Methodological Evaluation And Influencing Factors Analysis Of Low Platelet Detection

Part I Evaluation and Analysis of Low Platelet Test by Different MethodologyResearch background and purposeBlood platelet(PLT)is a biologically active small cell cytoplasm that is detached from the cytoplasm of bone marrow mature megakaryocytes.It has a relatively constant amount in normal blood,platelet adhesion,aggregation,and release mechanism in hemostasis.It plays an important role in physiological and pathological processes such as wound healing,inflammation,thrombosis and organ transplant rejection.Platelet detection plays an important role in the diagnosis and treatment of clinical diseases.Platelet count test is a very important clinical test index in routine blood tests.Especially for patients with multiple causes of thrombocytopenia,the precision and accuracy of platelet test are crucial for the diagnosis and treatment of patients' diseases.effect.With the continuous improvement of the level of medical science and technology,more and more platelet detection methods are used clinically.However,in clinical work practice,we have found that platelet counts due to various reasons are at a relatively low level,and platelet detection is affected by its own physiology.Characteristics,diseases,and the test environment affect many factors,interfere with the normal test methods for the correct determination of platelet counts,resulting in the detection of low platelets often have a false increase or false reduction,accurate and rapid detection of low platelets Counting still needs to explore more appropriate test methods in the current inspection work.For the examination of low platelet counts,there are differences in the results of the platelet counts measured by each test method.Due to the limitations of the methodology,thrombocytopenia caused by different diseases and pathological conditions is difficult to detect automatically through machine detection.This situation leads to misdiagnosis and missed diagnosis of the disease,which will bring fatal risks to patients.To this end,we used the traditional platelet counting method for optical microscopy as the gold standard and analyzed impedance,optical,and flow cytometric methods for the detection of low-value platelets,looking for the most appropriate low-value platelet detection under different conditions.method.Research objects and methodsA total of 2823 patients with low platelet counts with platelet counts of less than 100 x 109/L were collected from outpatients and inpatients at Qilu Hospital,Shandong University from February 2016 to December 2017.Impedance method(PLT-I),optical method(PLT-O),and fluorescent dye-binding method(PLT-F)were used to detect low platelets(PLT count<100×109/L)specimens collected in laboratory departments,respectively.The traditional platelet counting method using light microscopy to count platelet counts as the gold standard compares the accuracy and precision of the three methods for low-value platelet detection due to different causes,with a view to seeking the best for low-value platelets caused by different detection method.Research result(1)When MCV<80fl,the correlation coefficient between PLT-I and OM is r = 0.617,which is moderately correlated.The slope of the linear regression equation of Passing-Bablok regression PLT-I and OM is not included in the 95%CI.Terman analysis has a high degree of bias,and there is a statistically significant difference between the PLT-I and OM platelet counts;the correlation analysis between PLT-O,PLT-F and OM shows a significant correlation;PLT-O,PLT-There was no statistical difference between the linear regression equations of F and OM and the reference method OM.Bland-Altman's analysis of PLT-O,PLT-F and OM counts were slightly biased,but PLT-O was slightly less biased than PLT-F.(2)When the MCV was between 80-100fl,the correlation coefficients of PLT-I,PLT-O,PLT-F and OM were r = 0.899,r = 0.973,r = 0.983,both of which were highly correlated;Passing-Bablok Regression analysis results PLT-I,PLT-O,PLT-F and OM linear regression equation slope 95%CI both contain 1 and the reference method OM showed no statistical significance.Bland-Altman analysis results PLT-I,PLT-O The PLT-F and OM counts were slightly biased.The PLT-F method was the least biased.The samples with MCV between 80-100 fl were divided into three groups according to the platelet count.See Table 2:PLT between 20-100× 109/1,there was no significant difference between the three methods and the reference method OM.PLT-I,PLT-O,PLT-F and OM counts were slightly biased,and PLT-I was biased.Higher than PLT-O and PLT-F methods;PLT-F method is more stable,does not change with the reduction of platelet count,bias changes occur,PLT-O method counts the number of platelets with platelet count,the degree of bias increases,and OM PLT-I There was a statistically significant difference between OM and OM,and platelets could not be accurately counted.