Nephritic & Nephrotic Syndrome Flashcards
What are the 3 layers of the Glomerular Filtration Barrier?
Endothelial Cell layer - fenestrated
GBM - Type 4 collagen & laminin with embedded mesangial cells (smooth muscle)
Podocytes (Podocin & nephrin proteins)
Define Nephritic vs Nephrotic Syndrome? [2]
Nephritic = High haematuria & intravascular overload
Nephrotic = High proteinuria & intravascular depletion
What would Nephrotic syndrome look like? [5]
Pathophysiology [2]
Edema in face, legs, ascites and pleural effusions Hypoalbuminemia ~Raised BP Frothy Urine ~Pale - third space loss
Pathophys: a drop in oncotic pressure creates increased proteinuria [1] and intra-vascular depletion with fluid loss into the third space [1]
What causes Nephrotic Syndrome? [2]
85% are Minimal Change Disease
15% are termed “Steroid REsistant nephrotic syndrome” which includes:
- Congenital NPHS1 or 2
- Acquired FSGS (Focal segmental glomerular sclerosis)
How do we confirm minimal change disease? [4]
Urinalysis (proteinuria +++)
Urine protein creatinine ration >250mg/mmol
24h urine collection - gold standard
U&E, Cr, albumin
Why don’t we biopsy in most nephrotic syndromes? [1]
Most it’s almost always minimal change disease so we just trial treatment
Nephrotic Syndrome is treated with 8wks of prednisolone. What are the major SEs?
Common [4]
Uncommon [2]
Long term prognosis of nephrotic syndrome [1]
Commonest: GI upset due to high acid Behaviour (irritable/moody/don't sleep) HTN Weight Gain
Uncommon:
Glucose intolerance
Adrenal crisis
Growth problems with recurrent courses
Describe the outcome of MCD? [2]
95% go into remission in 2-4wks
80% will relapse
How do you treat Steroid Resistant Nephrotic Syndromes e.g. FSGS? [1]
Second line immunosuppression
Try to list 8 major causes of childhood haematuria? [3] + [5] that cause hematuria
UTI
Trauma
Stones
Glomerulonephritis due to:
- Post-infective GN
- IgA nephropathy / HSP
- Membranoproliferative GN
- SLE
- ANCA +ve vasculitis e.g. GPA
What’s the classic presentation of Nephritic Syndrome? [7]
- Haematuria (frank or microscopic)
- Proteinuria
Reduced GFR:
–> Oligura
–> Fluid overload (JVP/oedema)
–> HTN
–> High creatinine
Often comes post-infection, particularly throat
What’s the most common nephritic syndrome in kids vs adults? [2]
Kids - Post-infective Glomerulonephritsi
Adults – IgA Nephropathy
What causes Post-infective Glomerulonephritis?
Group A strep
Throat infections 7-10days later
skin 2-4wks later
Nephrogenic strep antigens bind to sites in glomeruli & form immune complexes which are deposited there
This triggers Alternative Complement activation & Adaptive immune response leading to the nephritis
How can you diagnose Post-infective Glomerulonephritis?
A bacterial culture & throat swab for Strep A
+ve ASO Titre
Low C3 (used up)
Normal Renal US
ANA (SLE) + ANCA (GPA) to rule out autoimmune
So child with nephritic syndrome presents a week after having a throat infection.
Tests show Strep A culture, +ve ASO titre, low C3
Renal US, ANA & ANCA were all -ve
How would you treat the kid?
Diagnosis of Post-infective GN
Abx
Diuretic for fluid overload
Support renal function (e.g. restrict fluid, restrict Na, ACEI etc)
It will be self-limiting
IgA nephropathy is a commoner cause of nephritic syndrome in older kids/adults. What causes it?
Often comes 1-2days post or during an URTI (So much quicker than post-infective GN)
How do you diagnose and treat IgA nephropathy?
Clinical diagnosis with biopsy to confirm
ACEI
If severe give Immunosuppression
What is IgA Vasculitis / HSP?
Henoch-Sholein Purpura
It’s very similar to IgA nephropathy but comes with more systemic problems. You need Palpable purpura + 1 of
- Renal involvement
- Abdo pain
- Arthritis
- Renal biopsy showing IgA deposits
Again it comes 1-3days post viral URTI
How do you treat HSP/IgA vasculitits?
Symptomatic treatments for joint/gut symptoms e.g. analgesia & NSAIDs
CCS may help gut
Immunosuppression if severe, prednisolone for GI sx
ACEI Ramipril for kidneys
Long term monitor for HTN & Proteinuria
Which Glomerulonephritidis affect which layer of the Glomerular Filtration BArrier?
Podocytes = MCD & SLE
GMB = Membranous & Post-infective (PIGN)
Endothelial cells = PIGN, HUS, Membranoproliferative glomerulonephritis or SLE
mesangial = HSP, IgA nephropathy or SLE
Management of acute post-infective GN
Penicillin
Diuretics
NOT ACEi as can cause AKI
Haemolytic uremic syndrome
Epidemiology
Aetiology [2]
Presentation [2]
Ep: <5y/o in outbreaks of contaminated undercooked meat
Ax: secondary to infection with E. coli O157 shiga like-toxin (also strep pneumoniae, HIV) or primary immune dysregulation
Presentation: starts with colitis then hemoglobinuria then oliguria
- CNS signs then encephalopathy > coma
Haemolytic uremic syndrome
Pathophysiology [4]
- microangiopathic haemolytic anaemia (intravascular haemolysis and red cell fragmentatation).
- Endothelial damage triggers:
> thrombosis, platelet consumption (causing thrombocytopenia)
> fibrin deposition in the glomeruli
> causing AKI
Haemolytic uremic syndrome
Investigations [3] - what would you see on routine bloods? [5]
Mx [2]
FBC, blood film (normochromic normocytic anaemia, schistocytes, burr cells, elevated WCC, thrombocytopenia)
U&E, Cr (reduced GFR)
LDH raised
Coombs test negative
Mx:
- Supportive (blood transfusion, fluid & electrolyte balance, RRT)
- Plasma exchange if severe
