Renal Medicine - Glomerulonephritis

Question 1

What is nephritis?

Answer 1

Nephritis is a very generic term that means inflammation of the kidneys.

NB: It is a very non-specific descriptive term and is not a diagnosis or syndrome that has any criteria. It is easy to get confused and think that when a patient is described as having “nephritis” this is a diagnosis. It is not, they are simply saying that the patient has inflammation of the kidney.

Question 2

What is nephritic syndrome?

Answer 2

Nephritic syndrome or acute nephritic syndrome refers to a group of symptoms, not a diagnosis.

NB: When we say a patient has “nephritic syndrome” it simply means they fit a clinical picture of having inflammation of their kidney and it does not represent a specific diagnosis or give the underlying cause. Unlike nephrotic syndrome, there are no set criteria.

Question 3

What are the features of nephritic syndrome?

Answer 3

• haematuria
• oliguria
• proteinuria <3g/24hr)
• fluid retention

Question 4

What is nephrotic syndrome?

Answer 4

Nephrotic syndrome refers to a group of symptoms without specifying the underlying cause.

NB: Therefore, nephrotic syndrome is not a disease, but is a way of saying “the patient has these symptoms”, which indicates there is an underlying disease present but doesn’t specify the disease.

Question 5

What are the criteria a patient must fulfil to have nephrotic syndrome?

Answer 5

• peripheral oedema
• proteinuria >3.5g/24hr)
• serum albumin <30g/L
• hypercholesterolaemia

Question 6

What are some causes of nephrotic syndrome?

Answer 6

• minimal change disease (most common in children)
• membranous nephropathy
• diabetes

Question 7

What are some complications of nephrotic syndrome?

Answer 7

• higher risk of infection
• venous thromboembolism
• progression of CKD
• hypertension
• hyperlipidaemia

Question 8

What is glomerulonephritis?

Answer 8

Glomerulonephritis is an umbrella term applied to conditions that cause inflammation of or around the glomerulus and nephron. There are many conditions that can be described as glomerulonephritis.

Question 9

What is glomerulosclerosis?

Answer 9

Glomerulosclerosis is a term to describe the pathological process of scarring of the tissue in the glomerulus. It is not a diagnosis in itself and is more a term used to describe the damage and scarring done by other diagnoses.

Glomerulosclerosis can be caused by any type of glomerulonephritis or obstructive uropathy (blockage of urine outflow), and by a specific disease called focal segmental glomerulosclerosis.

Question 10

What is the most common cause of primary glomerulonephritis?

Answer 10

IgA nephropathy (AKA Berger’s disease)

Question 11

Presentation of IgA nephropathy.

Answer 11

Haematuria following:
- URTI
- GI infection
- intense exercise

Question 12

Investigation findings of IgA nephropathy?

Answer 12

• increased serum IgA
• normal C3, C4
• asymptomatic microhaematuria with intermittent visible haematura

Question 13

Biopsy findings of IgA nephropathy?

Answer 13

Mesangial immune complex deposits within the glomeruli.

Question 14

What proportion of patients progress to end stage renal failure within 20-25 years, following a diagnosis of IgA nephropathy?

Answer 14

30%

Question 15

What is the most common type of glomerulonephritis overall?

Answer 15

Membranous glomerulonephritis

Question 16

Presentation of membranous glomerulonephritis?

Answer 16

Idiopathic glomerulonephritis with bimodal peak in 20s and 60s.

Can be secondary to malignancy, rheumatoid disorders and drugs (e.g. NSAIDs).

Question 17

Biopsy findings of membranous glomerulonephritis.

Answer 17

IgG and complement deposits on the basement membrane.

Question 18

What is the aetiology of post-streptococal glomerulonephritis?

Answer 18

Group A b-haemolytic streptococci infections (e.g. Streptococcus pyogenes).

Question 19

Presentation of post-streptococcal glomerulonephritis.

Answer 19

Typically presenting in patietns under 30yrs of age, within 1-3 weeks of streptococcal infection (e.g. tonsillitis, impetigo, cellulitis).

Patients typically develop a nephritic syndrome, but usually make a full recovery.

Question 20

Investigation findings of post-streptococcal glomerulonephritis.

Answer 20

• positive anti-streptococcal antibodies
• low serum C3

Question 21

Biopsy findings of post-streptococcal glomerulonephritis.

Answer 21

Immune complex deposition of C3, IgM and IgG.

Question 22

Pathology of Goodpasture syndrome?

Answer 22

Anti-GBM antibodies attack the glomerulus and pulmonary basement membrane, causing glomerulonephritis and pulmonary haemorrhage.

Question 23

Presentation of Goodpasture syndrome?

Answer 23

• AKI
• haemoptysis

Question 24

Investigation findings of Goodpasture syndrome?

Answer 24

• anti-GBM antibodies
• pulmonary infiltrates on CXR

Question 25

What types of small vessel vasculitis are associated with glomerulonephritis?

Answer 25

• glanulomatosis with polyangiitis (GPA) is associated with c-ANCA (PR3)
• microscopic polyangiitis (MPA) is associated with p-ANCA (MPO)
• eosinophilic granulomatosis with polyayngiitis is associated with p-ANCA (MPO) and eosinophilia

Question 26

What is thin basement membrane disease?

Answer 26

A hereditary cause of glomerulonephritis, in which type IV collagen is affected.

Patients present with perisstent microscopic haematuria, and biopsy reveals diffuse thinning of glomerular basement membrane.

Question 27

What is Alport syndrome?

Answer 27

An X-linked genetic cause of glomerulonephritis, causing a mutation of the gene coding for Type V collagen. Associated with hearing loss and abnormalities of the eyes.

Question 28

What is lupus nephritis?

Answer 28

Glomerulonephritis arising as a complication of SLE, with patients presenting with nephrotic or nephritic syndromes.

ANA and anti-dsDNA positive

Question 29

How is glomerulonephritis generally managed?

Answer 29

• immunosuppression (e.g. steroids)
• blood pressure control (ACEi or ARBs)
• renal replacement therapy if severe AKI or ESRF
• discuss with renal team - MDT approach

Question 30

What is interstitial nephritis?

Answer 30

Inflammation within the intertitium of the kidneys, with two types:
- acute interstitial nephritis
- chronic tubulointerstitial nephritis

Question 31

What is acute interstitial nephritis?

Answer 31

Hypertensitivity reaction to drugs (e.g. NSAIDs) or infection, causing acute inflammation of the tubules and interstitium, leading to AKI.

Question 32

What is chronic tubulointerstitial nephritis?

Answer 32

Chronic inflammation of the tubules and interstitium, presenting as CKD.

Causes include autoimmune, infectious, iatrogenic and granulomatous disease.