1Department of Pathology and Laboratory Medicine, Vancouver. General Hospital and University of British Columbia vancouver,. BC, Canada, 2Department of ...
International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology
Poster Presentation Abstracts 39
Cellular Analysis 100 MEASUREMENT OF RETICULOCYTE HEMOGLOBIN (RET HE) PARAMETER ON SYSMEX XE 2100 IN HEMODIALYSIS PATIENTS ON ERYTHROPOIETIN STIMULATING AGENT (ESA) IN TERTIARY CARE HOSPITAL. Shadhiya Al Khan1, Monika Hudoba De Badyn1, Jim Yakimec1, Karen Shalansky2, Jason Pal1, Kin Cheng1, Jacek Jastrzebski3 1 Department of Pathology and Laboratory Medicine, Vancouver General Hospital and University of British Columbia vancouver, BC, Canada, 2Department of Pharmacy, Vancouver General Hospital and University of British Columbia vancouver, BC, Canada, 3Department of Medicine, Vancouver General Hospital and University of British Columbia Vancouver, BC, Canada Introduction: Chronic kidney disease (CKD) patients on dialysis complicated with anemia are usually treated with both ESA and intravenous (IV) iron. Optimization of this therapy requires a target hemoglobin level and avoiding an excessive body iron overload. Ret He has shown to be useful in screening for iron deficiency anemia (IDA) in chronic renal failure where conventional serological parameters are not helpful. We have evaluated the performance of Ret He in hemodialysis patients placed on ESA ± IV iron. Methods: A total of 155 CKD patients (mean age 74 years) on ESA (mean dose of ESA 35.9 microgram per week) with (44 patients) or without (111 patients) IV iron have undergone routine hemodialysis. Monthly routine complete blood count (CBC) and Ret He were measured over the period of 3 months. Serum ferritin (SF) and transferrin saturation (TSAT) were measured once in 3 months. Pearson’s correlation coefficient measurement analysis was performed between Ret He and hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), TSAT and SF. Results: Ret He reference range for our laboratory was established at 30-38pg with 2SD.The mean Ret He in hemodialysis patients on ESA was 33.4pg. There was a significant correlation between Ret He and TSAT (r = 0.408, coefficient 4.230, SE +/0.763, P 12.7 fl and RDW-SD >46.1 fl. Results: Among the 806 samples used, 395 (49.0%) were positive and 411 (51.0%) were negative for the presence of anisocytosis by the manual microscopic method. The RDW-CV showed a better negative predictive value (72.2%) than RDW-SD and MATH-1SD (both 37.5%) in microcytic samples, indicating that the RDW-CV increases the likelihood of not finding anisocytosis below the cut off limits. The RDW-CV had the best sensitivity (86.8%) and efficiency (86.8%) in detecting anisocytosis in microcytic MCV ranges. The RDW-SD and the MATH-1SD were more sensitive and efficient in normocytic (82.9% and 83.3%; 92.1% and 92.3% respectively) and macrocytic (90.2% and 90.2%; 95.1% and 95.1% respectively) MCV ranges. A ROC curve analysis demonstrated that RDW-CV was more efficient in detecting anisocytosis in microcytics MCV ranges (p< 0, 05 vs. RDW-SD and MATH-1SD). In normocytics and macrocytics MCV ranges, RDW-SD and MATH-1SD show similar efficiency in detecting anisocytosis (p< 0, 05 vs. RDW-CV). Conclusions: The RDW-SD, RDW-CV, and MATH-1SD have different performances in detecting blood smear anisocytosis according to MCV values, so they are parameters that complement each other and should be used in conjunction to identify erythrocyte size heterogeneity.
