(31) Renal System Disease 1 Flashcards
1
Q
What are the functions of the kidney?
A
- eliminating metabolic waste products
- regulating fluid and electrolyte balance
- influencing acid-base balance
- production of some hormones
2
Q
Which hormones does the kidney produce and what is their function?
A
Renin = fluid balance
Erythropoietin = stimulates red cell production
3
Q
How many people develop acute renal failure?
A
Around 26,000 per year in England
4
Q
What is the prognosis for patients with acute renal failure?
A
Most will recover but around 10,000 will need dialysis. For these patients, mortality is around 50%
5
Q
How many people develop chronic renal failure?
A
Around 5,500 per year in England
Around 41,000 patients with CRF in England at any one time
6
Q
What proportion of those with chronic renal failure need transplant or dialysis?
A
- 50% will have a transplant at some point
- 40% haemodialysis
- 10% peritoneal dialysis
7
Q
How many transplants occur?
A
- 1020 living donor renal transplants
- 1667 deceased donor transplants
- 7000 patients still on the transplant waiting list
(in 2010-2011)
8
Q
In what 6 ways can patients with renal disease present?
A
- acute renal failure
- nephrotic syndrome
- acute nephritis/nephritic syndrome
- chronic renal failure
- isolated haematuria
- isolated proteinuria
9
Q
Patients with renal disease may present with acute renal failure. What is this?
A
- rapid rise in creatinine and urea
- generally unwell
(most common presentation)
10
Q
Patients with renal disease may present with nephrotic syndrome. What is nephrotic syndrome?
A
- oedema + proteinuria + hypoalbuminaemia
- proteinuria >3g per 24 hours (mostly albumin)
Combination of these 3 things define nephrotic syndrome
11
Q
Patients with renal disease may present with acute nephritis/nephritic syndrome. What is this?
A
Oedema + proteinuria + haematuria + renal failure
proteinuria normally not as heavy as in nephrotic syndrome
12
Q
What defines chronic renal failure?
A
Slowly declining renal function
13
Q
Which 5 different specialties are involved in diagnosing renal disease?
A
- renal physician
- biochemist
- pathologist
- urologist
- radiologist
14
Q
What role does a renal physician play in diagnosis of renal disease?
A
- clinical history
- examination
15
Q
What role does a biochemist play in diagnosis of renal disease?
A
Blood tests:
- urea
- creatine
Urine analysis:
- protein
- electrolytes
16
Q
What role does a pathologist play in diagnosis of renal disease?
A
Renal biopsy:
- light microscopy (common)
- immunofluorescence (special test)
- electron microscopy (special test)
17
Q
What role does a urologist play in diagnosis of renal disease?
A
Cytoscopy may be needed:
- obstruction
- some cases of haematuia
18
Q
Why might a urologist be needed if haematuria is found?
A
Common symptom of bladder cancer
19
Q
What role does a radiologist play in diagnosis of renal disease?
A
- obstruction
- kidney size
- structural abnormalities
20
Q
What is the glomerulus?
A
A network of capillaries located at the beginning of a nephron in the kidney. It serves as the first stage in the filtering process of the blood carried out by the nephron in its formation of urine - then passes along tubules
Coiled capillary
21
Q
What is the glomerulus surrounded by?
A
Bowman’s capsule
22
Q
What are the 2 main parts of the kidney?
A
- cortex (outside part)
- medulla (inside part)
23
Q
What does the renal cortex contain?
A
Renal tubules and glomeruli
24
Q
What are the 3 layers of the wall of the glomerul?
A
- podocyte foot processes
- basement membrane
- endothelial cells
(and then the capillary lumen)
25
What allows filtration at there glomerulus?
The podocyte foot processes, basement membrane and endothelial cells (endothelial cells have little pores) - damage to any of these can cause kidney disease
26
What are the different parts (in order) of the renal tubules in the nephron?
- Bowman's capsule
- proximal convoluted tubule (PCT)
- descending limb of Henle
- loop of Henle
- ascending limb of Henle
- distal convoluted tubule (DCT)
- collecting duct (leading to the renal pelvis)
27
What are the different parts (in order) of the blood flow through the nephron?
- branches of the renal artery
- afferent arteriole
- glomerulus (capillary bed)
- efferent arteriole
- vasa recta
- branches of renal vein
28
In which part of the kidney is the loop of Henle?
