Endothelial Injury Syndromes after Allogeneic Hematopoietic Stem Cell Transplantation: Angiopetin-2 as a Novel Predictor of the Outcome and the Role of Functional Autoantibodies against Angiotensin II Type 1 and Endothelin A Receptor.

Transplant-associated thrombotic microangiopathy (TMA) occurs in a significant percentage of patients after allogeneic stem cell transplantation (allo-SCT) and is associated with significant morbidity and mortality. The aim of the present study was to examine the association of serum angiopoetin-2 (Ang2) levels and the presence of antibodies against angiotensin II type 1 (AT1R) and ndothelin A Recreptor (ETAR) with the outcome of patients with TMA and/or graft-versus-host disease (GVHD) after allo-SCT. Analysis of our data showed that elevated serum Ang2 levels at the time of TMA diagnosis are significantly associated with increased non-relapse mortality and decreased overall survival. To our knowledge, this is the first study demonstrating an association between raised Ang2 levels and poor outcomes in patients with TMA. Antibodies against AT1R (AT1R-Abs) and ETAR (ETAR-Abs) were detected in 27% and 23% of the patients, respectively, but there was no association between the presence of autoantibodies and the outcome of patients with TMA. However, a significant finding was the strong positive correlation between the presence of AT1R-Abs with the occurrence of chronic fibrotic GVHD, such as scleroderma and cryptogenic organizing pneumonia, raising the possibility of the contribution of autoantibodies in the pathogenesis of fibrotic GVHD manifestations.

Positive impact of brentuximab vedotin on overall survival of patients with classical Hodgkin lymphoma who relapse or progress after autologous stem cell transplantation: A nationwide analysis.

The outcome of patients with relapsed/refractory classical Hodgkin lymphoma (R/R cHL) after autologous stem cell transplantation (auto-SCT) is poor. Recently, the anti-CD30 monoclonal antibody-drug conjugate, brentuximab vedotin (BV), has shown remarkable activity in the setting of R/R cHL. In the pivotal phase II study, BV produced an overall response rate of 75% and a median progression-free survival of 6.7 months. Although these results have been reproduced by large registry studies, the impact of BV on the overall survival (OS) of patients with R/R cHL has not been addressed so far. The aim of this study was to examine the impact of BV on OS in the setting of post auto-SCT R/R cHL. Analysis was performed in a group of patients with R/R cHL after a previous auto-SCT reported in the Greek registry during the last 2 decades. By using a multivariate model and censoring patients at the time of subsequent allo-SCT or treatment with immune checkpoint inhibitors, we showed that treatment with BV in the posttransplant relapse setting has a positive impact on the outcome and results in significant improvement of OS. To our knowledge, this the first published study, addressing the impact of BV on the OS in the setting of posttransplant relapse.

The Impact of the Doctor-Patient Relationship on the Treatment Goal in Rheumatology.

Objectives: To assess the perceptions of patients with rheumatic diseases about the doctor-patient relationship and the impact on their treatment and their quality of life. Methods: A quantitative study collecting data from patients with rheumatic diseases using the following tools: (a) the Doctor-Patient Relationship Assessment Questionnaire-16 (DoPRAQ-16), assessed the quality of doctor-patient relationship, (b) the Short Form 36 (SF-36) assessed the quality of life of patients, and (c) the Health Assessment Questionnaire (HAQ), assessed the functional ability of patients. From the statistical analysis, it appears that there is no linear correlation between the DoPRAQ-16 scales and the dimensions of the SF-36 Health Survey, except for the scale of negative emotions and the dimension of Physical Functioning. The nonparametric Kruskal-Wallis H test was performed to investigate the existence of statistically significant differences between the categories of duration of the relationship with the doctor to Physical Functioning, Physical Role, Emotional Role, and Social Functioning. The test was significant (p<0.05) for the dimensions of Body Role and Social Functioning. Conclusions: Patients with long term relationship with the doctor have better health quality in the dimension of Physical Role and Social Functioning compared to people whose relationship with the doctor lasts fewer years.

