Week 3 - A - Pathology 1 - Glomerulonephritis and Pyelonephritis (and renal function scans))

Question 1

What is the renal parenchyma?

Answer 1

The renal parenchyma is the functioning part of the kidney that filters blood and makes urine

Question 2

What is the difference between glomerulonephritis and pyelonephritis?

Answer 2

Glomerulonephritis is non-infective inflammation of the glomerular tufts leading to glomerular dysfunction
Pyelonephritis is infection in the kidneys

Question 3

Glomerulonephritis primarily starts in the glomerular tufts before affecting other areas, where is affected secondarily?

Answer 3

In then goes on to have tubelointerstitial changes

Question 4

There are a variety of different types of glomerulonephritis which we will be taught about Which type of glomerulonephritis is associated with changes to podocytes?

Answer 4

This would be minimal change glomerulonephritis (effacement of podocytes)

Question 5

Why does the effacement (wiping out) of the podocyte foot process occur and what does this cause?

Answer 5

Thought to occur due to T cells releasing cytokines
This causes the negatively charged podocyte foot processes to be wiped out and therefore cant repel large proteins like albumin leading to the proteinuria and hypoalbuminaemia

Question 6

What is the most common type of nephrotic syndrome seen in children?

Answer 6

This is minimal change nephrotic syndrome

Question 7

What is the anti-glomerular basement antibody syndrome features? What is the syndrome known as?

Answer 7

Goodpasture’s syndrome
Glomerulonephritis and alveolar pulmonary haemorrhage causing haemoptysis

Question 8

Pyeloneprhtiis is Bacterial infection of renal pelvis, calyces, tubules and interstitium.
What is the most common causative organism?

Answer 8

Escherichia coli

Question 9

Pyeloneprhitis is usally caused by coliforms, name 2 of the coliforms and describe the distribution of infection?

Answer 9

Escherichia coli
Klebsiella pneumoniae
The infection of the kidneys usually has a patchy distribution

Question 10

What other organ is also usually infected in pyelonephritis due to the ascending infection?

Answer 10

Cystitis - bladder

Question 11

Why are girls more likely to get urinary tract infection? Why are pregnant women also more likely to get pyelonephritis?

Answer 11

They have a shorter urethra (4cm compared to 20cm)
Pregnant women have ureteric dilatation and therefore infection can more likely reach the kidneys

Question 12

Any urinary tract obstruction can increase the chances of pyelonephritis Name some causes of urinary tract obstruction?

Answer 12

Renal caliculi
Prostatic hyperplasia
Strictures (in ureter)
Tumour, within or pressing on urinary tract

Question 13

Congenital condition in which urine flows retrograde, or backward, from the bladder into the ureters/kidneys. (can be congenital, primary or it can be secondary due to ostruction)

Answer 13

This is known as vesicoureteric reflux - congenital is due to valves not closing properly leading to backflow of urine

Question 14

The reflux can lead to infection and cause scarring of the bladder What can this scarring lead to?

Answer 14

Scarring can lead to secondary hypertension

Question 15

What is one other condition that may predispose to pyelonephritis? Affects the sugar levels

Answer 15

Diabetes

Question 16

Characterized by renal inflammation and fibrosis induced by recurrent or persistent renal infection, vesicoureteral reflux, or other causes of urinary tract obstruction. The persistent infection can cause bad scarring What is this?

Answer 16

Chronic pyelonephritis - can lead to acute kidney injury

Question 17

Large histological section of kindey in pyelonephritis- emphasizes how patchy pyelonephritis is What inflammatory cells are circled here?

Answer 17

The neutrophils

Question 18

How is tuberculosis spread?

Answer 18

Spread via the haematogenous route

Question 19

In tuberculous pyelonephritis, what are the presenting features?

Answer 19

Haematuria, loin pain

Question 20

Which part of the kidney is usually affected by tuberculous pyelonephritis?

Answer 20

The renal parenchyma is usually affected

Question 21

Renal TB is most commonely found with pyuria (pus in urine) in the absence of other common bacteria What bacteria causes TB? Describe TB lesion?

Answer 21

Most usually caused by mycobacterium tuberculosis
It is a caseating granulomatous inflammation (cheesy necrosis)

Question 22

Mycobacterium may be seen on histology using special stains What is this stain known as?

Answer 22

Zeehl-Neilsen stain
Absence does not exclude TB

Question 23

What is the large lesion at the bottom right of the right hand pic?

Answer 23

This would be a large caseous mass

Question 24

What is inflammation of the bladder known as and what usually causes it?

Answer 24

It is known as cystitis
Usually caused by coliforms such as Klebsiella, proteus and pseudomonas

Question 25

What is the common presenting complaint of a UTI?

Answer 25

Painful haematuria usually with signs of a fever

Question 26

multiple small fluid filled cysts projecting into lumen of the bladder What is this type of cystitis?

Answer 26

This is known as ureteritis cystica (cystitis cystica)

Question 27

Why is it important to biopsy cystitis cystica?

Answer 27

To differentiate from tumours This is cystitis cystica on US but need to biopsy to differentiate

Question 28

Tuberculosis; follows renal disease. Urinary spread of mycobacteria. What parasite – found in many tropical countries particularly in Egypt These can predispose to urothelial malignancy? What is the type of urethelial malignancy commonly?

Answer 28

This is Schistosomiasis Can predispose to squamous cell carcinoma Can see the egg deposits of Schistosomiasis in SCC

Question 29

Urethral obstruction usually confined to males. Stricture, posterior urethral valves, prostatic disease. How can the urethral obstruction lead to the fromation of diverticulum?

Answer 29

This is due to the hypertrophied detrusor muscle trying to push out urine and this can cause bladder diverticulum

Question 30

Dilatation of pelvicalyceal system with parenchymal atrophy. Main causes are urinary tract obstruction and reflux. What is this?

Answer 30

This is hydronephrosis

Question 31

When is hydronephrosis bilateral?

Answer 31

In urethral obstruction Unilateral tends to be more caliculi or strictures

Question 32

Due to the stasis of urine in hydronephrosis, what can often follow?

Answer 32

Pyelonephrosis can often follow Pyelonephrosis -secondary infection to kidney (pyelonephritis) in hydronephrosis Can see increased diameter of ureter and a very thin rim of cortex due to dilated renal calyces

Question 33

What surrounds urethra between internal and external urethral sphincter? (in men)

Answer 33

The prostate gland

Question 34

What does a benign vs malignant enlargment of prostate feel like?

Answer 34

Benign feels like smooth and can have either a unilateral or bilateral enlargemnt Malignant feels nodular/bumpy

Question 35

How can GFR be measured accurately? (creatinine provides an estimate)

Answer 35

Inulin clearance is gold standard as 100% is filtered in the urine - however requires urine collection over several hours so is inconvenient Radioisotope scans - inject radioisotope eg \* 51Cr-EDTA and then measure blood levels can be used to estimate GFR with high accuracy \* 99mTc-DTPA and then carry out an isotope scan

Question 36

State what each of the following scans are used for when assessing renal functioning: (these are randionuclide renal scans) \* Tc99m-MAG3 renogram (MAG3 is also called mercaptoacetyltriglycine) \* Tc99m-DMSA scan (Dimercaptosuccinic acid)

Answer 36

MAG3 renogram - assesses drainage / flow of urine (useful for assessing recurrent UTIs in children) DMSA scan - gold standard for assessing renal scarring eg from vesicoureteric reflux causing reflux nephropathy