Large Volume Plasma Research Articles

Continuous production of large volumes of plasma activated water for agriculture

Continuous production of large volumes of plasma activated water for agriculture

Highly Sensitive Molecular Diagnostic Platform for Scrub Typhus Diagnosis Using O. tsutsugamushi Enrichment and Nucleic Acid Extraction.

Scrub typhus is caused by the Gram-negative obligate intracellular bacterium Orientia tsutsugamushi, and this tick-borne disease is difficult to distinguish from other acute febrile illnesses as it typically presents with symptoms such as rash, crusting at the bite site, headache, myalgia, lymphadenopathy, and elevated liver transaminases. It can often be diagnosed clinically, but not all patients present with characteristic symptoms, so serological diagnosis and molecular techniques may be required. However, existing diagnostic tests often have low sensitivity and specificity, making early detection difficult. This study presents a nucleic acid extraction method using large volumes of plasma and buffy coat to increase sensitivity, as well as an improved detection method using two target genes. Using the I-PULL device, nucleic acids can be extracted from up to 4 mL of sample in 30 min, avoiding contamination. The extracted DNA detects two genes of O. tsutsugamushi, increasing sensitivity compared to single-gene detection. Clinical validation in 38 patient samples showed 100% specificity and 95.24% sensitivity for the single target gene, with specificity and sensitivity rising to 100% when both genes are analyzed. This molecular diagnostic platform can be useful for distinguishing scrub typhus from similar diseases.

Investigation of electromagnetic fluctuations in a magnetically screened high beta plasma

We report low-frequency electromagnetic turbulence in large-volume plasma devices in a region that receives magnetically screened plasma. The magnetic screen is produced by the activation of a large solenoid that generates a strong magnetic field ( BEEF ) transverse to the background axial magnetic field ( Bz ). The magnetic field strength variation in BEEF controls the plasma diffusion and is responsible for parametric profile modifications in large volume plasma devices. The turbulence is characterized by the observed features of an electromagnetic mode having frequency ordering in the lower hybrid range (f ci < f < f LH). The free energy source for the excited turbulence is believed to be the prevalent finite radial pressure gradient in the system. The excited electromagnetic mode shows typical scales for the wave number, k⊥ ∼ 0.13 cm−1 and frequency f ∼ 6 kHz and propagates with phase velocity comparable to ion acoustic velocity, C s in electron diamagnetic drift direction. It is believed that the low-frequency pressure gradient-driven electromagnetic mode exhibits coupling with the lower hybrid or whistler wave.

Efficient ECCD non-inductive plasma current start-up, ramp-up, and sustainment for an ST fusion reactor

The elimination of the need for an Ohmic heating solenoid may be the most impactful design driver for the realization of economical compact fusion tokamak reactor systems. However, this would require fully non-inductive start-up and current ramp-up from zero plasma current and low electron temperature of sub-keV to the full plasma current of ∼10–15 MA at 20–30 keV electron temperature. To address this challenge, an efficient solenoid-free start-up and ramp-up scenario utilizing a low-field-side-launched extraordinary mode at the fundamental electron cyclotron harmonic frequency (X–I) is proposed, which has more than two orders of magnitude higher electron cyclotron current drive (ECCD) efficiency than the conventional ECCD for the sub-keV start-up regime. A time dependent model was developed to simulate the start-up scenarios. For the Spherical Tokamak Advanced Reactor (STAR) (Menard et al 2023 Next-Step Low-Aspect-Ratio Tokamak Design Studies (IAEA)), it was found that to fully non-inductively ramp-up to 15 MA, it would take about 25 MW of EC power at 170 GHz. Because of the relatively large plasma volume of STAR, radiation losses must be considered. It is important to make sure that high Z impurities are kept sufficiently low during the early current start-up phase where the temperature is sub-keV range. Since the initial current ramp up takes place at a factor of ten lower density compared to the sustained regimes, it is important to transition into a higher bootstrap fraction discharge at lower density to minimize the ECCD power requirement during the densification. For the sustainment phase an array of eight gyrotron launchers with a total of about 60 MW of fundamental O-mode was found to be sufficient to provide the required axis-peaked external current drive. High efficiencies between 19–57 kA MW−1 were found with optimal aiming, and these were resilient to small changes in aiming angles and density and temperature profiles.

