Renal - Glomerulonephritis Flashcards
Features of nephritic syndrome
Haematuria means blood in the urine. This can be microscopic (not visible) or macroscopic (visible).
Oliguria means there is a significantly reduced urine output.
Proteinuria is protein in the urine. In nephritic syndrome, there is less than 3g / 24 hours. Any more and it starts being classified as nephrotic syndrome.
Fluid retention
Criteria for nephrotic syndrome diagnosis
Peripheral oedema
Proteinuria more than 3g / 24 hours
Serum albumin less than 25g / L
Hypercholesterolaemia
What does glomerulonephritis refer to
Glomerulonephritis is an umbrella term applied to conditions that cause inflammation of or around the glomerulus and nephron
What is interstitial nephritis
Interstitial nephritis is a term to describe a situation where there is inflammation of the space between cells and tubules (the interstitium) within the kidney
What is glomerulosclerosis
Glomerulosclerosis is a term to describe the pathological process of scarring of the tissue in the glomerulus. It is not a diagnosis in itself and is more a term used to describe the damage and scarring done by other diagnoses
What can cause glomerulosclerosis
Glomerulosclerosis can be caused by any type of glomerulonephritis or obstructive uropathy (blockage of urine outflow), and by a specific disease called focal segmental glomerulosclerosis.
What are most types of glomerulonephritis treated with
Immunosuppression (e.g. steroids)
Blood pressure control by blocking the renin-angiotensin system (i.e. ACE inhibitors or angiotensin-II receptor blockers)
Most common cause of nephrotic syndrome in children
Minimal change disease
Most common cause of nephrotic syndrome in adults
Focal segmental glomerulosclerosis
Aetiology of minimal change disease
Majority are idiopathic
drugs: NSAIDs, rifampicin
Hodgkin’s lymphoma, thymoma
infectious mononucleosis
Features of minimal change disease
nephrotic syndrome
normotension - hypertension is rare
highly selective proteinuria
only intermediate-sized proteins such as albumin and transferrin leak through the glomerulus
What might a renal biopsy show in minimal change disease
normal glomeruli on light microscopy
electron microscopy shows fusion of podocytes and effacement of foot processes
Mx of minimal change disease
majority of cases (80%) are steroid-responsive
cyclophosphamide is the next step for steroid-resistant cases
What is focal segmental glomerulosclerosis(FSGS)
Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome and chronic kidney disease. It generally presents in young adults.
Causes of FSGS
idiopathic secondary to other renal pathology e.g. IgA nephropathy, reflux nephropathy HIV heroin Alport's syndrome sickle-cell
In which patients is FSGS likely to recur
Patients with renal transplants
What might a renal biopsy show in FSGS
focal and segmental sclerosis and hyalinosis on light microscopy
effacement of foot processes on electron microscopy
Mx of FSGS
steroids +/- immunosuppressants
What does nephrotic syndrome predispose patients to
Nephrotic syndrome predisposes patients to thrombosis, hypertension and high cholesterol.
Most common cause of primary glomerulonephritis
IgA nephropathy(Berger’s disease)
How does IgA nephropathy classically present
It classically presents as macroscopic haematuria in young people following an upper respiratory tract infection.
Conditions associated with IgA nephropathy
alcoholic cirrhosis
coeliac disease/dermatitis herpetiformis
Henoch-Schonlein purpura
Histology in IgA nephropathy
Mesangial hypercellularity
Positive immunofluorescence for IgA and C3
IgA nephropathy presentation
young male, recurrent episodes of macroscopic haematuria
typically associated with a recent respiratory tract infection(1-2 days after URTI)
nephrotic range proteinuria is rare
renal failure is unusual and seen in a minority of patients
Differentiation of IgA nephropathy and post-strep glomerulonephritis
post-streptococcal glomerulonephritis is associated with low complement levels
main symptom in post-streptococcal glomerulonephritis is proteinuria (although haematuria can occur)
there is typically an interval between URTI and the onset of renal problems in post-streptococcal glomerulonephritis(Posy-strep glomerulonephritis develops 1-2 weeks after URTI)
Mx of IgA nephropathy if isolated hematuria with no/minimal proteinuria
no treatment needed, other than follow-up to check renal function
Mx of IgA nephropathy if persistent proteinuria, a normal or only slightly reduced GFR
initial treatment is with ACE inhibitors
if there is active disease (e.g. falling GFR) or failure to respond to ACE inhibitors
immunosuppression with corticosteroids
What is the most common type of glomerulonephritis overall
Membranous glomerulonephritis
How does membranous glomerulonephritis usually present
Nephrotic syndrome or proteinuria
What might a renal biopsy demonstrate in membranous glomerulonephritis
electron microscopy: the basement membrane is thickened with subepithelial electron dense deposits. This creates a ‘spike and dome’ appearance
Causes of membranous glomerulonephritis
diopathic: due to anti-phospholipase A2 antibodies
infections: hepatitis B, malaria, syphilis
malignancy (in 5-20%): prostate, lung, lymphoma, leukaemia
drugs: gold, penicillamine, NSAIDs
autoimmune diseases: systemic lupus, thyroiditis, rheumatoid
Mx of membranous glomerulonephritis
all patients should receive an ACE inhibitor or an angiotensin II receptor blocker (ARB)
A combination of corticosteroid + another agent such as cyclophosphamide is often used
What is post strep glomerulonephritis
Post-streptococcal glomerulonephritis typically occurs 7-14 days following a group A beta-haemolytic Streptococcus infection (usually Streptococcus pyogenes).
