Kidney diseases Flashcards
Nephrotic syndrome presentations
- massive proteinuria (more than 3.5g/day)
- low serum albumin
- generalised oedema
- Hyperlipidemia
Nephrotic syndrome causes
- membranous nephropathy
- membranoprolierative glomerulonephritis
- minimal change disease
- focal segmental glomerulosclerosis
Nephrotic syndrome complications
- hypercoagulopathy
- hyperlipidemia/ lipiduria
- infection risk (due to reduction in Ig, complement and neutrophil phagocytic properties)
- decreased serum binding protein
- renal failure
Nephritic syndrome
- mild to moderate proteinuria
- gross or microscopic haematuria (red cell cast in UUTI)
- hypertension
- reduction in GFR
- acute postinfectious glomerulonephritis
AKI
rapid reduce in GFR, with increase in serum creatinine and urea
maybe glomerulus, tubules, interstitium or blood vessel problem
Chronic kidney disease CKD
progressive reduction in GFR, lower than 60 from 3 months
may result from glomerulus, interstitium, tubules or blood vessel problem
ESRD End stage renal disease
less than 5% GFR, irreversible and terminal
need renal replacement therapy
Membranous nephropathy- pathogenesis
- usually in middle aged people
- immune complex glomerulonephritis
- Primary: M-type phospholipase A2 receptor on podocytes (foot processes)
- Secondary: hepatitis B or C, SLE, drug (NSAID), malignancy
Membranous nephropathy- pathology
- silver stain: spikes formation
- granular immune deposits (IgG)
- subepithelial electron dense deposits (beneath the podocytes)
Membranous nephropathy- treatment
steroid
membranoproliferative glomerulonephritis- pathogenesis
- usually in children and young adult if idiopathic
- secondary: hepatitis B or C, lymphoid malignancy, syphilis
- C3 glomerulonephritis
- dense deposit disease
- nephrotic syndrome + haematuria
membranoproliferative glomerulonephritis- pathology
- markedly increase in number of cells, thickened capillary wall and spitting of GBM
- immune deposits (IgG) at mesangial cells and GBM
- splitting of GBM and subepithelial electron dense deposits
membranoproliferative glomerulonephritis- treatment
- steroid and immunosuppressants usually not useful
- treatment underlying cause and complement pathway
- poor prognosis
Minimal change disease- pathogenesis
- usually in children
- not immune complex mediated
- primary damage is in the podocytes -> loss of protein filtration function
- associated factor (but not cause): recent vaccination/infection, drug (NSAID, lithium, interferon), lymphoma
Minimal change disease- pathology
- normal in light microscopy and direct immunofluorescent studies
- diffuse effacement of foot processes of podocytes in electron microscopy
Minimal change disease- treatment
- steroid, use other immunosuppressant if develop steroid resistance or dependence
- prognosis: excellent
Focal segmental glomerulosclerosis- pathogenesis
- focal: less than 50%
- segmental: only portion of glomerulus involved
- glomerulosclerosis: capillary loops got replaced by acellular amorphous mass (collagen, plasma protein, basement membrane components)
- primary/ idiopathic and secondary (HIV, obesity, hypertension)
Focal segmental glomeruolosclerosis- pathology
- if primary, very similar to minimal change
- but do not respond/ very little response to steroid therapy
- progress to CKD and may recur after transplant
Acute postinfectious glomerulonephritis- pathogenesis
- nephritis syndrome
- immune complex glomerulonephritis
- usually 1-4 weeks after pharyngitis or skin infection by group A beta hemolytic strep
- may also be caused by staphylococcal, pneumococcal, viral or parasitic infection
- usually in children
Acute postinfectious glomerulonephritis- pathology
- hypercellular glomeruli with neutrophils
- spotty immune deposits
- subepithelial humps (electron dense deposits)
Acute postinfectious glomerulonephritis- treatment
- conservative therapy
- 1% progress to rapidly progressive glomerulonephritis
AKI- rapidly progressive (cresentic) glomerulonephritis- types
Type I (anti-GBM Ab)- goodpasture syndrome Type II (immune complex)- IgA nephropathy, post infectious glpomerulonephritis, lupuc nephritis Type III (pauci-immune)- ANCA-associated
Goodpasture syndrome- pathogenesis
- usually in older age patients
- autoantibodies against NC1 domain of alpha 3 chain of type 4 collagen in GBM
- can cross-react with alveolar basement membrane, causing pulmonary haemorrhage and death
- preceded by flu-like illness, hydrocarbon or solvent exposure
Goodpasture syndrome- pathology
- GBM breaks
- cellular crescent formation (epithelial proliferation in response to GBM in the bowman’s space)
- fibrin deposits
- linear staining pattern for IgG
