Interlaboratory Reproducibility of Blood Morphology Using the Digital Microscope.

Differential counting of peripheral blood cells is an important diagnostic tool. However, manual morphological analysis using the microscope is time-consuming and requires highly trained personnel. The digital microscope is capable of performing an automated peripheral blood cell differential, which is as reliable as manual classification by experienced laboratory technicians. To date, information concerning the interlaboratory variation and quality of cell classification by independently operated digital microscopy systems is limited. We compared four independently operated digital microscope systems for their ability in classifying the five main peripheral blood cell classes and detection of blast cells in 200 randomly selected samples. Set against the averaged results, the R(2) values for neutrophils ranged between 0.90 and 0.96, for lymphocytes between 0.83 and 0.94, for monocytes between 0.77 and 0.82, for eosinophils between 0.70 and 0.78, and for blast cells between 0.94 and 0.99. The R(2) values for the basophils were between 0.28 and 0.34. This study shows that independently operated digital microscopy systems yield reproducible preclassification results when determining the percentages of neutrophils, eosinophils, lymphocytes, monocytes, and blast cells in a peripheral blood smear. Detection of basophils was hampered by the low incidence of this cell class in the samples.

Automated morphological analysis of cells in body fluids by the digital microscopy system DM96.

BACKGROUND: Differential counting and morphological analysis of nucleated cells in body fluids (eg, cerebrospinal fluid and pleural fluid) are of great diagnostic importance to the clinician. A recent development in this field was the introduction of an application for an automated microscopy system, the DM96 Body Fluid module, enabling the automated analysis of body fluid samples. This computerised system provides an automated morphological analysis of body fluids, including an automated classification of all nucleated cells. AIMS: To investigate the ability of the digital microscopy system, DM96, to automatically classify cells in different types of body fluids. METHODS: A total of 177 body fluids (including cerebrospinal fluid, abdominal fluid and continuous ambulant peritoneal dialysis fluid) were analysed on the DM96, and results were compared with the manual microscopy method. RESULTS: A study in 177 samples demonstrates an overall preclassification accuracy of 90% in spinal fluid and 83% in other body fluids using the automated system. Correlation coefficients for postclassification as compared with manual review range from 0.92 to 0.99 for spinal fluid sample analyses and from 0.83 to 0.98 for other body fluids. The within-run variation of automated classification is less than 6% for all cell categories (4% excluding macrophages). CONCLUSION: The DM96 has proven to be reliable and efficient, contributing to overall quality improvement in morphological analysis and automated cell classification of peripheral blood and other body-fluid samples.

Does the band cell survive the 21st century?

OBJECTIVES: The differentiation of white blood cells is a worldwide-accepted method to obtain medical information. The conventional microscopic differential, however, is a laborious and expensive test with a low statistical value. Especially for band cell identification there is a wide range of variance. In this report we describe the intervariability of band cell enumeration. METHODS: From a septic patient, an EDTA anti-coagulated blood sample was obtained and a smear was made and stained (May-Grünwald Giemsa). A PowerPoint presentation was made twice of 100 random cells and sent to 157 different hospital laboratories in the Netherlands for a leukocyte differential. In the first survey neutrophils were differentiated in segmented and band neutrophils whereas in the second survey no discrimination was made between segmented and band neutrophils. RESULTS: The first survey was responded by 68% of the laboratories (756 individuals) and the second survey by 73% of the laboratories (637 individuals). The laboratory mean values of the segmented neutrophils were 42.9% (SD: 7.8, range 22-64%) and 69.9% (SD: 1.4, range 62-72%) for the first and second survey respectively. For the individual technicians the values of the segmented neutrophils were 43.9% (SD: 11.2, range 15-72%) and 70.0% (SD: 2.0, range 59-77%) for the first and second survey respectively. CONCLUSIONS: Because of the enormous variation of band cell counting we recommend to cease quantitative reporting of band cells, especially since the results only have a clinical relevance in a limited number of pathological circumstances.

Recurrent acute hemolytic transfusion reactions by antibodies against Doa antigens, not detected by cross-matching.

An 81-year-old male patient suffered from recurrent acute hemolytic transfusion reactions after transfusion with phenotyped cross-match-negative red blood cells (RBCs). Extensive posttransfusion workup eventually revealed Dombrock (a) (Do(a)) antibodies. Because commercially available cell panels do not allow for identification of anti-Do(a) and owing to the lack of Do(a) typing serum samples, selection of matched units of RBCs is dependent on negative cross-match results. In this case, selection of Do(a-) units by cross-matching failed, indicating that serologic methods were not reliable. A polymerase chain reaction with sequence-specific priming assay was used to detect DOA and DOB alleles, which encode Do(a) and Do(b) antigens, respectively. The patient was confirmed to be DOB/DOB by DNA sequencing. Furthermore, the involved mismatched units in each of the three hemolytic episodes were shown to be Do(a+). In the presenting case, DNA typing appeared to be superior to serologic methods in selecting matched RBC units in the presence of anti-Do(a).