Avaliação de neutrófilos circulantes em pacientes com neoplasias mieloproliferativas philadelphia negativas em tratamento quimioterápico

Abstract

Myeloproliferative neoplasms (MPNs) are a group of blood cell diseases that arise from a change in the hematopoietic stem cell. The most classic are Polycythemia vera (PV) and Essential thrombocythemia (ET). Negative Ph1 NMPs have a long and relatively benign clinical course but have no cure. Cytoreductive chemotherapy acts not only on erythrocytes and megakaryocytes, but also has its action on leukocytes, specifically neutrophils. One of the therapies employed is Hydroxyurea (HU), which has neutropenia as one of its side effects, studies show that this drug can have direct effects on neutrophils. The identification of possible quantitatively and qualitatively changes of neutrophils under the effects of cytoreductive chemotherapy in patients with negative Ph1 MPNs represents an advance in the understanding of the treatment in these MPNs. Hemogram and leukogram are part of the treatment follow-up protocol. In order to qualitatively evaluate some functions, the neutrophils were sensitized with zymosan, thus stimulating the phagocytosis, in relation to the metabolism, the cytochemical test of spontaneous reduction of nitroblue tetrazolium (NBT), besides quantification of myeloperoxidase (MPO) through flow cytometry. In this study, all methodologies previously cited for quantitative and qualitative evaluation were performed on blood samples from 46 patients (PV = 17; ET = 29). The patients with PV had lower IF than the control group, with p = 0.0002 (2.83 ± 1.28, 3.83 ± 1.38, respectively). The same was observed in the patients with ET who presented lower index than the control subjects with p = 0.0002 (2.85 ± 1.34, 3.83 ± 1.38 respectively). Our results showed that there was no difference in the activation of the oxidative metabolism in the NBT reduction test, between the control group and the PV group in HU use, with p = 0.9047 (5 ± 2.7, 2.9 ± 3.5 respectively) and control group with ET group in HU use, presenting p = 0.2870 (5 ± 2.7, 5 ± 6.9 respectively). The MPO test was performed on all patients with NMPs who were undergoing treatment with HU. Our results showed that there was no difference between the control group and the patients in the PV group, with p = 0.8438 (98.47 ± 1.15, 98.54 ± 1.46, respectively). controls and patients with ET, with p = 0.5842 (98.47 ± 1.15, 97.93 ± 3.21 respectively). Patients with PV and ET who used HU presented qualitative changes in neutrophils, in which the use of HU decreased the phagocytic activity of neutrophils in these patients.