Spurious thrombocytopenia in the mother and baby – A red herring clinical entity

Spurious thrombocytopenia or pseudothrombocytopenia (PTCP) is an important clinical entity, in which the presence of autoantibodies or anticoagulants used during blood sampling causes in vitro clumping of platelet and thereby resulting in a falsely low automated platelet count. The most common cause of platelet clumping is ethylenediaminetetraacetic acid used as an anticoagulant in the blood samples. The other reasons for PTCP include the presence of autoantibodies such as cold agglutinin, giant platelet, and platelet satellitism. There are very few cases of spurious thrombocytopenia in the newborn period published in the literature. We are reporting a case of PTCP due to platelet satellitism in a baby born to a mother with a similar condition

Thrombogram: case report of pseudothrombocytopenia / Plaquetograma: relato de caso de pseudotrombocitopenia

ABSTRACT The thrombogram is one of the components of the blood count that includes platelet quantification and evaluation. The presence of laboratory artifacts, such as incorrect platelet counts by autoanalyzers, can lead to pseudothrombocytopenia, which is responsible for 15% to 30% of the cases of isolated thrombocytopenia observed in laboratory routine. Pseudothrombocytopenia induced by the anticoagulant ethylenediaminetetraacetic acid (EDTA) is one of the most frequent cases in which the presence of anticoagulant in blood samples can cause platelet aggregation or platelet satellitism. Careful observation of the data emitted by autoanalyzers, such as platelet and flag histograms, is crucial. Other procedures, such as checking for clotting in the sample, repeating the sample and viewing a peripheral blood smear, requesting a new sample taken with another type of anticoagulant, such as citrate, are imperative for the confirmation of cases of pseudothrombocytopenia.

RESUMEN El plaquetograma es uno de los componentes del hemograma que incluye la cuantificación y la evaluación de las plaquetas. La presencia de artefactos de laboratorio, como los recuentos incorrectos del número de plaquetas por los analizadores hematológicos puede originar casos de pseudotrombocitopenia (del 15% al 30% de los casos de trombocitopenias aisladas observados en la rutina del laboratorio). La pseudotrombocitopenia inducida por el anticoagulante ácido etilendiaminotetraacético (EDTA) es uno de los casos más comunes en los que la presencia de anticoagulante con muestras de sangre puede producir agregación plaquetaria o satelitismo plaquetario. La observación criteriosa de los datos emitidos por los autoanalizadores (por ejemplo, histogramas plaquetarios y alarmas) es crucial. Otros procedimientos, como la verificación de la existencia de un coágulo en la muestra, la repetición del frotis de sangre periférica, además de la solicitud de nueva muestra con otro tipo de anticoagulante, como el citrato, son importantes para confirmar casos de pseudotrombocitopenia.

RESUMO O plaquetograma é um dos componentes do hemograma que inclui a quantificação e a avaliação plaquetária. A presença de artefatos laboratoriais, como as contagens incorretas do número de plaquetas pelos analizadores hematológicos, pode originar casos de pseudotrombocitopenia (15% a 30% de casos de trombocitopenias isoladas observados na rotina laboratorial). A pseudotrombocitopenia induzida pelo anticoagulante ácido etilenodiaminotetracético (EDTA) é um dos casos mais comuns em que a presença do anticoagulante em amostras de sangue pode provocar agregação plaquetária ou satelitismo plaquetário. A observação de forma criteriosa dos dados emitidos pelos analizadores (por exemplo, histograma de plaquetas e flags) é crucial. Outros procedimentos, como a verificação da existência de coágulo na amostra, a repetição da amostra e a visualização de um esfregaço de sangue periférico, além do pedido de nova amostra colhida com outro tipo de anticoagulante, como o citrato, são importantes para confirmar casos de pseudotrombocitopenia.

