Platelet histogram revealed saw-tooth appearance (Figure 4). Figure 1. Sometimes, changing the anticoagulant in which the blood is collected from EDTA to citrate or heparin may solve the problem but rarely, platelets may clump on being exposed to any anticoagulant. If a platelet count is still required in such cases, a manual platelet count is done using finger-prick blood and directly collecting the blood into . It is a rare condition that occurs when an IgG antibody forms in the presence of EDTA, the anticoagulant that is used for the collection of hematology blood specimens. When the number of platelets measured by the instrument is normal, the presence of platelet clumping is of little clinical significance. The patient doesn't have thrombocytopenia. Hence, we considered that this low platelet count was due to EDTA-PTCP. Also, what causes platelet clumping? For patients with suspected cold agglutinins, pre-warm all collection materials using a hot pack or heel warmer. INF typically causes thrombocytopenia (decline of platelet count ) Ribavirin typically causes thrombocytosis (increase of platelets) My guess is one suppresses platelet production and the other stimulates it. EDTA is the anticoagulant of choice for a complete blood count (CBC) because of its ability to preserve blood cells. Jul 28, 2010 #1 Does anyone have a diagnosis code for pseudothrombocytopenia due to EDTA platelet clumping? EDTA lavender-top tube or microcollection tube. The platelet count was higher in all CTAD-supplemented tubes except one, . 1, 2 However, there have been incidents of falsely low platelet counts with various hematology analyzers because of platelet clumping when EDTA is used as the anticoagulant for blood collection. Collect sample in pre-warmed EDTA tube and place in fresh hot pack or . We would emphasize that in the present study the phenomenon of platelet clumping took place 7 mL whole blood collected in an EDTA (lavender-top) tube. The most common cause of this phenomenon is platelet clumping. Norman, EJ, Barron, RC, Nash, AS, Clampitt, RB. (1) 16 level 1 Tigerwraith Because the EDTA-PTCP condition indicates a tendency for platelet clumping upon in vitro exposure to EDTA. Selection of Auxiliary Reagents to EDTA. (10) Commonly, this clumping is caused by an alteration of the platelet surface glycoproteins when they are incubated with a calcium chelator such as EDTA. Tube must be full. The Epic . This behaviour may affect a sure identification of EDTA-dependent platelet clumping and may compromise the intra- and especially interlaboratory reproducibility of the results. Whole blood should be collected venous in EDTA-2K or EDTA-3K anticoagulant. Furthermore, true pseudothrombocytopenia was not confirmed in these animals. When this occurs the platelet count will be removed from the FBC . So, now they draw Grant's blood using sodium citrate. In many cases the EDTA in a lavender top tube causes the platelet clumping which does not occur in a blue top (citrate tube). Several remedies have been proposed, such . ACD is pretty good as an anticoagulant, although - the same as for 3.2% citrate . The Thromboexact specimen is used when a patient has EDTA mediated platelet clumping and a true platelet count can not be obtained. On theoretical grounds (backed by some empirical facts), and since EDTA is a primary ingredient of the AZ vaccine, this, in turn, suggests that the injection of the AZ vaccine in vivo runs the risk of creating blood clots. 1, 2 However, there have been incidents of falsely low platelet counts with various hematology analyzers because of platelet clumping when EDTA is used as the anticoagulant for blood collection. Clumping of platelets in blood anticoagulated with EDTA is a main cause of reports of falsely low platelet counts by automated analyzers. ACD is pretty good as an anticoagulant, although - the same as for 3.2% citrate . To test the effects of different auxiliary reagents on K 2-EDTA-treated blood samples, 10 mg of amikacin, 13 mg of aminophylline, 0.5 mg of vitamin B 6, and 8,000 IU of gentamicin was added to the K 2-EDTA-treated blood samples.The results showed that the platelet count of the amikacin-treated blood sample remained unchanged for up to 4 hours after . When blood was processed within 5 minutes of phlebotomy, the percent of platelets activated in response to ADP was greater with citrate than with EDTA (activation of platelets in response to 0.8 mol/L ADP for platelets in citrate was 406%; for platelets in EDTA, 265%, Fig 2). EDTA leads to platelet shinkage and was once widely reported as the cause of the so called pseudothrombocytopenia. Collection Instructions. In the presence of EDTA in vitro, cryptic epitopes of the glycoprotein IIb/IIIa complex on the platelet membrane suffer a conformational change and are exposed to acquired or naturally . cases, clumping of the platelets occurs well after blood collection. This test may be ordered when platelets show clumping in EDTA anticoagulant. 