Risk factors for Nocardia infection among allogeneic hematopoietic cell transplant recipients: A case-control study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

OBJECTIVES: Nocardiosis is a rare but life-threatening infection after hematopoietic cell transplantation (HCT). We aimed at identifying risk factors for nocardiosis after allogeneic HCT and clarifying the effect of trimethoprim-sulfamethoxazole prophylaxis on its occurrence. METHODS: We performed a retrospective multicenter case-control study of patients diagnosed with nocardiosis after allogeneic HCT between January 2000 and December 2018. For each case, two controls were matched by center, transplant date, and age group. Multivariable analysis was conducted using conditional logistic regression to identify potential risk factors for nocardiosis. Kaplan-Meier survival curves of cases and controls were compared using log-rank tests. RESULTS: Sixty-four cases and 128 controls were included. Nocardiosis occurred at a median of 9 months after allogeneic HCT (interquartile range: 5-18). After adjustment for potential confounders in a multivariable model, Nocardia infection was associated with tacrolimus use (adjusted odds ratio [aOR] 9.9, 95 % confidence interval [95 % CI]: 1.6-62.7), lymphocyte count < 500/µL (aOR 8.9, 95 % CI: 2.3-34.7), male sex (aOR 8.1, 95 % CI: 2.1-31.5), recent use of systemic corticosteroids (aOR 7.9, 95 % CI: 2.2-28.2), and recent CMV infection (aOR 4.3, 95 % CI: 1.2-15.9). Conversely, use of trimethoprim-sulfamethoxazole prophylaxis was associated with a significantly decreased risk of nocardiosis (aOR 0.2, 95 % CI: 0.1-0.8). HCT recipients who developed nocardiosis had a significantly decreased survival, as compared with controls (12-month survival: 58 % and 90 %, respectively; p < 0.0001). CONCLUSIONS: We identified six factors independently associated with the occurrence of nocardiosis among allogeneic HCT recipients. In particular, trimethoprim-sulfamethoxazole prophylaxis was found to protect against nocardiosis.

Epidemiology of Mucormycosis in Greece; Results from a Nationwide Prospective Survey and Published Case Reports.

Mucormycosis has emerged as a group of severe infections mainly in immunocompromised patients. We analysed the epidemiology of mucormycosis in Greece in a multicentre, nationwide prospective survey of patients of all ages, during 2005-2022. A total of 108 cases were recorded. The annual incidence declined after 2009 and appeared stable thereafter, at 0.54 cases/million population. The most common forms were rhinocerebral (51.8%), cutaneous (32.4%), and pulmonary (11.1%). Main underlying conditions were haematologic malignancy/neutropenia (29.9%), haematopoietic stem cell transplantation (4.7%), diabetes mellitus (DM) (15.9%), other immunodeficiencies (23.4%), while 22.4% of cases involved immunocompetent individuals with cutaneous/soft-tissue infections after motor vehicle accident, surgical/iatrogenic trauma, burns, and injuries associated with natural disasters. Additionally, DM or steroid-induced DM was reported as a comorbidity in 21.5% of cases with various main conditions. Rhizopus (mostly R. arrhizus) predominated (67.1%), followed by Lichtheimia (8.5%) and Mucor (6.1%). Antifungal treatment consisted mainly of liposomal amphotericin B (86.3%), median dose 7 mg/kg/day, range 3-10 mg/kg/day, with or without posaconazole. Crude mortality was 62.8% during 2005-2008 but decreased significantly after 2009, at 34.9% (p = 0.02), with four times fewer haematological cases, fewer iatrogenic infections, and fewer cases with advanced rhinocerebral form. The increased DM prevalence should alert clinicians for timely diagnosis of mucormycosis in this patient population.

Internal Quality and Job Satisfaction in Health Care Services.

(1) Background: The main purpose of this study was to evaluate the health services' internal quality level in Greek public hospitals and to investigate whether there is a relation between internal quality and health care professionals' job satisfaction. (2) Material and Methods: A cross-sectional study was conducted in six public hospitals (four general and two specialized hospitals). The following tools were used to collect data: (a) the SERVQUAL questionnaire, which is designed to measure service quality through five dimensions, and (b) the Job Satisfaction Survey (JSS) questionnaire, which is designed to measure employees' job satisfaction. Convenience sampling was used as a sampling technique. (3) Results: The level of internal quality service was found to be low as regards the dimensions of: reliability, assurance, responsiveness, and empathy, while the "tangibles" dimension was the only one which was assessed as having a satisfactory internal quality level. Τhe results also revealed a positive correlation between the job satisfaction subscales and the quality dimensions. Regarding demographic characteristics and their effect on employees' perceptions of internal quality dimensions, the study found that the gender and the educational factor had no effect while younger employees have a more positive perception of the quality of responsiveness dimension in the health organizations where they work. In terms of profession, administrative staff had a lower perception of the quality of tangibles dimension than doctors and nurses. Concerning years of experience, the results indicated that employees with more previous working experience had a worse perception of the quality of reliability, responsiveness, and assurance dimensions. (4) Conclusions: According to the results, establishing a sense of trust and understanding between management and health professionals through effective communication, transparent evaluation, and reward is critical to developing, enhancing, and promoting an internal quality culture in a hospital setting.