Trombocitopenia inducida por fármacos / Drug-induced thrombocytopenia

La trombocitopenia puede tener varias causas, como la utilización de determinados fármacos. Los mecanismos causantes de la trombocitopenia inducida por fármacos incluyen disminución en la producción (supresión medular) o incremento en la destrucción (por mecanismos inmunes). Adicionalmente, la seudotrombocitopenia es un efecto in vitro, que se distingue de una real trombocitopenia inducida por medicamentos. Los estudios epidemiológicos son pocos, difieren en la metodología utilizada y describen una incidencia de 10 casos por millón de habitantes por año. El mecanismo fundamental de la trombocitopenia inducida por fármacos no está completamente esclarecido, pero al menos se plantean seis posibles mecanismos: anticuerpos inducidos por haptenos, anticuerpos dependientes del fármaco, inhibidores del complejo GP IIb-IIIa, autoanticuerpos inducidos por la droga, complejos inmunes y trombocitopenia inducida por heparina. La diana para los anticuerpos dependientes del fármaco son las glucoproteínas de la membrana plaquetaria, como las glucoproteínas Ib/IX y GPIIb/IIIa. El diagnóstico de trombocitopenia inducida por fármacos puede consistir en la identificación de síntomas clínicos (hematomas, petequias, sangramientos), la cuidadosa evaluación de la relación causal con el fármaco sospechoso, las investigaciones generales de laboratorio (conteos en sangre total, extendidos de sangre periférica, para descartar seudotrombocitopenia) y las pruebas serológicas para plaquetas. La trombocitopenia inducida por fármacos es una reacción adversa a medicamentos relativamente raros cuyas sus consecuencias pueden ser graves.

Thrombocytopenia can have several causes, including the use of certain drugs. The mechanism behind drug-induced thrombocytopenia is either a decrease in platelet production (bone marrow suppression) or an increased destruction (immune-mediated thrombocytopenia). In addition, pseudothrombocytopenia, an in vitro effect, has to be distinguished from true drug-induced thrombocytopenia. A small number of epidemiological studies, differing largely in the methodology used, describe incidences in the magnitude of 10 cases per 1 000 000 inhabitants per year. The underlying mechanism of drug-induced immune thrombocytopenia is not completely clarified, but at least six different types of antibodies appear to play a role; hapten-induced antibody, drug-dependent antibody ("compound" or "conformational-dependent" antibody), GPIIb-IIIa inhibitors, drug-induced autoantibody, immune complex and heparin-induced thrombocytopenia. Targets for drug-dependent antibodies are glycoproteins on the cell membrane of the platelets, such as glycoprotein (GP) Ib/IX and GPIIb/IIIa. Diagnosis of drug-induced immune thrombocytopenia may consist of identifying clinical symptoms (bruising, petechiae, bleeding), a careful evaluation of the causal relationship of the suspected causative drug, general laboratory investigation, such as total blood count and peripheral blood smear (to rule out pseudothrombocytopenia), and platelet serology tests. Although drug-induced thrombocytopenia is a relatively rare adverse drug reaction, its consequences may be severe.

According to the platelet of Chinese people biological reference interval change the microscope review rules / 国际检验医学杂志

Objective To discuss change the platelet counts by microscope rule by the platelet of Chinese people biological refer‐ence range in this laboratory blood analysis requirement .Methods Retrospectively analyzed according to the platelet of Chinese people biological reference range change the lab Sysmex XE‐5000 automatic blood cell analyzer platelet review rules .Change the platelet counts by microscope rules ,the differences between the microscopy rate and the microscopic examination of the platelet ag‐gregation rate .Results Before change the platelet counts by microscope rules the microscopy rate was 1 .94% .After change the platelet counts by microscope rules the microscopy rate was 3 .99% ,after change the platelet counts by microscope rules pushing blood piece rate increased significantly ,the difference was statistically significant(P<0 .05) .Conclusion According to the platelet of Chinese people biological reference range change the lab platelet review rules .We can increase the rate of microscopy ,and effec‐tively avoid the pseudothrombocytopenia and accurately guide clinical treatment .

Analysis of characters and biochemical profiles of 27 cases with EDTA-Dependent Pseudothrombocytopenia / 国际检验医学杂志

