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Publications (3)6.57 Total impact

  • Article: Monitoring of donor/recipient T-cell engraftment kinetics in myeloablative allogeneic stem cell transplantation using short tandem repeat amplification from cell lysates.
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    ABSTRACT: Molecular monitoring of donor/recipient T-cell kinetics early post-transplant can provide clues to the immunological events that govern host-versus-graft reaction (HVGR) and graft versus-host-disease (GVHD). We have previously used fluorescence in situ hybridization (FISH) with X and Y probes to monitor recipient T (R-T) cell clearance early after myeloablative allogeneic stem cell transplantation (ASCT). We demonstrated that impaired clearance of residual host-T-cells in the early days post-transplant was associated with graft rejection, while enhanced clearance could be an indicator of increased donor anti-host alloreactivity and predictive of acute GVHD. Although FISH is the most accurate quantitative molecular tool for the determination of the exact donor/recipient-T-cell numbers at any time points post-transplant, it has the disadvantage of being limited to sex mismatched donor/recipient pairs. Our goal was to develop a molecular approach that, irrespective of gender, would be comparable to FISH in accurately determining host residual T-cell clearance after myeloablative conditioning for ASCT. We have genotyped DNA from cell lysates using polymerase chain reaction (PCR) amplification of short tandem repeats (STR) with fluorescently labeled oligonucleotide primers, and used the Genescan 672 software for accurate quantitative analysis of the amplified alleles. Here, we show that this approach allowed us to achieve in T-cells accurate quantitative analyses of amplified donor/recipient alleles in sex matched patients on days +5, +8 and +12 post-transplant, despite severe leukopenia.
    Leukemia and Lymphoma 07/2002; 43(6):1281-7. · 2.58 Impact Factor
  • Article: Immunophenotyping of acute leukemia at King Faisal Specialist Hospital and Research Centre.
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    ABSTRACT: During a 20 month period, 133 bone marrow samples from an equal number of patients with acute leukemia were immunophenotyped. Patients ranged in age from two to 68 years with a mean of 23 years. Eighty-four (63.2%) were classified as acute lymphocytic leukemia (ALL) with the following immunologic subclassification: common ALL 83.3%, T-cell ALL 11.9%, null-cell ALL 2.4% and 2.4% differentiated B-cell ALL. Twenty-eight cases (21%) were classified as acute myeloid leukemia (AML) and 16 cases (12%) demonstrated biphenotypic features. Concordance with morphology and cytochemistry was observed in 129 cases (97%). Four cases (3%) manifested discrepancy between immunophenotyping, morphology and cytochemistry. We conclude that immunophenotyping by flow cytometry is a useful and reliable method for classification of acute leukemia, especially when interpreted in the light of morphology and cytochemistry.
    Annals of Saudi medicine 04/1995; 15(2):137-9. · 1.07 Impact Factor
  • Article: Immunophenotyping of childhood acute lymphoblastic leukemia in Saudi Arabia: second look.
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    ABSTRACT: Geographical variations in the incidence of disease are of considerable theoretical and practical importance. It has been claimed that the distribution of acute lymphoblastic leukemia (ALL) phenotypes in Saudi Arabia is different from that recorded in the Western literature. One hundred and twelve (112) patients under 15 years of age, diagnosed as ALL between January 1992 and May 1994 had immunophenotypes performed on their blast cells. Common ALL (cALL) together with pre-B-ALL, formed 86.5% of the total; B-cell 3%, T-cell 6% and null cell 4.5%. These figures are not significantly different from the Western literature. A previous claim from this institution in 1990, that both null and B-cell ALL were significantly increased compared with elsewhere, is not supported by the present figures. Age and sex distribution, and FAB classification, L1 77%, L2 20% and L3 3%, were also of the same order as described elsewhere and, in particular, there was no increase in the frequency of L3 subtype.
    Leukemia Research 01/1995; 18(12):881-3. · 2.92 Impact Factor