Short description of the progress of the project:

Background:

In this project we aim to characterize in detail the factors related to immune tolerance in leukemia patients by analysing the expression of inhibitory receptors and ligands (checkpoint molecules) on the primary patient cells. In addition, we will assess the function of immune effector cells and correlate that to therapy responses. When succeeding, this study may open the way to find new diagnostic and therapeutic targets for leukemia patients. We also aim to characterize the effects of tyrosine kinase inhibitor treatment on different immune cell subsets and evaluate the importance of early treatment response in chronic myeloid leukemia (CML).

Current status and preliminary results:

We have collected blood and bone marrow samples from 20 patients with CML at the diagnosis and during treatment. We have measured the expression of various immune checkpoint receptors by flow cytometry in these samples and data analysis is ongoing.

We have also collected data from 105 first line tyrosine kinase inhibitor (TKI) treated patients (71 patients on imatinib, 25 on dasatinib and 9 on nilotinib ) to analyze the bone marrow lymphocyte composition at the diagnosis and during the treatment. In addition, we included 14 healthy persons as controls. We took BM aspirate samples at diagnosis and at 3, 6, 12 and 18 months post TKI start. BM morphology was examined from MGG stained slides and proportions of different cell subsets were counted. In addition, peripheral blood samples were taken from the same times points. Treatment responses were checked with karyotyping and molecular real time PCR. Moreover, flow cytometric analysis was done in parallel for the bone marrow and peripheral blood samples to examine different cell types and populations.

Among 105 CML patients, we found an early (3 months) expansion of BM lymphocytes during all different TKI therapies. Increased peripheral blood (PB) lymphocyte count was only observed during dasatinib therapy. The BM lymphocyte expansion was associated with better early molecular response; patients with 3 months BCR-ABL<10% showed higher lymphocyte counts than patients with BCR-ABL>10%. Detailed phenotypic analysis showed that lymphocyte expansion consisted of various lymphocyte subclasses, but especially the proportion of CD19+ B cells and CD3negCD16/56+ NK cells increased from diagnostic values. During dasatinib treatment the lymphocyte balance both in BM and PB was shifted more to cytotoxic direction (increased CD8+CD57+ and CD8+HLA-DR+ cells, and low T regulatory cells). Results from these experiments have been finalized and manuscript has been submitted in July 2015.

In the next project we studied the importance of initial decrease in the BCR-ABL transcript level after the start of TKI therapy. A fold change (FC) factor was calculated by dividing the initial diagnostic BCR-ABL values by 1 month values, and we examined if this initial decline was able to predict the later responses to the treatment (3, 6, 12, 18, 24, and 36 months time points). The study included 52 first-line CML patients; 26 on imatinib, 21 dasatinib, and 5 nilotinib. Results confirmed that the initial decrease was able to predict well later responses. We are currently writing the second manuscript of these results.

 

Manuscripts/abstracts related to this work:

Manuscript 1: Submitted to the journal (Experimental Hematology)

 

Mohamed El Missiry, Shady Adnan, Hanna Rajala , Ahmed Al-Samadi, Marja Ekblom, Berit Markevän, Ingbritt Åstrand-Grundström, Maren Wold, Ellen Rabben Svedahl, Birgitte Ravn Juhl, Inger Haulin, Kimmo Porkka, Ole Weis Bjerrum, Ulla Olsson-Strömberg, Henrik Hjorth-Hansen, Satu Mustjoki.^. Assessment of bone marrow lymphocytic status during tyrosine kinase inhibitor therapy and its relation to therapy response in chronic phase chronic myeloid leukemia patients

Abstract 1: Submitted to American Society of Hematology (ASH) Annual Conference (December 5-8, 2015-Orlando, FL).

Mohamed El Missiry, Shady Adnan, Hanna Rajala , Ahmed Al-Samadi, Marja Ekblom, Berit Markevän, Ingbritt Åstrand-Grundström, Maren Wold, Ellen Rabben Svedahl, Birgitte Ravn Juhl, Inger Haulin, Kimmo Porkka, Ole Weis Bjerrum, Ulla Olsson-Strömberg, Henrik Hjorth-Hansen, Satu Mustjoki.^.Bone marrow lymphocytic status during tyrosine kinase inhibitor therapy and its relation to therapy response in chronic phase chronic myeloid leukemia patients

 

Manuscript 2:

Mohamed El Missiry, Anna Kreutzman, Kimmo Porkka, Ulla Olsson-Strömberg, Johan Richter, Henrik Hjorth-Hansen, Satu Mustjoki. Early response predictor in the treatment of CML. (manuscript in preparation)