Exosomal-miRNas expression and growth factors released by mononuclear cells of CLAD patients in response to extracorporeal photopheresis.

BACKGROUND: CLAD (Chronic Lung Allograft Dysfunction) remains a serious complication following lung transplantation. Some evidence shows that portions of Extracorporeal Photopheresis (ECP)-treated patients improve/stabilize their graft function. In spite of that, data concerning molecular mechanisms are still lacking. Aims of our study were to assess whether ECP effects are mediated by Mononuclear Cells (MNCs) modulation in term of microRNAs (miRNAs) expression and growth factors release. METHODS: Cells from leukapheresis of 16 CLAD patients, at time 0 and 6-months (10 cycles), were cultured for 48h ± PHA (10 ug/ml) or LPS (2 ug/ml). Expression levels of miR-146a-5p, miR-155-5p, miR-31-5p, miR181a-5p, miR-142-3p, miR-16-5p and miR-23b-5p in MNCs-exosomes were evaluated by qRT-PCR, while ELISA assessed different growth factors levels on culture supernatants. RESULTS: Our result showed miR-142-3p down-regulation (p = 0.02) in MNCs of ECP-patients after the 10 cycles and after LPS stimulation (p = 0.005). We also find miR-146a-5p up-regulation in cells after the 10 cycles stimulated with LPS (p = 0.03). Connective tissue growth factor (CTGF) levels significantly decreased in MNCs supernatant (p = 0.04). The effect of ECP is translated into frequency changes of Dendritic Cell (DC) subpopulations and a slight increase in T regulatory cells (Treg) number and a significant decrease in CTGF release. CONCLUSIONS: ECP might affect regulatory T cell functions, since both miR-142 and miR-146a have been shown to be involved in the regulation of suppressor regulatory T cell functions and DCs. On the other side ECP, possibly by regulating macrophage activation, is able to significantly down modulate CTGF release.

A retrospective study assessing the characteristics of COVID-19 convalescent plasma donors and donations.

BACKGROUND: Although many trials are currently investigating the safety and efficacy of convalescent plasma (CP) in critically ill COVID-19 patients, there is a paucity of ongoing and published studies evaluating the CP donors' side. This retrospective study reports the first Italian experience on CP donors' selection and donations. METHODS: Patients aged 18-68 years who had recovered from COVID-19 at least 2 weeks previously were recruited between March 18 and June 30, 2020 in a study protocol at the Italian hospitals of Pavia and Mantova. RESULTS: During the study period, 494 of 512 donors recruited were judged eligible and underwent 504 plasmapheresis procedures. Eighty-five percent (437/512) of the CP donors were males. The average time between symptom recovery and CP donation was 36.6 (±20.0) days. Four hundred and eighty-eight plasmapheresis procedures (96.8%) were concluded and each unit was divided into two subunits (total 976) with an average volume of 316.2 (±22.7) mL. Ninety-three percent (460/494) of CP donors at the time of plasma donation had a neutralizing IgG titer ≥1:80. Plasmapheresis-related adverse reactions occurred in 2.6% (13/504) of cases; all the reactions were mild and none required therapeutic intervention. Donors' age and COVID-19 severity were positively associated with greater antibody responses. CONCLUSION: This study demonstrates the feasibility and safety of a pilot CP program conducted in Italy. The identification of factors (ie, age and severity of COVID-19) positively associated with higher neutralizing antibody titers at the time of donation may help to optimize the selection of CP donors.

Circulating endothelial progenitor cells during pregnancy in multiple sclerosis.

