Convalescent or standard plasma versus standard of care in the treatment of COVID-19 patients with respiratory impairment: short and long-term effects. A three-arm randomized controlled clinical trial.

BACKGROUND: The efficacy of early treatment with convalescent plasma in patients with COVID-19 is debated. Nothing is known about the potential effect of other plasma components other than anti-SARS-CoV-2 antibodies. METHODS: To determine whether convalescent or standard plasma would improve outcomes for adults in early phase of Covid19 respiratory impairment we designed this randomized, three-arms, clinical trial (PLACO COVID) blinded on interventional arms that was conducted from June 2020 to August 2021. It was a multicentric trial at 19 Italian hospitals. We enrolled 180 hospitalized adult patients with COVID-19 pneumonia within 5 days from the onset of respiratory distress. Patients were randomly assigned in a 1:1:1 ratio to standard of care (n = 60) or standard of care + three units of standard plasma (n = 60) or standard of care + three units of high-titre convalescent plasma (n = 60) administered on days 1, 3, 5 after randomization. Primary outcome was 30-days mortality. Secondary outcomes were: incidence of mechanical ventilation or death at day 30, 6-month mortality, proportion of days with mechanical ventilation on total length of hospital stay, IgG anti-SARS-CoV-2 seroconversion, viral clearance from plasma and respiratory tract samples, and variations in Sequential Organ Failure Assessment score. The trial was analysed according to the intention-to-treat principle. RESULTS: 180 patients (133/180 [73.9%] males, mean age 66.6 years [IQR 57-73]) were enrolled a median of 8 days from onset of symptoms. At enrollment, 88.9% of patients showed moderate/severe respiratory failure. 30-days mortality was 20% in Control arm, 23% in Convalescent (risk ratio [RR] 1.13; 95% confidence interval [CI], 0.61-2.13, P = 0.694) and 25% in Standard plasma (RR 1.23; 95%CI, 0.63-2.37, P = 0.544). Time to viral clearance from respiratory tract was 21 days for Convalescent, 28 for Standard plasma and 23 in Control arm but differences were not statistically significant. No differences for other secondary endpoints were seen in the three arms. Serious adverse events were reported in 1.7%, 3.3% and 5% of patients in Control, Standard and Convalescent plasma arms respectively. CONCLUSIONS: Neither high-titer Convalescent nor Standard plasma improve outcomes of COVID-19 patients with acute respiratory failure. Trial Registration Clinicaltrials.gov Identifier: NCT04428021. First posted: 11/06/2020.

Local aberration control to improve efficiency in multiphoton holographic projections.

Optical aberrations affect the quality of light propagating through a turbid medium, where refractive index is spatially inhomogeneous. In multiphoton optical applications, such as two-photon excitation fluorescence imaging and optogenetics, aberrations non-linearly impair the efficiency of excitation. We demonstrate a sensorless adaptive optics technique to compensate aberrations in holograms projected into turbid media. We use a spatial light modulator to project custom three dimensional holographic patterns and to correct for local (anisoplanatic) distortions. The method is tested on both synthetic and biological samples to counteract aberrations arising respectively from misalignment of the optical system and from samples inhomogeneities. In both cases the anisoplanatic correction improves the intensity of the stimulation pattern at least two-fold.

Holographic two-photon activation for synthetic optogenetics.

Optogenetic tools provide users the ability to photocontrol the activity of cells. Commonly, activation is achieved by expression of proteins from photosynthetic organisms, for example, microbial opsins (e.g., ChR2). Alternatively, a sister approach, synthetic optogenetics, enables photocontrol over proteins of mammalian origin by use of photoswitches, visible light (typically), and genetic modification. Thus, synthetic optogenetics facilitates interrogation of native neuronal signaling mechanisms. However, the poor tissue penetration of visible wavelengths impedes the use of the technique in tissue, as two-photon excitation (2PE) is typically required to access the near-infrared window. Here, we describe an alternative technique that uses 2PE-compatible photoswitches (section 1) for photoactivation of genetically modified glutamate receptors (section 2). Furthermore, for fast, multi-region photoactivation, we describe the use of 2P-digital holography (2P-DH) (section 3). We detail how to combine 2P-DH and synthetic optogenetics with electrophysiology, or with red fluorescence Ca2+ recordings, for all-optical neural interrogation. The time required to complete the methods, aside from obtaining the necessary reagents and illumination equipment, is ~3 weeks.

Fast Calculation of Computer Generated Holograms for 3D Photostimulation through Compressive-Sensing Gerchberg-Saxton Algorithm.