The renal medulla
29
What is the renal tubule doing?
Concentrating the urine, excreting and reabsorbing substances
30
What else would a disease of the glomerulus affect?
It will cut off the blood supply to the rest of the nephron (tubules)
31
What rare the immunological mechanisms of glomerular damage?
- circulating immune complexes deposit in glomerulus
- circulating antigens deposit in glomerulus
- antibodies to basement membrane or other components of glomerulus
32
What do all of the immunological mechanisms of glomerular damage lead to?
Damage to basement membrane
- complement activation
- neutrophil activation
- reactive oxygen species
- clotting factors
Glomerular damage
33
What are the non-immunological mechanisms of glomerular damage?
- injury to endothelium of vessels
- altered basement membrane due to hyperglycaemia in diabetes
- abnormal basement membrane or podocytes due to inherited disease
- deposition of abnormal proteins in the kidney e.g. amyloid
34
What are the 2 categories of glomerular damage mechanisms?
- immunological
| - non-immunological
35
What are the 2 categories of tubular damage mechanisms?
- ischaemic
| - toxic
36
What are the ischaemic mechanisms of tubular damage?
- hypotension
- damage to vessels within kidney
- glomerular damage
37
What do the ischaemic mechanisms of tubular damage lead to?
Reduced blood supply to tubules and therefore tubular damage
38
What are the toxic mechanisms of tubular damage?
- direct toxins
- hypersensitivity reactions eg. to drugs
- deposition of crystals in tubules eg. in gout
- deposition of abnormal proteins in tubules e.g. amyloid
39
The degree of damage to renal tubules correlates with what?
Renal function
40
What are the potential mechanisms of vascular damage?
- hypertension
- diabetes
- atheroma eg. renal artery stenosis
- thrombotic microangiopathy
- vasculitis
41
What is thrombotic microangiopathy?
- thrombi in capillaries and small arterioles
- due to endothelium damage
- endothelium damage due to bacterial toxins, drugs, abnormalities in complement or clotting systems etc
42
Give an example of a thrombotic microangiopathy
Haemolytic uraemic syndrome
43
What is vasculitis?
- acute or chronic inflammation of blood vessel walls
- obliteration of lumen by inflammation
- various different types
- adults and children affected
44
Give an example of a type of vasculitis
Wegener's granulomatosis
45
Damage to the vessels can also lead to damage to what?
- damage to the glomerulus
- damage to the tubule
(due to reduced blood flow)
46
Damage to the glomerulus can also lead to damage to what?
Damage to the tubule
47
Why are glomerular diseases so confusing?
- many names refer to microscopic appearances rather than actual disease
- some names are both diseases (when idiopathic) or just appearances (when secondary to a known cause)
48
Give some examples of glomerular diseases where the name is both a disease and also just a description of appearance
- membranous nephropathy (idiopathic disease vs. secondary to known cause)
- FSGS
- mesangiocapillary glomerulonephritis
49
Give some other examples of glomerular diseases (names of actual diseases)
- minimal change disease
- post-infective glomerulonephritis
- anti-GBM disease
- IgA nephropathy
- Henoch-Schonlein purpura
- lupus nephritis (in SLE)
50
Give some other examples of appearances of glomerular diseases (appearance on biopsy)
- proliferative glomerulonephritis
- crescentic glomerulonephritis
- thrombotic microangiopathy
51
What is nephrotic syndrome always due to?
Damage to the glomerulus
52
What does nephrotic syndrome consist of?
- oedema
- proteinuria (>3g in 24h)
- hypoalbuminaemia
- +/- hypertension
- +/- hyperlipidaemia
53
What are the complications associated with nephrotic syndrome?
- infection
| - thrombosis
54
What are the common causes of nephrotic syndrome in adults?
- membranous nephropathy
- focal segmental glomerulosclerosis (FSGS)
- minimal change disease
- other causes eg. diabetes, lupus nephritis, amyloid
55
What is the most common cause of nephrotic syndrome in adults?
Membranous nephropathy
56
What is membranous nephropathy?
Thickening of the glomerular basement membrane
- primary glomerular disorder of unknown cause
- idiopathic
57
Who is usually affected by membranous nephropathy?