BACKGROUND: Endothelial progenitor cells (EPCs) have been shown to increase during physiological pregnancy and are believed to play a fundamental role in the process of placentation. Reduced levels of EPCs during pregnancy have been associated with preeclampsia and miscarriage. Women with multiple sclerosis (MS) are not at increased risk of preeclampsia nor of general adverse obstetric outcome, in contrast with some other autoimmune diseases. OBJECTIVE: The aim of this study was to evaluate circulating EPCs levels in pregnant patients with MS. METHODS: CD34+ and CD133+ were longitudinally detected by flow cytometry in the maternal plasma of 29 healthy controls and 9 MS patients and in the cord blood of their newborns. RESULTS: EPCs were affected by pregnancy with the same trend in both groups (CD34+ p = 0.0342; CD133+ p = 0.0347). EPCs during pregnancy were increased in MS (mean ± SD: CD34+ cells 0.038 ± 0.010; CD133+ 0.024 ± 0.009) with respect to healthy controls (mean ± SD: CD34+ cells 0.022 ± 0.006; CD133+ 0.016 ± 0.004), CD34+ p = 0.0004; CD133+ p = 0.0109. EPCs levels of the cord blood of MS patients' newborns mild correlated with maternal EPC levels at delivery (CD34+: spearman's Rho 0.658, p = 0.054; CD133+: spearman's Rho 0.758, p = 0.018). CONCLUSIONS: This work identified increased circulating EPC levels during pregnancy, following the same trend both in MS patients and healthy controls. Despite the similar trend, the levels of circulating EPCs were significantly higher in MS patients with respect to the control population. A correlation was also found in MS patients between cord blood EPCs and circulating EPCs at delivery.

Automated mononuclear cell collection: a feasibility study employing a new software for extracorporeal photopheresis.

BACKGROUND AND OBJECTIVES: Very recently, Fresenius Kabi, improved the software (autoMNC lymphocytes, SW 04.03.08) for mononuclear cells (MNCs) collection with the aim to ameliorate the quality of harvest, employing the automated autoMNC lymphocytes software SW 04.03.09. Herein, we report the results of an observational study evaluating the feasibility of MNCs collection in patients undergoing extracorporeal photopheresis (ECP) at our centre, using the new COM.TEC software 04.03.08c for MNC collection, afterwards integrated in the software 04.03.09, available on the market since November 2018. MATERIALS AND METHODS: Thirty adult patients (21 males and 9 females) with GvHD, Chronic Lung Allograft Dysfunction or renal rejection, were consecutively enrolled to undergo 1 ECP procedure by the offline technique, according to our internal protocol, processing 1·5 blood volumes. Feasibility of collection was defined as: Hct in collection bag ≤5%, MNCs purity (percentage of MNCs/bag) ≥80%, MNCs collection efficiency (CE2) ≥60%, patient's platelet depletion ≤50%. RESULTS: Thirty ECP procedures were evaluated. Feasibility (defined by the four parameters previously described) of MNCs collection was observed in 1 out of the 30 harvests analysed. Median Hct in the product was 3·45% (IQR: 2·6-5·0), and median MNCs purity was 97·2% (IQR 89·1-98·6). Median CE2 for MNCs was 21·4% (IQR: 11·9-41·2), and median patient's platelet depletion was 36·2% (IQR 21·9-51·4). CONCLUSION: The autoMNC lymphocytes software SW 04.03.08c for MNCs collection in ECP setting demonstrated to collect a good quality product in terms of purity and RBC contamination even if the collection efficiency and platelet contamination must be improved.

Automated red blood cell depletion in ABO incompatible grafts in the pediatric setting.

Bone marrow ABO incompatible transplantations require graft manipulation prior to infusion to avoid potentially lethal side effects. We analyzed the influence of pre-manipulation factors (temperature at arrival, transit time, time of storage at 4°C until processing and total time from collection to red blood cell depletion) on the graft quality of 21 red blood cell depletion procedures in ABO incompatible pediatric transplants. Bone marrow collections were processed using the Spectra Optia® (Terumo BCT) automated device. Temperature at arrival ranged between 4°C and 6°C, median transit time was 9.75h (range 0.33-28), median time of storage at 4°-6°C until processing was 1.8h (range 0.41-18.41) and median time from collection to RBC depletion was 21h (range1-39.4). Median percentage of red blood cell depletion was 97.7 (range 95.4-98.5), median mononuclear cells recovery was 92.2% (range 40-121.2), median CD34+ cell recovery was 93% (range 69.9-161.2), median cell viability was 97.7% (range 94-99.3) and median volume reduction was 83.9% (range 82-92). Graft quality was not significantly different between BM units median age. Our preliminary data show that when all good manifacturing practices are respected the post-manipulation graft quality is excellent also for those units processed after 24h.

