Identification of blast cells in peripheral blood through automatic assessment of nuclear density: a new tool for monitoring patients with acute leukaemia.
The Technicon H*1 haematology system is provided with a new method for basophil count, neutrophil lobularity assessment and detection of blasts in peripheral blood through automated measurement of nuclear density. We compared the results of the H*1 blast flag with those of the microscope examination in 131 peripheral blood samples from 43 patients with acute leukaemia in different phases of their disease, to determine the degree of sensitivity and specificity of the system in this setting. In six patients at diagnosis or in overt relapse, all having large percentages of blasts at the manual differential count, a typical deformation of the profile of the mononuclear cell population on the display was consistently observed, regardless of the morphological subtype of leukaemic cell which was involved. Amongst 34 samples with 4-95% morphologically recognizable blasts on the peripheral blood film, the sensitivity of the system was 100% with no false negatives at all. In 43 samples, on the other hand, the H*1 blast flag was positive in the absence of any morphological evidence of blasts on the smear. These 'false positives', however, were always obtained from leucopenic patients who had more than 12% blast infiltration in the bone marrow, compared to the 0-6% value that was found in patients with a negative H*1 blast flag. These results suggest that the H*1 system is a highly sensitive tool for the detection in peripheral blood of even small concentration of leukaemic cells, which escape morphological identification.
d'Onofrio
G
G
Istituto di Semeiotica Medica, Universita' Cattolica del Sacro Cuore, Roma, Italy.
Mancini
S
S
Leone
G
G
Bizzi
B
B
Mango
G
G
D000208:Acute Disease; D000328:Adult; D002467:Cell Nucleus; D003720:Densitometry; D006403:Hematologic Tests / Q000295:instrumentation; D006801:Humans; D007938:Leukemia / Q000097:blood* / Q000473:pathology