Evaluation of the Dynamiker® Fungus (1-3)-ß-D-Glucan Assay for the Diagnosis of Invasive Aspergillosis in High-Risk Patients with Hematologic Malignancies.

INTRODUCTION: The Dynamiker® Fungus (1-3)-ß-D-glucan assay (DFA) allows the testing of samples in smaller batches compared to the well-established Fungitell® assay (FA) making the assay cost-effective in centers with small numbers of samples. Evaluations of its performance for the diagnosis of invasive aspergillosis (IA) are limited. Therefore, we compared the two assays and evaluated their clinical performance in diagnosing IA. METHODS: A total of 60 adult hematology patients were screened for IA, 13 with probable IA, 19 with possible IA, and 28 with no IA. Serum specimens (n = 166) were collected twice-weekly and tested for (1-3)-ß-D-glucan (BDG) using FA and DFA which were compared quantitatively with Spearman rank correlation analysis and qualitatively with the Chi-square test. Agreement and error rates were determined using FA as the reference method. Sensitivity, specificity, and positive predictive and negative predictive values in diagnosing IA were calculated. RESULTS: The performance of the DFA was highly consistent with that of the FA, both quantitatively (rs = 0.913) and qualitatively (kappa = 0.725). The agreement was 85% with 8% minor, no major, and 7% very major errors (FA+/DFA-). Using a cut-off value of 20 pg/mL for DFA, very major errors were reduced to 1%, although 5% major errors were detected. BDG levels were lower with DFA than FA (slope 0.653 ± 0.031). Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) was 67%, 53%, 44%, and 74% for FA, and 53%, 67%, 49%, and 71% for DFA, respectively. The optimal BDG positivity threshold calculated did not lead to significant test quality improvement for either assay. However, a higher % of patients with probable IA (62%) had ≥ 2 consecutive positive specimens compared to patients with no IA (FA-BDG 26%, p = 0.10, and DFA-BDG 10%, p = 0.01) leading to improved sensitivity and NPV (71% and 85% for DFA, and 95% and 96% for FA, respectively). CONCLUSION: DFA could be a valuable alternative to the FA, particularly in laboratories with small numbers of samples. The results of the BDG testing should be carefully interpreted in the high-risk setting of patients with hematologic malignancies. Higher NPV was found using as criterion ≥ 2 consecutive positive samples for diagnosing IA.

Differences of mentally ill patients' satisfaction degree during their involuntary or voluntary stay in a psychiatric clinic.

BACKGROUND: Mental health illness is not considered as a private matter, as it affects not only the mental patient's life and those who are considered his/her immediate family, but also the society as a whole. The involuntary examination and/or hospitalization in the field of mental health as the basic first-line therapeutic solution in Greece, calls for an immediate intervention, which is supposed to counterbalance the need for therapy and patient's rights of personal freedom and safety. DESIGN AND METHODS: A research using questionnaire was realized, consisting of 100 hospitalized patients in psychiatric clinics (50 voluntarily and 50 involuntarily hospitalized) at the Psychiatric Hospital of Attica. The sampling scheme was the stratified sampling and the level of statistical significance was set to α=0.05. RESULTS: The results have shown that involuntarily and voluntarily hospitalized mental patients did not differ significantly with almost the entirety of the questionnaire; however, the involuntary patients were significantly more satisfied with the conditions of hospitalization as well as assessing the overall quality of the services provided during their hospitalization. CONCLUSIONS: For mentally ill patients, greater importance and stronger correlation with gratification, does not constitute the admission procedure to the psychiatric clinic but the development of effective communication and therapeutic relationship with the staff, full knowledge and update about patient's health condition, medication, participation in therapeutic planning and hospitalization in a regime of autonomy and respect for their rights.

Learning Organizational Culture in Greek Public Hospitals.