Usually adults 30-60
M>F
58
How many with membranous nephropathy will progress to end stage renal failure?
20-30%
59
What is focal segmental glomerulosclerosis?
Scar tissue formation in some of the glomeruli
60
What are the causes of focal segmental glomerulosclerosis?
Various possible causes
- most are idiopathic
- genetic
- heroin use
- HIV
61
Which gender is more commonly affected by FSGS?
M>F
62
What is seen in minimal change disease?
Biopsy is normal on light microscopy
| changes only seen on electron microscopy - glomerular damage
63
Which gender more commonly gets minimal change disease?
M=F
64
What are the common cause of nephrotic syndrome in children?
- minimal change disease
- focal segmental glomerulosclerosis
- other causes are rare
65
What is the most common cause of nephrotic syndrome in children?
Minimal change disease
66
What are the causes of minimal change disease?
Cause is unknown the disease may occur after or be related to:
- allergic reactions
- NSAID use
- tumors
- vaccinations
- viral infection
67
What signs make up acute nephritis?
- oedema
- haematuria
- proteinuria
- acute renal failure
(another presentation of kidney disease)
68
What are the common causes of acute nephritis in adults?
- post-infective glomerulonephritis
- IgA nephropathy
- vasculitis
- lupus
- other forms of primary glomerulonephritis
69
Post-infective glomerulonephritis typically occurs after what?
A few weeks after Streptococcal throat infection
Most recover completely
70
What is the most common primary glomerular disease worldwide?
IgA nephropathy
71
What is the damage in IgA nephropathy caused by?
Abnormal deposits of IgA protein in the glomeruli
72
What is the most common sign of IgA nephropathy?
Haematuria (also swelling of feet)
Typically teenagers and young adults with haematuria
73
How many with IgA nephropathy will progress to renal failure?
20-50% will progress to renal failure over 20 years
74
What are the signs of vasculitis?
- fever
- generally unwell
- may have rash
- myalgia
- arthralgia
75
Who typically gets lupus?
Young women
| autoimmune disease with many manifestations
76
What are the common causes of acute nephritis in children?
- post-infective glomerulonephritis
- IgA nephropathy
- Henoch-Schonlein purpura
- haemolytic-uraemic syndrome
77
What is Henoch-Schonlein purpura?
- specific type of IgA nephropathy
| - M>F
78
What is the typical presentation of Henoch-Schonlein purpura?
Typically young boys/teenagers with
- arthralgia
- abdo pain
- rash
- haematuria
- acute renal failure
Most recover completely
79
What is haemolytic-uraemic syndrome characterised by?
- acute nephritis
- haemolysis
- thrombocytopaenia
80
Who typically gets haemolytic-uraemic syndrome?
Children with E. coli 0157 enteritis
81
What is the diagnosis of acute renal failure based on?
- anuria/oliguria
- raised creatinine
- raised urea
82
What is oliguria?
Production of abnormally small amounts of urine
83
What is the usual prognosis in acute renal failure?
Many patients will recover and have good renal function if they had previously healthy kidneys
Short term dialysis may be needed in some patients
84
What are the 3 categories of causes of acute renal failure?
- pre-renal (most common)
- renal
- post-renal
85
What do pre-renal causes mean?
Reduced blood flow to kidney (MOST COMMON)
86
What do renal causes mean?
Damage to kidney
87
What do post-renal causes mean?
Obstructed urinary tract
88
Give examples of pre-renal causes of acute renal failure
- severe dehydration
| - hypotension eg. bleeding, septic shock, left ventricular failure
89
Give some examples of post-renal causes of acute renal failure
- tumours of urinary tract
- tumours in renal pelvis
- bladder stones
- prostatic enlargement
90
In which causes of acute renal failure is a renal biopsy useful?
Useful in renal causes.
Not helpful in pre- or post- renal causes
91
What will all biopsies show in acute renal failure?
ATN - acute tubular necrosis/injury/damage/acute kidney injury (ATI/ATD/AKI)
92
What are the causes of acute renal failure in adults?
- vasculitis
| - acute interstitial nephritis/tubulointerstitial nephritis
93
What is acute interstitial nephritis/tubulointerstitial nephritis?
Tubular damage with inflammation, most commonly caused by drug reactions - most recover
94
What are the causes of acute renal failure in children?
