questions Flashcards
(40 cards)
47 year old person with peripheral leg oedema, htn, tachypnoea, urinalysis with red cells, protein, cast and UEC given
- what features are consistent with acute renal failure
- How do you calculate GFR
- how does hyperkalaemia occur? where is potassium stored
- what complicaiton can occur with high potassium? how does potassium do this?
- ARK also known as acute renal injury is define as abrupt decline in renal function with increase Creatinine and increase BUN (blood urea nitrogen) over period of several days.
Define the following terms:
- oliguria
- nephritic syndrome
- nephrotic syndrome
- acute renal failure
- chronic renal failure
- Oliguria = abnormally low urine output (< 3.5g/day)
- haematuria
- azotemia
- red cell casts
- oliguira
- haematuria (glomerula capillary endothelium damage) - Nephrotic snydrome (LEAP) = clinical syndrome associated with disorders affecting kidneys, commonly caused by injury to the glomerular basement membrane, define by:
- Lipid increase
- edema
- azotemia
- proteinuria (> 3.5 g/day) - Acute renal failure = rapid decline in renal function occuring over hours/days with increase creatinine and increase BUN (blood urea and nitrogen) which is usually reversible. May have no symptoms, but oliguria is common.
5. Chronic Renal Failure = progressive and irreversible loss of renal function over months/ years, gradual decrease in GFR GFR values (ml/min): mild 30-50, moderate 10-29, severe /= 90)
if 25 year old female presented with anorexia, lethargy, pallor with long history of recurrent urinary tract infections and suffered from several episode of acute pyelonephritis during childhood (none current 5 year), over 12 month noticed increase nocturia. what further aspects of hx and examination are relevant to case?
what investigation?
Time frame of symptoms, if acute (more urgent and potentially reversible)
other symptoms of CRF (MAD HUNGER) from inability to make urine and excrete nitrogenous wastes:
- metabolic acidosis
- dyslipidemia (increase triglyceride)
- hyperkalemia
- uremia (increase BUN and CR, anorexia, N&V, pruritis, malaise, drowsiness, hiccups, seizures, encephalopathy, asterixis, pericarditis, platelet dysfunction - easy brusing), Na/H20 retention (pulmonary oedema - crackles, CHF, hypertension, oedema/ ankle swelling), growth retardation and developmental delay in children, erythropoietin failure (aneamia), renal osteodystorphy (bone pain)
symptoms of ARF - anuria, hypovolaemia, flank pain
childhood enuresis (bedwetting) past 3 yo: associated with vesicoureteric reflux
hx of DM, HTN, vasculitis, drug hx - risk factors)
family of kidney disease (polycystic kidney disease)
Examination:
lung and heart for signs of oedema (na/h20 retention), palpate kidney (palpable may be polycystic kidney disease) and any tenderness
Investigation:
FBC - anaemia
UEC - increase urea, cr, potassium, decrease GFR
24 hour urine collection for protein, nephritic/ nephrotic
MSU if urinary symptoms
Renal U/S - size and cyst
IVP (intravenous pyelogram) - contrast xray via cannula (excrete via kidney) to visualize kidney, ureter, bladder) CI if poor renal funciton and metformin (must stop 24 hrs)
KUB (kidney ureter bladder xray)
what are the features visible on IV pyelogram suggestive of kidney damage due to vesico-ureteric reflux?
parachymal scarring of renal cortex (thinning of cortex)
calyceal clubbing (blunting: due to pyelonephritis)
ureteric dilatation
what is significance of nocturia, glycosuria? Why do you get increase serum chloride in kidney failure?
nocturia: sign of renal impairment, where kidney cannot concentrate urine normally
glycosuria: renal glycosuria due to impair tubular ability to absorb glucose
increase serum cholride due to hyperchloraemic metabolic acidosis is a normal side effect of HCO3 loss, which is due to decrease resorption of HCO3 in PCT
what are the major indication of renal biopsy?
acute nephritic syndrome, unexplained acute/ rapidly progressive renal failure, nephrotic syndrome
what is the appearance of kidey in reflux nephropathy cause CRF both macroscopically and microscopically?
macroscopic:
irregular parenchymal scarring with focal thinning of cortex
corticomedullary scarring associated with deformed renal calyx and calyceal clubbing
dilated ureters
microscopic:
tubular hypertrophy/ dilatation
dilated tubules filled with colloid casts
interstitial inflammation and fibrosis of crotex and medulla
inflammatory infiltrate, include neutrophils and macorphages interstitium
a 45 year old man complained of progressive lethargy and swelling of ankles over the past 3 weeks. examination revealed a pale and ill-looking man with pitting oedema of both ankles. The JVP was raised 3 cm, there was a fourth heart sound and crepitations were heard at both lung bases. Microscopy of fresh urinary sediment showed granular and red cell casts. over next 24 hours the total urine volume was 400mL.
