Kidneys & Systemic Disease

Question 1

Heres some systemic disorders than can affect the kidneys:

Answer 1

DM - Diabetic Vascular disease
Hypertension, HF, atheroemboli & atherosclerosis
Infections - Post infective GN, infective endocarditis, sepsis

Inflammatory - SLE, Wegener’s

Myeloma

Amyloidosis

Drug Treatments e.g. Aminoglycosides and ACE inhibitors, penicillamine or gold, NSAIDS or contrast

Question 2

Review the NKF DOQI staging of chronic kidney disease?

Answer 2

National Kidney Foundation Dialysis Outcome Quality Initiative.
1 - Kidney damage but GFR >90
2 - Kidney damage, GFR 60-89
3 - Moderate impairement, GFR 30-59
4 - Severe Impairment - GFR 15-29
5 - Advanced impairment (probably on dialysis) - GFR <15

Question 3

When a patient presents with impaired renal function or abnormal urinalysis, what symptoms might suggest a systemic disease?

Answer 3

Fever - Malaise - Weight Loss

Arthralgia or Myalgia (incl joint swelling)

Vasculitic Rash - Scleroderma- Splinter haemorrhages

Breathlessness - Haemoptysis - Crepitations
Hypertension - Murmur

Epistaxis - Scleritis/uveitis - nasal cartilage deformity - retinal vasculitis - hypertensive retinopathy

Haematuria
Oedema

Stroke or encephalopathy

Question 4

What blood tests might suggest a systemic disorder?

Answer 4

An elevated CRP
Thrombocytosis (platelets)
Anaemia
Raised ALKP

Question 5

How does diabetic nephropathy progess?

Answer 5

1) Silent subclinical phase in which GFR may increase due to hyperfiltration
2) Microalbuminuria phase in which 20-200ug/d reaches the urine
3) Clinical Nephropathy phase in which proteinuria exceeds 0.5g/d & GFR starts to fall
4) Renal Failure where GFR is very low and proteinuria is very high or eventually falls off to 0 as the kidneys fail completely

Question 6

How does type of DM affect

Nephropathy risk?

Answer 6

Types 1 & 2 are equally at risk

DM is the commenest cause of ESRF

Question 7

How does infective endocarditis lead to kidney disease?

Answer 7

Immune complex formation in response to endocarditis. Complexes become trapped in the glomeruli –> Glomerulonephritis +/- small vessel vasculitis

You may see:

• Abnormal U&Es
• Haematuria & Red cell casts (nephritic syndrome)
• Reduced complement

Question 8

How do we handle glomerulonephritis from infective endocarditis?

Answer 8

IF the underlying infection is treated the kidneys should recover

Question 9

What is wegener’s Granulomatosis?

Answer 9

A multi-system granulomatous inflammatory disorder, specifically vasculitic.

It affects:

• Resp tract
• Joints
• Eyes
• Heart
• Skin
• Kidneys

Question 10

How might wegener’s present? (assuming kidneys are involved)

Answer 10

Generally in men in their 40s-60s:
Focal Necrotising Glomerulonephritis in kidneys +:
Epistaxis/nasal defomity/sinusitis/deafness/cough/dyspnoea/haemoptysis/haemorrhage of the respiratory tract.

Arthralgia & Myalgia

Slceritis in the eyes

Pericarditis in the heart

SYstemic signs including fever, weight loss and a vasculitis skin rash

Question 11

How would we diagnose Wegener’s?

Answer 11

Urinalysis - confirm nephritic syndrome
RFTS - Raised U&Es + Creatinine
Inflammatory so a raised CRP
Raised ALKP & low albumin
Many cases have a +ve C-anca

Chest CT for visible granuomas

Anaemia, thrombocytosis and leucocytosis

A renal biopy

Question 12

What is myeloma?

Answer 12

A monoclonal proliferation of plasma cells –> Excess immunoglobulins & Light chains

Quite common in the elderly

Question 13

What features would make you think myeloma?

Answer 13

Renal Disease along with:

• Markedly elevated ESR
• Anaemia
• Weight loss
• Fractures
• Infections
• Back pain/cord compression

Question 14

If you suspect myeloma how would you confirm?

Answer 14

Bone marrow aspirate looking for >10% clonal plasma cells.

Serum paraprotein +/- immunoparesis

Urinary Bence-jones protein (BJP)

Skeletal survey for lytic lesions

Question 15

What test would confirm endocarditis?

Answer 15

Echocardiography