Combination of miRNA499 and miRNA133 exerts a synergic effect on cardiac differentiation.

Several studies have demonstrated that miRNA are involved in cardiac development, stem cell maintenance, and differentiation. In particular, it has been shown that miRNA133, miRNA1, and miRNA499 are involved in progenitor cell differentiation into cardiomyocytes. However, it is unknown whether different miRNA may act synergistically to improve cardiac differentiation. We used mouse P19 cells as a cardiogenic differentiation model. miRNA499, miRNA1, or miRNA133 were transiently over-expressed in P19 cells individually or in different combinations. The over-expression of miRNA499 alone increased the number of beating cells and the association of miRNA499 with miRNA133 exerted a synergistic effect, further increasing the number of beating cells. Real-time polymerase chain reaction showed that the combination of miRNA499 + 133 enhanced the expression of cardiac genes compared with controls. Western blot and immunocytochemistry for connexin43 and cardiac troponin T confirmed these findings. Importantly, caffeine responsiveness, a clear functional parameter of cardiac differentiation, was increased by miRNA499 in association with miRNA133 and was directly correlated with the activation of the cardiac troponin I isoform promoter. Cyclic contractions were reversibly abolished by extracellular calcium depletion, nifedipine, ryanodine, and IP3R blockade. Finally, we demonstrated that the use of miRNA499 + 133 induced cardiac differentiation even in the absence of dimethyl sulfoxide. Our results show that the areas spontaneously contracting possess electrophysiological and pharmacological characteristics compatible with true cardiac excitation-contraction coupling. The translational relevance of our findings was reinforced by the demonstration that the over-expression of miRNA499 and miRNA133 was also able to induce the differentiation of human mesenchymal stromal cells toward the cardiac lineage.

Comparison of two automated mononuclear cell collection systems in patients undergoing extracorporeal photopheresis: a prospective crossover equivalence study.

BACKGROUND: Extracorporeal photopheresis (ECP) is an effective cell therapy employed in several diseases, including graft versus host disease (GVHD) and organ rejection. When ECP is performed using an off-line technique, mononuclear cell (MNC) collection by leukapheresis is necessary for further manipulation (addition of 8-methoxypsoralen and ultraviolet A irradiation before reinfusion to the patient). We report the results of the first crossover equivalence study on yield and purity of MNCs collected from patients undergoing ECP with two different automated systems: MNC and CMNC (working with intermittent and continuous-flow collection, respectively), released by Terumo BCT. STUDY DESIGN AND METHODS: Fifty-one patients (15 males and 36 females) with GVHD or chronic lung allograft dysfunction were consecutively enrolled and randomly assigned to MNC collection alternatively by the CMNC or MNC system within each ECP cycle (two procedures) in two consecutive cycles. ECP procedures were performed using the off-line technique, according to our internal protocol, processing 1.5 blood volumes. RESULTS: A total of 204 ECP procedures were evaluated. The MNC system showed a higher MNC concentration capacity than the CMNC (mean difference, -13.46; 95% confidence interval, -21.05 to -5.47; p < 0.001). Collection efficiency was higher with the CMNC system as well as total MNC bag content, while MNC bag purity was equivalent for both systems. Platelet loss was higher with the CMNC. Equivalence was shown for MNC purity and anticoagulant infused to the patient. CONCLUSION: CMNC and MNC systems offer different advantages in different clinical conditions, and both are safe and efficient in collecting MNCs for ECP.

Increased plasma nicotinamide phosphoribosyltransferase is associated with a hyperproliferative phenotype and restrains disease progression in MPN-associated myelofibrosis.

