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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A077
As the incidence of B-cell chronic lymphocytic leukemia (B-CLL), the most
common form of human leukemia, increases in an aging population, it becomes
more important to correlate the heterogenity in clinical courses of B-CLL
with the determination of the surface membrane marker phenotype of the
leukemic B-cells. Results of flow cytometric immunophenotyping of peripheral
blood (PB) and bone marrow (BM) samples were compared in a series of B-CLL
patients to establish if they match at a sufficiently acceptable level for
routine diagnostic purposes.
DIAGNOSTIC VALUE OF FLOW CYTOMETRIC IMMUNOPHENOTYPING IN B-CHRONIC
LYMPHOCYTIC LEUKEMIA - CORRELATION BETWEEN BONE MARROW AND PERIPHERAL
BLOOD SAMPLES
Kardum MM, Siftar Z, Nazor A, Kardum-Skelin I*, Jaksic O*, Maric-Besic K*,
Jaksic B*
Institute of Clinical Chemistry and *Department of Medicine, University
Hospital "MERKUR" Zagreb, Croatia
Design and methods: PB and BM samples of 138 patients with B-CLL
(66 females/72 males, median age 62.5 years) were analysed by flow cytometric
method on Coulter Epics XL. For diagnosis of B-CLL the primary panel of MoAbs
included CD19, CD20, CD5+/B-ly, CD23 together with the expression of either
kappa or lambda-light chain on B-cells, and determination of CD22, CD24 and
HLA D/DR.
Results: As expected, the majority of cases expressed monoclonal
(-light chains (66% kappa positive related to 33% lambda positive).
Median and probability of difference in paired samples is shown in the table,
along with correlation coefficient:
ly gate | CD19 | CD20 | CD22 | CD23 | CD24 | HLA D/DR | kappa | lambda | CD5 | CD5/B | |
PB | 90.0 | 87.2 | 81.3 | 17.3 | 67.7 | 74.4 | 87.3 | 15.1 | 2.1 | 92.2 | 77.6 |
BM | 90.0 | 89.6 | 86.9 | 21.6 | 69.3 | 80.5 | 90.4 | 23.5 | 1.7 | 93.3 | 78.2 |
diff p | NS | NS | NS | NS | NS | NS | NS | <0.04 | <0.03 | NS | NS |
corr r | 0.78 | 0.71 | 0.73 | 0.88 | 0.72 | 0.75 | 0.73 | 0.75 | 0.75 | 0.72 | 0.72 |
We confirmed that expression tended to be higher in BM compartment,
but the median was higher at a statistically significant level only for
light chains. The percentages of the leukemic cells and the surface antigen
positivities obtained in different tumor mass-sections (PB;BM) were fully
comparable in their mean expressions, medians and min/max values. Highly
significant correlation (p<0.0001) was observed between individual samples
with high respective correlation coefficient. Factor analysis performed on
12 variables disclosed two factors at a significant level. First factor
was significantly (r>0.7) associated with CD19, 20, 23, 24, 5 and CD5/B,
HLA/DR, while second factor is associated only with the expression of
light chains. Only CD22 did not correlate neither with factor 1 or 2, so
that its role in routine diagnostics remain to be elucidated.
Conclusions: This study has confirmed high correlation of routine MoAb
expression in PB and BM, but the addition of more B-cell markers did not
improve our diagnostic process. However, for research of adhesion molecules
which are expected to be responsible for tumor cell re-circulation,
simultaneous evaluation of PB, BM and lymph node compartments may be
essential and therefore warranted.