Katarzyna Szmigielska

Polymorphism of CD44 Influences the Efficacy of CD34+ Cells Mobilization in Patients with Hematological Malignancies

In the last decade, peripheral blood was the main source of hematopoietic stem cells (HSC) for autologous and allogeneic transplantation. The exact mechanisms of HSC mobilization are still not clear and the efficacy of the procedure is hardly predictable. Ligand-receptor interactions of adhesion molecules, such as SDF1/CXCR4, VLA4/VCAM-1, or CD44/osteopontin, play an important role in homing of HSC in the hematopoietic niche. There is some evidence that disruption of the ligand-receptor complex leads to the egress of HSCs to the peripheral blood. The aim of the present study was the evaluation of constitutive polymorphism of genes encoding cytokines and receptors present in the HSC niche and their impact on the efficacy of mobilization of HSCs in patients with hematological malignancies. We enrolled 110 patients (60 females and 50 males) in the study. The median age of the patients was 55 (range, 22 to 69) years. The group consisted of patients with multiple myeloma (n = 74), non-Hodgkin lymphoma (n = 19), Hodgkin lymphoma (n = 15), or acute myeloid leukemia (n = 2). The mobilization procedures comprised chemotherapy and subsequent granulocyte-colony stimulating factor (G-CSF) at a dose of 10 μg/kg daily. The poor mobilizers group was defined according to Italian National Bone Marrow Transplant Registry criteria: patients with peak CD34(+) in the peripheral blood < 20/μL or total yield < 2 × 10(6) CD34(+) cells/kg body weight in maximum 3 aphereses. Genotyping was performed using standard PCR-based assays. The group of patients (N = 108) who achieved minimal threshold for collections (CD34(+) at least 10/μL) proceeded to apheresis. The median total yield of CD34(+) in this group was 5.6 × 10(6) cells/kg body weight, whereas the median number of cells collected during the first apheresis was 3.3 × 10(6) cells/kg body weight. Median number of days of G-CSF treatment before first apheresis was 10. Fifteen patients fulfilled the criteria for poor mobilizer. The group of poor mobilizers had higher frequency of TT genotype in rs13347 (CD44) gene (CC+ CT versus TT P = .047). Patients homozygous for T allele had a lower total yield of CD34(+) cells/kg body weight than the group with allele C (median, 3.7 × 10(6)/kg versus 5.8 × 10(6)/kg; P = .019) and a lower number of CD34(+) cells gathered during first apheresis (.95 × 10(6)/kg versus 3.3 × 10(6)/kg, P = .04). Multivariate logistic regression analysis revealed that the CD44 TT genotype was the only factor associated with 5-fold higher risk of poor mobilization (P = .037). Polymorphic variants of CXCR4 and VCAM-1 did not significantly influence the efficacy of HSCs mobilization in our group of patients. In conclusion, our results indicate that among investigated single nucleotide polymorphisms (SNPs), only CD44 rs13347 has an impact on the efficacy of HSCs mobilization in patients with hematologic malignancies. CD44 SNPs analysis may be helpful for predicting the poor mobilizers population who may benefit from newer modalities using adhesion molecules inhibitors.

Circulating endothelial cell kinetics and their potential predictive value during mobilization procedure.

Objective: Circulating endothelial cells (CECs) in patients with hematological malignancies are assessed as a noninvasive marker of angiogenesis. The aim of this study was to evaluate the numbers of CECs and their subsets during mobilization of hematopoietic stem cells. Patients and methods: Thirty‐eight patients were enrolled to the study (19 females and 19 males) at median age of 56.5 years. The group consisted of patients with multiple myeloma (26), lymphoma (10), and acute myeloid leukemia (2). Blood samples were collected before chemotherapy (0), 1 day after chemotherapy (Cht+1), on the day G‐CSF commenced (G0), after 1 day of G‐CSF (G+1), and on the day of the first apheresis. CECs were evaluated by four‐color flow cytometry. Circulating progenitor cells were defined as CD45−/CD34+/CD31+/CD133+. Apoptotic CECs (ApoCECs) were defined as CD146+/AnnexinV+. Results: Median (Me) CECs number was 10.5/µl and it decreased after chemotherapy (Me = 8.3/µl, P < 0.001 when compared with baseline). Based on the number of aphereses needed to obtain 2 × 106/kg CD34+ cells, patients were divided into “highly efficient” (one apheresis) and “poorly efficient” mobilizers (two or more aphereses). Median ApoCEC at Day G+1 was lower in highly efficient than in poorly efficient mobilizers (Me = 3.1/µl vs. Me = 5.1/µl, P = 0.02). ApoCEC at Day G+1 correlated with the number of aphereses (r = 0.48, P = 0.03). In multivariate analysis, ApoCEC at Day G+1 was an independent factor for successful mobilization during one apheresis. Conclusions: CECs and their subsets change significantly during mobilization of HSCs. ApoCECs measured at the time of G‐CSF commencement can predict the efficacy of HSC collection. J. Clin. Apheresis 28:341–348, 2013.

Blood Pressure Response to Submaximal Exercise Test in Adults

Background. The assessment of blood pressure (BP) response during exercise test is an important diagnostic instrument in cardiovascular system evaluation. The study aim was to determine normal values of BP response to submaximal, multistage exercise test in healthy adults with regard to their age, gender, and workload. Materials and Methods. The study was conducted in randomly selected normotensive subjects (n = 1015), 512 females and 498 males, aged 18–64 years (mean age 42.1 ± 12.7 years) divided into five age groups. All subjects were clinically healthy with no chronic diseases diagnosed. Exercise stress tests were performed using Monark bicycle ergometer until a minimum of 85% of physical capacity was reached. BP was measured at rest and at peak of each exercise test stage. Results. The relations between BP, age, and workload during exercise test were determined by linear regression analysis and can be illustrated by the equations: systolic BP (mmHg) = 0.346 × load (W) + 135.76 for males and systolic BP (mmHg) = 0.103 × load (W) + 155.72 for females. Conclusions. Systolic BP increases significantly and proportionally to workload increase during exercise test in healthy adults. The relation can be described by linear equation which can be useful in diagnostics of cardiovascular diseases.