- Henoch-Schonlein purpura
- haemolytic uraemic syndrome
- acute interstitial nephritis
95
What are the complications associated with acute renal failure?
- cardiac failure (fluid overload)
- arrhythmias (electrolyte imbalance)
- GI bleeding
- jaundice (hepatic venous congestion)
- infection, especially lung and urinary tract
96
What is the treatment for acute renal failure?
- short term dialysis may be needed
| - treat the underlying cause
97
What is chronic renal failure defined by?
Permanently reduced GFR - reduced number of nephrons
98
What is stage 1 chronic renal failure?
kidney damage with normal or increased GFR (>90mL/min/1.73m2)
99
What is stage 2 chronic renal failure?
mild reduction in GFR (60-89mL/min/1.73m2)
100
What is stage 3 chronic renal failure?
moderate reduction in GFR (30-59mL/min/1.73m2)
101
What is stage 4 chronic renal failure?
severe reduction in GFR (15-29mL/min/1.73m2)
102
What is stage 5 chronic renal failure?
kidney failure (GFR
103
At what stage of chronic renal failure is treatment required and more problems start occurring?
Stages 4 and 5
104
What are the common causes of chronic renal failure in adults?
- diabetes
- glomerulonephritis
- reflux nephropathy
105
What is the commonest cause of chronic renal failure in this country?
Diabetes
106
What is reflux nephropathy?
Chronic reflux of urine up the ureter leading to repeated infections and scarring of the kidney
107
What are the common causes of chronic renal failure in children?
- developmental abnormalities/malformations
- reflux nephropathy
- glomerulonephritis
108
What does renal biopsy show in chronic renal failure?
Kidney shows severe scarring with loss of glomeruli and tubules
109
Why is a renal biopsy often unhelpful in established chronic renal failure?
Similar changes are seen in end-stage renal disease due to any cause - so hard to identify the cause
Most biopsies will look the same at this stage
110
What are the effects on the body of chronic renal failure?
- reduced excretion of water and electrolytes cause oedema and hypertension
- reduced excretion of toxic metabolites
- reduced production of erythropoietin leading to anaemia
- renal bone disease
111
What is the likely diagnosis for an elderly patient with acute renal failure?
- acute interstitial nephritis due to drug reactions
| - myeloma
112
What is the likely diagnosis for a young male with haematuria and rash?
Henoch-Schonlein purpura
113
What is the likely diagnosis for a teenager/young adult with haematuria?
- post-infective glomerulonephritis
| - IgA nephropathy
114
What is the likely diagnosis for an adult with acute renal failure, fever and myalgia?
Vasculitis
115
What is the likely diagnosis for a young woman with haematuria and facial rash?
Lupus
| butterfly rash
116
What is the likely diagnosis for an adult with nephrotic syndrome?
Membranous nephropathy (most cases idiopathic)
117
What is the likely diagnosis for a child with nephrotic syndrome?
Minimal change disease
118
What tests may be need din isolated haematuria?
Cytoscopy and other urological investigating as bleeding may be from urinary tract tumours
119
What is cytoscopy?
Camera into the bladder
120
What are the likely renal causes of haematuria with normal renal function?
- IgA nephropathy
- thin basement membrane disease
- Alport type hereditary nephropathy
121
What is thin basement membrane disease?
- inherited condition causing abnormally thin basement membranes in the glomeruli
- if no other renal disease is present, kidney function will remain normal
122
What is Alport type hereditary nephropathy?
- inherited abnormalities of collagen type IV causing abnormal basement membrane in the glomerulus
- sometimes have eye and ear problems
123
What are the signs of Alport syndrome?
- renal failure
- +/- deafness
- +/- ocular problems
124
What is the genetic pattern in Alport syndrome?
May be autosomal or X-linked
125
What is isolated proteinuria defined by?
Proteinuria less than the nephrotic range, without haematuria, renal failure or oedema
126
Isolated proteinuria might be benign, due to what?
- postural
| - related to pyrexia or exercise
127
Isolated proteinuria might be due to renal disease. What are the common causes in adults?
- FSGS
- diabetes
- lupus
128
Isolated proteinuria might be due to renal disease. What are the common causes in children?
- Henoch-Schonlein purpura
| - FSGS
129
What causes renal artery stenosis?
Atheroma (most common)
or arterial dysplasia
130
What does renal artery stenosis lead to?
