Kidneys in Systemic Disease

Question 1

What is needed to diagnose diabetic kidney disease?

Answer 1

Persistent albuminuria 300mg/24hours at least two samples 3-6 months apart

Question 2

Describe the pathogenesis of diabetic nephropathy

Answer 2

Haemodynamic changes - increased GFR as afferent arteriolar vasodilation is mediated by vasoactive mediators
Renal hypertrophy - plasma glucose stimulates growth factors in the kidney

Question 3

What do haemodynamic changes and renal hypertrophy lead to?

Answer 3

Mesangial expansion, nodule formation, proteinuria and tubule-interstitial fibrosis

Question 4

How is diabetic nephropathy treated?

Answer 4

BP target 120/70
ACEi or ARB
Lipid control
Kidney/pancreas transplant

Question 5

Define vasculitis

Answer 5

Inflammation of blood vessels

Question 6

Why is ANCA vasculitis often misdiagnosed initially?

Answer 6

Presents with very vague symptoms and prodromal symptoms may last months before specific organ involvement

Question 7

Name the three types of ANCA vasculitis

Answer 7

• eosinophilic granulomatosis polyangiitis
• granulomatosis with polyangiitis
• microscopic polyangiitis

Question 8

Describe eosinophilic GPA

Answer 8

Presents with last onset asthma, rhinosinusitis, palpable purpura, subcutaneous nodules

Question 9

What is granulomata?

Answer 9

Dead tissue that does not function due to macrophage

Question 10

Describe GPA

Answer 10

Nasal crusting, saddle nose, blood discharge, ulcers, sinusitis

Question 11

Describe microscopic polyangiitis

Answer 11

Cough, hoarseness, SOB, haemoptysis

Question 12

How will ANCA vasculitis affect the kidneys?

Answer 12

Haematuria and proteinuria

Biopsy will show segmental necrotising glomerulonephritis

Question 13

How is ANCA vasculitis diagnosed?

Answer 13

Immunology - GPA (anti-PR3) Microscopic (anti-MPO)

Virology

Question 14

Describe the treatment of ANCA vasculitis

Answer 14

Immunosuppression (cyclophosphamide/rituximab)
Plasma exchange
Supportive (dialysis and ventilation)

Question 15

What percentage of patients with SLE will develop nephrotic syndrome?

Answer 15

50%

Question 16

What antibodies are associated with SLE?

Answer 16

ANA
dsDNA
Sm

Question 17

Describe the classification of SLE renal disease

Answer 17

I - minimal mesangial proliferation 
II - mesangial proliferation 
III - focal proliferative
IV - diffuse proliferative 
V - membranous 
VI - advanced sclerosing

Question 18

What is the treatment for class I and II SLE renal disease?

Answer 18

I - extra renal manifestations treated

II - if >3g proteinuria steroids, BP control

Question 19

What is the treatment for class III and IV SLE renal disease?

Answer 19

III - steroids and either cyclophosphamide or MMF

IV - maintenance, azathioprine/MMF and low dose steroids

Question 20

What is the treatment for membranous SLE renal disease?

Answer 20

Steroids, cyclophosphamide/MMF/Azathioprine

Question 21

What should all patients with SLE be on?

Answer 21

Hydroxychloroquine

Question 22

What are dysproteinaemias?

Answer 22

Overproduction of immunoglobulin by clonal expansion of cells from B cell lineage

Question 23

What are the sub-types of dysproteinaemias?

Answer 23

Deposition,
Complement and cytokine activation
Precipitation/crystallisation

Question 24

Describe the pathology of myeloma

Answer 24

Lymphoid disease where DNA damage leads to multiple myeloma cell formation. M proteins are produced instead of antibodies due to abnormal plasma cells collecting in the bone marrow

Question 25

What are the clinical manifestations of myeloma?

Answer 25

Bone pain, weakness, fatigue, anaemia, infections, hypercalcaemia, renal failure and lytic bone lesions

Question 26

What are the red flags for myeloma?

Answer 26

Back pain and renal failure

Question 27

State the renal manifestations of myeloma

Answer 27

- M proteins clog up renal tubuli - amyloidosis - dehydration - hypercalcaemia

Question 28

How is myeloma diagnosed?

Answer 28

Serum protein electrophoresis/free light chains Bence Jones Protein Bone marrow/skeletal/renal biopsy

Question 29

How is myeloma managed?

Answer 29

``` Chemotherapy Stem cell transplant Plasma exchange Dialysis Stop nephrotoxic drugs and treat hypercalcaemia ```

Question 30

What is given to treat hypercalcaemia?

Answer 30

IV NaCl | Pamidronate

Question 31

Define amyloidosis

Answer 31

Deposition of extracellular amyloid (insoluble protein fibrils) in tissues/organs. The precursor is soluble but abnormal folding and aggregation leads to amyloid.

Question 32

Name four common forms of amyloidosis

Answer 32

- light chain (AL) - systemic (AS) - dialysis - hereditary

Question 33

Describe AL

Answer 33

Abnormal Ig light chains from plasma cells enter the blood and deposit in kidneys, heart, bowel, skin and nerves

Question 34

Describe AA

Answer 34

Acute phase protein - serum amyloid protein associated with inflammatory disease affects liver, spleen and adrenal glands

Question 35

How does amyloidosis present?

Answer 35

``` Nephrotic syndrome Cardiomyopathy Neuropathy Malabsorption Hepato/splenomegaly ```

Question 36

What investigations are carried out in suspected amyloidosis?

Answer 36

Urinalysis and PCR Blood tests (renal function, protein electrophoresis, inflammatory markers) Renal biopsy (congo red staining - apple green) SAP scan

Question 37

What is a SAP scan?

Answer 37

Scintigraphy with radio labelled serum amyloid shows extent of disease

Question 38

How is amyloidosis managed?

Answer 38

Immunosuppression and treat the underlying condition