8 years ago by Dr.AG 0. the clump of platelets on peripheral blood smear are usually duo to poorly anticoagulated blood or In vitro artifact caused by EDTA or cold and leads to false low platelet count. 2, 3 platelet clumping in the presence of edta is caused by an autoantibody against glycoprotein iib/iiia located on the cell membrane of platelets. WBC histogram showed a left peak (Figure 3). Messages 5 Best answers 0. Ordering Instructions. Addition of CTAD to EDTA when sampling feline blood is a useful option to reduce platelet clumping. Pseudothrombocytopenia is defined as a falsely low platelet count, with an estimated frequency of between 1 in 1,000 and 1 in 10,000 . Invert tubes 8-10 times, do not shake as it may cause foaming or hemolysis. To obtain reliable platelet counts in such cases, laboratorians often collect and analyze a citrated or nonanticoagulated blood specimen. Refrigeration can precipitate fibrin and trap WBC and platelets. Do not refrigerate. Several methods such as vortex mixing, changing anticoagulant to sodium citrate or heparin, and adding amikacin to ethylenediaminetetraacetic acid (EDTA) have been routinely used for managing pseudothrombocytopenia. Interface Order Alias. Figure 1). If the platelet count is less than 20,000/ccm, submit 7-10 mL of whole blood. These antiplatelet antibodies, usually IgG or IgM, and rarely IgA, recognize platelet antigens on the platelet membrane modified by EDTA 1, 3, 4, 7). 5, 6 misdiagnosis of ptcp It is often, but not always, a phenomenon commonly caused by the anticoagulant EDTA. Results from warmed EDTA tube (left) and Na Citrate tube (right). However, aggregation of platelets was not detected in blood samples with sodium citrate, and platelet count was normal. In vitro platelet clumping caused by ethylenediaminetetraacetic acid (EDTA)-dependent agglutinins (naturally occurring antibodies) In vitro platelet clumping caused by an insufficiently anticoagulated specimen: In vitro platelet clumping caused by glycoprotein IIb/IIIa inhibitors (eg, abciximab) (NOTE: these can also cause true thrombocytopenia) These bleeding or clotting disorders or bone marrow diseases require the . Pseudothrombocytopenia is a condition in which individuals with preexisting antibodies have platelet clumping when blood is drawn into an Ethylenediaminetetraacetic acid (EDTA)-containing tube. The patient's sample has been drawn in sodium citrate, EDTA K2, sodium heparin, and warm saline replacements, and a true platelet count cannot be obtained. This article discusses the mechanism briefly: The term pseudothrombocytopenia is used to define a state with a falsely low platelet count reported by automated hematology analyzers due to platelet clumping. Causes of platelet clumping include platelet activation (due to traumatic venipuncture) and EDTA-dependent antibodies that react with platelet glycoprotein IIb/IIIa. 1. Four hours after the bolus, the platelet count from EDTA blood was 51 000/L; at the same time, an automated platelet count from citrated blood was 215 000/L. (3) These modified platelet antigens then react to anti-platelet autoantibodies (Immunoglobulins of both the IgG and IgM types (2)) to form these large agglutinates. Insufficient, delayed, or inadequate mixing may result in platelet clumping, clotting, and/or incorrect test results. EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is an in vitro phenomenon of platelet clumping that leads to spuriously low platelet counts by automatic hematology analyzers. Other Comments: A Citrated Platelet Count will be suggested by Haematology when clumped platelets have been seen on a blood film on one or more occasions, significantly lowering the platelet count. By using the Thromboexact tube a true platelet count . Test Name Alias. The result is a low platelet count that is . The Sodium Citrate is now stable for 24 hours. Platelet satellitism was first reported in the early 1960s. Image 1. References. Platelet Count: Minimum Volume: 2 mL : 20,000-45,000 : 5 . The pathophysiology of pseudothrombocytopenia is not clearly defined, but it is suggested that an immune-mediated mechanism accounts for platelet clumping. H. HNISHA Networker. Figure 3: Left peak in WBC histogram. Both increases and decreases in the platelet count can point to abnormal conditions of excess bleeding or clotting. Pseudothrombocytopenia is an in vitro phenomenon that can be transient or persistent, and platelet clumping is most often due to antibodies directed against epitopes on the platelets. 