TLS

Question 1

Laboratory feature of TLS?

Answer 1

> / 2 of following:
-hyperuricemia- uric acid > upper limit rang of normal
-hyperkalemia- K >/ 6.0
-hyperphosphatemia PO4 >2.2
-hypocalcemia </1.75

Question 2

timing of lab finding for TLS in order to make a dx?

Answer 2

> /2 of labs findings within same 24 hour period, 3 days before chemo or 7 days after starting chemo

Question 3

Clinical dx of TLS includes?

Answer 3

> /2 lab findings PLUS >/1 of following:
-creatinine >/1.5 upper limit normal for age
-Cardiac arrhythmia or sudden death
-seizure
-neuromusc instability

Question 4

overview of patho of TLS

Answer 4

-malignant cells lyse spontaneously or result of chemo
-release intracellular phos, K, nucleic acids–>metabolized into uric acid)

Question 5

What is the worry re: hyperkalemia in TLS?

Answer 5

-cardiac arrhythmia and sudden death

Question 6

What is worry re: hyperphosphatemia in TLS?

Answer 6

-results in intravascular calcium phosphate formation leading crystallization in various organs, mainly kidney, leading to AKI

Question 7

Why does hypocalcemia occur in TLS?

Answer 7

-excess phosphate binds calcium

Question 8

Consequences of hypocalcemia?

Answer 8

-cardiac dysrhythmia (increased issue when hyperkalemia present)
-deposition of calcium phosphate in cardiac conduction system
-tetany
-seizures

Question 9

hyperuricemia is a result of what process in TLS?

Answer 9

-release of cellular DNA nucleic acids

Question 10

How is uric acid normally excreted from body?

Answer 10

-via kidney and relies on normal GFR and urine PH because uric acid is an insoluble metabolite

Question 11

consequence of elevated uric acid from TLS?

Answer 11

-urine crystallization in renal collecting system and AKI

Question 12

In addition to uric acid, what other metabolite is released as a consequence of nucleic acid breakdown?

Answer 12

Xanthine

Question 13

Excess Xanthine from TLS causes?

Answer 13

Xanthine precipitation in the renal collection system and AKI?

Question 14

What are 3 the mechanisms causing renal collecting system issues and AKI in TLS?

Answer 14

-calcium phosphate crystallization
-uric acid crystallization
-Xanthine precipitation

Question 15

2 mechanism of How does Allopurinol work to lower uric acid levels?

Answer 15

-inhibits xanthine oxidase which converts Xanthine into uric acid
-converts uric acid into soluble allanton, which is easily excreted in urine

Question 16

TLS more likely to occur in tumors that have______and______?

Answer 16

-high proliferation rate
-great tumor MASS

Question 17

Examples of pediatric cancers at highest risk for TLS?

Answer 17

-DLBC lymphoma
-Burkitts leukemia/lymphoma
-ALL
-first Burkitts and ALL highest risk; then DLBC

Question 18

Why TLS in Burkitts leukemia and lymphoma?

Answer 18

-tumor with high proliferation rate that outgrows metabolic needs resulting in spontaneous TLS on presentation

Question 19

What 3 markers determine risk of TLS?

Answer 19

-tumor stage
-WBC
-LDH level as a marker of cellular proliferation and turnover

Question 20

what are the WBC parameters for marker for risk for TLS in LEUKEMIAS?

Answer 20

->/100 in ALL is high risk
-<100 in ALL is intermediate
->/100 in AML is high
->/25-99 in AML is intermediate risk
-<25 in AML is low risk
-Burkitt leukemia always high risk