Comparison of Blood Volume Profiles in Heart Failure With Preserved and Reduced Ejection Fractions: Sex Makes a Difference.

Blood volume (BV) profiles vary markedly in patients with heart failure (HF), but how HF phenotypes and patient sex impact volume profiles remain to be explored. The aim of the study was to differentiate BV, plasma volume, and red blood cell mass profiles by phenotypes of preserved and reduced left ventricular ejection fractions and assess the impact of patient sex on profile heterogeneity. Retrospective analysis of clinical and BV data was undertaken in patients with chronic New York Heart Association II-III heart failure. BV was quantitated using the nuclear medicine indicator-dilution methodology. A total of 530 BV analyses (360 HF with reduced ejection fraction and 170 HF with preserved ejection fraction) were identified in 395 unique patients. Absolute BV was greater in HF with reduced ejection fraction (6.7±1.8 versus 5.9±1.6 liters: P<0.001); however, large variability in frequency distribution of volume profiles was observed in both phenotypes (-22% deficit to +109% excess relative to normal volumes). HF with reduced ejection fraction was characterized by a higher prevalence of BV expansion ≥+25% of normal (39% versus 26%; P=0.003), and HF with preserved ejection fraction was characterized a by more frequent normal BV (42% versus 24%; P<0.001). Male sex in both phenotypes was associated with a larger absolute BV (7.0±1.6 versus 5.1±1.3 liters; P<0.001) and higher frequency of large BV and plasma volume expansions above normal (both P<0.001), while females in both phenotypes demonstrated a higher prevalence of normal BV and plasma volume (both P<0.001). Findings support significant differences in BV, plasma volume, and red blood cell mass profile distributions between heart failure phenotypes, driven in large part by sex-specific factors. This underscores the importance of identifying and distinguishing individual patient volume profiles to help guide volume management strategies.

Patient Sex Impacts Volume Phenotypes and Hemodynamics in Chronic Heart Failure: A Multicenter Analysis

BackgroundQuantitative methods have shown clinically significant heterogeneity in blood volume (BV) profiles in patients with chronic heart failure (HF). How patient sex might impact this volume heterogeneity and relationship to cardiac hemodynamics remains to be defined. MethodsRetrospective analysis of clinical and quantitative BV, plasma volume (PV) and red blood cell (RBC) mass data was undertaken across three medical centers. BV was quantitated using nuclear medicine I-131-labelled plasma albumin indicator-dilution methodology with cardiac hemodynamics obtained within 24 hours. ResultsIn an analysis of 149 males and 106 females absolute BV was greater on average in males (6.9±1.7 vs. 5.0±1.2 liters, p<0.001) however, a wide range in BVs was demonstrated in both sexes (2.9 to 14.5 liters). Male sex was associated with higher prevalence of large (>+25% of normal) BV and PV expansions (36% vs. 15% and 51% vs. 21%, respectively, both p<0.001). In contrast, female sex was associated with higher prevalence of normal total BV (44% vs. 27%, p=0.005), PV (54% vs. 27%, p<0.001), hypovolemia (23% vs. 11%, p=0.005) and true anemia (42% vs. 26%, p<0.001). Cardiac hemodynamics differed by sex but only modest associations were demonstrated between volume profiles and cardiac filling pressures. ConclusionsFindings support unique intravascular volume profiles reflecting sex-specific differences in the prevalence and distributions of total BV, PV and RBC mass profiles in chronic HF patients. This underscores the importance of recognizing patient sex as a significant factor influencing volume homeostasis which needs to be taken into account to effectively individualize volume management strategies.

