الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Acute leukemias are one of the most common hematological malignancies with varying clinical, morphologic, immunologic and molecular characteristics. Leukemia is diagnosed by morphology and cytochemistry. Immunophenotyping, cytogenetic and molecular genetics further help in confirmation. Aberrant phenotypes in AL are defined as the expression of lymphoid-associated markers in myeloblasts or that of myeloid associated markers in lymphoblasts. Aberrant expression helps in sub-classifying the type of leukemia and in MRD detection. Aberrant phenotypes in AL have variable frequency. Their prognostic relevance is controversial and dissimilar results have been reported by different groupsThis study aims to determine frequency of aberrant marker expression in AL at SECI over 10 years duration from 2008 to 2018 and to relate these expression with patient outcome and cytogenetic abnormality With reviewing medical records of patients admitted to SECI in this period, a total number of patients with different types of malignancies was 27551. Out of those, there were 1134 diagnosed with AL (4.11%). It was found that there was a male predominance (56.5%) in AL either as a whole or in AL subtypes (54.4% and 58.4% for AML and ALL, respectively). Pediatrics were more frequently affected (59.4%) with AL than adults and similarly in ALL (73.1%) while in AML, adults represent the greater fraction (60.7%). As for the types of acute leukemia, there was a prevalence of B-ALL (43.6%) followed by AML (40.4%), then T-ALL (13.8%) and 2.2% of the cases were BAL. ETP represented 12.7% from patients with T-ALL. Regarding AML subtypes, AML with monocytic differentiation has the highest frequency (48%) followed by AML-M3 (22.7%), AML-M1/M2 (16%), then AML-M0 (5.7%), AML-M7 and AML-M6 (5% and 2.6%, respectively). Follow up data was avaliable for only 277 AL patients, those patients were distributed as follow: 97 (35%) patients with AML, 143 (51.6%) with B-ALL, 33 (11.9 %) with T-ALL and 4 (1.4%) patients with biphenotypic type.The patients with and without aberrant expression in each group were followed up and compared for CR achievement and occurance of relapse after CR and for the duration of DFS. Cytogenetic data was available for 52 patients out of 302 AL patients with aberrant expression. Analysis of the relation between aberrant expression in AL and the prescence of cytogenetic abnormality was done for occurance of CR, relapse and DFS. Aberrant expression was detected in 19.9% AML patients. The most frequent aberrant markers expressed in AML patients with aberrant expression were CD56 and CD19 (74.7%, 36.3% respectively). While CD5 and CD79a in 4.4% and 1.1%. Aberrant expression in AML carries no significant prognostic value for CR, relapse and DFS when compared with those without. Aberrant expression was detected in 30% B-ALL patients. Aberrant MyAg expression in B-ALL was more common than T-cell Ags where CD33 was the most frequent aberrant marker (77%) followed by CD13 (16.2%), CD117 was expressed in 6.8%, CD56 in 4.7% and CD5 in 3.4% of B-ALL patients with aberrant expression. CD4 and CD7 were expressed in 1.4 and 0.7% B-ALL patients with aberrant expression respectively. Aberrant expression in B-ALL was a poor progostic factor for relapse but of no prognostic value for CR and DFS when compared with those without. Aberrant expression was detected in 40.1% T-ALL patients. Aberrant B-cell Ag expression in T-ALL was more common than MyAg where CD10 was the most frequent aberrantly expressed marker (71.4%) followed by CD33 (12.7%), CD56 (11.1%). CD117 and CD19 were expressed in 9.5% and 4.8% while CD13 was expressed in 3.2% B-ALL patients with aberrant expression. Aberrant expression in T-ALL carries no significant prognostic value for CR, relapse and DFS when compared with those without. There were 21 B-ALL patients with aberrant expression had positive BCR/ABL and 16 B-ALL patients with aberrant expression were BCR/ABL-. CD33 was the most frequent aberrant marker in BCR/ABL+ cases (81%) followed by CD13 (23.8%) and CD117 (9.5%) and the expression of these markers were higher in BCR/ABL+ than BCR/ABL- cases. BCR/ABL positivity in B-ALL patients with aberrant expression was a good prognostic factor for DFS, but of no significant value for CR and relapse when compared to those with BCR/ABL-. So, aberrant expression presented with a considerable frequency among patients with various subtypes of AL at SECI. It was presented in 19.9% AML patients, 30% B-ALL patients and 40.1% T-ALL patients. CD56 was the most common aberrant expressed antigen in AML, CD33 in B-ALL and CD10 in T-ALL. Aberrant expression in AL subtypes had no prognostic value except it was an adverse prognostic factor for relapse in B-ALL. Individual aberrant antigens may be related to certain cytogenetic abnormalities. CD33, CD13 and CD117 were more common in BCR/ABL+ B-ALL cases, CD56 in AML cases with t(15;17), CD19 and CD56 in AML with t(8;21), CD19 in the AML case with Monosomy7 and CD33 in the B-ALL patient with t(1;19) and the B-ALL patient with t(8;14). Aberrant phenotypes-cytogenetics relation needs larger studies to confirm. Flow cytometry immunophenotyping plays an important role in the diagnosis and classification of AL. Aberrant expression helps in sub-classifying the type of leukemia and MRD detection. Aberrant expression in AL was presented with a considerable frequency at SECI. It was presented in 19.9% AML patients, 30% B-ALL patients and 40.1% T-ALL patients which was comparable with many international studies. CD56 was the most commonly aberrant expressed antigen followed by CD19 in AML, CD33 followed by CD13 in B-ALL and CD10 followed by CD33 in T-ALL. Aberrant expression in AL subtypes had no prognostic value except in B-ALL where it was an adverse prognostic factor for relapse. Individual aberrant antigens may be related to certain cytogenetic abnormalities as CD33, CD13 and CD117 were more common in B-ALL with positive BCR/ABL than those with negative BCR/ABL. BCR/ABL positivity in B-ALL with aberrant expression may be a good prognostic factor for DFS. CD56 was the only aberrant expressed marker in AML cases with t(15;17), CD19 and CD56 in AML with t(8;21), CD19 in the AML patient with Monosomy7 and CD33 in the B-ALL patient with t(1;19) and the B-ALL patient with t(8;14). Aberrant phenotypes-cytogenetics correlations need larger studies for confirmation