HR 80, BP 150/110, RR 22, temp 36.3, urinalysis pH 7, protein ++, blood ++, sodium 133, potassium 5.2, cholride 92, bicarbon 18, urea 15, cr 210.
what is your pdx and ddx
what further hx and examination
what investigations
PDX is nephritic syndrome
hx: presenting symptoms, PMHx, Fhx medicaitons
examination: other S and S of uraemia:
- increase BUN and Cr
- N&V, anorexia, pruritis, malaise
- hiccups, drowsy, seizures, encephalopathy
- platelet dysfunction
- asterixis, pericarditis
what is the likely pathology of haematuria, oliguria, cast formation in nephritic syndrome?
haematuria: due to immune mediated process -> glomerular inflammation -> increase BM permeability -> RBC escape to bowman’s space -> haematuria
oliguria: immune mediate process -> glomerular inflammation -> glomerular compression, tubular obsturction, arteriolar vasoconstrictio, capillary thrombosis -> decrease GFR -> oliguria
cast formation -> immune mediated process -> glomerula inflammation -> increase BM permeability -> RBC escape into bowman space -> formation of RBC casts from slow tubular flow
why in nephritic syndrome, you get HTN, elevated JVP, periphearl oedema?
HTN = immune mediated process -> glomerular inflammation -> glomerula compression, tubular obstruction, arteriolar vasoconstriciton, capillary thrombosis -> decrease GFR -> RAS activation -> HTN
Increase JVP and periphearl oedema = immune mediated process -> glomerular inflammation -> increase BM permeability -> proteins escape into bowman’s space > pronteinuria -> oedema
what investigations would you do in nephritic syndrome? how about nephrotic syndrome?
Nephritic:
blood - FBC, U&E, LFT, ESR, CRP, immunoglobulins, electrophoresis, complement (C3, C4), autoantibodies (ANA, ANCA, anti-dsDNA, anti-GBM, blood culture, ASOT, HBsAg, anti-HCV)
urine: rbc cast, MC&S, bence-jones protein
24 urine: protein (protein: creatinine/ albumin:Cr)
CXR
renal U/S
Renal biopsy
nephrotic: same as nephritic + also check cholesterol
what is ASOT invesitgations?
asot = anti-streptolysin o titre -> exposure of streptococci, low specification: include culture throat swab and other micro sample like skin swab)
Name the different type of nephritic syndrome and which of these are associated with acute renal failure?
acute poststreptococcal glomerulonephritis, rapidly progressive glomerulonephrtiis, diffuse proliferative glomerulonehpritis, IgA nepropathy, Alport syndrome
acute renal failure associated with rapidly progressive glomerulonephritis
Describe about acute poststreptococcal glomerulonephritis
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
Also known as proliferative GN:
LM - glomerula enlarged and hypercellular (uniform increase -diffuse)
IF - ‘starry sky’, granular appearance (lumpy bumpy) due to IgG, IgM, C3 deposit along GBM and mesangium
EM - subepithelial immune complex (IC) humps - clear over 2 months
most frequently seen in children, occurs 2 weeks after group A streptococcal infection of pharynx or skin cause a type 3 hypersensitivity reaction which resolves spontaneously (95%) - the streptococcal antigen is deposited on the glomerulus cuasing host reaction and immune complex formation
Biopsy is rarely needed if typical of IgG and C3 deposits in IF, serology = incrase ASOT, and decrease C3
renal biopsy will show inflammatory reaction affecting mesangial and endothelial cells
present with peripheral and periorbital edema, dark urine (cola-coloured), HTN, increase anti-DNase B titers and decrease complement
Mx: Renal function will begin to increase spontanesouly within 10-14 days, manage maninly by supportive via adequate fliud, Na restriction, diuretics, hypotensive agent to aim bp less then 130/80 or 125/75 (if proteinuria > 1g/d) - ACEI
pathology due to hypercelluity due to proliferation and swelling of endothelial and mesangial cells by neutrophil and mnocystic infiltrate of kidney
describe IgA nephropathy (berger disease)
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
IgA nephropathy (Berger disease) is a type of nephritic syndrome, it is the most common GN in developed world, mostly presented with macro/microscopic haematuria.
Typical patient: young male with episodic macroscopic haematuria/ red cell casts, occuring a few days after URTI eg. pharyngitis, recover is rapid between attacks. Can also presents/ flare up with URI/ acute gastroenteritis.
