Contributions
Abstract: EP908
Type: E-Poster Presentation
Session title: Myelodysplastic syndromes - Biology & Translational Research
Background
Myeloid neoplasms (MN) are diagnosed by a combination of clinical, morphologic and genetic findings. Aberrant immunophenotype of myeloid cells by flow cytometry immunophenotyping (FCIP) is frequently associated with MN. However, by itself FCIP is insufficient for establishing the diagnosis of MN due to (I) lack of specificity and (II) marked variability in appraches by different laboratories. We have previously shown that abnormalities of CD13/HLA-DR expression on CD34-positive blasts could be a sensitive and specific method for a simple assessment of myeloid dysmaturation.
Aims
To determine whether a simple immunophenotyping approach using aberrant expression of CD2, CD7 and CD56 on myeloid blasts, and qualitatively abnormal FCIP patterns on CD13/HLA-DR and CD13/CD16 plots could predict development of MN in a subpopulation of patients with clonal cytopenia of undetermined significance (CCUS).
Methods
Bone marrow aspirates were analyzed using 2 8-color FCIP tubes (see table below). A total of 500,000 events were collected per tube, using BD Canto II instruments. The data were analyzed using Kaluza software. CD34+CD45dim blasts were evaluated for the aberrant expression of CD2, CD7 and CD56 (cut-offs 10%, 30%, and 10%, respectively, were established previously by adding 2 SD to the mean of the expression in the normal cohort. In addition, CD34-positive blasts were evaluated for the aberrant expression pattern of CD13/HLA-DR, as previously described [AJCP (2014) 142:292]. Aberrancies of granulocyte maturation were evaluated on the CD13/CD16 plot.
Relevant clinical and laboratory data, including CBC and the presence of genetic abnormalities, were extracted from the electronic medical record. Statistical analysis was done using R statistical software.
Results
Out of 86 patients with CCUS, 21 developed MN over the follow-up time period (median follow-up 28 months). FCIP abnormalities detected at diagnosis of CCUS were predictive of the future developmen of MN, with the most significant abnormalities being: (I) aberrant expression of CD7 on CD34-positive myeloid blasts (p=0.014, HR 3.74), (II) aberrant pattern of CD13/HLA-DR expression on CD34-positive myeloid blasts (p=0.019, HR 2.59), and (III) presence of multiple (>1) FCIP abnormalities (p=0.003, HR 1.90).
Conclusion
A simple FCIP approach, which includes assessment of CD13/HLA-DR pattern on CD34-positive myeloid blasts, can be useful in predicting the development of MN in CCUS patients.
Keyword(s): Flow cytometry, MDS, Myeloid malignancies
Abstract: EP908
Type: E-Poster Presentation
Session title: Myelodysplastic syndromes - Biology & Translational Research
Background
Myeloid neoplasms (MN) are diagnosed by a combination of clinical, morphologic and genetic findings. Aberrant immunophenotype of myeloid cells by flow cytometry immunophenotyping (FCIP) is frequently associated with MN. However, by itself FCIP is insufficient for establishing the diagnosis of MN due to (I) lack of specificity and (II) marked variability in appraches by different laboratories. We have previously shown that abnormalities of CD13/HLA-DR expression on CD34-positive blasts could be a sensitive and specific method for a simple assessment of myeloid dysmaturation.
Aims
To determine whether a simple immunophenotyping approach using aberrant expression of CD2, CD7 and CD56 on myeloid blasts, and qualitatively abnormal FCIP patterns on CD13/HLA-DR and CD13/CD16 plots could predict development of MN in a subpopulation of patients with clonal cytopenia of undetermined significance (CCUS).
Methods
Bone marrow aspirates were analyzed using 2 8-color FCIP tubes (see table below). A total of 500,000 events were collected per tube, using BD Canto II instruments. The data were analyzed using Kaluza software. CD34+CD45dim blasts were evaluated for the aberrant expression of CD2, CD7 and CD56 (cut-offs 10%, 30%, and 10%, respectively, were established previously by adding 2 SD to the mean of the expression in the normal cohort. In addition, CD34-positive blasts were evaluated for the aberrant expression pattern of CD13/HLA-DR, as previously described [AJCP (2014) 142:292]. Aberrancies of granulocyte maturation were evaluated on the CD13/CD16 plot.
Relevant clinical and laboratory data, including CBC and the presence of genetic abnormalities, were extracted from the electronic medical record. Statistical analysis was done using R statistical software.
Results
Out of 86 patients with CCUS, 21 developed MN over the follow-up time period (median follow-up 28 months). FCIP abnormalities detected at diagnosis of CCUS were predictive of the future developmen of MN, with the most significant abnormalities being: (I) aberrant expression of CD7 on CD34-positive myeloid blasts (p=0.014, HR 3.74), (II) aberrant pattern of CD13/HLA-DR expression on CD34-positive myeloid blasts (p=0.019, HR 2.59), and (III) presence of multiple (>1) FCIP abnormalities (p=0.003, HR 1.90).
Conclusion
A simple FCIP approach, which includes assessment of CD13/HLA-DR pattern on CD34-positive myeloid blasts, can be useful in predicting the development of MN in CCUS patients.
Keyword(s): Flow cytometry, MDS, Myeloid malignancies