Objective To analyze the characters about anticoagulation EDTA on the platelet aggregation ,and discuss the risk factors about EDTA‐PTCP by analyzing the biochemical parameters .Methods 30 700 EDTA‐K3 blood samples were collected from January 2014 to August 2015 .WBC was performed using Sysmex XN‐3000 and 27cases were identified of EDTA‐PTCP .The blood samples of 27 subjects were recollected and WBC was repeated using EDTA‐K3 and sodium citrate blood ,respectively .Manual platelet counting and smear microscope examination on periphery blood were also performed .Biochemical parameters of 27 subjects with EDTA‐PTCP were compared with 50 randomly selected non EDTA‐PTCP controls .Results Platelet counts in citrated blood were significantly higher than EDTA blood ,the difference was statistically significant(P0 .05) .ALT ,Glu and TG in patients with EDTA‐PTCP were significantly higher than normal people ,but HDL was significantly lower than control group ,the difference was statistically significant(P<0 .05) .Conclusion EDTA‐dependent pseudo‐thrombocytopenia varies from people with different disease or using different medicine .It may be relative to hyperglycemia and hy‐perlipidemia .Another approach for rectifying ,changing anticoagulant or manual platelet counting is a better way lead to correctly di‐agnose when EDTA‐PTCP occurred .

Clinical application of platelet aggregation for white blood cell count / 国际检验医学杂志

Objective To analyze the cause of platelet aggregation in blood specimens ,so as to provide basis for reducing platelet aggregation ,and avoiding false positive of platelet count ,false report ,misdiagnosis and mistreatment .Methods The blood speci-mens which platelet was below 80 × 109 /L ,below 125 × 109 /L with histogram hinted platelet aggregation ,were smeared ,stained with Wright-Giemsa ,and observed by microscope for platelet morphological changes .The data between each groups were calculated and analyzed by statistical software SPSS version 18 .0 .Results A total of 184 cases of ethylenediaminetetraacetic acid dependent pseudothrombocytopenia(EDTA-PTCP) were found ,accounted for 0 .444 ‰ totally ,including 0 .244 ‰ of out-patients (101 cases) , 0 .159 ‰ of hospitalized patients (66 cases) ,and 0 .041 ‰ of health examination personnel (17 cases) .3 cases of multi-dependent pseudothrombocytopenia and 25 cases of pseudo platelet aggregation were found ,and accounted for 0 .007 ‰ and 0 .060 ‰ respec-tively .Conclusion The discovery of platelet aggregation which caused mainly by EDTA-PTCP ,still relies on microscopy ,and pseu-do platelet aggregation comes mainly from sampling ,so it needs to strengthen the skills training .

Influence of anticoagulants on platelet count / 国际检验医学杂志

Objective To analyze the influence of anticoagulants on platelet count .Methods A total of 5 patients with decreased platelet level ,detected by using haemocyte analyzer and samples anticoagulated by ethylene diamine tetraacetic acid dipotassium (EDTA‐K2 ) ,were enrolled ,and EDTA‐K2 ,sodium citrate ,heparin lithium ,sodium fluoride anticoagulated venous blood samples and fingers peripheral blood samples were collected and detected for platelet by using haemocyte analyzer and microscopic detection . Wright‐Giemsa′s stained cell smears were prepared and observed by using microscope .Results Platelet levels of anticoagulated samples ,detected by haemocyte analyzer and microscopic detection were obviously decreased ,and with large platelet aggregation ob‐served under microscope .Platelet levels of finger peripheral blood samples detected by haemocyte analyzer and microscopic detection were normal ,and without platelet aggregation observed under microscope .Conclusion Various anticoagulants could cause pseudo‐thrombocytopenia ,and fingers peripheral blood samples ,without anticoagulants ,should be used for platelet count to obtain accurate results .

Thrombocytopenia as a surrogate marker of hepatosplenic schistosomiasis in endemic areas for Schistosomiasis mansoni

Introduction This study aimed to evaluate whether a low platelet count is a good surrogate marker of hepatosplenic schistosomiasis (HSS) in a rural area of Brazil. A small district in southeastern Brazil, with a population of 1,543 individuals and a 23% prevalence of schistosomiasis, was selected for this investigation. Methods In July 2012, 384 volunteers were subjected to clinical, ultrasonography (US), and laboratory examinations, including stool sample analysis. The HSS patients were classified into four groups: Group 1 consisted of patients with a spleen >13cm and liver fibrosis; Group 2 consisted of patients with a palpable spleen and spleen>13cm measured by US; Group 3 consisted of patients with a spleen >13cm measured by US; and Group 4 consisted of patients with a palpable spleen. Results Eight patients were in Group 1 (2.1%), twenty-one were in Group 2 (5.5%), eight were in Group 3 (2.1%), and eighteen were in Group 4 (4.7%). A significant difference in the mean platelet counts was observed between the patients with and without HSS (p<0.01). Based on the receiver operating characteristic (ROC) curve (platelet count <143,000/mm3), the sensitivity was greater than 92% in all groups, and the specificity varied from 44.4% to 75%. Conclusions We concluded that in endemic areas, thrombocytopenia demonstrates good sensitivity for detecting HSS and may be used as a screening tool to identify patients with HSS. .