It is caused by immune complex (IgG, IgM and C3) deposition in the glomeruli. Young children are most commonly affected.
Features of post strep glomerulonephritis
headache malaise visible haematuria proteinuria this may result in oedema hypertension oliguria
Renal biopsy features of post strep glomerulonephritis
endothelial proliferation with neutrophils
electron microscopy: subepithelial ‘humps’ caused by lumpy immune complex deposits
immunofluorescence: granular or ‘starry sky’ appearance
What is Anti-GBM/goodpasture’s syndrome
Is a rare type of small-vessel vasculitis associated with both pulmonary haemorrhage and rapidly progressive glomerulonephritis. It is caused by anti-glomerular basement membrane (anti-GBM) antibodies against type IV collagen.
Features of Anti-GBM disease
pulmonary haemorrhage
rapidly progressive glomerulonephritis
this typically results in a rapid onset acute kidney injury
nephritis → proteinuria + haematuria
IX for Anti-GBM disease
renal biopsy: linear IgG deposits along the basement membrane
raised transfer factor secondary to pulmonary haemorrhages
Mx of Anti-GBM disease
plasma exchange (plasmapheresis)
steroids
cyclophosphamide
Factors that increase likelihood of anti-gbm disease
smoking lower respiratory tract infection pulmonary oedema inhalation of hydrocarbons young males
What does rapidly progressive glomerulonephritis refer to
Rapidly progressive glomerulonephritis is a term used to describe a rapid loss of renal function associated with the formation of epithelial crescents in the majority of glomeruli.
Causes of rapidly progressive glomerulonephritis
Goodpasture’s syndrome
Wegener’s granulomatosis
others: SLE, microscopic polyarteritis
Features of rapidly progressive glomerulonephritis
nephritic syndrome: haematuria with red cell casts, proteinuria, hypertension, oliguria
features specific to underlying cause (e.g. haemoptysis with Goodpasture’s, vasculitic rash or sinusitis with Wegener’s)
Gene associated with Anti-GBM disease
HLA DR2
What is granulomatosis with polyangiitis (Wegener’s granulomatosis)
It is an autoimmune condition associated with a necrotizing granulomatous vasculitis, affecting both the upper and lower respiratory tract as well as the kidneys.
Features of wegener’s granulomatosis
upper respiratory tract: epistaxis, sinusitis, nasal crusting
lower respiratory tract: dyspnoea, haemoptysis
rapidly progressive glomerulonephritis (‘pauci-immune’, 80% of patients)
saddle-shape nose deformity
also: vasculitic rash, eye involvement (e.g. proptosis), cranial nerve lesions
Wegener’s granulomatosis vs Churg-Strauss syndrome
Wegener’s granulomatosis - Renal failure, epistaxis/haemoptysis, cANCA
Churg-Strauss syndrome - Asthma, pANCA, eosinophilia
IX for wegner’s disease
cANCA positive in > 90%, pANCA positive in 25%
chest x-ray: wide variety of presentations, including cavitating lesions
renal biopsy: epithelial crescents in Bowman’s capsule
Causes of transient or spurious non-visible haematuria
urinary tract infection
menstruation
vigorous exercise (this normally settles after around 3 days)
sexual intercourse
Causes of persistent non-visible haematuria
cancer (bladder, renal, prostate) stones benign prostatic hyperplasia prostatitis urethritis e.g. Chlamydia renal causes: IgA nephropathy, thin basement membrane disease
Spurious causes of haematuria where blood is not present on dipstick
foods: beetroot, rhubarb
drugs: rifampicin, doxorubicin
When should urgent referral be made for haematuria
Aged >= 45 years AND:
unexplained visible haematuria without urinary tract infection, or
visible haematuria that persists or recurs after successful treatment of urinary tract infection
Aged >= 60 years AND have unexplained nonvisible haematuria and either dysuria or a raised white cell count on a blood test
What might bloods show in post strep glomerulonephritis
bloods:
low C3
raised ASO titre
