The patients do not have any signs and symptoms of bleeding, since this is a laboratory artifact and not an in vivo decrease in platelet count. . In the latter case, the clumping can be corrected by using blood collection tubes containing an alternative anticoagulant, such as sodium citrate. Conclusion: Platelets are adequate and estimated to be about 200,000/L. Repeat the platelet count. Platelet clumping can happen if there was a traumatic venipuncture, that is collection of the blood from the vein caused platelet activation that led to clumping of the platelets. This test may be ordered when platelets show clumping in EDTA anticoagulant. Whole blood should be collected venous in EDTA-2K or EDTA-3K anticoagulant. Both increases and decreases in the platelet count can point to abnormal conditions of excess bleeding or clotting. Pseudothrombocytopenia is a condition in which individuals with preexisting antibodies have platelet clumping when blood is drawn into an Ethylenediaminetetraacetic acid (EDTA)-containing tube. Results from warmed EDTA tube (left) and Na Citrate tube (right). Diagnosis and discussion. So, why can't we just order one of these other tubes and start reporting results? Also, what causes platelet clumping? 1. All other CBC parameters are reported from the EDTA tube. Download Image Share Image Platelet histogram revealed saw-tooth appearance (Figure 4). This behaviour may affect a sure identification of EDTA-dependent platelet clumping and may compromise the intra- and especially interlaboratory reproducibility of the results. Jack, Grant has had EDTA platelet clumping before. As in other literature cases, a clear correlation between the . Bali05. Conclusions: Prewarming EDTA blood samples to 37C prior to hematologic analysis increased platelet counts overall in canine, feline, and equine blood, but did not abrogate platelet clumping and pseudothrombocytopenia fully in some cases. Selection of Auxiliary Reagents to EDTA. WBC histogram showed a left peak (Figure 3). It was when he had ET instead of CMML and his platelets were normally over a million. Platelets clump in all tubes, and multiple platelet clumps are observed under the microscope. Furthermore, true pseudothrombocytopenia was not confirmed in these animals. ACD is pretty good as an anticoagulant, although - the same as for 3.2% citrate . The three different scenarios in which pseudothrombocytopenia can be seen are EDTA-induced platelet clumping, platelet satellitism, and giant platelet syndromes.3-5 in all three; the platelet count is falsely low because giant platelets and aggregates are not counted by the electronic particle counter. Platelet Count (Citrate/Blue Tube) is for platelet clumping due to EDTA. EDTA-dependent PTCP is the phenomenon of a spurious low platelet count due to the appearance of antiplatelet autoantibodies that cause platelet clumping in blood anticoagulated with EDTA 5, 6). 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) Platelet satellitism and platelet clumping can cause pseudo-thrombocytopenia. We got a platelet count back at like 300,000 and knew something was up. In the latter case, the clumping can be corrected by using blood collection tubes containing an alternative anticoagulant, such as sodium citrate. 11643. platelets were seen in peripheral smear (Figure 2). Image 1. Platelet Count: Minimum Volume: 2 mL : 20,000-45,000 : 5 . cases, clumping of the platelets occurs well after blood collection. Messages 77 Best answers 0. Similarly, the numbers of platelets cannot be accurately counted manually (with a hemocytometer) in clumped samples (it is impossible . However, aggregation of platelets was not detected in blood samples with sodium citrate, and platelet count was normal. References. Transport Container. The decline in the platelet . It is often, but not always, a phenomenon commonly caused by the anticoagulant EDTA. (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. 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. Insufficient, delayed, or inadequate mixing may result in platelet clumping, clotting, and/or incorrect test results. February 2017I have an oncology patient with a diagnosis of immune thrombocytopenia. 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). We would emphasize that in the present study the phenomenon of platelet clumping took place EDTA leads to platelet shinkage and was once widely reported as the cause of the so called pseudothrombocytopenia. 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. Collection Instructions. Does this seem accurate? SPECIMEN PROCESSING: . These antibodies can react with certain receptors present on the platelet causing clamping. Platelet changes. EDTA platelet clumping. 2. The abciximab infusion was stopped. The pathophysiology of pseudothrombocytopenia is not clearly defined, but it is suggested that an immune-mediated mechanism accounts for platelet clumping. In this article, a 10-year-old boy with EDTA- and heparin-dependent PTCP is presented because of rare presentation. Tube must be full. 4, 5 although other anticoagulants such as heparin and sodium citrate rarely induce such a phenomena, it is possible. Maintain specimen at room temperature. In order to continue our current process, I am in the midst of doing a correlation between EDTA platelet counts vs. citrated counts. Individual platelets normally shrivel and disappear when exposed to the lysing reagents used to obtain automated WBC counts. Image 1. Clumping of platelets in blood anticoagulated with EDTA is a main cause of reports of falsely low platelet counts by automated analyzers. Interface Order Alias. The platelet count was higher in all CTAD-supplemented tubes except one, . If the platelet count is less than 20,000/ccm, submit 7-10 mL of whole blood. Thread starter amyhawk; Start date Jul 28, 2010; A. amyhawk New. 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. it has also been observed in disease-free patients. These antiplatelet antibodies, usually IgG or IgM, and rarely IgA, recognize platelet antigens on the platelet membrane modified by EDTA 1, 3, 4, 7). EDTA lavender-top tube or microcollection tube. ACD is pretty good as an anticoagulant, although - the same as for 3.2% citrate . 5, 6 misdiagnosis of ptcp For the resolution of spurious thrombocytopenia due to platelet clumping in EDTA. Hence, we considered that this low platelet count was due to EDTA-PTCP. EDTA whole blood smear had many platelet clumps noted (EDTA induced thrombocytopenia). The patient doesn't have thrombocytopenia. Platelet aggregation (clumping) will affect platelet counts. It is often, but not always, a phenomenon commonly caused by the anticoagulant EDTA. This behaviour may affect a sure identification of EDTA-dependent platelet clumping and may compromise the intra- and especially interlaboratory reproducibility of the results. By using the Thromboexact tube a true platelet count . 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 . ( Bobba RK, Doll DC. . 7 mL whole blood collected in an EDTA (lavender-top) tube. For EDTA platelet clumping ONLY, draw an additional blue-top sodium citrate tube. Causes of platelet clumping include platelet activation (due to traumatic venipuncture) and EDTA-dependent antibodies that react with platelet glycoprotein IIb/IIIa. April 3, 2008 at 5:43 pm #20425. 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. The Sodium Citrate is now stable for 24 hours. Do not refrigerate. Quantitative platelet disorders have varied etiology. Another reason can be presence of EDTA dependent antibodies in the blood. EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a common laboratory phenomenon. Platelet Clumping or Aggregation. 1. The Thromboexact specimen is used when a patient has EDTA mediated platelet clumping and a true platelet count can not be obtained. For the specific diagnosis of EDTA-induced thrombocytopenia, follow these steps: Collect the blood specimen in an EDTA-containing tube. The method of screening for platelet clumping with the help of XE5000 images is convenient. This is due to EDTA-induced exposure of platelet antigens, which causes clumping in patients with antibodies (which can be naturally occurring) to these antigens. For patients with suspected EDTA platelet clumping, the EDTA and Sodium Citrate specimens should be drawn together. A peripheral blood film from EDTA blood (Figure 2) showed marked platelet clumping, which was not present on a film from citrated blood. Our retrospective review underscores the importance of recognizing the principle of Pseudothrombocytopenia due to EDTA-induced Platelet Satellitism. 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. The MPV from the citrate tube is also reported, but no correction factor is applied because the MPV is not affected by dilution. EDTA leads to platelet shinkage and was once widely reported as the cause of the so called pseudothrombocytopenia. Figure 3: Left peak in WBC histogram. Image 2. Jul 29, 2010 #2 Ordering Instructions. Platelet clumping is a common laboratory phenomenon that complicates or precludes reporting of platelet count. The Epic . 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. Oxalate and heparin are too occasionally reported to induce platelet clumping. Because the EDTA-PTCP condition indicates a tendency for platelet clumping upon in vitro exposure to EDTA. 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 . 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. H. HNISHA Networker. Tags: EDTA, Platelet Aggregation, Platelet Clumping. So, now they draw Grant's blood using sodium citrate. All I can find on the web is stories about Pseudothrombocytopenia or platelet clumping - basically a sample processing issue (i.e., I don't see medical literature on clumping with thrombocytopenia). Novel method to dissociate platelet clumps in EDTA-dependent pseudothrombocytopenia based on the pathophysiological mechanism Abstract Background: EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is an in vitro phenomenon of platelet clumping that leads to spuriously low platelet counts by automatic hematology analyzers. Figure 1). Platelet satellitism was first reported in the early 1960s. (yellow-top) tubes will no longer be accepted because of the high incidence of platelet clumping associated with this anticoagulant. This becomes very apparent when those meds are taken separately.