Alina Dulau Florea

Purpose and criteria for blood smear scan, blood smear examination, and blood smear review.

A microscopic examination of an appropriately prepared and well-stained blood smear by a knowledgeable laboratory professional is necessary and clinically useful in a number of circumstances and for a variety of reasons. In this article, an attempt is made to delineate the purpose and criteria for blood smear examination in a variety of circumstances that are encountered in everyday laboratory hematology practice. A blood smear scan serves to at least (a) verify the flagged automated hematology results and (b) determine if a manual differential leukocyte count needs to be performed. Blood smear examination/manual differential leukocyte count with complete blood count (CBC) provides the complete hematologic picture of the case, at least from the morphologic standpoint. Blood smear review with or without interpretation serves to ensure that no clinically significant finding is missed, besides providing diagnosis or diagnostic clue(s), particularly if and when interpreted by a physician.

Automated Lymphocyte Counts vs Manual Lymphocyte Counts in Chronic Lymphocytic Leukemia Patients

Objective: This study was undertaken to determine if automated differential leukocyte counts (A-DIFF) can be used in place of manual differential leukocyte counts (M-DIFF) in chronic lymphocytic leukemia (CLL) patients. Methods: Relative and absolute automated lymphocyte counts obtained from 83 specimens from 76 CLL patients were compared with corresponding manual counts obtained by performing differential on albuminized blood smears. Means and correlation coefficients were calculated using Excel software. Results: The mean relative lymphocyte count by automated method was 73.6% as compared to 75.6% by the manual method. The mean absolute lymphocyte count by automated method was 32.1 × 10 3 /µL as opposed to 32.9 × 10 3 /µL by the manual method. The correlation coefficients were 0.928 and 0.998 for the relative lymphocyte counts and absolute lymphocyte counts, respectively. Conclusion: Automated differential leukocyte counts can be used in place of M-DIFF in CLL.

Detection of Platelet Clumps on Peripheral Blood Smears by CellaVision DM96 System and Microscopic Review.

OBJECTIVE To determine and optimize the sensitivity of the CellaVision DM96 automated image-analysis system in detecting platelet (PLT) clumps on blood smears and to assess the reliability of the traditional laboratory practice of examining only the feather edge of the smear for PLT clumps. METHODS We processed 102 blood smears that revealed PLT clumps on microscopic review, using the CellaVision DM96, and reviewed the results for the ability of the analyzer to detect these clumps. We obtained the data regarding relative distribution of PLT clumps on different parts of the blood smear (feather edge, lateral edges, and readable area) from our microscopic-review observations. RESULTS The sensitivity of the Cellavision DM96 in detecting PLT clumps was between 40.4% and 82.8%, depending on the number of screens reviewed for this variable. Via microscopic review of the smears, the PLT-clump detection rate increased from 85.3%, obtained by examining only the feather edge, to 99.0%, obtained by examining the feather edge plus the readable area. CONCLUSION The sensitivity of the DM96 for detecting PLT clumps can be maximized to 82.8% by reviewing the entire white blood cell screen and the entire PLT screen. Microscopic review of the blood smears yielded a PLT-clump detection rate of 99.0% when we examined the feather edge and the readable area of the smear.

The Results of Hemoglobin Variant Analysis in Patients Revealing Microcytic Erythrocytosis on Complete Blood Count

Background Microcytic erythrocytosis is an underrecognized and underevaluated complete blood count (CBC) finding. The literature pertaining to the determination of its etiology specifically by hemoglobin variant analysis is limited. Methods We performed hemoglobin variant analysis by high performance liquid chromatography on 137 patients who revealed microcytic erythrocytosis on CBC, and reviewed the results for the diagnosis of hemoglobin-associated disorders. Results A diagnosis of thalassemia trait and/or a hemoglobinopathy was established in 93 of 137 (67.9%) patients. Amongst these, ß-thalassemia trait topped the list with 69 cases (74.1%), followed by hereditary persistence of fetal hemoglobin with 5 cases (5.5%), Hemoglobin E disease with 4 cases (4.3%), and ∂/ß-thalassemia with 2 cases (2.1%). Compound heterozygous conditions with 1 or more hemoglobinopathies and/or thalassemias were diagnosed in 13 cases (14.0%). Abnormal hemoglobins in the compound heterozygosity group included C, S, HPFH, and 2 unknowns. Conclusion Hemoglobin variant analysis provided a very high positive yield in determining the etiology of microcytic erythrocytosis.

Evaluation of Automated Versus Manual Immature Granulocyte Counts

Objective: Immature granulocyte (IG) count is the latest addition to the automated leukocyte differential generated by the Sysmex analyzers. The objective of this study was to assess the reliability of the automated IG counts. Methods: Automated IG percentages were compared with the corresponding manual IG percentages of 418 blood specimens. The data were divided into five groups. The difference between individual automated IG percentages and corresponding manual IG percentages was plotted and the number of outliers, based on Rumke’s published 95% confidence limits, was determined for each group. Results: Of 418 automated IG percentages, 392 were within 95% confidence limits, with 26 outliers. More than half of the outliers carried also the “blast” flag, prompting a smear review. A significant difference between manual and automated IG percentage was noted when the manual IG count was greater than 10%. Conclusion: Automated and manual IG percentages compared fairly well with each other. We concluded that automated IG counts less than or equal to 10% may be considered reportable without a smear review.