Observation of turbulence-induced reduced electrostatic particle flux in the presence of QL whistlers in large laboratory plasma

The electrostatic particle flux is measured in the presence of obliquely propagating quasi-longitudinal (QL) whistler turbulence (ωci&amp;lt;ωLH≈ω&amp;lt;ωce) in the large-volume plasma device (LVPD). The QL whistler is observed with frequency band between 40 and 100 kHz, and the characteristic wave numbers k∥≪k⊥ are excited by the reflected energetic electrons via loss cone (localised mirror type magnetic geometry) formation in the presence of a transverse magnetic field [BEEF(x̂)] of electron energy filter and axial magnetic field of LVPD [Bo(ẑ)]. The effect of mirror strength on radial particle flux is explored by changing the BEEF as this variation changes the excited QL-whistler turbulence. We observed that the increase in QL-whistler turbulence level, the radial particle transport, i.e., the radial particle flux subsides, is accompanied by particle flux direction reversal from radially inward to outward.

Blood volume phenotypes and patient sex in resistant hypertension.

The relationship of blood volume (BV) to systemic blood pressure (BP) is not well defined in resistant hypertension (RH). The goal of this study was to examine the extent to which systemic BP stratified by patient sex would impact BV phenotypes. A retrospective analysis of clinical and quantitative BV data was undertaken in a cohort of ambulatory patients with a history of controlled and uncontrolled RH. We analyzed 253 unique BVs with 54% of patients above goal BP of <150 mmHg. BV phenotypes were highly variable but no correlation of systolic BP to absolute BV or percentage deviation from normal volume was identified in either sex. Males demonstrated overall larger absolute BVs with higher prevalence of large plasma volume (PV) expansion; females were overall more hypovolemic by total BV but with a higher frequency of normal PV than males. Females trended towards more RBC mass deficit (true anemia) (49% vs. 38%. P = 0.084) while more males demonstrated RBC mass excess (erythrocythemia) (21% vs. 11%, P = 0.029). Importantly, a significant portion (52%) of patients with true anemia identified by BVA would go undetected by hemoglobin measurement alone. BV phenotypes are highly diverse in patients with RH. However, absolute BV or variability in BV phenotypes even when stratified by patient sex did not demonstrate an association with systemic BP. BV phenotyping provides a key to optimizing clinical management by identifying RBC mass profiles particularly distinguishing true anemia, dilutional anemia, and erythrocythemia and the contribution of PV expansion. Findings support the clinical utility of BV phenotyping in RH.

Large volume plasma device-upgrade: A versatile plasma system for electron emitter, beam and wave based diagnostics

Large volume plasma device-upgrade: A versatile plasma system for electron emitter, beam and wave based diagnostics

Dynamics of a Plasma Cloud Generated by a Compact Coaxial Gun upon Expansion into Vacuum and Large-Volume Background Plasma in an External Magnetic Field

Results of experiments on injection of dense plasma clouds created by a small-scale coaxial generator into vacuum and large-volume background plasma in an ambient magnetic field are presented. The regime of an “infinite” background medium that allows studying the plasma-cloud dynamics on the scale of about one meter in the directions perpendicular and parallel to a quasi-uniform magnetic field is realized on “Krot” plasma device. The dynamics of the diamagnetic cavity appearing upon magnetic-field expulsion by a plasma blob, the electromagnetic noise appearing in the cavity, along with the evolution of plasma-cloud structure during injection and at the stage of its decay, were studied. It is demonstrated that the key properties of the cloud dynamics that are typical of the active space and high-energy laboratory experiments, including complete expulsion of the magnetic field from the cloud and development of the flute instability at its boundary, are reproduced at low injection speed (below 30 km/s) and low plasma energy (on the order of 0.1 J).

Benefits of FAIMS to Improve the Proteome Coverage of Deteriorated and/or Cross-Linked TMT 10-Plex FFPE Tissue and Plasma-Derived Exosomes Samples.

