Application:
• Blood cells, glucose, proteins and drugs are detected in urinary tests
Kidney diseases are conditions which incapacitate the kidney’s ability to filter waste products from the blood
- Individuals with kidney diseases will demonstrate a reduced glomerular filtration rate (GFR)
- If untreated, kidney diseases can lead to kidney failure – which is life threatening
Urinary Analysis
Kidneys prevent the excretion of blood cells and proteins (during ultrafiltration), as well as glucose (selective reabsorption)
- Hence the presence of these materials in urine can be used as an indicator of disease
Glucose: The presence of glucose in urine is a common indicator of diabetes (high blood glucose = incomplete reabsorption)
Proteins: High quantities of protein in urine may indicate disease (e.g. PKU) or hormonal conditions (e.g. hCG = pregnancy)
Blood cells: The presence of blood in urine can indicate a variety of diseases, including certain infections and cancer
Drugs / toxins: Many drugs pass through the body into urine and can be detected (e.g. performance enhancing drugs)
Using Urinary Analysis to Detect Disease
Application:
• Treatment of kidney failure by hemodialysis or kidney transplant
Hemodialysis
Kidney dialysis involves the external filtering of blood in order to remove metabolic wastes in patients with kidney failure
Blood is removed and pumped through a dialyzer, which has two key functions that are common to biological membranes:
- It contains a porous membrane that is semi-permeable (restricts passage of certain materials)
- It introduces fresh dialysis fluid and removes wastes to maintain an appropriate concentration gradient
Kidney dialysis treatments typically last about 4 hours and occur 3 times a week – these treatments can be effective for years
Overview of Kidney Dialysis
Kidney Transplant
Hemodialysis ensures continued blood filtering, but does not address the underlying issue affecting kidney function
The best long-term treatment for kidney failure is a kidney transplant:
- The transplanted kidney is grafted into the abdomen, with arteries, veins and ureter connected to the recipient’s vessels
- Donors must typically be a close genetic match in order to minimise the potential for graft rejection
- Donors can survive with one kidney and so may commonly donate the second to relative suffering kidney failure