(1) Background: A learning organizational culture is crucial to the safety of patients and the quality of public health care. The aim of this study was to assess the learning organizational culture and capacity of Greek public hospitals. (2) Materials and Methods: A cross-sectional analysis was carried out in six public general hospitals and stratified sampling was used as the sampling technique. A total of 480 questionnaires were distributed to health care professionals and 380 valid questionnaires were returned (78% response rate). The comprehensive form of the Dimensions of Learning Organization Questionnaire (DLOQ), which was adapted and translated into Greek, was used for data collection in this survey. (3) Results: The level of learning organizational culture and capacity in the health units are very low. All seven dimensions of the learning organizational instrument are lower than the theoretically neutral median (3.0). Health care employees believe that the hospital's existing culture and management practices do not foster and contribute to continuing learning, which is the fundamental aspect of self-development, department development and performance improvement. (4) Conclusions: Greek public hospitals need to adopt different types of leadership practices and culture in order to be able to facilitate organizational learning. Organizational learning (OL) is based on collaborative working, a culture that encompasses learning as participation in the organizational work practice. This transformation of culture should take place at all levels of learning to enhance results.

Assessment of Health Professionals' Attitudes on Radiation Protection Measures.

(1) Background: Health professionals' knowledge, beliefs and perceptions concerning radiation protection may affect their behaviour during surgery and consequently influence the quality of health services. This study highlights the health professionals' average knowledge level and captures the beliefs, perceptions, and behaviours in a large public Greek hospital. (2) Materials and Methods: A cross-sectional study was carried out, including health professionals working in operating rooms. One hundred thirty-two staff members participated by responding to an original questionnaire. The sample consisted of nurses, radiographers and medical doctors of various specialties involved daily in surgical procedures where ionizing radiation is required. The survey was conducted from March to June 2021, and the response rate was 97%. (3) Results: The level of overall knowledge of health professionals regarding radiation protection safety was not satisfactory. Females and employees with a lower level of education had more misconceptions about radiation and radiation protection. Employees of younger ages and with less previous experience were more likely to have negative emotions towards radiation exposure. Finally, employees with fewer children tended to express physical complaints caused by their negative emotions due to radiation exposure. (4) Conclusions: Health professionals' lack of basic and specialized knowledge concerning radiation protection safety had a negative impact on the provision of health services. The continuing training of the staff seemed to be the only solution to reverse this trend. The training should highlight how radiation exposure can be minimized, safeguarding health professionals' trust and sense of security by significantly improving their working environment.

Public Hospital Quality Assessment. Evidence from Greek Health Setting Using SERVQUAL Model.

(1) Background: Health care service quality has been equated with preparedness to provide, accessibility, suitability, adequacy, friendliness and ongoing support and has been connected to service excellence. The main aim of this study was to investigate patients' perceptions and expectations regarding the quality of health services. (2) Materials and Methods: A cross-sectional analysis was carried out in 5 public general hospitals and convenience sampling was used as the sampling technique. Questionnaires were distributed to inpatients and outpatients and 700 valid questionnaires were returned. The SERVQUAL questionnaire was used for data collection in this survey. (3) Results: Overall, in this study, it became apparent that patients' expectations as regarding the quality of the provided services were not met. All of the five quality dimensions had a negative gap between patients' expectations and perceptions. (4) Conclusions: The findings suggested that hospital managers and health care professionals should be interested about patient expectations and subsequently they should search out ways and means to meet them. Open communication with patients, individualized attention, as well as responsiveness to their requirements, polite behavior, trustful atmosphere across the hospital and better physical facilities are the key elements that determine the patient's judgment about quality.

Allogeneic Stem Cell Transplantation with a Novel Reduced Intensity Conditioning Regimen for the Treatment of Patients with Primary Cutaneous T-cell Lymphomas.

The prognosis of patients with mycosis fungoides (MF) and Sezary Syndrome (SS) varies greatly, from near normal life expectancy in patients with early stage, to a median survival of less than 2 years for those diagnosed with advanced stage disease. Initial response to treatment is almost always followed by relapse and, finally, most of patients enter a phase of advanced multi-drug resistant disease with a short life expectancy after multiple lines of treatment. Allogeneic stem cell transplantation (allo-SCT) is usually limited to patients with advanced disease resistant to multiple treatments. Retrospective registry-based studies have shown increased Non-relapse Mortality (NRM) rates in patients with poor performance status, as well as in patients treated with myeloablative conditioning regimens. Another major limitation of allo-SCT is the increased relapse rate which occurs in nearly 50% of the cases, and is probably due to the fact that only heavily pretreated patients with advanced disease are referred for allo-SCT. Due to the paucity of data, the ideal conditioning regimen which will provide the maximum therapeutic benefit without the cost of increased NRM is not currently known. In this article we present our experience with a novel regimen in the treatment of patients with advanced MF/SS.