The proteome characterization of complex, deteriorated, or cross-linked protein mixtures as paired clinical FFPE or exosome samples isolated from low plasma volumes (250 µL) might be a challenge. In this work, we aimed at investigating the benefits of FAIMS technology coupled to the Orbitrap Exploris 480 mass spectrometer for the TMT quantitative proteomics analyses of these complex samples in comparison to the analysis of protein extracts from cells, frozen tissue, and exosomes isolated from large volume plasma samples (3 mL). TMT experiments were performed using a two-hour gradient LC-MS/MS with or without FAIMS and two compensation voltages (CV = -45 and CV = -60). In the TMT experiments of cells, frozen tissue, or exosomes isolated from large plasma volumes (3 mL) with FAIMS, a limited increase in the number of identified and quantified proteins accompanied by a decrease in the number of peptides identified and quantified was observed. However, we demonstrated here a noticeable improvement (>100%) in the number of peptide and protein identifications and quantifications for the plasma exosomes isolated from low plasma volumes (250 µL) and FFPE tissue samples in TMT experiments with FAIMS in comparison to the LC-MS/MS analysis without FAIMS. Our results highlight the potential of mass spectrometry analyses with FAIMS to increase the depth into the proteome of complex samples derived from deteriorated, cross-linked samples and/or those where the material was scarce, such as FFPE and plasma-derived exosomes from low plasma volumes (250 µL), which might aid in the characterization of their proteome and proteoforms and in the identification of dysregulated proteins that could be used as biomarkers.

Marked reduction in the incidence of transfusion-transmitted hepatitis B virus infection after the introduction of antibody to hepatitis B core antigen and individual donation nucleic acid amplification screening in Japan.

In Japan, 41 million blood donations have been screened for hepatitis B virus (HBV) during the past 8.4 years using individual donation nucleic acid amplification testing (ID-NAT) and antibody to hepatitis B core antigen (anti-HBc) screening. Transfusion-transmitted HBV infection (TT-HBV) incidence was examined. Donated blood implicated in TT-HBV was analyzed for infection stage and DNA levels. Causative HBV strains were phylogenetically analyzed. Among 5162 (0.013%) ID-NAT positives, window period (WP) and occult HBV infection (OBI) accounted for 3.4% (176) and 11.5% (594), respectively. No OBI-related TT-HBV occurred. Seven blood donations caused eight TT-HBV cases, six of which were in the pre-ID-NAT WP, leaving one with an unresolved infection stage. Seven cases were caused by platelet concentrate (180 mL plasma) and one case by fresh-frozen plasma (200 mL plasma), which contained estimated infectious doses varying between 2 and 2300 HBV virions. HBV subgenotypes in five cases were HBV/A2. Complete genome sequences of the transmitting A2 strains were nearly identical (99.6%-100%) and clustered in a group that included HBV/HIV-1 coinfections and a higher proportion of donors in the acute infection phase (69%) than the other group of HBV/A2 sequences (5%). The incidence of observed TT-HBV cases has significantly reduced to 0.19 per million in the ID-NAT screening period. OBI-related TT-HBV was eliminated by anti-HBc screening. Established TT-HBV cases were caused by blood products with large plasma volumes containing extremely low HBV concentrations derived from blood donors at a very early infection stage.

Simultaneous estimation of five biomarkers of neuroprotective herb Ashwagandha NMITLI-118R AF1 in rat plasma and brain using LC-ESI-MS/MS: Application to its pharmacokinetic and stability studies

