Glomerulonephritis - Nephrotic and Nephritic Flashcards
What is the quadrad of nephrotic syndrome?
- Proteinuria (>3g/24hr)
- Hypoalbuminemia (<30g/L)
- Oedema
- Dyslipidemia/ hypercholesterolemia
What is the basic process underpinning nephrotic syndrome?
- Inflammation and damage to the glomerulus -> more permeable but dec GFR (can lead to HTN)
- Proteins filtered into urine (may be followed with haematuria depending on extent of damage) - includes antibody loss so increased risk of infection
- Hypoproteinemia (low albumin) cause water and electrolyte loss into interstittium -> odemea -> low cardiac output = low eGFR = activating RAAS which worsens oedema
- Liver inc protein and cholesterol production to compensate -> dyslipidemia -> may also increase coagulation proteins -> inc risk of thromboembolic events
What are the different primary causes of glomerulonephritis?
- Minimal change GN = children
- Membranous GN
- Focal segmentation glomerulosclerosis = adults
- Membranoproliferative GN
What are some secondary causes of nephrotic syndrome?
Diabetes mellitus
SLE
Amyloidosis
What are some outlier causes of nephrotic syndrome?
Gold (sodium aurohtimalate), penicillamine
Congenital
Neoplasia = carcinoma, lymphoma, leukaemia, myeloma
Infection = bacterial endocarditis, hepatitis B, malaria
What is the relationship between glomerulonephritis, nephrotic syndrome and nephritic syndrome?
GN = inflammation of glomeruli
Can result in nephrotic (protein uria and oedema) or nephritic (haematuria, HTN and less proteinuria) syndrome
How might nephrotic syndrome present?
Proteinuria = frothy urine
Hypoalbuminemia = fatigue, leukonychia
Odema = peripheral, periorbital, pulmonary or pleural effusions (breathlessness) or ascities
Dyslipidemia = xanthelasma and xanthomata
What are some key investigations for nephrotic syndrome?
Bedside - urine dip (frothy, protein uria >3.5g/24hr), urine immunoglobulins, protein: creatinine ratio.
Bloods - U&Es, ()(), lipid profile (dysplipemia), FBC, LFTs, Ca2+, CRP, Glucose, Serum immunoglobulins, autoimmune screen (Hep B/C, HIV)
Imaging - ultrasound, kidney biopsy, CXR (pulmonary oedema/effusion)
What is the most common cause of nephrotic syndrome in children?
Minimal change disease
What is the most common cause of nephrotic syndrome in adults?
Membranous nephropathy
What are the suspected blood test results in nephrotic syndrome?
LFTs = hypoalbuminemia
U&Es = renal function
FBC = anaemia
Vitamin D = low
Bone profile = hypoCa2+
Coagulation screen = hyper
HbA1c or fasting glucose = diabetes
Lipid profile = dyslipidemia
CRP and ESR = rasied
Myeloma screen (just in case)
Autoimmune screen (SLE)
Infection screen (Hep B/C, HIV)
What is the golden standard investigation for the diagnosis of nephrotic syndrome?
Renal biopsy
What is the typical conservative management for nephrotic syndrome?
Restrict salt intake <2g/day
Fluid restriction <1.5g/day
Weight monitoring
Diet - avoid high protein
Mechanical thromboprophylaxis
What is the medical management for nephrotic syndrome?
Corticosteroids - until remission
Immunosuppressive drugs - if severe or refractory
Diuretics - for sig perph oedema norm LOOP
Consider need for: prophylactic anti-coag, anti-hypertensives, vaccination (NOT live), statins, PPI (if on steroids).
What is the damage to the glomerulus in nephrotic syndrome?
Typically main damage to podocytes but all layers may be affected due to close proximity
Damaged by immune complexes or complement
What is the key process in minimal change disease?
Childhood
Light microscopy - low/no change
Immunology = occasional IgM in mesangium
Electron microscopy = podocyte effacement (loss fo feet) = allows for protein to filter out
What are the key features of membranous glomerulus nephritis?
Adulthood
Light microscope = capillary wall thickening, mesangial expansion
IF = IgG and C3
Electron microscope = GBM thickening
Subepithelial deposits of immune components are termed spikes -> this damages podocytes
What are the key features of focal segmental glomerulosclerosis?
Light microscope = focal, sgemental glomerular sclerosis
IF = no
Electron microscopy = GBM thickenining from sclerosis -> dec urine output and damage surrounding podocytes.
What is the surgical treatment for nephrotic syndrome?
Renal Replacement Therapy - dialysis or renal transplantation.
If nephrotic syndrome results in end-stage renal failure.
What are some common complications of nephrotic syndrome?
Infection risk inc
Thrombembolism risk
AKI - due to excessive diuresis or renal vein thrombosis
CKD - secondary
Hypothyroidism - due to urinary loss of T4 and T3 with their binding proteins
VitD loss
Anaemia - iron bound to transferrin and EPO are lost in urine
What are the key urinary features of nephritis syndrome?
Micro/macroscopic haematuria
Proteinuria
Sterile pyruia (wbcs with no infection)
HTN (due to dec GFR)
What is the key damage and process within the nephron in nephritic syndrome?
- Inflammation and damage to glomerulus -> particularly BM (rbcs),
- Leakage of rbcs into filtrate - clump to form clasts or become dysmorphic = acanthocyte
- Leakage of wbcs into filtrate
- Damage to podocytes = some proteinuria (less than nephrotic)
- Dec GFR = oliguria, AKI (inc creatinine), azotemia (retained uria)
- RAAS stimulated = HTN.
What are some specific causes of glomerulonephritis?
Rapidly progressive GN
Anti-GBM antibody GN (goodpastures)
ANCA associated GN
Immune complex mediated GN
Membranoproliferative GN
Post-streptococcal GN
What is the overview of rapidly progressive GN?
Caused by other glomerulonephric disease
Loss of GFR >50%
Extensive glomerular cresents (rupture of glomerular capillary wall with macro and fibro accumulation)