Myeloproliferative neoplasm (MPN)-associated myelofibrosis is a clonal, neoplastic disorder of the hematopoietic stem cells, in which inflammation and immune dysregulation play an important role. Extracellular nicotinamide phosphoribosyltransferase (eNAMPT), also known as visfatin, is a cytokine implicated in a number of inflammatory and neoplastic diseases. Here plasma levels of eNAMPT in patients with MPN-associated myelofibrosis and their effects on disease phenotype and outcomes were examined. The concordance of eNAMPT levels with the marker of general inflammation high-sensitivity C-reactive protein (hs-CRP) was also studied. A total of 333 MPN-associated myelofibrosis patients (187 males and 146 females) and 31 age- and gender-matched normal-weight healthy subjects were enrolled in the study main body. Levels of eNAMPT and hs-CRP were simultaneously assayed in 209 MPN-associated myelofibrosis patients. Twenty-four polycythemia vera or essential thrombocythemia patients were used as controls. eNAMPT was over expressed in MPN-associated myelofibrosis, and eNAMPT expression was correlated with higher white blood cell count, higher hemoglobin, and higher platelet count, suggesting that eNAMPT is an indispensable permissive agent for myeloproliferation of MPN-associated myelofibrosis. The lack of correlation between eNAMPT and hs-CRP revealed that eNAMPT in MPN-associated myelofibrosis does not behave as a canonical inflammatory cytokine. In addition, higher levels of eNAMPT predicted longer time to blast transformation, and protected against progression toward thrombocytopenia and large splenomegaly. In conclusion, in MPN-associated myelofibrosis high levels of eNAMPT mark the myeloproliferative potential and, at variance with a high number of cancers, are protective against disease progression. Am. J. Hematol. 91:709-713, 2016. © 2016 Wiley Periodicals, Inc.

Autologous immuno magnetically selected CD133+ stem cells in the treatment of no-option critical limb ischemia: clinical and contrast enhanced ultrasound assessed results in eight patients.

OBJECTIVES: Demonstrate the safety and effectiveness of highly purified CD133+ autologous stem cells in critical limb ischemia (CLI). DESIGN: Prospective single-center not randomized. Clinicaltrials.gov identifier: NCT01595776 METHODS: Eight patients with a history of stable CLI were enrolled in a period of 2 years. After bone marrow stimulation and single leukapheresis collection, CD133+ immunomagnetic cell selection was performed. CD133+ cells in buffer phosphate suspension was administered intramuscularly. Muscular and arterial contrast enhanced ultra sound (CEUS), lesion evolution and pain management were assessed preoperatively and 3, 6 and 12 months after the implant. RESULTS: No patient had early or late complications related to the procedure. Two patients (25 %) didn't get any relief from the treatment and underwent major amputation. Six patients (75 %) had a complete healing of the wounds, rest pain cessation and walking recovery. An increase in CEUS values was shown in all eight patients at 6 months and in the six clinical healed patients at 12 months and had statistical relevance. CONCLUSIONS: Highly purified autologous CD133+ cells can stimulate neo-angiogenesis, as based on clinical and CEUS data.

Megakaryocytes contribute to the bone marrow-matrix environment by expressing fibronectin, type IV collagen, and laminin.