LM - mesangial proliferation
EM - mesangial IC deposits
IF - IgA based IC deposits in mesangium + C3 **
renal biopsy - mesangial proliferation
Mx - general measures. role of immunosuppresion not certain, steroid may decrease proteinuria and slow down decline of renal function, cyclophosphamide in some with rapid deteriorating renal function
Clinical course - last several days, subsites and return every few months, slow progression to CRF in 25-50% in 20 years, worst prognosis if increase BP, male, proteinuira, / renal failure at presentation
ddx of IgA deposite in mesangium = Henoch-Schonlein purpura (IF - IgA based IC deposite in mesangium + C3, properdin, smaller # of IgG and IgM), this is a systemic syndrome invovle skin (pupura rash), GIT (abdo pain), Joint (artheritis), kidney (nephritic)
IgA (main immunoglobulin in mucosal secretion) increase by 50% in patient with this disease
pathology is MAYBE due to increase IgA synthesis in reponse to resp/ GIT exposure to virus, bacteria, food protein -> deposition of IgA and IgA contain immune complex in mesasngium -> activate alternative complement pathway -> glomerular injury
High risk in celiac disease/ liver disease (due to decrease defective hepatobiliary clearance of IgA complex -> secondary IgA nephropathy)
Describe about alport syndrome
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
Alport syndrome is mutation in type IV collagen -> thinning and splitting of glomerular BM, most commonly x-linked (m > F)
Type IV collagen helps maintain normal function of cochlea, lens and glomerulus, therefore alport syndrome will have glomerulonephritis, deafness (nerve), less commonly eye problems (lens dislocation, posterior cataract, corneal dystrophy)
describe about anti-glomerular basement membrane disease
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
It is a type of GN (nephritic syndrome), also known as goodpasture’s disease, caused by development of auto-antiboidies to type IV collagen (essential part of GBM). Also found in lungs -> haemoptysis (esp. smokers)
Commonly affect young males, but any age/ gender
Present: macroscopic haematuria + oliguria, renal failure may occur in days of onset
Tx: plasma exchange, corticosteroids +/- cytotoxics (start early can cure and relapse is rare)
Describe about diffuse proliferative glomerulonephritis
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
Due to SLE/ MPGN, it is the most common death of SLE (1/3 of patients with SLE will have evidence of renal involvement with vascular , glomerular, tubulointerstitial damage)
LM - wire looping of capillaries
EM - subendothelial and sometime intramembrnous IgG based ICs often with C3 deposit
IF - granular
DPGN/ MPGN can present as nephrotic/ nephritic
describe about rapidly progressive glomerulonephritis
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
it is a type of nephritic*/nephrotic syndrome, GN.
Characterised by rapid + progressive loss of renal function + nephrotic (serve oliguria) and death if untreated
Histology:
Present of cresent* (fibrin + plasma protein) - due to proliferation of parietal epithelial cell of bowman’s capsule + infiltration of monocyte and macrophages
Divided into 3 groups based on immunology, 12% have anti-GBM antibody mediated GN (type I CrGN) +/- lung involvement, 44% have type II CrGN, 44% have pauci immune type III
general:
LM and IF - crescent moon shape ** (cresent consist of fibrin + plasma protein + glomerular parietal cells, monocytes, macrophages)
clinical features = signs of renal failure, features of systemic disease (fever, malaise, myalgia, wt loss, haemoptysis) Massive pulmonary haemorrhage is most common cause of death in those with +ve ANCA
Tx - aggressive immunosuppression with high dose corticosteroids and cyclophosphamide with plasma exchange to remove existing antibodies
Prognosis poor if serum Cr > 600 umol/L, below this 80% improve with tx, present nephrotic like but MORE oliguria & azotemia, proteinuira > 3.5 g/d (maybe), anuric, Long term dialysis/ transplant needed.Prognosis also depend on # of cresent, linear IF)
type II (immune complex mediated 45% of cases) cause: idiopathic/ postinfectious/ SLE/ IgA neuropathy/ Henoch Schonelein purpura
morphology
- severe injury + segmental necrosis cresent (GBM break), segment without necrosis have underlying immune complex***,
- IF: granular pattern
- EM: deposits
Type III CrGN (50% of cases, 80-90% ANCA +ve)
- causes: idiopathic/ wegener granulomatosis/ microscopic angitis
- wegner = granulomatosis with polyangiitis (PR3-ANCA/ c-ANCA)
- microscopic angiitis (MPO-ANCA/p-ANCA)
= due to lack of anti GBM antibodies/ significant immune complex deposit ion detectable by IF and EM, serum have antineutrophil cytoplasmic antibodies*** (role in some vasculitis), mostly limit to kidney