Withania Somnifera (WS) is a popular nutritional supplement in the USA, Europe, and Asia, known for its pharmacological effects on neurological disorders. However, the bioanalytical method development, validation, and pharmacokinetics of WS NMITLI-118R AF1 biomarkers Withanolide A (WLD A), Withanone (WNONE), Withanolide B (WLD B), Withaferin A (WF A), and 12 Deoxywithastramonolide (12 DEOXY) in rats have not been comprehensively explored. This study aimed to develop and validate a sensitive and selective LC-ESI-MS/MS method for these biomarkers in male Sprague Dawley rats plasma and brain matrix. Rats were divided into eight groups, each containing five rats. A plant extract of NMITLI-118R AF1 at 50 mg/kg was orally administered to the rats for in-vivo pharmacokinetic investigation. All the analytes had a linear calibration curve (r2 > 0.999), and intra-day and inter-day precision (%) were found in the range of 2.46 – 13.71% and accuracy were within the acceptable range (±15%). The biomarkers of NMITLI-118R AF1 were found stable in in-vitro plasma and simulated gastro-intestinal fluids. The observed (Cmax) and (Tmax) values for the biomarkers in the systemic circulation were WLD A (5.59 ± 0.34 ng/mL, Tmax 1.00 ± 0.00 h), WNONE (6.28 ± 0.41 ng/mL, Tmax 0.95 ± 0.11 h), WLD B (6.45 ± 2.87 ng/mL, Tmax 0.95 ± 0.11 h), WF A (6.50 ± 0.27 ng/mL, Tmax 1.00 ± 0.00 h), and 12 DEOXY (5.68 ± 0.39 ng/mL, Tmax 1.00 ± 0.00 h). In contrast to the old method, our approach exhibits a lower limit of quantification (LLOQ), shorter run time (less than10 min), and enables the detection of WF A and WNONE in fresh rat plasma by other quantitative analysis of mass spectrometry (m/z) [M]+. Shows high sample volumes for both, larger plasma volumes, costlier sample collection techniques dried blood spot (DBS), more expensive solid phase extraction techniques (SPE) and longer analysis time 14 min. Moreover, our method requires a smaller sample volume 10 µL, offers faster analysis time 4 min, and achieves a higher sensitivity 1 ng/mL. This is the first report of a comprehensive study on in-vitro and in-vivo pharmacokinetics of NMITLI-118R AF1 biomarkers, which may aid in further pre-clinical and clinical trial investigations.

Production of high-density metastable argon atoms with periodic fast pulsed DC discharge.

Optically pumped metastable rare gas laser (OPRGL), as a potential high-energy laser has attracted much attention. During extensive research on OPRGL, the realization of volume discharge with high-metastable density has always been a priority and is essential to the efficient lasing of OPRGL. A large-volume plasma of He/Ar with high metastable density at atmospheric pressure can be generated by applying peaking capacitors near the electrodes. In this article, 0.8 cm3 of He/Ar plasma at a pressure of 900 mBar, with a peak value of metastable argon density higher than 1014 cm-3 was realized. The metastable density was measured by absorption spectroscopy based on the absorption bandwidths acquired at a pressure range of 400-900 mbar where a probe beam at a weak line with wavelength 772.38 nm was applied. Furthermore, the high metastable density was verified by the laterally-observed laser-induced fluorescence, as well as the laser oscillation of 100 mW under a longitudinal pumping with a short gain length of 8 mm.

Experimental and numerical investigation on the uniformity of nanosecond pulsed dielectric barrier discharge influenced by pulse parameters

Nanosecond (ns) pulsed dielectric barrier discharge (DBD) is considered as a promising method to produce controllable large-volume and high activity low-temperature plasma at atmospheric pressure, which makes it suitable for wide applications. In this work, the ns pulse power supply is used to excite Ar DBD and the influences of the pulse parameters (voltage amplitude, pulse width, pulse rise and fall times) on the DBD uniformity are investigated. The gas gap voltage (U g) and conduct current (I g) are separated from the measured voltage and current waveforms to analyze the influence of electrical parameters. The spectral line intensity ratio of two Ar excited species is used as an indicator of the electron temperature (T e). The time resolved discharge processes are recorded by an intensified charge-coupled device camera and a one-dimensional fluid model is employed to simulate the spatial and temporal distributions of electrons, ions, metastable argon atoms and T e. Combining the experimental and numerical results, the mechanism of the pulse parameters influencing on the discharge uniformity is discussed. It is shown that the space electric field intensity and the space particles’ densities are mainly responsible for the variation of discharge uniformity. With the increase of voltage and pulse width, the electric field intensity and the density of space particles increased, which results in the discharge mode transition from non-uniform to uniform, and then non-uniform. Furthermore, the extension of pulse rise and fall times leads to the discharge transition from uniform to non-uniform. The results are helpful to reveal the mechanism of ns pulsed DBD mode transition and to realize controllable and uniform plasma sources at atmospheric pressure.

