Krzysztof Lewandowski

Background and Objectives: The effective treatment of chronic myeloid leukemia leads to the restoration of proper immune system function. We aimed to investigate fluctuations in circulating cytokines, angiogenic factors and complement components in patients with CML during the first year of treatment with TKI and correlate them with the degree of achieved molecular response. Material and Methods: We recruited 31 patients with newly diagnosed CML. Peripheral blood and bone marrow samples were obtained, and concentrations of serum proteins were measured using an immunology multiplex assay. Results: The study cohort was divided into two groups of optimal or non-optimal in accordance with the European Leukemia Net (ELN) guidelines. We found significantly higher concentrations of C1q, C4 and C5a in serum after 3 months of TKI treatment in patients who achieved optimal responses in the 6 months after diagnosis. The most alterations were observed during 12 months of therapy. Patients in the optimal response group were characterized by higher serum concentrations of TGF-β, EGF, VEGF, Angiopoietin 1, IFN-γ and IL-8. Conclusions: The later plasma concentrations of complement components were significantly increased in patients with optimal responses. The changes after 12 months of treatment were particularly significant. Similar changes in bone marrow samples were observed.

Out of BCR‐ABL negative myeloproliferative neoplasm (MPNPh − ) patients, 3%–14% display a concomitant monoclonal gammopathy of unknown significance (MGUS). In most cases, the diagnosis of plasma cell dyscrasia is either synchronous with that of MPNPh − or occurs later on. We present a 50‐year‐old patient with type 2 CALR Lys385Asnfs*47 mutation positive essential thrombocythemia (ET) who developed symptomatic multiple myeloma (MM) 13 years after the diagnosis of ET during PEG‐INF2α treatment. The NGS study performed at the time of the MM diagnosis revealed the HRAS Val14Gly/c.41T〉G mutation and the wild type CALR , JAK2 and MPL gene sequence. In the presented case, the complete molecular remission of ET was achieved after 16 months of PEG‐INF2α treatment. The origin of MM cells in MPNPh − patients remains unknown. Published data suggests that type 2 CALRins5 up‐regulate the ATF6 chaperone targets in hematopoietic cells and activate the inositol‐requiring enzyme 1α‐X‐box‐binding protein 1 pathway of the unfolded protein response (UPR) system to drive malignancy. It cannot be excluded that endoplasmic reticulum stress induced by the increased ATF6 resulted in an abnormal redox homeostasis and proteostasis, which are factors linked to MM. The presented case history and the proposed mechanism of mutant CALR interaction with UPR and/or ATF6 should initiate the discussion about the possible impact of the mutant CALR protein on the function and genomic stability of different types of myeloid cells, including progenitor cells.