Ischaemia of the affected kidney - kidney left scarred and shrunken - reduced renal function due to loss of renal tissue
Also hypertension
131
What causes hypertension in renal artery stenosis?
Stenosis leads to activation of RAAS leading to hypertension
132
What is pyelonephritis?
Infection of the kidney
133
How can infection of the kidney (pyelonephritis) occur?
- via haematogenous spread
| - via ascending route from bladder
134
What causes acute pyelonephritis?
- more common in women (ascending infection)
- instrumentation of urinary tract
- diabetics
- structural abnormalities or urinary tract
135
What are the complications associated with acute pyelonephritis?
- abscess formation
136
What are the causes of chronic pyelonephritis?
- obstruction or urinary tract
- reflux of urine up ureter
leads to scarring of kidney and can lead to renal failure
137
What are the complications associated with chronic pyelonephritis?
- scarring of kidney
| - chronic renal failure
138
How can vasculitis affect the kidneys?
- affect glomerular vessels leading to clotting with obliteration of capillary lumens and destruction of glomerulus
- inflammation of larger arterioles within kidney leading to hypoxia of tubules
139
Vasculitis also often affects other vessels around the body leading to what symptoms?
- rash
- muscle pain
- joint pain
Can also have fever and weight loss due to the inflammation
140
On histology, what does bright pink in the glomerulus indicate?
Bright pink = fibrin - indicated thrombosis within glomerulus
May not be able to see capillary lumens
141
On histology, what do dark dots around an artery indicate?
Inflammatory cells surrounding artery which has fibrin in wall - indicating damage to wall
142
How does hypertension affect the kidneys?
- damages renal vessels leading to thickening of vessel wall and reduction in size of lumen
- produces chronic hypoxia which leads to loss of renal tubules and reduced renal function
- reduced blood flow activates RAAS which exacerbates hypertension
143
How is hypertension shown on renal biopsy?
Can see thickening of the walls of small arteries ad arterioles and a reduction in the size of the lumen
144
What is the commonest cause of end-stage renal failure in Europe and the USA?
Diabetes
145
What about diabetes causes diabetic nephropathy?
Hyperglycaemia
146
How does diabetes cause damage to the kidneys?
- hyperglycaemia damages the basement membrane
- basemement membrane becomes thicker and the glomerulus produces excess extacellular matrix with forms nodules
- diabetes also damages small vessels leading to ischaemia and damage to renal tubules
147
How is diabetic nephropathy seen on renal biopsy/histology?
Can see nodules within the glomerulus
148
How does myeloma cause damage to the kidneys?
- tumour of plasma cells producing immunoglobins
- excess immunoglobins deposit in tubules
- tubules damaged
- inflammation and fibrosis of kidney
- loss of tubules = loss of renal function
149
Is renal impairment due to myeloma reversible?
No, usually irreversible
150
How does a kidney affected by myeloma look on histology?
- immunoglobin deposits in artery walls (smooth, pink, thickened walls)
- tubules destroyed by immunoglobin deposits (bright pink)
- fibrosis (scarring)
- residual tubules
151
What is the function of mesangial cells?
Involved in maintaining structure of glomerulus
remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris
152
What is the main sign of membranous nephropathy on histology?
Thickened glomerular capillary walls
153
What is the main sign of FSGS on histology?
Most of the glomerulus is normal, one area appears solid with loss of capillary lumens
154
What can post-streptococcal glomerulonephritis and IgA nephropathy both show on histology?
Glomeruli which have an increased number of cells and loss of capillary lumens
155
What is seen on histology in acute tubulointerstitial nephritis?
Many lymphocytes and other inflammatory cells (dark dots) present between renal tubules
156
What is a crescent (seen on kidney biopsy)?
Cells proliferating within Bowman's capsule as a response to severe glomerular injury
Crescent surrounds the glomerulus
157
What conditions may crescents be seen in?
```
Any condition where there is severe glomerular injury
- anti-GBM disease
- severe vasculitis
- severe-infective glomerulonephritis
etc
```
158
What is seen on histology in acute tubular necrosis/injury?
Loss of nuclei from tubular cells (cell death)
159
What is seen on histology in chronic kidney damage?
Tubular atrophy, shrunken tubules surrounded by interstitial fibrosis