Repetitively Administered Low-Dose Donor Lymphocyte Infusion for Prevention of Relapse after Allogeneic Stem Cell Transplantation in Patients with High-Risk Acute Leukemia.

BACKGROUND: Patients with high-risk acute leukemia have a high risk of relapse after allogeneic stem cell transplantation (allo-SCT). In an effort to reduce the relapse rate, various therapeutic methods have been implemented into clinical practice. Among them, prophylactic donor lymphocyte infusion (pro-DLI) has shown significant efficacy. However, the widespread application of pro-DLI has been restricted mostly due to concerns regarding the development of graft versus host disease (GVHD). In the present study, we tested the safety and efficacy of a novel method of prophylactic-DLI based by repetitive administration of low lymphocyte doses. METHODS: DLI was administered to patients with high-risk acute leukemia at a dose of 2 × 106/kg CD3-positive cells. DLI at the same dose was repeated every two months for at least 36 months post-allo-SCT, or until relapse or any clinical or laboratory feature suggested GVHD, whichever occurred first. Forty-four patients with a median age of 53 years (range 20-67) who underwent allo-SCT between 2011 and 2020 were included in our study. Thirty-three patients with high-risk acute myeloid leukemia (AML) and 11 with high-risk acute lymphoblastic leukemia (ALL) after allo-SCT from a matched sibling (MSD, no = 38 pts) or a matched-unrelated donor (MUD, no = 6 pts) received pro-DLI. Twenty-three patients were in CR1, all with unfavorable genetic features; 12 patients were in CR2 or beyond; and 9 patients had refractory disease at the time of transplant. Ten out of 23 patients in CR1 had detectable minimal residual disease (MRD) at the time of allo-SCT. Disease risk index (DRI) was high and intermediate in 21 and 23 patients, respectively. Conditioning was myeloablative (MAC) in 36 and reduced intensity (RIC) in 8 patients, while GVHD prophylaxis consisted of cyclosporine-A in combination with low-dose alemtuzumab in 39 patients or with low-dose MTX in 5 patients, respectively. RESULTS: Thirty-five patients completed the scheduled treatment and received a median of 8 DLI doses (range 1-35). Fifteen out of 35 patients received all planned doses, while DLI was discontinued in 20 patients. Reasons for discontinuation included GVHD development in nine, donor unavailability in seven, disease relapse in three, and secondary malignancy in one patient, respectively. Nine patients were still on treatment with DLI, and they received a median of four (range 2-12) doses. Fourteen percent of patients developed transient grade-II acute GVHD while 12% developed chronic GVHD post-DLI administration. Acute GVHD was managed successfully with short course steroids, and four out of five patients with cGVHD were disease-free and off immunosuppression. With a median follow-up of 44 months (range 8-120), relapse-free (RFS) and overall survival (OS) were 74%, (95% CI, 54-87%) and 78%, (95% CI, 58-89%) respectively, while the cumulative incidence of non-relapse mortality (NRM) was 13% (95% CI, 4-28%). The cumulative incidence of relapse in patients with intermediate and high DRI is 7% and 15%, respectively. CONCLUSION: Prolonged-up to three years-low-dose pro-DLI administered every two months is safe and effective in reducing relapse rate in patients with high-risk acute leukemia. The low-dose repetitive administration DLI strategy reduced the risk of DLI-mediated GVHD, while the prolonged repeated administration helped in preventing relapse, possibly by inducing a sustained and prolonged immunological pressure on residual leukemic cells. This novel strategy deserves testing in larger cohort of patients with high-risk acute leukemia.

Extramedullary leukemia relapse after allogeneic stem cell transplantation: a novel mechanism of immune escape?

