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THE IMPORTANCE OF IMMUNOPHENOTYPING OF HEMOPOIETIC PRECURSORS IN THE DIAGNOSIS OF CHILDHOOD MDS
Author(s): ,
Irene Lorand-Metze
Affiliations:
Internal Medicine,University of Campinas,Campinas,Brazil
,
Anita F Oliveira
Affiliations:
Pediatrics,Cancer Hospital Barretos,Barretos,Brazil
,
Aline Tanzini
Affiliations:
Pathology,Cancer Hospital Barretos,Barretos,Brazil
,
Luiz Fernando Lopes
Affiliations:
Pediatrics,Cancer Hospital Barretos,Barretos,Brazil
Konradin Metze
Affiliations:
Pathology,University of Campinas,Campinas,Brazil
(Abstract release date: 05/19/16) EHA Library. Lorand-Metze I. 06/09/16; 132770; E1221 Disclosure(s): I have nothing to disclose
Prof. Dr. Irene Lorand-Metze
Prof. Dr. Irene Lorand-Metze
Contributions
Abstract
Abstract: E1221

Type: Eposter Presentation

Background
 immunophenotyping of BM hemopoietic precursors has been recognized as useful ancillary technique to confirm the diagnosis of adult MDS. In children, few data about its utility are available.

Aims
 to analyze retrospectively the immunophenotypic features of bone marrow (BM) cells at diagnosis of patients registered in the Brazilian Pediatric Cooperative Group of Myelodysplastic Syndromes (2012-2015).

Methods
diagnosis of the patients was based on clinical data, peripheral blood (PB) counts, BM cytology and histology and cytogenetics. Deficiency anemias, autoimmune diseases and viral infections were excluded, as well as patients with Down’s syndrome. Classification was made by the WHO Pediatric Classification. Four pediatric deficiency anemias were used as controls. Immunophenotyping was made by an 8 color platform to evaluate myelomonocytic maturation and progenitor populations according to the recommendations of the European LeukemiaNet

Results
 32 patients (RCC = 6 cases; RAEB/-t = 13 cases; JMML = 13 cases) and 4 controls (deficiency anemias) were analyzed. Median age: controls = 20 months, RCC = 66 months, RAEB/-t  = 68 months and JMML = 29 months. The median number of abnormalities in myeloid maturation was 1.5 (0 - 4); 3 (0 - 6) and 3 (1 - 5) respectively. The median number of abnormalities in CD34+ cells were 2 (1 - 3); 2.5 (1 - 6) and 3 (1 - 5) respectively. So, the total number of phenotypic alterations was 4 (1 - 6); 3 (2 - 11) and 6 (2 - 9) respectively. The percentage of CD34+/CD117+/CD13+ cells was 0.5% (0.1 – 2.8); 3.7 % (0.5 - 8.6) and 4.2% (0.3 - 10.1) respectively, compared to 1.1% (0.7 – 1.6) of the control cases. Aberrant cross-lineage antigen expressions in myeloid progenitors were found in 63% of the cases of JMML, in 45% of RAEB/RAEB-t but in none of the RCCs. Hematogones type I (CD34+/CD19+/CD10+) were decreased in all groups: 0.28% (0 – 2.4); 0.5% (0 – 6.4) and 0.03% (0 -0.6) respectively, compared with the controls: 2.1% (0.9 – 3.2). The same occurred in %CD34- /CD19+/CD10+ cells: 1.6% (0 – 15.5); 0.8% (0 – 6.2) and 0.02% (0. – 2.1) respectively, compared with the controls: 12.0 (3.9 – 12.9). T lymphocytes were markedly decreased only in patients with JMML. In a discriminant analysis, a model containing age of the patient, percentage of CD34+/CD117+/CD13+ cells, hematogones type I, T lymphocytes and total number of phenotypic alterations were able to classify correctly 81% of the patients.

Conclusion
in childhood MDS, alterations in myeloid precursors and CD34+ myeloid progenitors presented similar changes as in adult MDS. However, the alterations in B cell precursors and T lymphocytes were more pronounced, even in very young children. Phenotypic abnormalities in JMML were more similar to those of RAEB, regardless of the number of BM blasts counted in cytology or any feature of PB counts.

Session topic: E-poster
Abstract: E1221

Type: Eposter Presentation

Background
 immunophenotyping of BM hemopoietic precursors has been recognized as useful ancillary technique to confirm the diagnosis of adult MDS. In children, few data about its utility are available.

Aims
 to analyze retrospectively the immunophenotypic features of bone marrow (BM) cells at diagnosis of patients registered in the Brazilian Pediatric Cooperative Group of Myelodysplastic Syndromes (2012-2015).

Methods
diagnosis of the patients was based on clinical data, peripheral blood (PB) counts, BM cytology and histology and cytogenetics. Deficiency anemias, autoimmune diseases and viral infections were excluded, as well as patients with Down’s syndrome. Classification was made by the WHO Pediatric Classification. Four pediatric deficiency anemias were used as controls. Immunophenotyping was made by an 8 color platform to evaluate myelomonocytic maturation and progenitor populations according to the recommendations of the European LeukemiaNet

Results
 32 patients (RCC = 6 cases; RAEB/-t = 13 cases; JMML = 13 cases) and 4 controls (deficiency anemias) were analyzed. Median age: controls = 20 months, RCC = 66 months, RAEB/-t  = 68 months and JMML = 29 months. The median number of abnormalities in myeloid maturation was 1.5 (0 - 4); 3 (0 - 6) and 3 (1 - 5) respectively. The median number of abnormalities in CD34+ cells were 2 (1 - 3); 2.5 (1 - 6) and 3 (1 - 5) respectively. So, the total number of phenotypic alterations was 4 (1 - 6); 3 (2 - 11) and 6 (2 - 9) respectively. The percentage of CD34+/CD117+/CD13+ cells was 0.5% (0.1 – 2.8); 3.7 % (0.5 - 8.6) and 4.2% (0.3 - 10.1) respectively, compared to 1.1% (0.7 – 1.6) of the control cases. Aberrant cross-lineage antigen expressions in myeloid progenitors were found in 63% of the cases of JMML, in 45% of RAEB/RAEB-t but in none of the RCCs. Hematogones type I (CD34+/CD19+/CD10+) were decreased in all groups: 0.28% (0 – 2.4); 0.5% (0 – 6.4) and 0.03% (0 -0.6) respectively, compared with the controls: 2.1% (0.9 – 3.2). The same occurred in %CD34- /CD19+/CD10+ cells: 1.6% (0 – 15.5); 0.8% (0 – 6.2) and 0.02% (0. – 2.1) respectively, compared with the controls: 12.0 (3.9 – 12.9). T lymphocytes were markedly decreased only in patients with JMML. In a discriminant analysis, a model containing age of the patient, percentage of CD34+/CD117+/CD13+ cells, hematogones type I, T lymphocytes and total number of phenotypic alterations were able to classify correctly 81% of the patients.

Conclusion
in childhood MDS, alterations in myeloid precursors and CD34+ myeloid progenitors presented similar changes as in adult MDS. However, the alterations in B cell precursors and T lymphocytes were more pronounced, even in very young children. Phenotypic abnormalities in JMML were more similar to those of RAEB, regardless of the number of BM blasts counted in cytology or any feature of PB counts.

Session topic: E-poster

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