1. Wedyan Meshreky Helen Naguib Sharon Naguib
Group C
Wedyan Meshreky
Helen Naguib
Sharon Naguib

2. Part One
Ms DF recently diagnosed with leukaemia and is receiving L-asparaginase, amongst other cytotoxic agents. There have been a number of reports linking the use of L-asparaginase to diabetes mellitis. Explain..

3. Diabetes Mellitus
Serum glucose levels are regulated by absorption, cellular uptake, gluconeogenesis, glycogenolysis.
These processes are regulated by the pancreas, intestine, liver, kidneys and muscle.
Hyperglycaemia can result from disruption of the hormones involved in glucose regulation such as insulin or glucagon or from dysfunction of the organs involved in glucose homeostasis.

4. L-asparaginase
Anti-leukaemic agent used in combination with prednisone and vincristine for remission induction.
Malignant cells must acquire asparagine from surrounding fluid (such as blood) for protein synthesis whereas normal cells can synthesise their own asparagine.

5. Cont.. Asparaginase is an enzyme derived from micro-organisms.
It deaminates asparagine to aspartic acid & ammonia in the plasma and ECF.
Therefore its deprives tumour cells of the AA asparagine for protein synthesis and so the cells die.

6. L-asparaginase & Diabetes
Hyperglycaemia is a well recognised side effect of therapy with L-asparaginase.
Hyperglycaemia & glycosuria without ketonemia occurs in 1-14% of patients treated with L-asparaginase, but is reversible upon discontinuation of the drug.
Insulin therapy is frequently required.
Hyperglycaemia can be worsened by the concurrent administration of high dose glucocorticoids in combination therapy.

7. Is the mechanism known?
Inhibition of insulin or insulin receptor synthesis leading to a combined insulin deficiency/resistance syndrome is the presumed mechanism.
It is unclear as to why L-asparaginase targets insulin, insulin receptors, thyroid binding protein and albumin synthesis but not other proteins such as glucagon.

8. Other mechanisms?
Another mechanism for the development of transient or permanent diabetes mellitus is pancreatitis which occurs in 1-2% of L-asparaginase treated patients.
Incidence of pancreatitis rises when L-asparaginase is combined with other cytotoxic agents.

9. Part two..
L-asparaginase may affect other clinical chemistry parameters such as potassium and lipids.
Please explain..

10. Hypertriglyceridemia
Parson’s et al observed an increase in fasting TG levels concluding it was due to an increase in endogenous synthesis of VLDLs
Apo-B100 is a major protein found in VLDLs increased levels detected suggesting an overproduction of VLDLs.

11. Hypertriglyceridemia…
Mechanism is unclear
Although the incidence of hypertriglyceridemia was 67%, this was found not to be associated with pancreatitis.

12. Hypercholesterolaemia
Changes in cholesterol levels not found to be related to treatment with l-asparaginase.
Most likely to be associated with the use of corticosteroids.

13. HDL HDL levels in px’s with ALL found to be low
Decrease in HDL levels due to either
decreased formation, or
Increased removal from circulationlow HDL levels indicative of active cell proliferation

14. HDL…
During and after treatment with l-asparaginase HDL levels increased
Structural change in HDL particle from a high to a lower density particle
L-asparaginase decreases hepatic protein synthesis
Changes in lipid metabolism is reversible

15. Hyperkalaemia
TLS – release of intracellular contents leading to: hyperuricaemia, hyperphosphataemia, hypocalcaemia and hyperkalaemia.
Can lead to renal failure.

16. Hyperkalaemia… Treatment: Px should receive IV fluids (no K+)
Use of sodium bicarbonate, insulin or glucose can cause transcellular shift of K+ into muscle cells  decrease in K+ levels.
Monitor px for signs of hyperkalaemia

17. Part Three
Describe techniques used in the general monitoring of proteinuria and specifically, the measurement of albumin levels in urine

18. Dipstick Method Semi-quantitative Inexpensive
Takes less than 5 minutes to complete
Most common commercial method

19. Basic Principle Uses a pH-dependent dye-buffer combination.
Paper spot impregnated with a citrate buffer, pH3 and a tetrabromphenol-blue indicator
Relies on the ability of amino acid groups in proteins to bind and alter the colour of the acid-base indicators.
Most sensitive to Albumin because it contains the most amino groups.

20. YELLOW = NO PROTEIN
GREEN =PROTEIN
RESULTS

21. Interpretation of Results
GRADE
PROTEIN (mg/dL)
negative
<10
Trace
10-20 1+ 30 2+
100 3+
300 4+
1000

22. . False Positive results Alkaline urine (pH>7.5)
Dipstick immersed for too long
Presence of penicillin, sulfonamides or tolbutamide
False Negative results
Dilute urine
Low molecular weight proteins
Non Albumin Proteins eg, Bence Jones Proteins .

23. The Sulfosalicylic Acid (SSA) Turbidity Test
Qualitative measure
Requires a few millilitres of freshly voided, centrifuged urine.
An equal amount of 3% SSA is added to the specimen
Acidification causes precipitation of protein in the sample.
Detects albumin, globulins and Bence-Jones proteins
In alkaline urine, it is a more accurate measure than the dipstick.

24. The turbidity of the suspension is proportional to the amount of protein precipitated
Amount of protein is also graded from 1 to 4