MedEd Histopath 2 Flashcards
Which pneumonia pathogen is associated with erythema multiforme?
Mycoplasma pneumonia
AKI - what is it?
acute decline in renal function
leads to fall in urine output
measured with Cr and Urea
CKD - what is it?
decline in renal function over >3 months
progressive damage
eGFR used to measure/stage it
eGFR - CKD staffing
1 - >90
2 60-89 (mild)
3A 45-59
3B 30-44
4 12-29
5 <15 (end stage)
no sx, no CKD
Causes of CKD
DM
HTN
ADPKD
untreated AKI (pyelonephritis, ATN, obstruction)
are AKI and CKD reversible?
AKI can be
CKD no
Causes of AKI
renal
- ischaemia
- nephrotoxins
- glomerulonephritis
- interstitial nephritis
- hepatorenal syndrome
- HUS/TTP
post-renal
Types of intrinsic renal pathology
Glomerulus
- nephrotic syndromes (minimal change, membranous, FSGS, secondary causes)
- nephritic syndromes (IgA, post streptococcal, rapidly progressive (crescentic) _>
add
Blood vessels
- HUS
TTP
Tubules
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Mesangium (kidney)
ECM
EC-tissue
which cells do the filtering ?
podocytes (check)
nephrotic syndrome triad
peripheral oedema
proteinuria (3g/d or PCR >300mg)
low serum albumin
also increased cholesterol and clotting tendencies
issues with podocytes -> protein get out
nephrotic syndrome triad
peripheral oedema
proteinuria (3g/d or PCR >300mg)
low serum albumin
also increased cholesterol and clotting tendencies
issues with podocytes -> protein get out
Minimal change disease
- affects children
- normal on light microscopy
- electron microscopy shows loss of food processes in podocytes
- nothing on immunofluorescence
- responds very well to steroids (90% poeple respond well to pred)
Membranous glomerulopathy
- immune complexes attach evenly to basement membrane
- responds poorly to steroids
Which antibodies are associated with membranous glomerulopathy?
FSGS
focal: only some glomeruli are damaged
segmental: only some regions of the glomerulus are damaged
sclerosis: scarring
affects adults
light microscopy shows focal and segmental scarring
EM: loss of foot processes
Responds less well to steroids (but better than)
secondary causes of nephrotic syndrome
Diabetes (kimmelstiel Wilson nodules)
Amyloidosis
- AA or AL
AA is chronic inflammation e.g. SLE, RA
AL is light chains -> multiple myeloma
Nephritic syndrome
haematuria
HTN
peripheral oedema
red cell casts in urine
red cells forced through the sieve
damage to kidney
β¦
IgA nephropathy
causes nephritic syndrome
post group A strep infection (1-2d, IgA = acute)
IgA immune deposits within glomeruli
IgA immune deposits in mesangium seen on IF
33% get better
33% get CKD
33% need dialysis
post strep glomerulonephritis
after group A strep infection (1-3w)
thought to be due to antigen mimicry and immune complex deposition
bloods: raised anti-streptolysin O titre, reduced C3
IF: granular IgG deposits in BM
Mx: supportive
Rapidly progressive (crescentic)
most aggressive form of glomerulonephritis causing renal failure in weeks
characterised by severity and presence of crescents (macrophages in Bowmanβs capsules)
acute onset
Anti-GBM - Goodpastures
Immune complex mediated
Pauci immune (ANCA-assocaited)
Goodpastures syndrome
anti-GBM disease
presence of anti-glomerular BM Ab
credence seen on LM
IF: linear deposition of IgG in GBM
also see pulmonary haemorrhage
Immune complex mediated - rapidly progressive GN causes
SLE
IgAa nephropathy
post-infection
HSP
bumpy deposition of immune complexes in GBM or mesangium
Pauci-immune/ANCA associated
cANCA: GPA
pANCA: MPA/eGPA
vasculitis affecting small micro blood vessels
LM;
IF: no/scanty immune complexes
Alpertβs syndrome
hereditary cause of glomerulonephritis
X-linked causing problem with type 4 collagen
triad:
causes progressive end stage renal failure with some extra-renal sx
benign familial haematurua - genetic issue
AD gene causing problem with type 4 collagen
benignfamilial haematurua
causes
ATN
- most common renal cause of AKI
- tubules will die and she leading to presence of brown casts in the urine
- caused by hypovolaemia
- toxins (aaminoglycosdies ee.g. gentamicin, myoglobin (rhabdomyolysis), contrast)
commonest cause of renal AKI
ATN
Acute interstitial nephritis
interstitial infiltrate of
kind of like an allergic rection
causes of white and brown cell casts in urine
white: AIN
brown: ATN