Glomerular disease, Tubulointerstitial nephritis and UTI Flashcards
Describe the normal glomerular membrane. (3)
Glomerular capillaries lined by fenestrated endothelium that rests on the glomerular basement membrane.
Podocytes are are the visceral epithelial cells of the Bowman’s capsule that make contact with the GBM with finger like projections called foot processes.
This accounts for the tremendous permeability.
What is GFR? (2)
Glomerular filtration rate
The permeability of the glomerulus; how much filtrate is formed every minute.
What site difference between glomerulonephritis and glomerulopathies? (1)
Glomerulonephritis has inflammation of the glomeruli, glomerulopathies does not.
Which regards to glomerular disease, what is crescent formation referring to? (1)
Epithelial cell proliferation with mononuclear cell infiltration in Bowman’s space.
Which regards to glomerular disease, what is membrane alterations referring to? (1)
Capillary wall thickening due to deposition of immune deposits or alteration in the basement membrane.
What are the 4 main classifications of glomerulopathies? (4)
Nephrotic syndrome
Acute glomerulonephritis (acute nephritic syndrome)
Rapidly progressive glomerulonephritis
Asymptomatic haematuria, proteinuria or both.
What abnormalities are seen in nephrotic syndrome? (4)
What causes these abnormalities? (1)
Hypoalbuminaemia
Hypercholesterolaemia
Oedema
Proteinuria (>3.5g in 24 hours)
There is massively increase filtration of macromolecules across the glomerular capillary wall due to structural and functional abnormalities of the podocytes.
What are the most common causes of nephrotic syndrome with “bland” urine sediments? (3)
Adults: membranous nephropathy and focal segmental glomerulonephritis.
Children: minimal change nephropathy
What are the causes of membranous nephropathy? (3)
What changes occur histologically? (2)
Idiopathic
Drugs: penicillamine, gold, NSAIDs
Autoimmune: SLE, thyroiditis
Neoplasia: lung, colon, stomach, breast, lymphoma
Infections: Hep B and C, Plasmodium malariae
Sarcoidosis
Sickle cell disease
There is IgG and complement C3 deposition in the outer aspect of the GBM.
Which groups of people are more prone to focal segmental nephropathy? (1)
Black people
HIV (similar histological type)
Name 2 diseases that may cause a non-immune mediated nephrotic syndrome. (2)
Diabetes
Amyloidosis
Polycystic kidneys and reflux nephropathy may cause proteinuria but rarely enough for nephrotic syndrome.
What are the clinical features of nephrotic syndrome? (2)
Oedema of the ankles, genitals, abdominal wall are usual findings.
Oedema may also affect the face and arms in severe cases.
What are the 2 main differentials for nephrotic syndrome? (2)
CCF (but raised JVP)
chronic liver failure (but other signs of liver disease)
What is the management of nephrotic syndrome? (4)
General
Oedema:
dietary salt restriction
diuretic- bendroflumethiazide first then furosemide or amiloride if unresponsive (sometimes IV may be required)
Proteinuria:
ACEi or ARBs
eat normal diet (high protein increases proteinuria)
Thrombotic tendency: long term anti-coguation
Infections: treat aggressively. Annual flu and pneumococcal vaccines.
Specific:
Treat underlying cause e.g. SLE or stop drug e.g. NSAIDs
Only in certain cases: cyclophosphamide and prednisolone.
Who should get specific treatment for glomerulonephropathy/nephritis? (2)
Why? (1)
Moderate - severe progressive idiopathic membranous nephropathy should receive specific therapy as there is a high rate of spontaneous improvement.
Treatment is with cyclophosphamide with prednisolone.
Minimal change disease responds to high dose prednisolone for 4-6 weeks or cyclophosphamide or ciclosporin are used in resistant cases.
Name 2 complications of glomerulonephritis. (2)
Venous thrombosis: loss of clotting factors in urine predisposes to thrombosis in peripheral and renal veins.
Sepsis: loss of immunoglobulins in the urine
AKI: more a consequence of hypovolaemia or renal vein thrombosis than underlying renal glomerular disease
Name 3 causes of acute nephritic syndrome. (3)
Post-streptococcal GN Non-streptococcal post infectious GN Infective endocarditis Shunt nephritis Visceral abscess SLE HSP Cryoglobulinaemia
What is the most typical presentation of acute nephritic syndrome? (2)
Pose-streptococcal glomerulonephritis occurring gin a child 1-3 weeks after pharyngitis or cellulitis caused by Group A beta-haemolytic streptococcus.
The bacterial antigen gets trapped in the glomerulus leading to an acute diffuse proliferative GN.
What are the clinical features of acute nephritic syndrome? (6)
Haematuria Hypertension Oedema Oliguria Uraemia Proteinuria (<2g in 24 hours)
Name 3 management steps in acute nephritic syndrome. (3)
Hypertension: Salt restriction, loop diuretics, vasodilators
Fluid balance: monitored with daily weights and recording of fluid input and output.
Oliguric with fluid overload: fluid restriction
Name 2 complications of acute nephritic syndrome. (2)
Hypertensive encephalopathy
Pulmonary oedema
Severe uraemia
Name 3 risk factors for developing UTI’s. (3)
Female
Sexual intercourse
Urethral catheterisation
Underlying urinary tract abnormality : urinary obstruction or stasis, previous damage to bladder epithelium, bladder stones, poor bladder emptying.
What is pyelonephritis? (2)
What are the clinical features of acute pyelonephritis? (2)
Infection ascending through the ureters to the renal parenchyma. There is neutrophil infiltration of the renal parenchyma. Small cortical abscesses and streaks of pus may be present in the medulla.
Fever, nausea, vomiting and loin pain
What is the difference between a complicated and uncomplicated urinary tract infection? (4)
Uncomplicated: UTI in healthy non pregnant individual with functionally normal urinary tract and will rarely result in kidney damage.
Complicated: UTI in patient with abnormal urinary tracts or systemic disease involving the kidney e.g. diabetes or sickle cell. They are more likely to fail treatment and develop complications.
NB UTI in men are usually considered complicated
