Paediatric Nephrology Flashcards
(35 cards)
what physiological process causes nephrotic syndrome?
Nephrotic syndrome occurs when the basement membrane in the glomerulus becomes highly permeable to protein, allowing it to leak from the blood into the urine.
what is the most common age group affected by nephrotic syndrome?
2-5 years old
what is the clinical presentation of nephrotic syndrome?
signs, investigation results
signs:
- frothy urine
- generalised oedema
- pallor
Nephrotic syndrome features a classic triad of:
- low serum albumin
- high urine protein content (> 3+ protein on urine dipstick)
- oedema
Other features:
- deranged lipid profile, with high levels of cholesterol, triglycerides and LDL
- high blood pressure
- hyper-coagulability
Causes of nephrotic syndrome
- Minimal change disease most common in children
- can also be secondary to intrinsic kidney disease e.g. focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis
- can also be secondary to underlying systemic illness e.g. Henoch scholein purpura (HSP), diabetes, infection, such as HIV, hepatitis and malaria
Describe minimal change disease.
Minimal change disease is the most common cause of nephrotic syndrome in children. It can occur in otherwise healthy children, without any clear risk factors or reason for developing the condition. It is not clear why it occurs in most cases.
A renal biopsy and standard microscopy in minimal change disease is usually not able to detect any abnormality. Urinalysis (analysis of the urine) will show small molecular weight proteins and hyaline casts.
minimal change disease management
- corticosteroids (i.e. prednisolone0
- most children make full recovery
Nephrotic syndrome management
- high dose steroids (i.e. prednisolone)
- low salt diet
- diuretics may be used to treat oedema
- albumin infusions in severe hypoalbuminaemia
- antibiotic prophylaxis in severe cases
- in steroid resistant children > ACEi’s, immunosuppresants such as cyclosporine, tacrolimus, or rituximab
what does nephritis refer to? what does it cause?
inflammation within the nephrons
It causes:
- reduction in kidney function
- haematuria
- proteinuria, although less than nephrotic syndrome
what are the two most common causes of nephritis in children?
- post-streptococcal glomerulonephritis
- IgA nephropathy (Berger’s disease)
what causes post-streptococcal glomerulonephritis?
- Post-streptococcal glomerulonephritis occurs 1 – 3 weeks after a β-haemolytic streptococcus infection, such as tonsillitis caused by Streptococcus pyogenes. - Immune complexes made up of streptococcal antigens, antibodies and complement proteins get stuck in the glomeruli of the kidney and cause inflammation.
- This inflammation leads to an acute deterioration in renal function, causing an acute kidney injury.
what causes IgA nephropathy (Berger’s disease)?
- This condition is related to Henoch-Schonlein Purpura, which is an IgA vasculitis.
- IgA deposits in the nephrons of the kidney causes inflammation (nephritis). When a renal biopsy is taken the histology will show “IgA deposits and glomerular mesangial proliferation”.
- It usually presents in teenagers or young adults.
- occurs 1-2 days after URTI
treatment for IgA nephropathy
- supportive treatment of the renal failure
- immunosuppressant medications such as steroid and cyclophosphamide to slow the progression of the disease.
signs and symptoms of babies with UTI
Babies will present with very non-specific symptoms:
- fever
- lethargy
- irritability
- vomiting
- poor feeding
- urinary frequency
Always consider (and exclude) a urinary tract infection in a child with a temperature, unless there is a clear alternative source of infection.
signs of symptoms of UTI in older infants and children (more specific)
- fever
- abdo pain, particularly suprapubic
- vomiting
- dysuria
- urinary frequency
- incontinence
Management of UTI in children < 3 months and > 3 months old.
- all children under 3 months with a fever should start immediate IV antibiotics (e.g. ceftriaxone) and have a full septic screen, including blood cultures, blood and lactate. Consider lumbar puncture.
- Oral antibiotics can be considered in children over 3 months if they are otherwise well.
- Children with features of sepsis or pyelonephritis will require inpatient treatment with IV antibiotics.
Typical Abx choices for UTI in children:
- trimethoprim
- nitrofurantoin
- cefalexin
- amoxicillin
when would you consdier a renal biopsy in a patient with nephrotic syndrome?
atypical features present:
- suggestions of autoimmune disease
- abnormal renal function
- steroid resistance
what cells are affected in minimal change disease?
podocytes (epithelial cells)
what are some acquired and congenital causes for steroid-resistant nephrotic syndrome?
Acquired:
- focal segmental glomerulosclerosis (FSGS): podocyte loss, progressive inflammation and slcerosis
Congenital:
- infant presentations
- NPHS1 - nephrin
- NPHS2 - podocin
- podocyte loss
what investigations can be used to diagnose acute post-infectious glomerulonephritis?
- bacterial culture
- positive antistreptolysin O titer (ASOT)
- low C3 normalises
Acute post-infectious glomerulonephritis treatment
- antibiotic
- support renal function: electrolyte/acid base
- overload/hypertension: diuretics
what cells of the glomerulus are affected in IgA nephropathy?
mesangial cells
what is the usual age of onset of Henoch Schonlein Purpura (HSP), an IgA related vasculitis?
5-15 years old
what criteria must be met for a diagnosis of Henoch Schonlein Purpura?
- mandatory palpable purpura
one of 4:
- abdominal pain
- renal involvement
- arthritis or arthralgia
- biopsy > IgA deposition
IgA vasculitis treatment
- symptomatic: gut, joints
- glucocorticoid therapy: may help with GI involvement
- immunosuppression: trial in moderate-severe renal disease
- long-term: hypertension and proteinuria screening