(3)When MCV>100fl,the results of Passing-Bablok regression analysis and the reference method OM showed no significant difference.Bland-Altman analysis showed that the PLT-I,PLT-O,PLT-F,and OM counts were both mild.Bias,PLT-I is more biased than PLT-O and PLT-F.ConclusionWhen the MCV value is lower than 70FL,the accuracy of the PLT-I detection method is poor due to the interference of the small red blood cells.There is no significant difference between the PLT-O and PLT-F detection methods and the OM,and these two methods can be used for these types of samples.Conduct the test.When the platelet count was lower than 20 x 109/L,the accuracy of PLT-I for platelet count was poor,and the PLT-F was the closest to the OM platelet count with the smallest deviation.Therefore,when the platelet count was less than 20 x 109/L According to the laboratory conditions,PLT-F method or OM method was used for accurate counting of platelets.Part II Clinical Analysis of EDTA-dependent PseudothrombocytopeniaResearch background and purposePseudothrombocytopenia refers to platelets at low levels detected by automated analyzers for platelet counts.When assessing peripheral blood smears,it is generally seen that platelets are counted in accidentally discovered patients with pseudothrombocytopenia.Normal range,and will not cause any clinical bleeding.Currently,a significant proportion of patients with thrombocytopenia diagnosed with thrombocytopenia are due to in-vitro coagulation,platelet saturation,the presence of giant platelets,platelet-induced autoagglutination,and EDTA as a sample tube anticoagulation.This study will conduct a clinical analysis of EDTA-PTCP to explore the best detection protocol for this type of patient specimen.Research objects and methodsThe Qilu Hospital of Shandong University was collected from February 2016 to December 2017.The laboratory used the hematology analyzer XN-3000 to test the patient's platelet count.In the results analysis system,the results showed that the patients with abnormal results and low platelet counts used SP-10 for blood cell coating.Tablets,and then two experienced experts observed parallel platelet counts.Microscopically,specimens with platelet aggregation were screened and 30 patients were found to have EDTA-dependent thrombocytopenia.When using a blood cell analyzer to count platelets,when the machine indicates platelet aggregation,replace the anticoagulant such as sodium citrate,heparin,and other anticoagulant blood collection tubes and retest.Since the ratio of anticoagulant to whole blood in the anticoagulant tube of sodium citrate is 1:9,the results obtained with sodium citrate anticoagulation tube must be multiplied by the dilution factor.The result is the true counting result and the direct blood collection.The slide microscopy was performed by two experienced blood cytology specialists to count the number of platelets under a light microscope.The correlations between different anticoagulant specimens and light microscopy platelet counts were compared and statistically significant.Research resultAccording to the study of 30 patients with EDTA-PCTP specimens,EDTA-PCTP patients had the following characteristics:(1)Platelets aggregated into clots in conventional EDTTA-K2 anticoagulant tubes;(2)Counted platelets using blood cell analyzer,platelets Count less than 100×109/L;(3)Replace anticoagulant tubes such as sodium citrate anticoagulation or heparin anticoagulation,platelets do not appear to aggregate into the phenomenon of clot;(4)this type of patients lack of clinical manifestations of thrombocytopenia no episodes of purpura,bleeding gums,hematuria,and increased volume were observed.Samples of the EDTA-PCTP phenomenon were retested after replacement of anticoagulant blood collection tubes such as sodium citrate and heparin.The results showed that sodium citrate anticoagulant tubes had the least influence on platelet counts and were EDTA-The best alternative to platelet counts in thiophenol patients.Among 30 patients with EDTA-K2-dependent platelet pseudoagglutination,platelet antibody test results showed that GP ?b/?a was positive in 12 cases,GP ?b/? was positive in 7 cases,double positive in 5 cases,and PAIgG was positive in 16 cases(>78.8 ng/107 platelets.).ConclusionThe timely identification and correct use of correct methods to correct EDTA-PCTP phenomenon is critical in clinical diagnosis and treatment.The most suitable anticoagulant choice for EDTA-PCTP correction is sodium citrate anticoagulant,in addition to the replacement of anticoagulants.Can be directly blood microscopy microscopy or without any anticoagulant after the blood is fully mixed for hemocytometer detection.In most cases,platelet autoantibodies were found in EDTA-PCTP,mainly Gp ?b/?a,PAIgG.