Lap (Leucocyte Alkaline Phosphatase) Score(Ref)
The Leucocyte Alkaline Phosphatase (LAP) Score Test is a laboratory test that measures the activity of the alkaline phosphatase enzyme in white blood cells (leukocytes), particularly neutrophils.
This test is primarily used to help differentiate between chronic myeloid leukemia (CML) and other conditions that cause elevated white blood cell counts, such as leukemoid reactions. Typically, LAP scores are low in CML and high in reactive conditions.
The purpose of this test is to:
- Measure alkaline phosphatase activity in white blood cells
- Differentiate between leukemia and reactive conditions
- Support diagnosis of hematological disorders
- Assist in evaluation of abnormal white blood cell counts
LAP (LEUCOCYTE ALKALINE PHOSPHATASE) SCORE(REF) Test
The LAP (Leucocyte Alkaline Phosphatase) Score test measures the activity of the alkaline phosphatase enzyme within certain white blood cells, mainly neutrophils. The result is reported as a score based on the intensity of enzyme staining in these cells.
The test can help differentiate certain myeloproliferative and hematological disorders, particularly when there is an unexplained increase in white blood cell count. Historically, the LAP score has been useful in distinguishing chronic myeloid leukemia (CML) from reactive conditions such as a leukemoid reaction.
Because modern molecular and genetic tests are available, LAP scoring is often used as a supplementary test rather than a standalone diagnostic test. Results should be interpreted together with the complete blood count (CBC), peripheral blood smear, clinical findings, and other investigations.
LAP (LEUCOCYTE ALKALINE PHOSPHATASE) SCORE(REF) Test is Recommended for Individuals:
- With unexplained or persistent elevated white blood cell counts
- Being evaluated for certain myeloproliferative or hematological disorders
- With abnormal findings on a complete blood count or peripheral smear
- Being evaluated for possible chronic myeloid leukemia (CML)
- Where differentiation between a leukemoid reaction and a myeloproliferative disorder is clinically required
- Requiring additional assessment of abnormal neutrophil activity
FAQs
1. What is the LAP (Leucocyte Alkaline Phosphatase) Score test?
The LAP Score test measures the activity of the alkaline phosphatase enzyme in neutrophils. It provides information that may help doctors evaluate certain white blood cell disorders.
2. What is the LAP score used for?
It can help differentiate chronic myeloid leukemia (CML) from some reactive causes of increased white blood cells, such as a leukemoid reaction. However, it is generally interpreted along with other blood and molecular tests.
3. What does a high or low LAP score mean?
A high LAP score may occur in reactive conditions and some other disorders, while a low LAP score can be seen in CML. However, LAP results are not diagnostic on their own, and the underlying cause must be determined using the patient's blood counts, symptoms, and other relevant investigations.