Convalescent Plasma as Adjunctive Therapy for Hospitalized Patients with COVID-19: The Co-CLARITY Trial.

Background and Objective: Convalescent plasma therapy (CPT) may reduce the risk of disease progression among patients with COVID-19. This study was undertaken to evaluate the efficacy and safety of CPT in preventing ICU admission among hospitalized COVID-19 patients. Methods: In this open-label randomized controlled trial, we randomly assigned hospitalized adult patients with COVID-19 in a 1:1 ratio to receive convalescent plasma as an adjunct to standard of care or standard of care alone. The primary endpoint was ICU admission within first 28 days of enrolment. Primary safety endpoints include rapid deterioration of respiratory or clinical status within four hours of convalescent plasma transfusion and cumulative incidence of serious adverse events during the study period including transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), severe allergic reactions, and transfusion-related infections. Results: A total of 22 patients were assigned to receive convalescent plasma as an adjunct to standard of care and 22 to receive standard of care alone. The median time from onset of COVID-19 symptoms to study enrolment was eight days (IQR, 4 to 10). Two patients (9.1%) in the CPT group and one patient (4.5%) in the control group were admitted to the ICU. The primary outcome measure, ICU admission, was not different between the two groups (q-value >0.9). No patient who received convalescent plasma had rapid deterioration of respiratory/clinical status within four hours of transfusion and none developed TRALI, TACO, anaphylaxis, severe allergic reactions, or transfusion-related infections. There was also no significant difference in the secondary outcomes of 28-day mortality (two patients in the CPT group and none in the control group, q-value >0.90), dialysis-free days, vasopressor-free days, and ICU-free days. Conclusions: Among hospitalized COVID-19 patients, no significant differences were observed in the need for ICU admission between patients given CPT as adjunct to standard of care and those who received standard of care alone. Interpretation is limited by early termination of the trial which may have been underpowered to detect a clinically important difference.

A Human Erythrocyte-based Haemolysis Assay for the Evaluation of Human Complement Activity.

The complement system consists of at least 50 proteins that serve as one of the first lines of defence against foreign, or damaged, cells and invading microorganisms. Its dysregulation underlies the pathophysiology of many different diseases, which makes functional assays of complement activity crucial; they are, however, underutilised. Standard haemolysis assays for the analysis of complement function employ sensitised non-human erythrocytes (e.g. from the sheep, guinea-pig or rabbit), the use of which raises animal welfare concerns. To provide an alternative to the use of such animal-derived products for complement function assays, we developed a method that employs modified human erythrocytes to evaluate the activity of complement pathways. Human erythrocytes were subjected to various chemical and/or proteolytic treatments involving 2,4,6-trinitrobenzene sulphonate (TNBS) and pancreatin. Haemolysis assays demonstrated that sequential treatment with TNBS and pancreatin resulted in significantly greater complement-mediated haemolysis, as compared to TNBS or pancreatin treatment alone. Evidence that lysis of the modified erythrocytes was complement-mediated was provided by the chelation and subsequent restoration of calcium in the plasma. Thus, such modified human erythrocytes could be used as an alternative to animal-derived erythrocytes in haemolysis assays, in order to evaluate complement activity in human plasma during, for example, the screening of patients for complement deficiencies and other abnormalities in a clinical setting.

Development and Characterization of Polymeric Peptides for Antibody Tagging of Bacterial Targets.

BACKGROUND: Microbe-Binding Peptides (MBPs) are currently being investigated to address the problem of antimicrobial resistance. Strategies enhancing their antimicrobial activity have been developed, including peptide dimerization. Here, we present an alternative approach based on peptide polymerization, yielding hapten-labelled polymeric MBPs that mediate tagging of bacteria with anti-hapten antibodies, for enhanced immune recognition by host phagocytes. METHODS: C-terminally amidated analogs of the bacterial-binding peptide IIGGR were synthesized, with or without addition of cysteine residues at both N- and C-termini. Peptides were subjected to oxidizing conditions in a dimethyl-sulfoxide/water solvent system, and polymerization was demonstrated using SDS-PAGE. Peptides were then N-terminally labelled with a trinitrophenyl (TNP) group using trinitrobenzene sulfonate (TNBS). Binding to representative bacteria was demonstrated by ELISA using anti-TNP antibodies and was quantified as half-maximal effective concentration (EC50). Minimum Inhibitory Concentration (MIC) and concentration yielding 50% hemolysis (H50) were estimated. Neutrophil phagocytic index was determined for TNP-labelled polymeric bacterial- binding peptide (Pbac) with anti-TNP antibodies and/or serum complement. RESULTS: Polydisperse Pbac was synthesized. EC50 was lower for Pbac than for the corresponding monomeric form (Mbac), for both Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922. MIC and H50 were >250µg/mL for both Pbac and Mbac. A complement-independent increase in neutrophil phagocytic index was observed for E. coli treated with TNP-labelled Pbac in conjunction with anti-TNP antibodies. CONCLUSION: Our data suggest that hapten-labelled polymeric bacterial-binding peptides may easily be produced from even crude synthetic oligopeptide precursors, and that such bacterial-binding peptides in conjunction with cognate anti-hapten antibodies can enhance immune recognition of bacteria by host phagocytes.

Long-term follow-up of infant malnutrition in Barbados studies of glucose tolerance in well-adapted young adults - abstract

Childhood origins of adult disease may be important in the Caribbean, for instance in the later sequelae, if any, of under and malnutrition. Several such hypotheses can be tested for diabetes, including severity of the initial episode(s) leading to pancreatic fibrosis, and weight gain after puberty, causing further B-cell stress. The 1985 WHO criteria defined a malnutrition-related diabetes (MRDM) category, but causal evidence is slim. We examined a series from a chort (N=311) of survivors of infant marasmus (M), Kwashiorkor (K) and age-matched controls (C), all followed since presentation, for over 20 years. Cases were defined on infant weight for age < 2 SDs below expected. Of the first 90 subjects invited, 84 (93 percent) attended for a standardized portocol by trained observers, of a full 2-hour glucose tolerance test and anthropometric measures. (The results are shown in a table). These preliminary results show that average catch-up growth was complete in these previously severely malnourished young adults. While fasting blood glucose (FG) results were similar, following challenge the 2 hr values (2hr G) were significantly higher in female M than respective C(t=3.25, p<0.001) not accounted for by their greater weight, and higher in all M than C (p=0.02). Waist/Hip ratios were no different. Thus, despite these young people being well-adapted in a generally favourable socioeconomic setting, there is some evidence of glucose intolerance following challenge. This could be a prodrome for later development of diabetes. As they are also the first to have responded to the follow-up invitation, those who may not respond may be less well-adapted and hence at even greater risk of glucose intolerance and perhaps other problems (AU)