Mortality outcomes with hydroxychloroquine and chloroquine in COVID-19: an international collaborative meta-analysis of randomized trials

Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aimed to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We conducted a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality was extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses included patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine was 1.11 (95% CI: 1.02, 1.20; I2=0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I2=0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine was associated with increased mortality in COVID-19 patients, and there was no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities.

Shared Antigen-specific CD8+ T cell Responses Against the SARS-COV-2 Spike Protein in HLA A*02:01 COVID-19 Participants

We report here on antigens from the SARS-CoV-2 virus spike protein, that when presented by Class I MHC, can lead to cytotoxic CD8+ T cell anti-viral responses in COVID-19 patients. We present a method in which the SARS-CoV-2 spike protein is converted into a library of peptide antigen-Major Histocompatibility Complexes (pMHCs) as single chain trimers that contain the peptide antigen, the MHC HLA allele subunit, and the {beta}-2 microglobulin subunit. This library is used to detect the evolution of virus-specific T cell populations in four COVID-19 study participants two of which share one HLA allele, and the other two a second HLA allele, at two time points over the initial course of infection. HLA-matched participants exhibit similar virus-specific T cell populations, but very different time-trajectories of those populations. This strategy can be used to track those virus-specific T cell populations over the course of an infection, thus providing deep insight into the SARS-CoV-2 immune system trajectories observed in different COVID-19 patients.

Effect of recipient mouse splenocytes taken orally by donor mouse on GVHD after splenocyte transplantation / 中国实验血液学杂志

This study was aimed to explore whether the GVHD in mice can be ameliorated and the GVL effect in mice can be reserved by transfusion of lymphocytes of donors fed with recipient splenocytes effect. Male (DBA-2) mice (H-2(d)) as donors were fed with BALB/c splenocytes, DBA-2 splenocytes, bovine serum albumin, or regular chow, every other day. Induction of tolerance was assessed by a mixed lymphocyte reaction (MLR). Female (BALB/c) mice (H-2(d)) as recipients received total body irradiation (TBI) of 6.0 Gy ((60)Cogamma-ray) followed by inoculation of 3 x 10(3) P388 mouse leukemia cells on the same day. Subsequently, tail vein injection of 2 x 10(7) splenocytes supplied by DBA-2 was undertaken. Control groups were fed identically without leukemia cell inoculation. The results showed that GVHD was significantly ameliorated and CD4(+)/CD8(+) ratio increased in recipient-mice transplanted with splenocytes of tolerated donors, compared with control animals. There was no significant difference in survival rate between different groups of recipients inoculated with leukemia cell. It is concluded that the peroral recipient-mouse splenocytes can ameliorate GVHD without hampering effect on GVL.

Selective elimination of alloreactive donor lymphocytes by using TBI and cyclophosphamide / 中国实验血液学杂志

This study was aimed to investigate a new method of avoiding graft-vs-host disease (GVHD) through selective elimination of alloreactive donor lymphocytes by using total body irradiation (TBI) and cyclophosphamide (Cy). Female (BALB/c x C57BL/6) F1 mice (H-2(d/b)) as recipients received (60)Co gamma-ray sublethal TBI of 4 Gy on day 0 followed by being inoculated with P388D1 leukemia cell line on day 1, injection of allogeneic splenocytes from C57BL/6 male mice (H-2(b)) was carried out for induction of graft-vs-leukemia (GVL) effect prior to stem cell transplantation (SCT), intraperitoneally injection of cyclophosphamide (Cy) (200 mg/kg) and TBI (9 Gy) was given on day 6. One day later, treated mice were rescued with bone marrow hematopoietic stem cells from (BALB/c x C57BL/6) F1 male mice (H-2(d/b)). The results showed that recipients had no occurrence of leukemia and GVHD through selective elimination of alloreactive donor lymphocytes by Cy and TBI, survived more than 210 days, the complete-donor chimerism occurred on day 21 after transplantation. The ratio of chimerism descended subsequently, but still displayed mixed-chimerism at 90 days. Control mice died of GVHD, leukemia or other death-related-transplantation within 20 to 36 days (P<0.01). It is concluded that to induce GVL effects by MHC mismatched splenocytes given before syngeneic bone marrow transplantation followed by selective elimination of alloreactive donor lymphocytes through TBI and Cy, graft-vs-host disease was thus avoided.