The use of spatial light modulators to project computer generated holograms is a common strategy for optogenetic stimulation of multiple structures of interest within a three-dimensional volume. A common requirement when addressing multiple targets sparsely distributed in three dimensions is the generation of a points cloud, focusing excitation light in multiple diffraction-limited locations throughout the sample. Calculation of this type of holograms is most commonly performed with either the high-speed, low-performance random superposition algorithm, or the low-speed, high performance Gerchberg-Saxton algorithm. This paper presents a variation of the Gerchberg-Saxton algorithm that, by only performing iterations on a subset of the data, according to compressive sensing principles, is rendered significantly faster while maintaining high quality outputs. The algorithm is presented in high-efficiency and high-uniformity variants. All source code for the method implementation is available as Supplementary Materials and as open-source software. The method was tested computationally against existing algorithms, and the results were confirmed experimentally on a custom setup for in-vivo multiphoton optogenetics. The results clearly show that the proposed method can achieve computational speed performances close to the random superposition algorithm, while retaining the high performance of the Gerchberg-Saxton algorithm, with a minimal hologram quality loss.

Consequences of ABO incompatibility in multiple myeloma patients undergoing peripheral blood stem cell transplantation after reduced intensity conditioning.

BACKGROUND: Although the ABO blood group is one of two major antigen systems of relevance for transplantation in humans, there are still conflicting data concerning the influence of ABO-incompatibility on transplant outcome. This study investigated the effect of ABO incompatibility in recipients of haematopoietic progenitor cell transplants from related donors after reduced intensity conditioning (RIC) regimens. MATERIALS AND METHODS: We retrospectively analysed data from 19 multiple myeloma patients included in a prospective RIC allogeneic haematopoietic progenitor cell transplantation protocol, focusing on engraftment, transfusion requirement, Graft-versus-Host Disease, transplant-related mortality and survival. RESULTS: Five out of the 19 patients (26%) received an ABO-incompatible transplant, with minor ABO-mismatch in two patients (10%), major ABO-mismatch in one case (5%), and bidirectional incompatibility in two cases. Neutrophil recovery was not significantly different between the ABO-compatible and ABO-incompatible groups (p=0.85). At 30 days after transplantation, 12 of 19 patients tested (63%) had engraftment with all cells of donor origin (100% chimeric), and continued to be fully chimeric on day 100+ evaluations. Patients with major/bidirectional ABO incompatibility required more red blood cell and platelet units after transplantation and were transfused for longer periods of time, as compared with patients with minor or no ABO incompatibility. Transient, mild haemolysis was noted in one patient between days 10 and 30. Graft-versus-Host Disease, disease progression and transplant-related mortality were not affected by ABO matching. DISCUSSION: Although delayed red blood cell engraftment and increased transfusion requirements were documented, in this study ABO incompatibility after the RIC protocol used did not impair the clinical outcome.

Platelet gel for the treatment of traumatic loss of finger substance.

BACKGROUND: Autologous or allogenic platelet gel is a blood component that exploits the effects of the cytokines contained in platelet α granules to stimulate repair processes. The properties of platelet gel were first tested on chronic ulcers to accelerate healing and later in orthopaedic, dental, vascular and cardiothoracic surgery. In our centre, we have been using platelet gel for 5 years, first for surgical patients with difficult wounds, then for orthopaedic patients undergoing osteosynthesis surgery and patients with ulcers not responding to traditional therapies. Subsequently we decided to extend the use of platelet gel also to amputations or traumatic loss of tissue of fingers. MATERIALS AND METHODS: In this article we present the results obtained over 5 years concerning 115 patients with finger amputations or wounds treated with platelet gel in our Service of Transfusion Medicine. Platelets were obtained fom allogeneic buffy coats (10 mL) and the gel was produced by adding thrombin to concentrated platelets. The decision to use homologous platelet gel was based on its limited cost, ease of preparation, almost unlimited availability, the fact that the number of platelets that can be collected is much higher than the therapeutic range and so able to replace the losses due to secondary medication, and last, but not least, it causes no discomfort to patients. The safety of the product was ensured by virology tests including molecular biology studies. RESULTS: The recovery of soft tissue in all patients ranged from 80 to 100%; the median time for this recovery was 3 weeks (range, 10 days - 6 weeks). Approximately 60% of the patients complained of local hypoaesthesia for some weeks; 30% of the patients developed hyperaesthesia, which resolved completely within 6-8 weeks from starting treatment. Loss of bone tissue represented an obstacle to total tissue recovery, but the aesthetic results were satisfactory in nearly all cases. CONCLUSION: All patients showed good compliance, both because of the low frequency of medications (at most, twice a week) and because of the painless platelet gel applications. The only negative aspect was abnormal nail growth in a case of distal partial amputation of a finger. In conclusion, we believe that platelet gel can be very useful in patients with traumatic or surgical loss of finger tissue, since it can resolve critical situations thus avoiding amputation of residual tissue and compromised joint function.