Background Early administration of convalescent plasma obtained from blood donors who have recovered from coronavirus disease 2019 (Covid-19) may prevent disease progression in acutely ill, high-risk patients with Covid-19. Methods In this randomized, multicenter, single-blind trial, we assigned patients who were being treated in an emergency department for Covid-19 symptoms to receive either one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or placebo. All the patients were either 50 years of age or older or had one or more risk factors for disease progression. In addition, all the patients presented to the emergency department within 7 days after symptom onset and were in stable condition for outpatient management. The primary outcome was disease progression within 15 days after randomization, which was a composite of hospital admission for any reason, seeking emergency or urgent care, or death without hospitalization. Secondary outcomes included the worst severity of illness on an 8-category ordinal scale, hospital-free days within 30 days after randomization, and death from any cause. Results A total of 511 patients were enrolled in the trial (257 in the convalescent-plasma group and 254 in the placebo group). The median age of the patients was 54 years; the median symptom duration was 4 days. In the donor plasma samples, the median titer of SARS-CoV-2 neutralizing antibodies was 1:641. Disease progression occurred in 77 patients (30.0%) in the convalescent-plasma group and in 81 patients (31.9%) in the placebo group (risk difference, 1.9 percentage points; 95% credible interval, −6.0 to 9.8; posterior probability of superiority of convalescent plasma, 0.68). Five patients in the plasma group and 1 patient in the placebo group died. Outcomes regarding worst illness severity and hospital-free days were similar in the two groups. Conclusions The administration of Covid-19 convalescent plasma to high-risk outpatients within 1 week after the onset of symptoms of Covid-19 did not prevent disease progression. (SIREN-C3PO ClinicalTrials.gov number, NCT04355767 .)

Cells of the immune system that reside in barrier epithelia provide a first line of defense against pathogens. Langerhans cells (LCs) and CD8+ tissue-resident memory T cells (TRM cells) require active transforming growth factor-β1 (TGF-β) for epidermal residence. Here we found that integrins αvβ6 and αvβ8 were expressed in non-overlapping patterns by keratinocytes (KCs) and maintained the epidermal residence of LCs and TRM cells by activating latent TGF-β. Similarly, the residence of dendritic cells and TRM cells in the small intestine epithelium also required αvβ6. Treatment of the skin with ultraviolet irradiation decreased integrin expression on KCs and reduced the availability of active TGF-β, which resulted in LC migration. Our data demonstrated that regulated activation of TGF-β by stromal cells was able to directly control epithelial residence of cells of the immune system through a novel mechanism of intercellular communication.

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Heparin was removed from the patient's plasma during TPE. Adjustment of the dose during TPE may be necessary to maintain therapeutic drug levels. Methods for monitoring UFH therapy may not agree. J. Clin. Apheresis 31:507-515, 2016. © 2016 Wiley Periodicals, Inc.

This study demonstrates that MSCs derived from cryopreserved marrow have the same growth characteristics as fresh marrow-derived MSCs. Further studies are needed to explore potential differences in clinical efficacy.