111 ESTABLISHMENT AND EVALUATION OF REVIEW CRITERIA FOR AUTOMATED COMPLETE BLOOD COUNTS APPLYING RECEIVER OPERATING CHARACTERISTICS (ROC) CURVE ANALYSIS Samuel Comar1, 2, Mariester Malvezzi1, Ricardo Pasquini1 1 Division of Hematology, Hospital de Clínicas, Universidade Federal do Paraná Curitiba, Brazil, 2Postgraduate Program in Internal Medicine and Health Sciences Curitiba, Brazil Introduction: To reduce costs and time to release complete blood count (CBC) results, there is great interest in reducing the amount of automated CBC requiring microscopic blood smear review without sacrificing quality in hematology laboratories. We aimed to establish and evaluate review criteria for automated complete blood counts (RCACBC) applying receiver operating characteristics (ROC) curve analysis. Methods: This work was carried according to the recommendations of the International Society for Laboratory Hematology (ISLH) for RCACBC. The hematology analyzers employed were the Sysmex XE-2100D and XT-2000i. Four sets of RCACBC were evaluated: 1 adapted from the ISLH and the other 3 localized according to pertinent criteria (Studies 1–3). For each RCACBC set, the false-positive, false-negative, true-positive, and true-negative rates; sensitivity; specificity; positive and negative predictive values; microscopic review rate; and efficiency were determined. Furthermore, the Youden index was calculated and a comparative analysis of receiver operating characteristic (ROC) curves was performed to evaluate the performance of the 4 RCACBC sets. Results: In Studies 1, 2, 3 and the adapted ISLH, the microscopic review rates were 73.85%, 54.52%, 46.33%, and 46.38%, respectively; the false-negative rates were 0.50%, 1.97%, 2.73%, and 3.95%, respectively and the false-positive rates were 49.52%, 31.66%, 24.23% and 25.49%, respectively. The efficiency were 49.97%, 66.36%, 73.04% and 70.56%, respectively; the specificity were 34.11%, 57.87%, 67.77% and 66.08%, respectively. Table 1, 2 and Figure 1 show the statistical analysis of the ROC curves of Studies 1–3 and the adapted ISLH. Table 1 Indexes
Study 1 vs. Study Study 1 vs. Study Study 1 vs. 2 3 Adapted ISLH
Difference between areas
0.090
0.124
0.092
0.015
0.016
p< 0.0001
p< 0.0001
Study 2 vs. Study 3 0.034
Study 2 vs. Adapted ISLH 0.001
Study 3 vs. Adapted ISLH 0.033
0.009
0.010
0.007
0.017–0.051
−0.019–0.022
0.019–0.047
p< 0.0001
p= 0.897
p< 0.0001
Standard error 0.014 95% confidence 0.063–0.117 interval Significance p< 0.0001
Table 2
Indexes Difference between areas Standard error 95% confidence interval Significance
0.095–0.154
0.061–0.122
Prevalence of positive samples: 24.84% (n = 1977).
© 2013 The Authors Journal Compilation © 2013 Blackwell Publishing Ltd, Int. Jnl. Lab. Hem. 2013 35 (Suppl. 1) 1-133
Poster Presentation Abstracts 45
Conclusions: Study 3 was the most cost effective and optimized the cost and quality for achieving complete blood counts (p < 0.0001 vs. others). Nevertheless, for an ROC curve analysis to be applicable, the false-negative rate should always be adapted ISLH > Study 2 > Study 1.
Δosmolality necessary to produce an MCV delta check alert was in the range 23-38mOsm/kg, corresponding with a change in glucose of 420-690mg/dL or sodium of 12.5-20.6mmol/L. The results of the underfilling experimentconfirmed the linear relationship between osmolality (range 303-389mOsm/kg) and MCV (range 89.1-97.1fL). K2-EDTA tubes need to be filled at least 25% to avoid erroneous MCV delta check results (figure1). Conclusions: Conditions that cause a marked increase in plasma osmolality may result in a falsely increased MCV, and hence, MCV delta alerts for sample mix-up. Based on our routine data, we found this phenomenon to occur regularly.