The kinetics of hematopoietic niche cytokines and their influence on mobilization efficacy and timing in patients with hematological malignancies.

The bone marrow niche functions are modulated by complicated cytokines network. The aim of our study was to evaluate the levels of VCAM‐1, VEGF, MMP‐9 and SDF during mobilization of CD34+ cells in patients with hematological malignancies. Thirty four patients were enrolled to the study (19F, 15 M) at median age of 57 years. The group consisted of patients with multiple myeloma (26) and lymphoma (8). The mobilization procedures comprised chemotherapy and then G‐CSF. Blood samples were collected before chemotherapy (N = 34) and on the day of the first apheresis (N = 26). Cytokines were evaluated with ELISA assay. We observed significant increase in VCAM‐1 levels during mobilization. On contrary, VEGF and SDF levels decreased during mobilization procedure. The levels of MMP‐9 were stable during mobilization. We divided patients according to baseline cytokines levels below and above median into “low” and “high” expressors. The group of VEGF “low” expressors had longer median time of G‐CSF treatment before first apheresis than ‘high’ expressors. Baseline VEGF levels correlated adversely with duration of G‐CSF treatment before first apheresis. Patients were also divided according to median cytokines levels at apheresis into “low” and “high” expressors. “High” VCAM‐1 expressors had higher CD34+in peripheral blood as well as higher CD34+numbers collected during first apheresis than “low” expressors. In conclusion, the levels of niche cytokines change significantly during mobilization in patients with hematopoietic malignancies. Baseline VEGF can influence timing of mobilization. Higher VCAM‐1 corresponds with higher mobilization efficacy. J. Clin. Apheresis 30:247–251, 2015.

Blood pressure response to exercise in young athletes aged 10 to 18 years

The aim of the study was to determine arterial blood pressure response to exercise in young athletes. The study group comprised 711 young athletes (457 boys, 254 girls) aged 10 to 18 years (mean 13.41 ± 3.12 years) who had been training for an average of 7.62 ± 4.2 h per week for an average of 4.01 ± 2.5 years. Participants with elevated arterial blood pressure above the 90th percentile at rest were excluded from investigation. A symptom-limited, multistage exercise test to exhaustion was performed using a Monark cycle ergometer. Arterial blood pressure was measured with an aneroid manometer in the third minute of each stage of the test. Mean systolic arterial blood pressure during peak exercise was significantly higher in boys than in girls: 183.21 ± 27.97 mm Hg and 170.97 ± 21.4 mm Hg, respectively (p = 0.03). Multivariate linear regression analysis showed that age and workload had significant effects on arterial blood pressure during the test. Systolic arterial blood pressure during the exercise can be described with the following equations: boys, SBPex (mm Hg) = -1.92 × age (years) + 0.55 × workload (W) + 120.84; girls, SBPex (mm Hg) = -0.88 × age (years) + 0.48 × workload (W) + 111.22. The study results describe reference values of arterial blood pressure during the exercise test. The presented equations and figures can help to assess whether the arterial blood pressure at each stage of the exercise test exceeds the normal range or not.

P-28 Heart rate variability indices in male patients with coronary artery disease after 8 weeks of regular aerobic training

Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are widely-used procedures in coronary artery disease (CAD) treatment. Functional disturbances of the autonomic nervous system, illustrated by decreased heart rate variability indices (HRV), are associated with increased risk of cardiac events and total mortality, especially in CAD patients. Parasympathetic activity reduction was observed in patients within 24 hours after PCI. However, this decrease of HRV indices seemed transitory. According to many studies, regular physical activity is one of the factors increasing HRV indices. An improvement of HRV indices after cardiac rehabilitation were observed in PCI patients. CABG, as a more invasive procedure, leads to more profound changes in autonomic regulation of heart function observed for several months or even years in HRV assessment. The aim of the study was to evaluate the influence of 8-week outpatient comprehensive cardiac rehabilitation program (CR) based on regular aerobic training on HRV indices in CAD patients treated with PCI and CABG. Methods The study population consisted of 110 male patients with CAD aged 35 to 76 years (mean age 55,13 ± 8,6 years) prospectively and consecutively admitted to an outpatient CR after PCI n = 62, or CABG n = 48. Participants performed cycle ergometer interval training for 45 minutes 3 times a week for 8 weeks. At baseline and after 8 weeks, all patients underwent exercise test and the HRV assessment in the time and frequency domains. Among the time domain parameters, the following were measured: the mean RR interval (mRR), the standard deviation of the normal RR interval (SDNN), square root of the mean square differences of successive RR intervals (rMSSD), and proportion of the total RR intervals that have differences of successive RR intervals greater than 50 milliseconds (pNN50). Parameters of the frequency domain were also assessed: low-frequency component (LF: 0.04–0.15 Hz), high-frequency component (HF: 0.15–0.4 Hz) and the LF/HF ratio. Results HRV indices in CAGB survivals were significantly lower in comparison to patients after PCI at baseline. Significant increases were seen for SDNN, rMSSD, and HF in the CABG group and only in HF component in PCI group after 8 weeks of CR. Conclusions Eight weeks of cardiac rehabilitation based on regular aerobic training, with respect to the HRV indices, seems to be more effective in patients who underwent CABG than patients after PCI. CR seems to be more beneficial to patients with reduced parasympathetic activity at baseline.