- no findings on electron microscope because too small
Goodpasture syndrome- treatment
plasmapheresis/ plasma exchange to wash away the autoAb
high dose steroid and cyclophosphamide
poor prognosis, needs renal replacement therapy
IgA nephropathy- pathogenesis
- wide age presentation, most common cause of glomerulonephritis
- immune complex glomerulonephritis
- nephritic syndrome
IgA nephropathy- pathology
- mesangial proliferation, increase in the size and matrix (normally 3 cells in one segment, now maybe 5)
- IgA immune deposits in the mesangium
- mesangial electron dense deposits
IgA nephropathy- treatment
- depends, if serious can give corticosteroid
- can recur even after transplant
Acute tubular injury/necrosis- cause
- usually ischemia
- direct toxic injury
- tubulointerstitial nephritis
- urinary obstruction by prostatic hypertrophy or tumour or blood clot
Acute tubular injury/necrosis- pathology
- necrotic tubular epithelial cells in the tubules
- dilated tubules
Acute tubular injury/necrosis- phases
- initiation phase: raised blood urea, creatinine, slight decrease in urine production
- maintenance phase: oliguria (40-400mL), raised urea and creatinine, water and salt retention, hyperkalemia and metabolic acidosis
- recovery phase: raised urine output up to 3L, decreased sodium and water and potassium
present as AKI
Tubulointerstitial nephritis- definition
inflammation of the tubules and interstitium
- present as acute or subacute worsening of kidney function
Tubulointerstitial nephritis- cause
- DRUGS: nsaid, radiology contrast, diuretics, antibiotics = hypersensitivity
- infections (acute and chronic pyelonephritis)
- light chain cast nephropathy
- immunological: sarcoidosis
- chronic urinary tract obstruction
- metabolic diseases: urate/oxalate nephropathy
Tubulointerstitial nephritis- pathology
- interstitial inflammation (if eosinophils present, hypersensitity to drugs)
- tubulitis (infiltration of inflammatory cells to tubules)
- interstitial edema (acute) or fibrosis (chronic)
Acute pyelonephritis- pathology
- a lot of inflammatory cells in the interstitium and tubules
- pus formation in gross anatomy
Acute pyelonephritis- presentations
failure to thrive in children
shaking chills
Acute pyelonephritis- complications
- perinephric abscess: perinephric tissue spread of the pus (out of the renal capsule)
- pyelonephrosis: the accumulation of pus in calyces, pelvis and the ureters (need surgical removal)
- scattered (minimal scar) formation
Chronic pyelonephritis- pathogenesis
- usually due to recurrent bacterial infections
- associated with vesicoureteral reflux/ urinary tract obstruction
Chronic pyelonephritis- pathology
very similar to other tubulointerstitial nephritis
may involve the glomerulus and cause glomerular damage in the long run
scar formation and thinning of the cortex/ medulla in gross
Chronic pyelonephritis- presentations
- commonly the recurrent acute pyelonephritis symptoms
- may be mild or none in the beginning: nocturia, polyuria due to loss of capacity to reabsorb
- may lead to CKD and ESRD- uremia
Light chain cast nephropathy
- usually in more than 50 yo
- neoplasm of plasma cells
- presentation: AKI and proteinuria
hypertensive nephrosclerosis
- associated with hypertension
- sclerosis of the small arteries and arterioles: intimal fibrosis and medial thickening (smooth muscle hypertrophy), hyalinization of arterioles (extravasation of plasma protein due to endothelial injury)
- due to wall thickening and lumen narrowing -> ischaemia -> glomerulosclerosis and chronic TI injury -> CKD/ESRD
Malignant nephrosclerosis
- associated with malignant nephrosclerosis (200/120)
- other symptoms: papilloedema, retinal haemorrhage, encephalopathy, CVS abnormality
- pathology: hyperplastic arteriolitis (onion-skin lesion), fibrinoid necrosis
- need aggressive and prompt anti-hypertensives
Diabetic nephropathy
- arteriolosclerosis (renal vascular lesion)
- affect the glomerulus (thickened GBM- normal 350nm, increased mesangial matrix, Kimmelstiel Wilson nodules)
- ischaemia -> glomerulosclerosis, chronic TI injury -> CKD and ESRD
ANCA-associated vasculitis- pathogenesis
- one of the cause of rapidly progressive glomerulonephritis
- pauci-immune because no immune complexes and anti-GBM Ab is detected in electron/ immunofluorescent
- antineutrophil cytoplasmic antibodies circulating in blood: c-ANCA, p-ANCA (perinuclear)
ANCA-associated vasculitis- disease entities
- wegener granulomatosis (granulomatosis with polyangiitis)
- microscopic polyangiitis
ANCA-associated vasculitis- pathology
- fibrin deposits in blood vessels (vasculitis)
- same as crescentic glomerulonephritis