Background: Relapse is a significant cause of treatment failure after allogeneic stem cell transplantation. In many cases relapse occurs when leukemic cells escape from immune surveillance. Methods & results: In the setting of haploidentical transplantation, immune escape is usually the result of the loss of the mismatched haplotype from leukemic cells, while downregulation of HLA-expression has been postulated as a significant cause of immune escape after transplantation with the use of HLA-matched donors. We observed that patients with acute leukemia who relapse at the time of active graft-versus-host-disease, usually develop extramedullary leukemia while they remain free of leukemia in peripheral blood and bone marrow. Conclusion: Our observation points toward a novel mechanism of immune escape which is microenvironment-specific.

Validation of Dimensions of Learning Organization Questionnaire (DLOQ) in health care setting in Greece.

Background: In health care systems the organizational learning is a continuous process to improve actions through better knowledge and detect or correct errors. This study examines the validity and reliability of the Dimensions of Learning Organization Questionnaire in addition to the applicability of the instrument in a Greek health care cultural context. Design and methods: A cross-sectional study was carried out in 6 general hospitals of Attica and the sampling scheme was the stratified sampling. Questionnaires were distributed to 487 healthcare professionals and 380 valid questionnaires were returned. The research tool used in this survey is the extensive form of DLOQ, which has been adapted and translated into Greek language. Data analysis was carried out with SPSS 25. Results: Three leading experts of the health sector examined the face validity assessment of the translated DLOQ and stated that it is characterized by high face validity. As regard construct validity of the DOLQ throughout Multitrait-Multimethod Matrix, was proved that all the variables of the same factors are statistically significantly correlated (p<0.001), and their correlation coefficients have moderate to high power ranging between 0.563 and 0.798. Moreover, the discriminant validity was demonstrated as certain correlation coefficients between variables of different factors were found to be higher than of certain correlation coefficients between variables of the same factors. The internal consistency among the items of the DOLQ range between 0.842 and 0.977 and they are considered to be good to excellent. Conclusions: Our results confirmed that DLOQ is a valuable tool in measuring Learning Organizational in Greek public hospitals.

Pretransplant Genetic Susceptibility: Clinical Relevance in Transplant-Associated Thrombotic Microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a life-threatening complication of allogeneic hematopoietic cell transplantation (HCT). We hypothesized that pretransplant genetic susceptibility is evident in adult TA-TMA and further investigated the association of TMA-associated variants with clinical outcomes. We studied 40 patients with TA-TMA, donors of 18 patients and 40 control non-TMA HCT recipients, without significant differences in transplant characteristics. Genomic DNA from pretransplant peripheral blood was sequenced for TMA-associated genes. Donors presented significantly lower frequency of rare variants and variants in exonic/splicing/untranslated region (UTR) regions, compared with TA-TMA patients. Controls also showed a significantly lower frequency of rare variants in ADAMTS13, CD46, CFH, and CFI. The majority of TA-TMA patients (31/40) presented with pathogenic or likely pathogenic variants. Patients refractory to conventional treatment (62%) and patients that succumbed to transplant-related mortality (65%) were significantly enriched for variants in exonic/splicing/UTR regions. In conclusion, increased incidence of pathogenic, rare and variants in exonic/splicing/UTR regions of TA-TMA patients suggests genetic susceptibility not evident in controls or donors. Notably, variants in exonic/splicing/UTR regions were associated with poor response and survival. Therefore, pretransplant genomic screening may be useful to intensify monitoring and early intervention in patients at high risk for TA-TMA.

Natural killer cell cytotoxicity is a predictor of outcome for patients with high risk myelodysplastic syndrome and oligoblastic acute myeloid leukemia treated with azacytidine.

The aim of the present study was to identify biomarkers predictive of the outcome of patients with high-risk myelodysplastic syndrome and oligoblastic acute myeloid leukemia (AML) treated with 5-azacytidine (AZA). We prospectively examined the association between NK-cytotoxic activity, myeloid-derived suppressor cells (MDSCs), and T-regulatory cells (Tregs) on the overall survival (OS) of patients. Patients with NK-cytotoxicity above a critical threshold had a longer duration of response and survived longer than patients with severe impairment of NK-cytotoxicity. The numbers of MDSCs, and Tregs in the PB of patients after a short exposure to AZA were not different from normal donors. In conclusion, the results of our study suggest that the therapeutic activity of AZA is at least partly mediated by an immunomodulatory effect. To our knowledge, this is the first study reported so far, that shows a positive correlation between NK cytotoxicity and OS of AZA-treated patients.