Membrane-based therapeutic plasma exchange: Proposed techniques for preventing filter failure.

Therapeutic plasma exchange (TPE) is commonly performed using membrane-based TPE (mTPE) and is prone to filter failure. We report on 46 patients, with a total of 321 mTPE treatments using the NxStage machine. This was a retrospective study with an aim to evaluate the effect of heparin, pre-filter saline dilution and the impact of total plasma volume exchanged (< 3 L vs. ≥3 L) on the rate of filter failure. Primary outcome was the overall rate of filter failure. Secondary outcomes included factors that may have indirectly influenced the rate of filter failure, including hematocrit, platelet count, replacement fluid (Fresh Frozen Plasma vs. albumin), and access type. We found that treatments that received both pre-filter heparin and saline had a statistically significant decrease in filter failure rate as compared to those that received neither (28.6% vs. 5.3%, P = .001), and compared to the treatments that received pre-filter heparin alone (14.2% vs. 5.3%, P = .015). In treatments that received both pre-filter heparin and saline predilution, we noted a significantly higher filter failure rate when the plasma volume exchanged was ≥3 L as compared to those that had <3 L exchanged (12.2% vs. 0.9%, P = .001). Rate of filter failure in mTPE can be reduced by implementing several therapeutic interventions including pre-filter heparin and pre-filter saline solution. These interventions were not associated with any clinically significant adverse events. Despite the above-mentioned interventions, large plasma volume exchanges of ≥3 L can negatively impact filter life.

The colliding planar shocks platform to study warm dense matter at the National Ignition Facility

We have developed an experimental platform at the National Ignition Facility that employs colliding planar shocks to produce warm dense matter with uniform conditions and enable high-precision equation of state measurements. The platform uses simultaneous x-ray Thomson scattering and x-ray radiography to measure the density, electron temperature, and ionization state in warm dense matter. The experimental platform is designed to create a large volume of uniform plasma (approximately 700×700×150μm3) at pressures approaching 100 Mbar and minimize the distribution of plasma conditions in the x-ray scattering volume, significantly improving the precision of the measurements. Here, we present the experimental design of the platform and compare hydrodynamic simulations to x-ray radiography data from initial experiments studying hydrocarbons, producing uniform densities within ±25% of the average probed condition. We show that the platform creates a homogeneous plasma that can be characterized using x-ray Thomson scattering. Thus, the new platform enables accurate measurements of plasma conditions necessary to test models for the equation of state and ionization potential depression in the warm dense matter regime.

Simple Bioparticle Filtration Device Based on an Ultralow-Fouling Zwitterionic Polyurethane Membrane for Rapid Large-Volume Separation of Plasma and Viruses from Whole Blood

Plasma separation from whole blood is oftent required as an essential first step when performing blood tests with a viral assay. However, developing a point-of-care plasma extraction device with a large output and high virus recovery remains a significant obstacle to the success of on-site viral load tests. Here, we report a portable, easy-to-use, cost-efficient, membrane-filtration-based plasma separation device that enables rapid large-volume plasma extraction from whole blood, designed for point-of-care virus assays. The plasma separation is realized by a low-fouling zwitterionic polyurethane-modified cellulose acetate (PCBU-CA) membrane. The zwitterionic coating on the cellulose acetate membrane can decrease surface protein adsorption by 60% and increase plasma permeation by 46% compared with a pristine membrane. The PCBU-CA membrane, with its ultralow-fouling properties, enables rapid plasma separation. The device can yield a total of 1.33 mL plasma from 10 mL whole blood in 10 min. The extracted plasma is cell-free and exhibits a low hemoglobin level. In addition, our device demonstrated a 57.8% T7 phage recovery in the separated plasma. The results of real-time polymerase chain reaction analysis confirmed that the nucleic acid amplification curve of the plasma extracted by our device is comparable to that obtained by centrifugation. With its high plasma yield and good phage recovery, our plasma separation device provides an excellent replacement for traditional plasma separation protocols for point-of-care virus assays and a broad spectrum of clinical tests.

