What causes pseudothrombocytopenia?

Pseudothrombocytopenia is caused by platelet clumping in vitro, which may be induced either by antibody‐mediated agglutination, the most important causes of which are ethylene‐diamine‐tetra‐acetic acid (EDTA)‐dependent agglutination and platelet satellitism, or aggregation secondary to platelet activation resulting …

How common is pseudothrombocytopenia?

EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a common laboratory phenomenon with estimated prevalence of 0.1%–2% in hospitalized patients [1, 2].

How do you test for pseudothrombocytopenia?

Pseudothrombocytopenia resulting from clumping of platelets collected in EDTA anticoagulant can also be identified by examining the blood film, and can be confirmed by re-collecting a specimen in citrateanticoagulant in which clumping will not occur.

How do you rule out pseudothrombocytopenia?

If the clumping is visible and the number of platelets appears normal, pseudothrombocytopenia may be concluded. A second sample run with a different anticoagulant such as citrate (blue top tube) to confirm the finding of pseudothrombocytopenia may be requested if there are doubts or concerns.

Why do platelets clump in blood test?

Platelet clumping occurs when the blood platelets responsible for coagulation stick to one another to form clusters. The presence of platelet clumping has no clinical consequences other than preventing instruments from properly counting blood platelets.

How do you deal with platelet clumping?

Causes of platelet clumping include platelet activation (due to traumatic venipuncture) and EDTA-dependent antibodies that react with platelet glycoprotein IIb/IIIa. In the latter case, the clumping can be corrected by using blood collection tubes containing an alternative anticoagulant, such as sodium citrate.

How does EDTA cause Pseudothrombocytopenia?

EDTA is commonly used as an anticoagulant for blood cell counts, but it may agglutinate the platelets in some patients. This EDTA-induced aggregation of platelets leads to pseudothrombocytopenia, so-called EDTA-dependent PTCP1).

Why do platelets aggregate?

This platelet aggregation often occurs when the endothelium is damaged, causing the platelets to become activated as they adhere to the exposed fibrous matrix [11]. Activating the platelets allows them to induce inflammatory responses and thrombus formation [11].

What happens when platelets clump?

Platelet clumping can lead to a falsely decreased automated platelet count. Causes of platelet clumping include platelet activation (due to traumatic venipuncture) and EDTA-dependent antibodies that react with platelet glycoprotein IIb/IIIa.

What medications can cause platelet clumping?

Other medicines that cause drug-induced thrombocytopenia include:

• Furosemide.
• Gold, used to treat arthritis.
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Penicillin.
• Quinidine.
• Quinine.
• Ranitidine.
• Sulfonamides.

What does it mean if you have platelet clumping?

Is platelet clumping normal?

A normal platelet count, even with clumping seen on a smear, is still usually estimated to be normal (or may occasionally be increased.) Thrombocytopenia, on the other hand, can be a challenge in the hematology laboratory. With thrombocytopenia, physicians need an accurate count to diagnose, treat or monitor patients.

How does pseudothrombocytopenia mislead the diagnosis?

Pseudothrombocytopenia or spurious thrombocytopenia is an in-vitro sampling problem which may mislead the diagnosis towards the more critical condition of thrombocytopenia. The phenomenon occurs when the anticoagulant used while testing the blood sample causes clumping of platelets which mimics a low platelet count.

How are platelets clumped together in pseudothrombocytopenia?

(B) In platelet satellitism, platelets adhere in a necklacelike pattern around neutrophils yet do not clump together. Platelet clumping and satellitism often occur together. ITP, Immune thrombocytopenia. Andy Nguyen, Amer Wahed, in Accurate Results in the Clinical Laboratory (Second Edition), 2019

What is the medical term for spurious thrombocytopenia?

Pseudothrombocytopenia. Pseudothrombocytopenia or spurious thrombocytopenia is an in-vitro sampling problem which may mislead the diagnosis towards the more critical condition of thrombocytopenia. The phenomenon occurs when the anticoagulant used while testing the blood sample causes clumping of platelets which mimics a low platelet count.

Which is the best anticoagulant for pseudothrombocytopenia?

The original blood sample used ethylenediaminetetraacetic acid (EDTA) as an anticoagulant. A repeat CBC was done in sodium citrate and the platelet count was normal. The patient was diagnosed with pseudothrombocytopenia and no further treatment or blood work was required.