Comparative Study of Peripheral Blood Morphology by Conventional Microscopy and Cellavision DM96 In Hematological and non Hematological Diseases

Microscopic examination of peripheral blood cells is an important diagnostic tool. We evaluated the CellaVision DM96 (CellaVision AB, Lund, Sweden), an automated image analysis system for digital peripheral blood cell analysis, comparing the results with direct manual microscopy. The system obtains digital images of the blood cells at high magnification and these images are analyzed using a neural network based on a large database of cells.

We analyzed 234 PB films stained with May-Grünwald-Giemsa from patients of the Hospital Clínic of Barcelona. Leukocyte values were from 1.12 to 282 × 10⁹/L (Advia 2120, Siemens Healthcare Diagnostics SL). 177 of the PB films were from patients with hematological diseases: lymphoid neoplasias: 83, acute leukemias: 52, chronic myeloproliferative diseases: 20, myelodisplastic syndromes: 18, paroxysmal nocturnal hemoglobinuria: 2, hemoglobin S: 1 and thrombotic thrombocytopenic purpura: 1. Manual differentials were performed using standard microscopy. After the microscopic analysis the slides were loaded into the CellaVision DM96 obtaining digital images of preclassified cells, which were verified or corrected when necessary by the hematologist (DM96POST). WBC differentials were abnormal in 120 cases. Statistical analysis was performed using correlation (Pearson) and concordance (Lin) tests.

Correlation coefficients between results obtained from the CellaVision DM96 preclassification and by conventional direct microscopy were excellent for segmented neutrophils, lymphocytes, monocytes and blasts (r>0.87<0.94 and p<0.0001) and good for band neutrophils, eosinophils, basophils and plasma cells (r>0.74<0.81 and p<0.0001). Concordance coefficients were higher than 0.7 for all of the white blood cell subtypes preclassified by the DM96. Pearson and Lin coefficients were higher when we compared DM96POST values. After the reclassification of the cells very good concordance coefficients were observed for promyelocytes and myelocytes (> 0.7), intermediates for reactive lymphocytes and erythroblasts (>0.5 and <0,7) and low (<0.5) for metamyelocytes. Whatever the pathology and the number of blasts on the manual review films all 97 patients were positive for blast detection on DM96. Pathological cells such as prolymphocytes, large granular lymphocytes, hairy cells, Sézary cells and other atypical lymphocytes were reclassified by the user. Digital images showed dysplastic features or inclusions in blood cells and morphologic alterations in red cells or platelets were easily identified.

Comparison of morphological classification of blood cells by the automated system DM96 shows good correlation and concordance values with respect to manual differentials. Advantages of the Cellavision DM96 over direct microscopy includes that requires less time than manual differentiation, allows the verification of the results by an expert from another location (telehematology), digital images can be stored and therefore available for re-evaluation, is a good tool for educational purposes and can improve the efficiency of a modern Hematology Laboratory.

No relevant conflicts of interest to declare.