Assessment of monocytic component in acute myelomonocytic and monocytic/monoblastic leukemias by a chemiluminescent assay.
BACKGROUND
Classically, the monocytic component of acute myelomonocytic (FAB-M4) and acute monocytic/monoblastic (FAB-M5) leukemias is demonstrated by nonspecific esterase positivity in cytochemical stainings. We have previously demonstrated that non-specific esterases from normal monocytes can be determined by a chemiluminescent method. In the present study, we investigated whether this assay can also determine the monocytic component of FAB-M4 and FAB-M5 and distinguish these acute myeloid leukemia (AML) categories.


METHODS
Bone marrow samples were obtained from 66 patients with AML (M0, two cases; M1, 12 cases; M2, 13 cases; M3, 10 cases; M4, 11 cases; M5, 12 cases; M6, two cases; M7, four cases). Cells were incubated with a standard reaction mixture and chemiluminescence was measured for 10 min. Two parameters were assessed, the peak (PLE) and the integrated light emission (ILE).


RESULTS
Both PLE and ILE were higher in FAB-M4 and FAB-M5 subtypes compared to other AML subtypes (P<0.001). In addition, the classification of AML cases into FAB-M4, FAB-M5 and nonmonocytic subtypes based on ILE analysis was concordant with alpha-naphthyl acetate esterase (ANAE) in 97% of cases (kappa coefficient 0.94, P<0.001).


CONCLUSIONS
These findings indicate that this chemiluminescent assay was able to determine the monocytic component of FAB-M4 and FAB-M5 cells, and the classification of AML subtypes based on chemiluminescent analysis strongly agreed with the cytochemical ANAE-staining. In conclusion, this chemiluminescent assay is a simple, fast and objective method, which may be useful as an alternative tool in the differential diagnosis of AML subtypes.
da Fonseca
Luiz M
LM
Department of Clinical Analysis, State University of São Paulo School of Pharmaceutical Sciences, Araraquara, Brazil.
Brunetti
Iguatemy L
IL
Campa
Ana
A
Catalani
Luiz H
LH
Calado
Rodrigo T
RT
Falcão
Roberto P
RP
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001565:Benzoates / Q000378:metabolism; D001853:Bone Marrow / Q000473:pathology*; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D015925:Cryopreservation; D003937:Diagnosis, Differential; D005260:Female; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D007948:Leukemia, Monocytic, Acute / Q000175:diagnosis / Q000201:enzymology / Q000473:pathology*; D007951:Leukemia, Myeloid / Q000473:pathology; D015479:Leukemia, Myelomonocytic, Acute / Q000175:diagnosis / Q000201:enzymology / Q000473:pathology*; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000201:enzymology / Q000473:pathology*; D009363:Neoplasm Proteins / Q000032:analysis; D014411:Neoplastic Stem Cells / Q000201:enzymology / Q000473:pathology*; D012969:Sodium Fluoride / Q000494:pharmacology
C101261:2-methyl-1-propenylbenzoate; D001565:Benzoates; D009363:Neoplasm Proteins; D012969:Sodium Fluoride; D006735:Horseradish Peroxidase; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase