, GI and cardiovascular complications
What liver enzyme is responsible for metabolising diltiazem, and what are the complications of co-prescribing with ciclosporin?
CYP3A4 is a major liver enzyme that metabolizes many drugs.
Diltiazem is metabolized by CYP3A4.
Ciclosporin is also metabolized by CYP3A4.
When you give diltiazem, it inhibits CYP3A4, meaning ciclosporin metabolism slows down → ciclosporin levels rise (by ≥50%).
➡️ This can lead to ciclosporin toxicity (e.g., nephrotoxicity).
Criteria for diagnosing Von Hippel–Lindau Syndrome ?
Von Hippel–Lindau (VHL) syndrome is an autosomal dominant condition that leads to retinal and central nervous system tumours, as well as phaeochromocytomas. Signs of VHL syndrome include balance disturbance, hypertension, headaches and dizziness. Death is often due to renal cell carcinoma.
A proportion of cerebellar haemangiomas secrete erythropoietin-like substances, leading to secondary polycythaemia.
Criteria for diagnosis:
- More than one haemangioblastoma in the CNS (brain, spinal cord) or eye.
- A single haemangioblastoma in the CNS or retina, plus a visceral manifestation (multiple renal, pancreatic or hepatic cysts; phaeochromocytoma; renal cancer).
- Positive family history plus any one of the above clinical manifestations.
- Elucidation of a deleterious mutation in the VHL gene.
What is the diagnostic function of of erythroid culture in the absence of erythroprotein?
- Erythroid colony studies suggest that her red cells do not show autonomous growth; autonomous growth of erythroid colonies is taken as a sign of primary polycythaemia, where erythropoiesis has escaped the control of erythropoietin.
- Erythroid colony studies are thought to have high specificity for detecting primary versus secondary polycythaemia, but the technique is poorly standardized so remains an experimental tool.
Symptoms of retroperitoneal fibrosis ?
- Vague : abdominal and flank pain, general malaise, lethargy.
- Compression symptoms : compression of the ureters casuing ureteric obstruction, compression of the arterial blood supply to the lower limbs causing intermittent claudication, compression of venous return from the lower limbs causing limbs swelling.
- chronic normocytic anaemia
- raised inflamatory markers
Difference in treatment of primary hyperparathyroidism versus secondary hyperparathyroidism?
Primary HPT ➔ Surgery first.
Secondary HPT ➔ Medical therapy first (cinacalcet, etc.).
Cinacalcet is a calcimimetic:
➔ It mimics calcium at the parathyroid gland, reducing PTH secretion.
➔ Lowers PTH, calcium, and phosphate levels
What is the X-ray appearance of bone in osteomalacia ?
- Diffuse demineralisation with chracteristic smudgy/erased appearance of the denineralisation with pseudo fractures (Looser zones).
What is nephrogeneic systemic fobrosis ?
A systemic fibrosig condition that happens to patient with signficant renal disease who have been exposed to gadolinium based contrasts used in MRI.
- The pahtophysiology involves excessive collagen deposition
The staged of lupus nephritis and appropriate treatment options?
Refer to the photo
What is pure red aplastic anaemia?
Pure red cell aplasia (PRCA) is a rare condition defined by the absence of erythroblasts in the bone marrow, leading to profound anaemia with normal leucocyte and platelet counts, and characterised by low or absent circulating reticulocytes. Serum iron and ferritin rise sharply as iron cannot be incorporated into the erythrocytes.
- Seen in patients on EPO developing antibodies against EPO, but also some other conditions.
-Treatment when it relates to EPO is to stop it and do blood transfusions.
Renal biopsy features of membranous glomerulonephritis?
- Light microscopy - thickened glomerular basement membrane.
- Electron microscopy - effacement of podocytes, subepithelial deposition of immune complexes - spike and dome appearance of GBM - IgG and C3 deposition
- Immunoflorescence - granular appearance of subepithelial immune complex deposits
Renal society indications for starting IV or Oral iron replacement , besdies obviously anaemia?
- Ferritinin > 100mg/L
- Transferatinin saturation over 20% or >10% of hypochromic red cells
Glomerulonephritist with first and 2nd highest rate of re-occurance?
- Membranoproliferative glomerulonephritis 30% to 90%, with type 2 causing re-occurance more often than type 1.
-2nd is focal segmental glomerulosclerosis - 40%
What type of renal stones are common in patients with short bowel syndrome and what are the treatment options?
- Oxelate renal stones - oxalate is absorbed through the small bowel , if you have had small bowl resection it is than absorbed by the colon and excreted in excess in the urine e.g stone formation.
- Treatment options are : increase fluid intake, reduce oxalate intake or supplementation with calcium citrate.
Types of rapidly progressive glomerulonephritis ?
- Type 1 RPGN is associated with anti-GBM disease, where linear staining related to IgG and C3 is seen.
- Type 2 is immune complex mediated and is associated with granular glomerular staining with diffuse IgG and complement deposition.
- Type 3 is pauci immune with much reduced staining for both IgG and complement versus the other types.