Megakaryocytes associate with the bone marrow vasculature where they convert their cytoplasm into proplatelets that protrude through the vascular endothelium into the lumen and release platelets. The extracellular matrix (ECM) microenvironment plays a critical role in regulating these processes. In this work we demonstrate that, among bone marrow ECM components, fibronectin, type IV collagen, and laminin are the most abundant around bone marrow sinusoids and constitute a pericellular matrix surrounding megakaryocytes. Most importantly, we report, for the first time, that megakaryocytes express components of the basement membrane and that these molecules contribute to the regulation of megakaryocyte development and bone marrow ECM homeostasis both in vitro and in vivo. In vitro, fibronectin induced a threefold increase in the proliferation rate of mouse hematopoietic stem cells leading to higher megakaryocyte output with respect to cells treated only with thrombopoietin or other matrices. However, megakaryocyte ploidy level in fibronectin-treated cultures was significantly reduced. Stimulation with type IV collagen resulted in a 1.4-fold increase in megakaryocyte output, while all tested matrices supported proplatelet formation to a similar extent in megakaryocytes derived from fetal liver progenitor cells. In vivo, megakaryocyte expression of fibronectin and basement membrane components was upregulated during bone marrow reconstitution upon 5-fluorouracil induced myelosuppression, while only type IV collagen resulted upregulated upon induced thrombocytopenia. In conclusion, this work demonstrates that ECM components impact megakaryocyte behavior differently during their differentiation and highlights a new role for megakaryocyte as ECM-producing cells for the establishment of cell niches during bone marrow regeneration.

Long-Term Off-Line Extracorporeal Photochemotherapy in Patients with Chronic Lung Allograft Rejection Not Responsive to Conventional Treatment: A 10-Year Single-Centre Analysis.

BACKGROUND: Extracorporeal photochemotherapy (ECP) for chronic lung allograft dysfunction (CLAD) has been reported as beneficial in a few short-term studies. OBJECTIVES: In this retrospective cohort study on 48 CLAD patients treated by ECP (off-line technique) for a period of >8 years (compared to 58 controls), we explored potential predictors of survival and response. METHODS: Failures were defined as a decrease in forced expiratory volume in 1 s (FEV1) of >10% from ECP initiation. RESULTS: ECP patients were enrolled between February 2003 and December 2013; 14 (29.2%) with restrictive allograft syndrome (RAS) and 34 with bronchiolitis obliterans syndrome. Grade 1 severity was indicated in 58.3%, grade 2 in 20.8%, and grade 3 in 20.8% of patients. The median follow-up was 65 months (cumulative 2,284.4 person-months). Twenty (41.7%) patients died, including 17 (85%) CLAD-related deaths. Among the controls, there were 42 deaths (72.4%), of which 32 (76.2%) were CLAD related, over a median of 51 months (cumulative 3,066.5 person-months; p = 0.09). Among ECP patients, the FEV1 slope flattened out after a decline in the initial months (slope -19 ml/month in months 0-6, +4 in months 36-48 and later; p = 0.001). RAS was associated with poorer survival, whereas a 'rapid decline in the previous 6 months' was not. No ECP side effects or complications were observed. CONCLUSION: Long-term ECP for CLAD is safe and reduces FEV1 decline over time; the RAS phenotype might show a poorer response. ECP deserves to be evaluated in a randomized controlled trial.

A3669G polymorphism of glucocorticoid receptor is a susceptibility allele for primary myelofibrosis and contributes to phenotypic diversity and blast transformation.

The frequency of A3669G single nucleotide polymorphism (SNP) of human glucocorticoid receptor has been reported increased in polycythemia vera. We investigated the frequency of A3669G SNP and its impact on disease phenotype and progression in 499 patients with primary myelofibrosis (PMF). The distribution of the A3669G allele differed between PMF patients and 2 healthy control populations (odds ratio, 1.6 and 1.8). The variant allele at the homozygous state (G/G) was associated with higher white blood cell count, larger spleen index, and higher frequency of circulating CD34(+) cells at diagnosis. The latter association remained significant after correction for the JAK2V617F genotype. In patients JAK2V617F mutated, the G/G genotype was associated with shorter overall survival (77.6 months vs 298 months, P = .049) and blast transformation (BT)-free survival (76.7 months vs 261 months; P = .018). The latter association remained significant after correction for the known BT risk factors, such as age, sex, white blood cell count, percentage of blasts, IPSS prognostic score, and homozygosity for JAK2V617F (hazard ratio = 3.3; P = .006). In conclusion, the glucocorticoid receptor A3669G is a susceptibility allele for PMF: it contributes to confer the phenotype of excess myeloproliferation, and it cooperates with the JAK2V617F mutation in determining BT.

