Glomerulonephritis Flashcards
What are the targets for pathology in the glomerulus?
- parietal epithelial cell
- podocyte
- mesangial cell
- endothelial cell
List the mechanisms for glomerulonephritis
- antibodies, immune complexes, complement
- cell-mediated (eg. growth factors, cytokines, proteinuria)
- metabolic, genetic, vascular
- acute/chronic
What investigation would you want to carry out if suspecting glomerulonephritis?
- kidney biopsy (US guided):
- light microscopy (look at tubules and interstitium - architecture)
- immunofluorescence (IgG/IgA/IgM etc. lighting up capillary wall)
- electron microscopy (look at ultrastructure for any deposits within glomerulus)
List the spectrum of presentations of renal disease
- incidental finding +/- impaired kidney function
- visible haematuria
- synpharyngitic (sore throat + visible haematuria)
- nephritic syndrome
- nephrotic syndrome
- acutely unwell with rapid glomerulonephritis
Define nephrotic syndrome
- 3.5g proteinuria per 24hr (PCR >300)
- serum albumin <30
- oedema (Na+ retention, decreased oncotic pressure etc.)
- hyperlipidaemia
- risk of venous thromboembolism + infection
Define nephritic syndrome
- hypertension
- blood and protein in urine
- declining kidney function
Describe the mechanisms of nephrotic syndrome
- high levels of proteinuria and lower levels of haematuria
- injury to podocytes
Results in:
- scarring
- deposition of matrix and other elements in glomeruli
Describe the mechanism of nephritic syndrome
- high levels of haematuria and lower levels of proteinuria (need both for diagnosis tho)
- inflammation and reactive cell proliferation
- breaks in basement membrane
- crescent formation
List some causes of nephritic and nephrotic syndrome
Nephritic (damage to glomeruli):
- IgA nephropathy
- small vessel vasculitis
- post-strep glomerulonephritis
Nephrotic (damage to podocytes):
- minimal change nephrotpathy
- membranous nephropathy
- diabetic nephropathy
- amyloidosis
Describe the progression of IgA nephropathy
- starts with minor urinary abnormalities
- hypertension
- renal impairment and heavy proteinuria
- rapidly progressive glomerulonephritis
Describe the features of IgA nephropathy
- can be precipitated by infection = synpharyngitic
- can be secondary to HSP, cirrhosis and coeliacs
- most common primary glomerular disease
- results in abnormal/over-production of IgA1, IgA I/C
- mesangial IgA, C3 deposition
- mesangial cell proliferation
Describe the clinical presentation and management of IgA nephropathy
- haematuria
- hypertension
- proteinuria (varying its prognosis)
- no specific treatment
- anti-hypertensives (ACEi)
- risk of progression to ESRF
Describe the features of membranous glomerulonephritis
- can occur secondary to malignancy, CTD or drugs (10%)
- contains anti-phospholipase A2 receptor antibody in primary cases (70%)
- commonest primary cause of nephrotic syndrome
- immune complex deposition in BM/sub-epithelial space
- risk of recurrence and progression to ESRF (1-2y)
Describe the approach to treatment of membranous nephropathy
- treat underlying disease if secondary
- supportive non-immunological treatment (ACEi, statin, diuretics, salt restriction)
- specific immunotherapy (steroids, alkylating agents - cyclophosphamide, alternative agents - rituximab, cyclosporin
Describe the features of minimal change disease
- commonest form of glomerulonephritis in children
- can cause nephrotic syndrome
- can be secondary to malignancy
- caused by T cell, cytokine mediated fusion of podocytes
