[Contribution of phenotyping cells in metaphase and interphase (MAC and MACISH techniques) to the study of hematologic neoplasms].

BACKGROUND

Banding techniques are essential in the chromosomal analysis for the cytogenetic diagnosis. Even that, conventional cytogenetic techniques destroy the cytoplasmic membrane and the lineage involvement of the karyotyped cells is unknown. In this work the usefulness of a method that keeps the cell intact and allows the sequential application of immunological, cytochemical, morphological and cytogenetic techniques in the same cell is shown. This technique is called MAC for morphology, antibodies and chromosomes. The combination of MAC and in situ hybridization techniques (MACISH method) allows the detection of a chromosome abnormality in all the cells even when no mitosis are present.

PATIENTS AND METHODS

The MAC method was applied in 51 patients and the MACISH method in 9 patients in order to identify the cells which karyotype is analyzed. We have studied 47 patients with normal karyotype (37 chronic lymphocytic leukaemia [CLL] and 10 essential trombocythaemias (ET) and 4 patients with different diseases and abnormal karyotype.

RESULTS

Among 37 patients with CLL and normal karyotype, in 9 cases only normal T-cells were in mitoses and in 28 cases the normal karyotype belonged to neoplastic B cells. Trisomy 12 has been confined exclusively to the leukaemic B cells with the MACISH technique in 3 of these CLL cases. In 10 patients with ET and normal karyotype the MAC method showed that in any case the mitosis analyzed belonged to the megakaryocyte lineage. In 4 patients with different chromosomal abnormalities the haematological cell lines involved in the neoplasia were known with the MAC method.

CONCLUSION

In this work is shown the usefulness of the combination of the MAC and MACISH techniques with conventional cytogenetics in order to complete the chromosomic study of the haematological neoplasms is confirmed. These methods are specially usefull when different cell lineages are involved in the neoplasia, reactive proliferations are suspected, or to discard false aneuploidies.