Pseudothrombocytopenia observed with ethylene diamine tetra acetate and citrate anticoagulants, resolved using 37°C incubation and Kanamycin.

Pseudothrombocytopenia (PTP) is defi ned by falsely low platelet counts on automated analyzers caused by in vitro phenomena including large platelet aggregates in blood samples. Diagnosis and resolution of PTP is crucial as it can lead to unwarranted interventions. We discuss a case of PTP in a pre-surgical setting, which was resolved using 37°C incubation and Kanamycin.

Dissociation of EDTA-dependent pseudo platelet aggregation by amikacin and its mechanism / 临床检验杂志

Objective To study the dissociation of EDTA-dependent pseudo platelet aggregation by amikacin and to clarify the potential mechanism.Methods At different time points,two concentrations of amikacin (6.5 mg/ml and 10.0 mg/ml) were respectively added to EDTA-K2 anti-coagulated whole blood samples collected from two subjects with EDTA-dependent pseudothrombocytopenia.The aggregated-platelet dissociation was investigated by platelet count and microscopical examination.CD41,CD61,CD62p,PAC-1,and IgG on the platelets of the two patients and of a normal control were determined by the FCS under various conditions.Results When amikacin (6.5 mg/ml) was added within 1 hour after blood collection,it dissociated the EDTA induced platelet aggregation and the platelet counts returned to the normal level. The expression of CD62p,PAC-1,and PA-IgG on the platelets was decreased,yet the expression of CD41 and CD61 had no change.Conclusion Amikacin supplementation (6.5 mg/ml) within 1 hour after blood sampling may dissociate the aggregated platelets caused by EDTA. The mechanism may be associated that amikacin might inhibit the expression of CD62p,PAC-1,and PA-IgG on platelets. The amikacin supplementation would be an inexpensive,effective,and practical method to solve the platelet aggregation induced by EDTA.

Prevention and Dissociation of the Platelet Aggregation in a Patient with EDTA-dependent Pseudothrombocytopenia by Supplementation of Kanamycin: A Case Report / 소아과

Pseudothrombocytopenia is usually associated with anticoagulant ethylene diaminetetraacetic acid (EDTA). The platelet clumping that occurs in EDTA-dependent pseudothrombocytopenia (EDPT) can sometimes be prevented by the use of other anticoagulants such as heparin or sodium citrate. As an alternative, we used kanamycin before or after the withdrawal of EDTA-anticoagulated blood in a 6-year-old boy with EDPT. Kanamycin used supplementarily during the differentiation of EDPT effectively prevented platelet clumping.

Correction of Platelet Count Using a Vortex in Pseudothrombocytopenia / 대한진단검사의학회지

BACKGROUND: Platelet clumping is a common cause of erroneous platelet counts by automated blood cell counter. The most commonly employed solution to this problem is to redraw the specimen into a different anticoagulant. However, this is unpleasant for the patient and not rapid for reporting of the corrected platelet count. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in blood and thus obtain accurate platelet counts. METHODS: Whole blood samples coated with ethylenediaminetetraacetic acid (EDTA) from 28 patients with platelet clumping and 20 controls without platelet clumping from July to September 2002 were mixed for 30 seconds with a vortex mixer. Platelet counts, blood smears, erythrocyte counts, Hgb, MCV and total leukocyte counts were evaluated before and after mixing. RESULTS: Vortex mixing of blood samples with platelet clumps caused an increased platelet count in 96% (27/28) and a decreased total leukocyte count in 68% (19/28). The mean platelet and total leukocyte counts of 28 blood samples before mixing were 155.0+/-89.6 (x10(3)/microL) and 12.9+/-5.5 (x10(3)/microL) and after mixing they were 249.2+/-116.2 (x10(3)/microL) and 12.0+/-5.4 (x10(3)/microL). Total erythrocyte counts, Hgb, MCV were not significantly affected by vortex mixing. Further, vortex mixing of 20 control samples had no consistent effect on each items. CONCLUSIONS: Vortex mixing of blood samples is a simple, rapid method without re-sampling in correction of erroneous platelet count induced by platelet clumps.

