Contributions
Abstract: PB1602
Type: Publication Only
Background
CD45 antigen, also known as Protein Tyrosine Phosphatase, receptor type, C (PTPRC), is expressed in hematopoietic cells and its expression is commonly quantified at diagnostic immunophenotyping. Overexpression of CD45 has been previously linked to poor prognosis in children with B- and T-cell ALL.
Aims
Our goal is to study the possible use of CD45 expression as a prognostic factor.
Methods
Bone marrow samples of children with B-cell ALL were studied at the time of diagnosis before treatment initiation according to ALL-BFM 2009. All patients that were admitted to our department from April 2013 to October 2017 were enrolled in the study (44 patients in total). CD45 expression was measured both in normal lymphocytes and leukemic blasts and a relative ratio of its expression (leukemic versus normal) was calculated. Statistical analysis was conducted with the Statistical Package for the Social Science (SPSS) for Windows, version 23 (SPSS Inc., Chicago, IL).
Results
We divided the sample into two groups according to the cell line affected (B- and T-cell leukemia). In our study group 39 children were diagnosed with B-ALL and only 5 with T-ALL. The expression of CD45 was assumed to be high when it exceeded the 75th percentile (relative ratio 12.4% for B-ALL). It was observed that the mean expression of CD45 in patients with B-ALL who had a relapse or died than in patients without an event was higher (Figure 1). We also found that there is a statistically important correlation between relapse or death and the expression of CD45 above the 75th percentile in patients with B-ALL, p<0.05 (p=0.011). Moreover, we calculated that the probability of an event (relapse or death) in patients with B-ALL was 18.67 times higher when the expression of CD45 was above the 75th percentile. Finally, patients with B-ALL and high expression of CD45 had a shorter 2-year event-free survival compared to patients with low expression (51.4% versus 96.6%, p<0.01) (Figure 2). Due to the small sample of patients with T-ALL we could not calculate statistically important correlations in that group.
Conclusion
The high expression of CD45 could be used as a prognostic factor in patients with acute lymphoblastic leukemia.
Session topic: 1. Acute lymphoblastic leukemia – Biology & Translational Research
Keyword(s): Acute lymphoblastic leukemia, CD45
Abstract: PB1602
Type: Publication Only
Background
CD45 antigen, also known as Protein Tyrosine Phosphatase, receptor type, C (PTPRC), is expressed in hematopoietic cells and its expression is commonly quantified at diagnostic immunophenotyping. Overexpression of CD45 has been previously linked to poor prognosis in children with B- and T-cell ALL.
Aims
Our goal is to study the possible use of CD45 expression as a prognostic factor.
Methods
Bone marrow samples of children with B-cell ALL were studied at the time of diagnosis before treatment initiation according to ALL-BFM 2009. All patients that were admitted to our department from April 2013 to October 2017 were enrolled in the study (44 patients in total). CD45 expression was measured both in normal lymphocytes and leukemic blasts and a relative ratio of its expression (leukemic versus normal) was calculated. Statistical analysis was conducted with the Statistical Package for the Social Science (SPSS) for Windows, version 23 (SPSS Inc., Chicago, IL).
Results
We divided the sample into two groups according to the cell line affected (B- and T-cell leukemia). In our study group 39 children were diagnosed with B-ALL and only 5 with T-ALL. The expression of CD45 was assumed to be high when it exceeded the 75th percentile (relative ratio 12.4% for B-ALL). It was observed that the mean expression of CD45 in patients with B-ALL who had a relapse or died than in patients without an event was higher (Figure 1). We also found that there is a statistically important correlation between relapse or death and the expression of CD45 above the 75th percentile in patients with B-ALL, p<0.05 (p=0.011). Moreover, we calculated that the probability of an event (relapse or death) in patients with B-ALL was 18.67 times higher when the expression of CD45 was above the 75th percentile. Finally, patients with B-ALL and high expression of CD45 had a shorter 2-year event-free survival compared to patients with low expression (51.4% versus 96.6%, p<0.01) (Figure 2). Due to the small sample of patients with T-ALL we could not calculate statistically important correlations in that group.
Conclusion
The high expression of CD45 could be used as a prognostic factor in patients with acute lymphoblastic leukemia.
Session topic: 1. Acute lymphoblastic leukemia – Biology & Translational Research
Keyword(s): Acute lymphoblastic leukemia, CD45