kidneys in systemic diseases Flashcards
what are some systemic causes of CKD?
- diabetes
- myeloma
- amyloidosis
- vasculitis
- SLE
what is myeloma?
- a dysproteinaemia
- overproduction of immunoglobulin (a protein) by clonal expansion of cells from B cell linage
- a cancer of plasma cells (WBC normally responsible for producing antibodies)
how does myeloma present?
classic presentation= back pain and renal failure
Symptoms:
- bone pain
- weakness
- fatigue
- weight loss
- recurrent infections
Signs:
- anaemia
- hypercalcaemia
- renal failure
- lytic bone lesions
what investigation is done for suspected myeloma?
Protein electrophoresis + BJP= first line
Skeletal survey (Xray of all skeleton): -shows lytic lesions
Bloods:
- serum protein electrophoresis (clonal Ig)
- serum free light chains (kappa/ lambda)
Urine:
-Bence Jones Protein
- Bone marrow biopsy
- skeletal survey
- renal biopsy
what are the renal manifestations of myeloma?
Renal manifestations:
20-40% present with renal impairment
Glomerular:
- AL amyloidosis
- monoclonal immunoglobin deposition (light/heavy chains)
Tubular:
-light chain cast nephropathy
Miscellaneous:
-dehydration/hypercalcaemia/ contrast/ bisphosphonates/ NSAIDs
what is amyloidosis?
-deposition of extracellular amyloid (insoluble protein fibrils) in tissues or organs
what are the 4 most common types of amyloidosis?
- Primary/ light chain (AL)
- secondary/systemic/inflammatory (AA)
- dialysis
- hereditary and old age (ATTR)
what is AL/ light chain amyloidosis?
- production of abnormal immunoglobulin light chains from plasma cells
- light chains enter the bloodstream and cause amyloid deposits
what does AL/light chain amyloidosis typically affect?
More commonly affects the heart, bowel, skin, nerves, kidneys
who is AL/light chain amyloidosis more common in?
55-60 year olds
what is AA amyloidosis?
- amyloidosis associated with systemic inflammation
- production of acute phase protein (serum amyloid A protein
who does AA amyloidosis typically affect?
Develops in roughly 5% of patients with chronic inflammatory conditions or chronic infections:
- RA, IBS, psoriasis
- TB, osteomyelitis, bronchiectasis
what structures does AA amyloidosis tend to affect?
More commonly affects the liver, spleen, kidneys and adrenals
how does amyloidosis present?
Renal- proteinuria +/- impaired renal function
Heart- cardiomyopathy
Nerves- peripheral or autonomic neuropathy
Hepatomegaly/splenomegaly
GI- malabsorption
what investigations are done for amyloidosis?
Urinanalysis + uPCR
Blood tests- renal function, markers of inflammation, protein electrophoresis, SFLC
Renal Biopsy: congo red staining (apple green under polarised light)
Can also biopsy other areas (easiest is abdominal fat pad or rectal biopsy)
To see extent of disease can do a SAP scan
what is the management for AL/ light chain amyloidosis?
- immunosuppression
- steroids
- chemotherapy
- stem cell transplant
what is the management for AA amyloidosis?
-treat underlying condition
investigations for MPA?
Urinalysis:
- ‘active urine’ so leakage of blood and protein
Bloods:
-raised inflammatory markers
Immunology:
- ANCA
- Anti MPO (p-ANCA)
Renal Biopsy:
- crescentic GN
- pauci immune
investigations for EGPA?
Urinalysis:
- ‘active urine’ so leakage of blood and protein
Bloods:
-raised inflammatory markers
Immunology:
- ANCA
- Anti MPO (p-ANCA)
Renal Biopsy:
- crescentic GN
- pauci immune
investigations for GPA?
Urinalysis:
- ‘active urine’ so leakage of blood and protein
Bloods:
-raised inflammatory markers
Immunology:
- ANCA
- Anti PR3 (c-ANCA)
Renal Biopsy:
- crescentic GN
- pauci immune
how does GPA present?
- fever, weight loss, anorexia, malaise
- necrotising granulomatous inflammation
- lung involvement (pulmonary/renal syndrome)
- saddle shaped nose deformity
how does EGPA present?
- fever, weight loss, anorexia, malaise
- associated with asthma and eosinophilia
- 2/3 have skin involvement
how does MPA present?
- fever, weight loss, anorexia, malaise
- small cell vasculitis with no granulomas
- systemic features/ renal/ lung/ skin/ GI/ nerves
what is the treatment for small cell vasculitis?
Immunosuppression:
- steroids
- cyclophosphamide/rituximab
- plasma exchange
Supportive:
- dialysis
- ventilation
what can be used to diagnose lupus?
what is the classification for lupus?
ISN classification