EDTA-dependent Pseudothrombocytopenia Confirmed by Supplementation of Kanamycin: A Case Report

EDTA-dependent pseudothrombocytopenia (PTCP) is the phenomenon of a spurious low platelet count due to EDTA-induced aggregation of platelets. Since the failure to recognize EDTA-dependent PTCP may result in incorrect diagnosis and inappropriate treatment, the recognition of this phenomenon is very important. We report an insidious case of EDTA-dependent PTCP confirmed by supplementation of kanamycin to anticoagulant in a 53-year-old women. Although sodium citrate and heparin usually prevented the aggregation of platelets in EDTA-dependent PTCP patients, these anticoagulants failed in preventing PTCP in our case. EDTA-dependent PTCP was confirmed by the findings that the clumping of platelets on microscopic evaluation was found in EDTA-anticoagulated blood samples, whereas thrombocytopenia and platelet aggregation were not revealed in the sample supplemented with kanamycin.

Amikacin inhibits and dissociates the aggregation of platelets in a patient with anticoagulants-induced pseudothrombocytopenia / 中华检验医学杂志

Objective To develop an effective way to evaluate the accurate platelet count in a patient with anticoagulants-induced pseudothrombocytopenia (PTCP).Methods It was studied that various anticoagulants effect on the platelets count for an infrequent patient with anticoagulants-dependent PTCP. When vitamin B6,aminophylline,gentamicin and amikacin were separately added to four anticoagulated blood samples from anticoagulants-dependent patient within 15 min after blood withdrawal,platelets count and morphological changes of blood cells after 4 hours of incubation at room temperature were investigated. The best anti-aggregating agent and its optimal concentration among them were explored.Results The four anticoagulants all could not inhibit the aggregation of the patient's platelets.Only amikaein among the above anti-aggregating agents can prevent and dissociate the aggregation of platelets without apparent morphological changes of blood cells and the platelet counts was stable within 4 hours after blood drawn when amikacin was added either before or after blood sampling.With increasing the concentration of amikaein,the platelet counts increase and then tend to be stable.The optimal concentration of amikacin is 5 mg/ml blood.Conclusions The supplementation of amikaein either before or after blood sampling is a useful method for the diagnosis anticoagulants-dependent PTCP and for the eva/uation of platelet counts in infrequent patients with anticoagulants-dependent PTCP.

Pseudothrombocytopenia Due to Anticoagulant-Independent Agglutinins / 대한임상병리학회지

Pseudothrombocytopenia is an in vitro phenomenon usually associated with anticoagulant (ethylene diaminetetraacetic acid, EDTA)-dependent IgG platelet agglutinins. Two cases of pseudothrombocytopenia due to EDTA-independent agglutinins are reported. The fingerstick blood smear showed platelet clumping as well as EDTA, citrate and heparin samples. In a case with malaria, serum IgM was 985 mg/dL and serum protein immunofixation demonstrated an additional IgM band which disappeared together with platelet clumping a month later. The increased immunoglobulin (especially, IgM) appeared to be associated with platelet agglutinin. Another case had cold reactive agglutinin because the electronic platelet counts were dependent on temperature. These cases illustrate that pseudothrombocytopenia may be caused by more than one type of agglutinin and can be confirmed by using a direct fingerstick, keeping the sample warm, or drawing the blood into another anticoagulant.

An Anesthetic Experience in a Patient with EDTA-induced Pseudothrombocytopenia: A case report / 대한마취과학회지

Pseudothrombocytopenia caused by platelet clumping is an in vitro phenomenon that occurs in ethylene-diamine-tetra-acetic acid (EDTA) anticoagulated blood at room temperature. Pseudothrombocytopenia may lead to erroneous diagnosis, unnecessary and costly additional laboratory examinations, and inappropriate medical or surgical therapy. We experienced 75-year old female pseudothrombocytopenia patient scheduled for orthopedic surgery, who showed abnormal thrombocytopenia (35,000/mm3) in preoperative routine platelet count using EDTA anticoagulant, but showed normal platelet count in sodium citrate anticoagulant.