الفهرس 
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Abstract
SUMMARY AND CONCLUSION
The Human Myeloid Inhibitory C-Lectin (hMICL) also known as Human C-type lectin-like molecule-1 (CLL-1), or
C-type lectin domain family 12 member A (CLEC12A), is a
type II transmembrane glycoprotein and member of the
large family of C-type lectin-like receptors involved in
immune regulation.
The hMICL is a pan-myeloid antigen that is absent on
normal uncommitted primitive CD34+ CD38- or CD34+
CD33- stem cells; which aids the discrimination between
normal and leukemic stem cells, as well as introduces
hMICL as a promising therapeutic target for eradication of
antigen-bearing leukemic cells and the subsequent reestablishment
of normal hematopoiesis through the
remaining normal stem cells.
In the absence of leukemia specific markers, the
distinction between leukemic and normal immature cell
relies on the expression of antigen combinations defining
leukemia-associated IPs (LAIPs), which are absent or
extremely infrequent in normal bone marrow (NBM).
There is, however, evidence in the literature which has
outlined that these LAIPs are very different from patient to
Summary and Conclusion
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patient and that they are not necessarily stable over the
course of disease.
Consequently, there is still a need for the identification
of new antigens contributing to diagnostic and prognostic
information, improving relapse detection, identification,
and ideally eradication of leukemic stem cells (LSCs)
through antibody mediated targeted therapy.
The aim of this work is to determine the diagnostic
impact and the applicability of the Human Myeloid
Inhibitory C-Lectin (hMICL) in routine clinical
flowcytometry in the diagnosis of Acute myeloid leukemia
(AML).
This study was conducted on 40 AML patients, 20
ALL patients and 20 healthy control subjects who were
investigated for hMICL by FCM. The hMICL was
expressed in all studied AML patients which was found to
be significantly high compared to ALL cases and the healthy
control subjects. Also, the hMICL MFI, was significantly
higher in AML patients compared to ALL cases and healthy
control subjects.
Summary and Conclusion
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Using the receiver operating characteristic (ROC)
curve, a cut-off was evaluated for hMICL% and hMICLMFI,
which allows significant separation and differentiation
between AML cases and normal subjects. The
hMICL% cut-off value was 9.5% showing sensitivity of
95% and specificity of 100% .The hMICL MFI cut-off was
2.3 showing sensitivity of 100% and specificity of 85.00%
In different FAB subtypes, expression of hMICL % was
heterogenous. The highest percentage was in M1 95% and
lowest in M4 20%. This heterogeneity of hMICL %
expression was found to be significant.
An interesting finding is that hMICL expression was
also found in all CD 34- cases with percentage that reached
87% which paves the way for improved LAIP
characterization and MRD quantification by multicolour
FCM in the otherwise poorly described CD34- AML cases.
In conclusion, the results of the present study
confirmed the importance of hMICL in diagnosis of AML
in order to be in the routine FCM setting