These include: different forms of glomerulonephritis, urinary stones, diabetic nephropathy, hypertensive nephrosclerosis and lupus nephritis.

All these diseases can lead to end-stage kidney failure, but many patients presents as early stage. It is important to reassure them but warn them the importance of follow up.

There is much confusion between acute nephritis syndrome, nephrotic syndrome and different types of glomerulonephritis.

Acute nephritic syndrome and nephrotic syndrome -- the doctor describe what clinical features he observe on these groups of patients at the 'bedside'. (A clinical diagnosis)

Different forms of glomerulonephritis -- the kidney tissue from the patient is observed under a microscope and the pathologist describes what he observes (a pathological diagnosis)

Common symptoms of renal diseases

• Asymptomatic, only proteinuria or red cells in urine detected on medical check.
• Acute nephritic syndrome (sudden onset of decreased urine output, edema and renal failure)
• Nephrotic syndrome - Clinical picture include ankle oedema, ascites and puffiness of face, there is heavy proteinuria (>3.5 g/day), low serum albumin and increased cholesterol.

The treatment is by high protein diet, rest, careful use of diuretics and treatment of the glomerulonephritis.

• .Kidney failure.

• Minimal change glomerulonephritis
• Membranous glomerulonephritis
• Proliferative glomerulonephritis (general and focal)
• Membrano-proliferative glomerulonephritis

A renal biopsy can give a pathological diagnosis and give a better guide to treatment.

Acute nephritic syndrome

1. 20 years ago, acute nephritis caused by Proliferative glomerulonephritis were common in Hong Kong. Usually caused by a streptococcal throat infection, affected young people. Clinical picture

a. usually preceeded by sore throat in previous 2 weeks

b. sudden onset of oliguria (urine output <400 ml/day), gross haematuria, puffiness of face, hypertension and increase in blood urea.

c. may develop hyperkalaemia, hypertensive heart failure and pulmonary oedema.

d. the great majority of patients usually recovered.

Treatment is fluid restriction during the oliguric phase, together with protein restriction and control of hypertension. Dialysis may be required in the acute stage.

The incidence decreased greatly over these years, possibly due to improved housing and the better medical care.

2. Chronic glomerulonephritis

IgA nephropathy,

Minimal change glomerulonephritis,

Membranous glomerulonephritis,

Membrano-proliferative glomerulonephritis

focal and segmental glomerulosclerosis.

1. this is the commonest type of glomerulonephritis in Hong Kong

2. usually presents as microscopic haematuria or gross haematuria

3. previously said to be 'benign', but we now know that about 15% of patients finally end up in end-stage renal failure.

4. control of hypertension is most important. Other supportive measures also useful.

5. dipyridamole and warfarin used with success in Singapore. Other therapies included fish-oil and vitamin E.

1. usually presents as nephrotic syndrome.

2. 85% of children with nephrotic syndrome has this disease.

3. Treatment is by steroids (prednisolone)

1.Also common in Hong Kong

2. Children in Hong Kong with membranous glomerulonephritis almost always have positive hepatitis B surface antigen.

1. Urine examination

- Albumin test with test strips useful and accurate, but may give false positive results with alkaline urine

- red cell test strips also accurate (tests the haeme part of the haemoglobin), but may give rise to false negative results with vitamin C.

- urine microscopy

detect red cells, white cells, casts

2. Renal function tests

a. blood urea (normal < 6 mmol/l)

affected by the protein intake

b. serum creatinine (normal <120 umol/l)

less affected by the protein intake

lab error great at 'normal range'

when the serum creatinine is twice normal, 50% renal function is gone.

c. creatinine clearance

an accurate estimation of renal function, measure the glomerular filtration rate.

need a timed collection of urine

For the result to be accurate,

1. detailed instruction on how to collect urine

2. collect two consecutive urine samples of possible

3. stop the diuretics if possible, or the diuretic should be taken at the start of urine collection.

4. Ask patients to micturate before defecation.

5. since creatinine is also secreted by renal tubules, can improve accuracy by giving cimetadine 200 mg orally.

Formula:

Ccr = Urine volume (ml) * urine creatinine concentration

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serum creatinine * 1440

Alternatively, the creatinine clearance can be calculated by the formula below

CCrl = 1.23 *BW * (140-Age) /(1000*Cr)

Cr stands for serum creatinine in umol/l.

Can give the histological diagnosis and serve as a guide to treatment

Indications:

• Nephrotic syndrome in adults
• Renal failure due to unknown cause
• Investigations of proteinuria and microscopic haematuria.

Complications of renal biopsy

• Macroscopic haematuria - incidence around 20%
• Profuse bleeding needing transfusion or 1-3%
• Pain
• Perirenal haematoma
• Arterioveonous aneurysm
• Overall mortality 0.1%.

• Checking the coagulation status pre-op. (save serum for x-matching)
• Explained to the patient about the procedure
• Accurate localization with ultrasound or X-ray.
• Biopsy with a spring-loaded biopsy gun - can control the depth, shorten the time.

• Bed rest with dressing applied to the biopsy site
• 1/4 hourly BP and pulse monitor for one hour, then hourly BP monitor for 6 hours
• fluid intake encouraged to prevent clot colic
• Avoid heavy work for 2 weeks.