SEED Haematology Sysmex

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Sysmex Educational Enhancement and Development 2,SEED Haematology No 6 2013. What type of flagging messages can we anticipate volume according to their cell type whereby they are. Some messages are common and their sources are readily identified as a separate population in the histogram After. identifiable while others may have more complicated origins this special lysis treatment cells will be shown in a. depending on the analytical technology used histogram according to their size see figure 1. 1 Abnormal or reference range messages LD T1 T2 UD fixed. These are messages that emanate from what the, laboratory has set as a reference or normal range for each. parameter and should reflect the profile of the population Baso. being served When properly set they allow the analyser Eo. to judge such results as either normal or abnormal and Lymph Neutro. indicate whether they are below or above the defined 0 50 100 150 200 250 300 fl. range Therefore the message thrombocytopenia, identifies the presence of a low platelet count whilst Fig 1 The 3 part diff histogram showing the 3 white cell. subpopulations,thrombocytosis is indicative of an elevated. platelet count,LD lower discriminator UD upper discriminator T1.
2 Suspect messages trough between lymphocytes and mixed cells T2 trough. Flagging messages alert the operator about possible between mixed cells and neutrophils. disturbances in the measurement chamber which may, affect the accuracy of the results as well as the possible Based on the analysis of many thousands of normal samples. existence of abnormal cells which may assist in reaching during the development phase of the analyser software the. timeous diagnosis of an underlying pathology Examples expected range of cell size has been determined This. here may range from detection of presence of platelet information is used to set the so called discriminators of the. clumps which may have an effect on the platelet count to WBC histogram Some of these are flexible i e the. detection of presence of leukaemic cells e g blasts boundary of population can be located between a set range. whereas others are fixed on an absolute value The WBC. White cell interferences and flagging on Sysmex 3 part histogram has to fulfil certain criteria in order for the. diff analysers resultant cell counts to be considered reliable. In 3 part diff analysers initial information about the possible. cause of an abnormal white blood cell count high or low is n The distribution curve should fall within the. provided by the classification of white blood cells into three discriminators. separate subpopulations This gives rise to the so called 3 n The curve should start and end at the base line. part differential count which broadly separates cells n The LD T1 T2 are flexible and can be adjusted for the. according lineage Sysmex 3 part differential analysers latest sample just processed by performing the manual. separate normal white blood cells into lymphocytes discrimination procedure but LD cannot be set lower than. neutrophils and a mixed group comprised of monocytes 30 fl The results are then recalculated and displayed. basophils and eosinophils, The measurement sample in the WBC channel includes. Reagent effect on cells white blood cells and platelets but not red blood cells as. During the analytical process the white blood cells are these have been lysed. treated with specific lyse reagents The lyse reagent effect. on white blood cells causes the cells to shrink to a defined. Sysmex Educational Enhancement and Development 3,SEED Haematology No 6 2013. The volume of platelets is usually between 8 12 fl n WU abnormal height at upper discriminator. therefore the LD of the WBC histogram separates the white n AG high number of cells to the left of the lower. blood cells from the platelets and thus they do not interfere discriminator. with the WBC result However please note that large PLT n T 1 no differentiation between lymphocytes and. clumps can be located immediately to the left of the 30 fl mixed cells. lower WBC discriminator n T 2 no differentiation between mixed cells and. neutrophils, In 3 part diff measurement only volume of cells is used to n F 1 relative height of T1 or T2 exceeds the limit. differentiate the white cell subpopulations As stated above n F 2 relative height of T1 or T2 exceeds the limit. the distribution curve must be within the discriminators and n F 3 relative height of T1 or T2 exceeds the limit. each curve must start and end at the base, Possible causes of white cell interferences and flags in 3.
Any particles in the measurement distorting this pattern part diff analysers. may result in flagging and possible incorrect results The various interferences and flags are described and. presented in tables 1 and 2 below Possible causes and. The following flag messages may appear solutions are also suggested see also figures 2 and 3 for. n WL abnormal height at lower discriminator illustration of related histograms. The WL AG and WU flags,LD T1 T2 UD LD T1 T2 T1 T2,300 100 200 300 100 200. Fig 2 The WBC histogram showing the a WL b AG and c WU respectively. It is important to note that in cases where the histogram does not reach the base at the lower or the upper discriminators. this may result in incorrect results In such cases the described flags will be displayed besides the numerical results. Table 1 The WL AG and WU flags,Flag Possible causes Possible solution. a WL abnormal height at lower n Lyse resistant RBC n Retesting a diluted sample with Cellpack. discriminator n PLT clumps or 0 9 NaCl will help to obtain correct. n EDTA incompatibility,n Samples showing platelet clumping. n Coagulated sample should be recollected in trisodium citrate. n Nucleated red blood cells NRBC anticoagulant and retested. n Clotted samples should be recollected and,n RBC cold agglutinins retested. n Presence of NRBCs poses a challenge,because after lysing their nuclei which.