γ-Irradiated cord blood MNCs: different paracrine effects on mature and progenitor endothelial cells.

Cell-based therapies have been employed to promote neovascularization mainly through the release of paracrine factors inhibiting apoptosis and supporting migration and proliferation of resident differentiated cells. We tested in vitro pro-angiogenic effects of apoptotic cord blood-derived mononuclear cells (CB-MNCs) and their conditioned medium (CM) on mature endothelial cells (HUVECs) and peripheral blood-derived endothelial progenitor cells (ECFCs). CB-MNCs were γ-irradiated to induce apoptosis and cultured for 72 h to obtain the release of CM. MNCs viability, evaluated by flow cytometry, decreased progressively after γ-irradiation reaching 41% at 72 h. γ-Irradiated MNCs (γMNCs) released increasing amounts of EGF, PDGF-AB and VEGF in their CM over time, as assessed by ELISA. γ-MNCs and their CM enhanced capillary-like network formation (in a dose-dependent and time-persistent manner), proliferation and migration of HUVECs in vitro, while they primed capillary-like network formation (dose-independent and not time-persistent) and induced migration but did not support proliferation of ECFCs. Our data support the hypothesis of paracrine mechanism as prevalent in regenerative medicine and demonstrate the efficacy of MNCs secretome in inducing neovascularization. To our knowledge, this is the first paper highlighting differential pro-angiogenic effects of CM on mature and progenitor endothelial cells, adding a tile in the understanding of mechanisms involved in neovascularization.

Mononuclear cell collection for extracorporeal photochemotherapy: a study comparing an automatic and a semiautomatic apheresis device.

BACKGROUND: Extracorporeal photochemotherapy (ECP) is an effective cell therapy employed in several diseases, including graft-versus-host disease (GVHD) and organ rejection after transplantation. When ECP is performed using the off-line technique, mononuclear cell (MNC) collection by leukapheresis is necessary for further manipulation. Semiautomated apheresis systems require experienced personnel to obtain a good MNC collection; an automated device, able to efficiently collect MNCs with high purity, is desirable. We compared the semiautomated COBE Spectra MNC and the new automated Spectra Optia v.5.0 MNC (Terumo BCT) devices in terms of efficacy and safety. STUDY DESIGN AND METHODS: Adult patients with GVHD or bronchiolitis obliterans syndrome (BOS) after lung transplant undergoing ECP at our center were alternatively assigned, within the same ECP cycle (composed by two procedures each), to MNC collection with either device. Patients' characteristics, procedure, and product-related variables were compared. RESULTS: Thirty-nine patients (24 with GVHD and 15 with BOS) underwent a total of 126 ECP procedures, with good compliance to both devices. Product volume and platelet (PLT) and red blood cell contamination were significantly lower with the Spectra Optia. MNC collection efficiency (CE), purity, and PLT loss were similar between the two devices, while white blood cells CE was in favor of the COBE Spectra. CONCLUSION: The Spectra Optia device proved to be a good option for MNC collection in the difficult ECP setting, since it ensures high-quality MNC collection, while at the same time saving personnel's time, guaranteeing optimal monitoring and care to this frail patient population.

Response and survival of patients with chronic graft-versus-host disease treated by extracorporeal photochemotherapy: a retrospective study according to classical and National Institutes of Health classifications.

