Background: Coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) collection began in two Brazilian hospitals for treatment of severe/ critical patients. Methods and Materials: Mild/moderate COVID-19 convalescents were selected as CCP donors after reverse transcription polymerase chain reaction (RT-PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and absence of symptoms for ≥14 days plus (a) age (18-60 years), body weight greater than 55 kg; (b) immunohematological studies; (c) no infectious markers of hepatitis B virus, hepatitis C virus, human immunodeficiency virus, human T-lymphotropic virus-1/2, Chagas and syphilis infection; (d) no HLA antibodies (multiparous); (e) second RT-PCR (nasopharyngeal swab and/or blood) negativity; (f) virus neutralization test (cytopathic effect-based virus neutralization test neutralizing antibody) and anti-nucleocapsid protein SARS-CoV-2 IgM, IgG, and IgA enzyme-linked immunosorbent assays. Results: Among 271 donors (41 females, 230 males), 250 presented with neutralizing antibodies. Final RT-PCR was negative on swab (77.0%) or blood (88.4%; P = .46). Final definition of RT-PCR was only defined at more than 28 days after full recovery in 59 of 174 (33.9%) RT-PCR-ve, and 25/69 RT-PCR +ve (36.2%;

Introduction Little is known about the neutralizing (nAb) and binding antibody kinetics in COVID‐19 convalescent plasma donors, especially during the first 100 days after disease onset. Materials and Methods A cohort of previously RT‐PCR positive (detected by nasopharyngeal swab during the acute phase), male convalescent patients, all with mild symptoms, were enrolled in serial blood sample collection for a longitudinal nAb titers and anti‐nucleocapsid (NP) antibodies (IgM, IgG and IgA) evaluation. NAbs were detected by a cytopathic effect‐based virus neutralization test (CPE‐based VNT), carried out with SARS‐CoV‐2 (GenBank: MT350282). Results A total of 78 male volunteers provided 316 samples, spanning a total of 4820 days of study. Although only 25% of donors kept nAb titers ≥160 within 100 days after the onset of disease, there was >75% probability of sustaining nAb titers ≥160 in volunteers whose initial nAb titer was ≥1280, weight ≥ 90 kg or obese, according to their body mass index (BMI), as evidenced by Kaplan–Meier analysis and Cox hazard regression (all p < .02). There was no correlation between the ABO group, ABO antibody titers and persistent high nAb titers. High IgG anti‐NP (S/CO ≥5.0) is a good surrogate for detecting nAb ≥ 160, defined by the ROC curve (sensitivity = 90.5%; CI95%: 84.5%–94.7%). Conclusion Selection of CCP donors for multiple collections based on initial high nAb titers (≥1280) or BMI ≥ 30 kg/m 2 provides a simple strategy to achieve higher quality in CCP programs. High IgG anti‐NP levels can also be used as surrogate markers for high nAb screening.

Background Blood groups and anti‐A isohemagglutinin may be involved in susceptibility to SARS‐CoV‐2 infection. Materials and Methods We retrospectively studied 268 COVID‐19 convalescent plasma donors and 162 COVID‐19 inpatients (total 430 subjects, confirmed by RT‐PCR) and 2,212 healthy volunteer first‐time blood donors as a control group. These were further divided into two groups: those with anti‐A (blood types O and B) and those without it (types A and AB). Titres of nucleoproteins, and neutralizing SARS‐CoV‐2 antibody were measured in the convalescent plasma donors and inpatients. Multivariate logistic regression and non‐parametric tests were applied. Results Persons having types O or B showed less infection prevalence than those of types A or AB (OR = 0·62, 95% CI 0·50–0·78; P < 0·001), but there was no difference when COVID‐19 inpatients were analysed. Immunoglobulins M, G and A were lower in COVID‐19 subjects of types O or B group than those of A or AB (0·16 vs. 0·19; P = 0·03, 2·11 vs. 2·55; P = 0·02, 0·23 vs. 0·32; P = 0·03, respectively). Conclusion In this retrospective cohort, COVID‐19 individuals were less likely to belong to blood types O and B, and also had lower SARS‐CoV‐2 antibody titres than A and AB individuals. COVID‐19 severity did not associate with the blood groups.

Vascular occlusion is responsible for most of the severe complications of sickle cell anemia (SCA). The involvement of muscle and fascia is uncommon in SCA, but myonecrosis may occur in SCA crisis. The data accumulated in the literature is limited to only a few reports describing mainly adult patients presenting with severe muscular pain. We report a rare case of sickle myonecrosis and secondary involvement of an associated joint after a severe painful crisis in the left thigh.

Our data collected prospectively demonstrated that: 1) positive DATs occurred in 15.7% of all patients up to Day +30 after a kidney transplant; 2) the DAT positivity occurred up to Day +10 in 9.7% of all transplanted patients; 3) the majority of the transplant recipients with a positive DAT had a nonreactive RBC eluate; and 4) PLS was the cause of a positive DAT in 13.5% of patients submitted to ABO-compatible nonidentical kidney transplants.