are about the same size as lymphocytes,Sysmex Educational Enhancement and Development 4. SEED Haematology No 6 2013,They will therefore be counted as white cells. and if a di erential count is also performed,then the lymphocyte count will also be. b WU ag abnormal height at n Extreme leukocytosis n In cases of extreme leukocytosis the. upper discriminator sample should be diluted at a ratio of 1 5. n WBC aggregation to obtain a reliable count, n PLT satellitism seldom n In rare cases of PLT satellitism. phenomenon aggregation of PLTs onto,neutrophil membranes often seen.
together with EDTA incompatibility,using trisodium citrate as an alternative. anticoagulant for blood collection may,resolve the problem. c AG Flag High number of n Platelet aggregation due to n PLT count should be microscopically. cells to the left of the lower checked for platelet aggregation. discriminator n EDTA incompatibility,n In case of EDTA incompatibility sample. n Lyse resistant RBC see WL should be recollected in citrated tubes. and reanalysed,n NRBC seldom see WL,The T1 and T2 flags. Although T1 and T2 discriminators are flexible and adjust to the sample in some extremely pathological. samples it may not be possible to differentiate between the lymphocytes and the mixed populations T1 and. between the mixed populations and neutrophils T2 This is illustrated in figure 3 and summarized in table 2. below However if either the T1 or T2 appear the total white cell count is not affected. LD UD LD T1 UD,a 100 200 300 b 100 200 300, Fig 3 The WBC abnormal histograms showing a combined T1 and T2 interference and b T2 interference.
Table 1 The WL AG and WU flags,Flag Possible causes Possible solution. Flags T1 and T2 Figures 3a and 3b Abnormal white blood cells Check smear for abnormal white blood cells. respectively No di erentiation e g blasts etc,between lymphocytes and mixed. If only T1 or T2 ag appear the total,cells or between mixed cells and. white cell count is not a ected,neutrophils respectively. Sysmex Educational Enhancement and Development 5,SEED Haematology No 6 2013.
The F1 F2 and F3 flags, In some abnormal samples the T1 and T2 do appear on the histogram but there is still no clear separation of white. cell types because the histogram does not reach the base at both these discriminators See figure 4 and table 3 below. for possible causes and suggested action,LD T1 T2 UD. T1 or T2 discriminators are set,However there is no clear. separation between the WBC,populations,0 50 100 150 200 250 300 fl. Fig 4 The F1 F2 and F3 flags showing identification of T1 and T2 discriminators but no clear separation of cell. populations,Table 1 The F1 F2 and F3 flags and interferences.
Flag Possible causes Possible solution, F1 F2 F3 Flags n Abnormal distribution of WBC Check smear Please note In the. populations showing morphological absence of WL or WU ags the. No clear di erentiation between, features that do not allow clear total WBC count is not a ected. lymphocytes mixed cells or,distinction between them. neutrophils due to presence of,abnormal cells n Abnormal or immature WBC. Summary Conclusion, The warning messages described above enable Automated full blood count analysers add great.
the user to detect abnormal samples and to react value in terms of providing useful information. with follow up actions based on the warnings that aids laboratory staff to correctly interpret. Morphological abnormalities mostly preliminary results and to help pathologists and clinicians. development stages of normal cells or abnormalities reach a correct diagnosis timeously Efficient or. of the myeloid and lymphatic cell series require optimal utilization of the analyser capability that. manual differentiation Pre differentiation helps in this process requires understanding of. information will reduce the rate of microscopic the basic workings of the analytical systems The. differentiation by restricting this to clinically numerical results must be reviewed and interpreted. relevant cases only Manual work can thus be in conjunction with careful inspection of the. minimised without any compromise in quality histograms and any accompanying alert messages. of results or flags,Sysmex Educational Enhancement and Development 6. SEED Haematology No 6 2013,Take home message, n While numerical values on their own give important. information about the patient state of health all, related information generated during analysis must be. taken into consideration in order for result,interpretation to be meaningful. n Any suspect or abnormal flags must be noted and their. source identified The potential impact of interference. on the accuracy of results must be assessed, Appropriate action must be taken wherever possible.
in order to eliminate or minimize the effect of,interferences. References, 1 Dacie and Lewis Practical Haematology ninth edition. by SM Lewis B J Bain I Bates,2 Sysmex XP 300 Instructions for Use. Compiled by,Ndwakhulu Nemuthengame,Sysmex applications specialist. Checked by,Dr Marion M nster,Sysmex South Africa Pty Ltd.
Fernridge Office Park Block 2 5 Hunter Avenue Ferndale Randburg 2194 South Africa Phone 27 11 3299480 Fax 27 11 7899276 info sysmex co za www sysmex co za. SEED Haematology Sysmex Educational Enhancement and Development No 6 2013 Introduction and background Full blood counting is a relatively easy process usually simply involving the mixing of blood in an EDTA collection tube mode selection introduction of sample for sampling and start of analysis A full profile of patient results follows within two minutes offering an invaluable tool for

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