L11. Renal disease, haematuria and proteinuria

Question 1

What is proteinuria, its causes, tests for diagnosis.

Answer 1

Protein (eg. Albumin) in the urine due to a glomerulus which is extra leaky. This can be associated with AKI or CKD (blocked filter) but may have normal kidney function.
So can be due to nephrotic syndrome, chronic glomerular disease or acute glomerulonephritis (nephritic syndrome)
Tests: 24 hour urine, albumin: creatinine, protein: creatinine, biopsy.
Treated: controlling blood pressure because decreasing bp will decrease excretion of protein even if the filter is leaky.

Question 2

What is microalbuminuria, causes and how is it diagnosed

Answer 2

Between being normal and having proteinuria, Albumin creatinine ratio of 2.5-25 mg/mmol. Caused by diabetes, fever, exercise, HF, poor glycaemic control

Question 3

What is nephrotic syndrome-associated conditions,

Answer 3

Nephrotic syndrome is when >3.5g/day of urinary protein= making it frothy with low serum albumin. Can be normal or impaired renal function.

Associated:

• Oedema due to low albumin ->low oncotic pressure and high hydrostatic pressure pushes water into extracellular compartment.
• Liver tries to increase albumin production but can’t keep up and while doing this also increases lipoprotein production then cholesterol.
• Increased risk of clotting- deep vein thrombosis.
• Reduction in antibody production, decreased complement pathway-> increased bacterial infection: chicken pox in children. (deadly)
• Malnutrition.

Question 4

What is diabetic nephropathy - type 1

Answer 4

When untreated, increased glucose in the blood means that kidney hyperfilters so GFR increases leading to microalbuminuria, but if glucose levels aren’t controlled or there is high bp then glomerulus is damaged and GFR goes down, and later there is overt proteinuria

Question 5

What is nephritic syndrome caused by, symptoms and diagnosis

Answer 5

Nephritic syndrome caused by acute glomerulonephritis. RPGN, which is an AKI. This leads to leaking glomeruli for blood and protein.
Symptoms: oedema, hypertension, oliguric, RBC in urine + RBC casts.
Diagnosed by renal biopsy where crescents of proliferating epithelial cells which are going to kill glomerular cells.

Question 6

What are the signs of glomerular haematuria and what is it associated with

Answer 6

Microscopic, Denotes an intrinsic renal disease, often associated with proteinuria, but may have normal kidney function or AKI, chronic kidney disease. RBCs will look irregular, abnormal and smaller than if it was non glomerular.

Question 7

What are the signs of haematuria from the collecting system and what are these commonly caused by

Answer 7

Usually macroscopic, with little/no proteinuria. Caused by blockages by stones or infections. Loin to groin pain and can be diagnosed on ultrasound as dark dilation in the kidney- backed up urine or stones on CT.

Question 8

What are the signs of haematuria from the Focal lesions and what are these commonly caused by

Answer 8

It can be either micro or macroscopic, often asymptomatic, anywhere in the urinary tract. Most caused by renal cell carcinoma which is good circle mass, red,yellow, brown, part cystic and may invade the renal vein. Can have some ectopic hormone production, back pain, flank pain with local spread not common, mostly blood borne metastases as it spreads into the renal vein. Diagnosed via radiology