Citrated Platelet Count
Clinical Background:
Pseudo thrombocytopenia (falsely low platelet count) occurs in up to 0.1% of FBC samples and is usually due to EDTA-dependent platelet agglutinating antibodies. These antibodies behave like cold ag...
Pseudo thrombocytopenia (falsely low platelet count) occurs in up to 0.1% of FBC samples and is usually due to EDTA-dependent platelet agglutinating antibodies. These antibodies behave like cold agglutinins and are usually only active at room temperature and not at 37°C. In vivo counts are normal. The analyser platelet counts are falsely low and platelet clumping or satellite formation around WBC is seen on the blood film
An alternative to providing an EDTA (FBC) sample tube warmed to 37°C and keeping it warm throughout the sample journey from patient to analyser, is to use a tube with an anticoagulant that does not induce platelet aggregation. Sodium citrate (the anticoagulant used in coagulation sample tubes) does not cause this phenomenon and is the anticoagulant of choice when investigating this problem.
Test Details
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Discipline:
Core Haematology
Core Haematology
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Specimen Container Adult:
Light blue – sodium citrate
Light blue – sodium citrate
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Specimen Container Paediatric:
Light blue – sodium citrate
Light blue – sodium citrate
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Minimum Volume Adult:
2.7ml
2.7ml
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Minimum Volume Paediatric:
1.3ml
1.3ml
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Special Requirement:
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
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Sample Stability:
24 hours
24 hours
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Transport Requirements:
Samples should be transported to lab without delay
Samples should be transported to lab without delay
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Freq Analysis:
As required
As required
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Add On Test:
Not available
Not available
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Quality Assurance:
UK NEQAS Full Blood Count
UK NEQAS Full Blood Count
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Reference Ranges:
N/A
N/A
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Routine Contact Name:
RVI or Freeman Section Leaders
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Routine Telephone:
RVI: 0191 2820332, Freeman: 0191 2231195
RVI: 0191 2820332, Freeman: 0191 2231195
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Routine Email:
Emily.lloyd21@nhs.net
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Specialist Test:
No
No
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Specialist Contact Name:
Haematology and Haemostasis Healthcare Scientist
Haematology and Haemostasis Healthcare Scientist
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Specialist Telephone:
0191 2139758
0191 2139758
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Specialist Email:
alison.brown93@nhs.net
alison.brown93@nhs.net