Inductively-coupled plasma discharge for use in high-energy-density science experiments

Inductively-coupled plasma discharges are well-suited as plasma sources for experiments in fundamental high-energy density science, which require large volume and stable plasmas. For example, experiments studying particle beam-plasma instabilities and the emergence of coherent macroscopic structures — which are key for modelling emission from collisionless shocks present in many astrophysical phenomena. A meter-length, table-top, inductive radio-frequency discharge has been constructed for use in a high-energy density science experiment at CERN which will study plasma instabilities of a relativistic electron-positron beam. In this case, a large volume is necessary for the beam to remain inside the plasma as it diverges to centimeter-scale diameters during the tens-of-centimeters of propagation needed for instabilities to develop. Langmuir probe measurements of the plasma parameters show that plasma can be stably sustained in the discharge with electron densities exceeding 1011 cm-3. The discharge has been assembled using commercially-available components, making it an accessible option for commissioning at a University laboratory.

Double Filtration Plasmapheresis for Desensitization during Haploidentical Stem Cell Transplantation in Patients with Positive Donor-Specific Anti-HLA Antibodies

Background:Donor-specific anti-HLA antibodies (DSA) are a major cause of engraftment failure in patients receiving haploidentical stem cell transplantation (HaploSCT). Effective treatments are needed for these patients, who often have no other donor options and/or are in need to proceed urgently to transplantation. Plasma exchange (PE) is an effective treatment widely used for DSA desensitization. However, a large volume of plasma is required. Double filtration plasmapheresis (DFPP) is a semi-selective blood purification modality derived from the PE modality. DFPP avoids the unnecessary loss of plasma proteins, reduces the need for plasma and increases the efficiency of purification. To define the efficacy of DFPP for DSA-positive patients in HaploSCT, we conducted a nested case-control study. Methods: Patients who underwent HaploSCT in the Bone Marrow Transplantation Center of the First Affiliated Hospital of Zhejiang University School of Medicine from March 2017 to November 2021 were enrolled in the study cohort. Thirty-two patients with positive DSA (MFI≥2000) were treated with desensitization protocol including DFPP. Ninety-six patients (1:3) with negative DSA were randomly matched according to gender, age and transplantation time as the control group. DSA positive patients were given alternate-day DFPP twice before starting one week before the beginning of transplant conditioning. DSA was retested after DFPP treatment. A single dose of rituximab (375 mg/m2) was administrated after completion of DFPP. Results: A total of 32 HaploSCT patients with DSAs were included in the study. The majority of patients in the DSA group were female (75%) and a mean age of 41 (13-63) years . 96 DSA negative patients were selected as controls. The two groups had equivalent subject and donor characteristics, including age, gender, underlying diseases, conditioning regimens and GVHD prophylaxis.20 (62.5%) patients presented anti-HLA class I DSAs (4 of them with > 10000 MFI), 9 (28.1%) presented anti-HLA class II DSA (2 with > 10000 MFI) and 3 (9.3%) presented both anti-HLA class I and II DSA (1 with > 10000 MFI). After DFPP treatment, levels of DSA decreased significantly. The mean MFI values before and after treatment were 7189.56 ±4294.01 vs. 2869.57±3454.55 (P < 0.001), respectively. All patients in DSA group achieved hematopoietic reconstitution within 28 day of transplantation. The mean neutrophils and platelets engraftment time was 13.44±2.42 days and 14.03±3.78 days respectively, which were comparable to control group. In the DSA and control groups, the incidence of grade III-IV aGVHD was 9.37% vs. 10.41% (P < 0.05), the 2-year cumulative recurrence rate was 26.35% vs. 15.62% (P < 0.05) and the overall survival (OS) was 77.20% vs. 81.20% (P < 0.05), respectively. Conclusion: DFPP can significantly reduce the level of DSA in patients before transplantation. Treatment with DFPP and rituximab is effective in promoting engraftment for DSA-positive patients in HaploSCT.