112 MCV DELTA CHECK METHOD TO DETECT SPECIMEN MIX-UP: OSMOLALITY AS A CONFOUNDING FACTOR Lien Cattoir, Karlien Vanhouteghem, Veronique Stove Department of laboratory medicine, Ghent University Hospital Ghent, Belgium Introduction: For clinical laboratories, astrategy to detect sample mix-up is required. Since mean corpuscular volume (MCV) is known for its low biological variability, the MCV delta check method is a valuable tool. However there are a number of confounding factors, for instance transfusion of packed red cells. The influence of other factors (e.g. pH, osmolality and underfilled EDTA tubes) is less known. Hyperosmolality for example leads to shrinking of erythrocytes in vivo, followed by osmotic swelling in the buffer of the hematology analyser. In this study we aimed to further characterize the effect of osmolality on MCV. Methods: MCV delta check results >0.05 were automatically generated by Sysmex XE-5000TM (Sysmex Corporation, Japan), based on the calculation |current result – previous result|/average, with maximum 4 days between both results. Venosafe K2-EDTA tubes (Terumo®, Belgium) were used for blood collection. In orderto obtainsampleswithan increasingosmolality, blood fromtwohealthyvolunteers was spiked with various glucose solutions (50-2000mg/dL). After an incubation period of 1.5h, we measured complete blood count and osmolality (Osmo stationTM, ARKRAY, Japan). Historical laboratory test results of 1 year werereviewed with a focus on the effect of the osmolality on MCV. In order to allow regression analysis, data werenormalized. For each patient, Δosmolality and ΔMCV were determined by comparing the data to the lowest available osmolality. Finally, the effect of underfilling of K2-EDTA tubes was studied. MCV and osmolality were measured on blood samples with increasing K2EDTA concentration (1.85-15.6mg/mL). Results: The addition of glucose to K2-EDTA blood resulted in a plasma osmolality range of 286-356 mOsm/kg, which in turn led to a proportional change in MCV (87.4-91.9fL for patient one and 88.9-94.1fL for patient two). This effect was confirmedby the examination of multiple historical MCV and osmolality results in individual patients. The lowest
113 DIAGNOSIS OF MALARIA ON THE XT-2000I pankhi dutta1, monisha sethi3, sandhya bastian2, chitrangi navadkar4 1 kokilaben dhirubhai ambani hospital Mumbai, India, 2Roche diagnostics Mumbai India, 3Sysmex India Pvt Ltd Mumbai India, 4 Kokilaben Dhirubhai Ambani Hospital Mumbai India Introduction: Introduction-The detection of malaria in an automated fashion is a potential novel apllication for some automated cell analyzers like Cell Dyn (Abbott Diagnostics, Santa Clara, CA), GEN-S and LH-750 (Beckman Coulter, Miami, Florida), XE-2100 and XS-1000i (Sysmex Corporation, Kobe Japan). However, not much data is available on the detection of malaria using the five-part automated cell counter, XT-2000i (Sysmex, Japan). Objective- This study was undertaken to assess the efficacy of the XT-2000i in detection of malaria. Methods: The complete blood counts of 446 febrile cases for whom slide examination for detection of malarial parasite was ordered were analyzed . A total of 390 samples were analyzed in the CBCDiff-Retic mode while the rest were analyzed in the CBC-Diff mode only. The variuos scattergrams obtained were analyzed for abnormalities. The thick and thin blood films were examined by 2 observers and the cases divided into malarial parasite (MP) positive and MP negative depending on the presence or absence of MP. The frequency of various abnormalities detected in the two groups were analyzed. Fischer’s Exact test was applied to look for significance in difference in the frequency of the various abnormalities in the two groups. The performance characteristics of the various abnormalities in predicting presence or absence of malaria were analyzed. Results: Of 446 samples, 276 were MP positive while 170 were MP negative.
© 2013 The Authors Journal Compilation © 2013 Blackwell Publishing Ltd, Int. Jnl. Lab. Hem. 2013 35 (Suppl. 1) 1-133
46 Poster Presentation Abstracts
Abnormalities detected Additional cluster on WBC/Diff scatter Complete voting out of automated differential count Flag of ‘abnormal WBC scatter’ Linearly extended ghost cluster on WBC/Baso scatter Abnormal events in the platelet-O scatter
MP positive 254/276 (93%)
MP negative 07/170 (4.10%)
P value