1. Diagnostic Use and Interpretation. . In the latter case, the clumping can be corrected by using blood collection tubes containing an alternative anticoagulant, such as sodium citrate. (10) Commonly, this clumping is caused by an alteration of the platelet surface glycoproteins when they are incubated with a calcium chelator such as EDTA. The antibodies are IgG (33-50% of the cases), IgM (10-63%), or IgA (4-40%) 12-15. Platelet satellitism as a cause of spurious thrombocytopenia. For the specific diagnosis of EDTA-induced thrombocytopenia, follow these steps: Collect the blood specimen in an EDTA-containing tube. Oxalate and heparin are too occasionally reported to induce platelet clumping. For patients with suspected EDTA platelet clumping, the EDTA and Sodium Citrate specimens should be drawn together. Platelet clumping in EDTA-anticoagulated blood occurs in vitro when the samples of some subjects are analyzed at room temperature, but not at 37C.1,2 This well-recognized phenomenon is caused by natural antiplatelet autoantibodies,3 and is responsible for spurious low platelet counts (pseudothrombocytopenia) when samples are analyzed by automatic instruments.4 On the other hand, erythrocyte . For EDTA platelet clumping ONLY, draw an additional blue-top sodium citrate tube. This often results in a falsely decreased count as clumps of platelets will not be counted with any automated hematology analyzers. In this article, a 10-year-old boy with EDTA- and heparin-dependent PTCP is presented because of rare presentation. EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a common laboratory phenomenon. 60 View 1 excerpt, references background Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia in a cardiac surgical patient. Platelet Clumping or Aggregation. This behaviour may affect a sure identification of EDTA-dependent platelet clumping and may compromise the intra- and especially interlaboratory reproducibility of the results. Published studies have shown that several other alternate methods have been helpful in resolving platelet clumping issues. EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is an in vitro phenomenon consisting of EDTA-induced platelet aggregation at room temperature ().This phenomenon occurs due to anti-platelet antibodies that cause platelet clumping in blood that had been . Causes of platelet clumping include platelet activation (due to traumatic venipuncture) and EDTA-dependent antibodies that react with platelet glycoprotein IIb/IIIa. Introduction. If multiple draw, collect EDTA (lavender-top) tube last. The abciximab infusion was stopped. Heparin causes clumping of platelets and is not recommended. Platelet aggregation (clumping) will affect platelet counts. Platelet clumping is not always corrected . I'm obviously not pleased about having low (and maybe falling) platelets, but three CBC's in seven days all coming back with unreadable numbers is . Ethylenediaminetetraacetic acid (EDTA) is commonly used as an anticoagulant in sampling tubes for blood cell counts. Does this seem accurate? 11643. Platelet clumping is a common laboratory phenomenon that complicates or precludes reporting of platelet count. April 3, 2008 at 5:43 pm #20425. We got a platelet count back at like 300,000 and knew something was up. it has also been observed in disease-free patients. We report that EDTA and heparin can induce platelet clumping, and thus spuriously low platelet counts. In order to continue our current process, I am in the midst of doing a correlation between EDTA platelet counts vs. citrated counts. February 2017I have an oncology patient with a diagnosis of immune thrombocytopenia. In rare situations, an EDTA-dependent pseudothrombocytopenia can occur. Platelet satellitosis and clumping is an in vitro phenomenon most often seen in blood films made from EDTA tubes, perhaps caused by EDTA-mediated IgG autoantibodies directed against the platelet glycoprotein IIb/IIIa complex and the neutrophil Fc receptor. Conclusion: Platelets are adequate and estimated to be about 200,000/L. Turnaround Time: Between 45 minutes and 2 hours. 4, 5 although other anticoagulants such as heparin and sodium citrate rarely induce such a phenomena, it is possible. In the latter case, the clumping can be corrected by using blood collection tubes containing an alternative anticoagulant, such as sodium citrate. Image 1. Quantitative platelet disorders have varied etiology. Platelet . This entity is in vitro phenomena which has no clinical bearing in terms of a predisposition to increased mucous membrane bleeding. Image 2. If platelet clumps are still present in the EDTA tube, the platelet count and white blood cell count from the citrate tube are multiplied by 1.1 and reported. Our retrospective review underscores the importance of recognizing the principle of Pseudothrombocytopenia due to EDTA-induced Platelet Satellitism. Similarly, the numbers of platelets cannot be accurately counted manually (with a hemocytometer) in clumped samples (it is impossible . Clumped platelets seen with EDTA. Individual platelets normally shrivel and disappear when exposed to the lysing reagents used to obtain automated WBC counts. Its prevalence is reported to vary between 0.1-2% among hospitalized patients [1-3] and 15-17% in outpatients evaluated for isolated thrombocytopenia [4, 5].In contrast to serious and potential life-threatening causes of thrombocytopenia [], EDTA-PTCP is solely an in vitro effect without any clinical .