Cycle threshold predicted mortality in a cohort of patients with hematologic malignancies infected with SARS-CoV-2 / El umbral de ciclado predijo la mortalidad en una cohorte de pacientes conneoplasias hematológicas infectados con SARS-CoV-2 / Microbiología clinica y enfermedades infecciosas

Abstract When a SARS-CoV-2 RT-qPCR test is performed, it may determine an indirect measureof viral load called cycle threshold (Ct). Respiratory samples with Ct <25.0 cycles are consideredto contain a high viral load. We aimed to determine whether SARS-CoV-2 Ct at diagnosis couldpredict mortality in patients with hematologic malignancies (lymphomas, leukemias, multiplemyeloma) who contracted COVID-19. We included 35 adults with COVID-19 confirmed by RT-qPCR performed at diagnosis. We evaluated mortality due to COVID-19 rather than mortalitydue to the hematologic neoplasm or all-cause mortality. Twenty-seven (27) patients survivedand 8 died. The global mean Ct was 22.8 cycles with a median of 21.7. Among the survivors,the mean Ct was 24.2, and the median Ct value was 22.9 cycles. In the deceased patients, themean Ct was 18.0 and the median Ct value was 17.0 cycles. Using the Wilcoxon Rank Sum test,we found a significant difference (p = 0.035). SARS-CoV-2 Ct measured in nasal swabs obtainedat diagnosis from patients with hematologic malignancies may be used to predict mortality.

Resumen Cuando se realiza una RT-qPCR para SARS-CoV-2, es posible determinar una medidaindirecta de la carga viral llamada umbral de ciclado (Ct). Las muestras respiratorias con Ct<25,0 ciclos se consideran de alta carga viral. Nos propusimos determinar si el Ct para SARS-CoV-2 al diagnóstico predice la mortalidad en pacientes con neoplasias hematológicas (linfomas,leucemias, mielomas) que contrajeron COVID-19. Incluimos 35 adultos con COVID-19 confirmadopor RT-qPCR al diagnóstico. Evaluamos la mortalidad por COVID-19, no la mortalidad por la neo-plasia hematológica o la mortalidad por cualquier causa. De los 35 pacientes, 27 sobrevivierony 8 fallecieron. El Ct global medio fue 22,8 ciclos con una mediana de 21,7 ciclos. Entre lossobrevivientes, el Ct medio fue 24,2 ciclos con una mediana de 22,9 ciclos. Entre los fallecidos,el Ct medio fue 18,0 y el Ct mediano fue 17,0 ciclos. Empleando la prueba de suma de rangosde Wilcoxon, encontramos una diferencia significative (p = 0,035). En pacientes con neoplasiashematológicas infectados con coronavirus, el Ct de SARS-CoV-2 medido en hisopados nasales almomento del diagnóstico podría ser utilizado para predecir la mortalidad.

Cycle threshold predicted mortality in a cohort of patients with hematologic malignancies infected with SARS-CoV-2.

When a SARS-CoV-2 RT-qPCR test is performed, it may determine an indirect measure of viral load called cycle threshold (Ct). Respiratory samples with Ct <25.0 cycles are considered to contain a high viral load. We aimed to determine whether SARS-CoV-2 Ct at diagnosis could predict mortality in patients with hematologic malignancies (lymphomas, leukemias, multiple myeloma) who contracted COVID-19. We included 35 adults with COVID-19 confirmed by RT-qPCR performed at diagnosis. We evaluated mortality due to COVID-19 rather than mortality due to the hematologic neoplasm or all-cause mortality. Twenty-seven (27) patients survived and 8 died. The global mean Ct was 22.8 cycles with a median of 21.7. Among the survivors, the mean Ct was 24.2, and the median Ct value was 22.9 cycles. In the deceased patients, the mean Ct was 18.0 and the median Ct value was 17.0 cycles. Using the Wilcoxon Rank Sum test, we found a significant difference (p=0.035). SARS-CoV-2 Ct measured in nasal swabs obtained at diagnosis from patients with hematologic malignancies may be used to predict mortality.

RBD-specific polyclonal F(ab´)2 fragments of equine antibodies in patients with moderate to severe COVID-19 disease: A randomized, multicenter, double-blind, placebo-controlled, adaptive phase 2/3 clinical trial.