BACKGROUND: Chronic graft-versus-host disease (cGVHD) classification has recently been improved by the National Institutes of Health (NIH); patients' stratification with those new criteria has implications for patients' prognosis. STUDY DESIGN AND METHODS: To assess whether the NIH consensus classification (NCC) better predicts survival and response to extracorporeal photochemotherapy (ECP), and to identify variables associated with response and survival, we retrospectively analyzed 102 patients with cGVHD reclassified according to NCC treated with ECP (1997-2010) at our center. Cox regression was used in univariate and multivariate models. RESULTS: Of the 102 patients, 64 (62.7%) had classic cGVHD, 24 (23.5%) had overlap cGVHD, and seven (6.9%) patients each had late and persistent acute GVHD. The cumulative ECP-specific follow-up was 2333.3 person-years. Response was complete in 16 (15.7%), partial in 38 (37.3%), minimal in 28 (27.5%), and absent in 20 (19.6%). Of the 22 deaths, 15 (68.2%) occurred among patients with minimal or no response (p = 0.031). The only variables associated with response were nonmyeloablative transplant (hazard ratio, 3.5; 95% confidence interval [CI], 1.36-9.08; p = 0.009), donor lymphocyte infusion (hazard ratio, 2.58; 95% CI, 1.2-5.56; p = 0.015), and lung involvement (hazard ratio, 0.34; 95% CI, 0.12-0.94; p = 0.038). CONCLUSION: ECP is a safe and effective treatment for cGVHD and response to ECP is the only variable that influences survival. We found no correlation between response and NCC clinical subtype, number, or degree of organ involvement, except for lung, or the variables mentioned above. Prospective studies are needed to identify subsets of patients with higher probability of response.

Endothelial colony-forming cells from patients with chronic myeloproliferative disorders lack the disease-specific molecular clonality marker.

Two putative types of circulating endothelial progenitor cells have been recently identified in vitro: (1) endothelial colony-forming cell (ECFC) and (2) colony-forming unit-endothelial cell (CFU-EC). Only the former is now recognized to belong to endothelial lineage. We have used the ECFC and CFU-EC assays to readdress the issue of the clonal relation between endothelial progenitor cells and hematopoietic stem cells in patients with Philadelphia-positive and Philadelphia-negative chronic myeloproliferative disorders. Both ECFCs and CFU-ECs were cultured from peripheral blood mononuclear cells, and either BCR-ABL rearrangement or JAK2-V617F mutation were assessed in both types of endothelial colonies. We found that ECFCs lack the disease-specific markers, which are otherwise present in CFU-ECs, thus reinforcing the concept that the latter belongs to the hematopoietic lineage, and showing that in chronic myeloproliferative disorders the cell that gives rise to circulating ECFC has a distinct origin from the cell of the hematopoietic malignant clone.

Endothelial Progenitor Cell CD34+ and CD133+ Concentrations and Soluble HLA-G Concentrations During Pregnancy and in Cord Blood in Undifferentiated Connective Tissue Diseases Compared to Controls.

The objective of this study is to evaluate endothelial progenitor cells (EPCs) CD34+ CD133- and CD34+ CD133+ and soluble HLA-G (sHLA-G) concentrations among undifferentiated connective tissue disease (UCTD) subjects, compared to controls, during pregnancy and in cord blood. This is a case-control study including 29 controls and 29 UCTDs. CD34+ CD133-, CD34+ CD133+, and sHLA-G concentrations were detected in maternal plasma and in cord blood. This study was approved by the Medical-Ethical Committee of our Institution (Current Research Project N. 901-rcr2017i-23 of IRCCS Foundation Policlinico San Matteo of Pavia). Circulating CD34+ CD133- and CD34+ CD133+ counts and sHLA-G (soluble human leucocyte antigen G) concentrations in maternal peripherical blood were higher in UCTD compared to those in controls in first and third trimester of pregnancy and at delivery (p < 0.001). Maternal CD34+ CD133- and CD34+ CD133+ counts were strongly and significantly correlated in UCTD (Spearman's rho = 0.79, p < 0.0001) but not in controls (Spearman's rho = 0.10, p = 0.35). Cord blood CD34+ CD133- and CD34+ CD133+ median counts and median sHLA-G concentrations were higher among UCTD subjects than in controls (p < 0.001). Cord blood CD34+ and CD133+ counts were inversely and significantly correlated with sHLA-G concentrations among UCTDs, but not in controls. Early UCTD is characterized by increased EPC levels in maternal plasma and in cord blood and higher levels of sHLA-G, compared to controls. Data suggest that fetoplacental unit plays an independent role in the EPC response to a systemic autoimmune disease.