morphology:
- segmental necrosis + cresent (GBM break)
- uninvolved area is normal
- IF: immunoglobuline and complement -ve, no deposit on EM**
Cresent body formation (shared feature between all RPGN) is from segmental necrosis -> GBM breakdown -> proliferation of parietal epithelial cells + response to exudation of plasma protein (fibrin) into bowman’s space
Describe the type of nephrotic syndrome:
focal segmental glomerulosclerosis, membranous nephropahy, minimal change disease, mebranoproliferative glomerulonephritis, diabetic glomerulonephropathy
Describe about focal segmental glomerulosclerosis
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
= lesion characterised histologically by sclerosis affecting some areas (focal involvement)
account of 20-30% of nephrotic syndrome (idopathic FSG), most common type in african americans, hispanics. important to differtial from minimial change disease in children as MCD response well to steroid thearpy while FSG have poor response to steroid thearpy 30% only and may -> CRF (FSG have higher HTN and hematuria)
Cause: idiopathic/ HIV infection, sickle cell disease, herion abuse, massive obesity, interferon tx, chronic kidney disease due to congenital absence/ surgical remove
Pathogensis:
unknown, suggestion are MCD -> FSG, injury to podocyte, permeability increase factors produced by lymphocyte (like MCD), deposit of hyaline masses in glomeruli represent entrapment of plasma protein and lipid in foci of injury where sclerosis develop and IgM and complement, circulating mediator cause damage to podocyte (24 hr of transplant -> recurrence of FSG)
LM - segemental sclerosis and hyalinosis
IF - neg, IgM and C3 deposit affected
EM - effacement of foot process similar to minimal change disease
morphology: segmental and focal involvement, increase mesangial matrix, obliterated cap lumen, deposit of hyaline masses (hyalinosis) and lipid droplet
progression of disease -> global sclerosis of glomeruli with pronounced tubular atrophy and interstitial fibrosis
Describe minimal change GN
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
Most common type of nephrotic syndrome in children (76%) and 20% adults, it is benign with no HTN and renal function preserve with selective proteinuria (commonly albumin).
May be triggered by recent infection, immunization, immune lymphoma (eg. cytokine-mediated damage)
Tx: steroid + cyclophosphamide/ cholrambucil if renal function deteriorates; excellent reponse to corticosteroids (>90% response but 2/3 may remit -> steroid dependent)
- adults also response to steroid but slower and more relapses
Prognosis:
good prognosis with CRF in 25 years, 40% have spontaneous remission,
LM - normal glomeruli (lipid in PCT cells + protein deposit)
EM - effacement of foot process (uniforma nd diffuse)
IF - neg
Describe membranous nephropathy
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
Causes:
MOST COMMON cause of primary nephrotic syndrome in caucasian adults
- 85% idiopathic
- 15% other: infections (chronic hep b, syphilis, schistosomiasis - disease caused by parastici worm infect urinary tract/ intestin), malignant tumour (ca of lung, colon, melanoma), SLE/ other autoimmune, exposure to inorganic salts (gold, mecury), drug (peniclinamine, captopril, NSAIDs)
pathology: unknown, induced by antibodies reacting in situ to endogenous/ planted glomerular antigens; type of chronic immune complex nephritis
morphology:
LM - diffuse capillary and GBM thickening (may be normal early on)
IF - granular as result of immune complex deposit (IgG and C3 subepithelial deposit)**
EM - “spike and dome” appearance with subeptiehlial deposits
- spike and dome = part by subepithelial deposits that nestel against GBM seperated by small spikelike protrusion of GBM matrix form as disease progress, spike close over deposit -> incoporatedin GBM and podocyte show effacement of foot process -> catabolized -> dissappear -> cavities in GBM + continue deposit in BM matrix -> progressive thicker BM -> sclerosed of glomeruli
Clinical course:
slow progressive, common in 30-50years old, 40% will spontaneous remission
poor response to steroid, 60% proteinuria persist, 4-% may -> CRF in 2-20years, 10-30% have benign course with partial/ complete remission of proteinuria
steroid + cyclophosphamide/ chlorambucil if renal function decrease (poor prognositc factors are decrease renal funciton, heavy proteinuria)
describe amylodosis nephrotic syndrome
what it is, LM, IF, EM, epidimiology, pathology, morphology, tx and clinical prognosis
LM - congo red stain show apple-green birefringence under polarized light
kidney most commonly involved organ in systemic amylodosi, associated with chronic conditions (eg. multiple myeloma, TB, RA)