BACKGROUND: passive immunotherapy is a therapeutic alternative for patients with COVID-19. Equine polyclonal antibodies (EpAbs) could represent a source of scalable neutralizing antibodies against SARS-CoV-2. METHODS: we conducted a double-blind, randomized, placebo-controlled trial to assess efficacy and safety of EpAbs (INM005) in hospitalized adult patients with moderate and severe COVID-19 pneumonia in 19 hospitals of Argentina. Primary endpoint was improvement in at least two categories in WHO ordinal clinical scale at day 28 or hospital discharge (ClinicalTrials.gov number NCT04494984). FINDINGS: between August 1st and October 26th, 2020, a total of 245 patients were enrolled. Enrolled patients were assigned to receive two blinded doses of INM005 (n = 118) or placebo (n = 123). Median age was 54 years old, 65•1% were male and 61% had moderate disease at baseline. Median time from symptoms onset to study treatment was 6 days (interquartile range 5 to 8). No statistically significant difference was noted between study groups on primary endpoint (risk difference [95% IC]: 5•28% [-3•95; 14•50]; p = 0•15). Rate of improvement in at least two categories was statistically significantly higher for INM005 at days 14 and 21 of follow-up. Time to improvement in two ordinal categories or hospital discharge was 14•2 (± 0•7) days in the INM005 group and 16•3 (± 0•7) days in the placebo group, hazard ratio 1•31 (95% CI 1•0 to 1•74). Subgroup analyses showed a beneficial effect of INM005 over severe patients and in those with negative baseline antibodies. Overall mortality was 6•9% the INM005 group and 11•4% in the placebo group (risk difference [95% IC]: 0•57 [0•24 to 1•37]). Adverse events of special interest were mild or moderate; no anaphylaxis was reported. INTERPRETATION: Albeit not having reached the primary endpoint, we found clinical improvement of hospitalized patients with SARS-CoV-2 pneumonia, particularly those with severe disease.

Complement regulator CD59 protects against atherosclerosis by restricting the formation of complement membrane attack complex.

Complement is a central effector system within the immune system and is implicated in a range of inflammatory disorders. CD59 is a key regulator of complement membrane attack complex (MAC) assembly. The atherogenic role of terminal complement has long been suspected but is still unclear. Here, we demonstrate that among mice deficient in apolipoprotein (Apo)E, the additional loss of murine CD59 (mCd59ab(-/-)/ApoE(-/-)) accelerated advanced atherosclerosis featuring occlusive coronary atherosclerosis, vulnerable plaque, and premature death and that these effect could be attenuated by overexpression of human CD59 in the endothelium. Complement inhibition using a neutralizing anti-mouse C5 antibody attenuated atherosclerosis in mCd59ab(-/-)/ApoE(-/-) mice. Furthermore, MAC mediated endothelial damage and promoted foam cell formation. These combined results highlight the atherogenic role of MAC and the atheroprotective role of CD59 and suggest that inhibition of MAC formation may provide a therapeutic approach for the treatment of atherosclerosis.

Generation and phenotyping of mCd59a and mCd59b double-knockout mice.

CD59 is a membrane protein inhibitor of the membrane attack complex (MAC) of complement. Humans express only one, whereas mice express two CD59 genes. We previously reported the targeted deletion of the mCd59b gene in which absence of mCd59b together with an unintended down regulation of mCd59a caused hemolytic anemia with spontaneous platelet activation. To confirm the complement role in the hemolytic anemia caused by abrogation of mCd59 function, we have developed a mCd59a and mCd59b double knock out mice and analyzed its phenotype in complement sufficient and deficient (C3(-/-)). We report here that total abrogation of mCd59 function in mCd59ab(-/-) mice results in complement-mediated hemolytic anemia that is rescued by the deficiency of C3 in compound mCd59ab(-/-)/C3(-/-) mice.

Further characterization of reproductive abnormalities in mCd59b knockout mice: a potential new function of mCd59 in male reproduction.

CD59 is a GPI-linked membrane protein that inhibits formation of the membrane attack complex of complement. We reported recently that mice have two CD59 genes (termed mCd59a and mCd59b), and that the targeted deletion of mCd59b (mCd59b-/-) results in spontaneous hemolytic anemia and progressive loss of male fertility. Further studies of the reproductive abnormalities in mCd59b-/- mice reported in this study revealed the presence of abnormal multinucleated cells and increased apoptotic cells within the walls of the seminiferous tubules, and a decrease in the number, motility, and viability of sperm associated with a significant increase in abnormal sperm morphologies. Both the capacitation-associated tyrosine phosphorylation and the ionophore-induced acrosome reaction as well as luteinizing hormone, follicle-stimulating hormone, and testosterone serum levels were similar in mCd59b-/- and mCd59b+/+. Surprisingly, the functional deficiency of the complement protein C3 did not rescue the abnormal reproductive phenotype of mCd59b-/-, although it was efficient in rescuing their hemolytic anemia. These results indicate that the male reproductive abnormalities in mCd59b-/- are complement-independent, and that mCd59 may have a novel function in spermatogenesis that is most likely unrelated to its function as an inhibitor of membrane attack complex formation.

Deficiency of the mouse complement regulatory protein mCd59b results in spontaneous hemolytic anemia with platelet activation and progressive male infertility.

Basal complement activity presents a potential danger for "self" cells that are tightly protected by complement regulators including CD59. Mice express two Cd59 genes (mCd59a and mCd59b); mCd59b has approximately a 6-fold higher specific activity than mCd59a. Consistently, mCd59b knockout mice present a strong phenotype characterized by hemolytic anemia with increased reticulocytes, anisopoikilocytosis, echinocytosis, schistocytosis, free hemoglobin in plasma, hemoglobinuria with hemosiderinuria, and platelet activation. Remarkably, mCd59b(-/-) males express a progressive loss of fertility associated with immobile dysmorphic and fewer sperm cells after 5 months of age. This work indicates that mCd59b is a key complement regulator in mice and that CD59 is critical in protecting self cells; it also provides a novel model to study complement regulation in human diseases.