Home / Health / Recuperative plasma antibody levels and mortality risk from COVID-19

Recuperative plasma antibody levels and mortality risk from COVID-19



The patient

This group consists of 3082 patients from 680 acute care facilities across the United States (Figure 1). Table 1 The main characteristics of the patients were divided into three groups based on anti-SARS-CoV-2 IgG antibody levels (based on the signal-to-cut ratio). Overall, 61% of the patients were men, 23% were black, 37% were men. Hispanic 69% were younger than 70 and two thirds had had a blood transfusion before using the invasive ventilator. The mean number of patients per site was 2 (between quartile range 1

to 6). The maximum number of patients from a single site was 59, as shown in Table 1All three groups (plasma transfusion patients with high, moderate and low IgG antibody levels) were generally similar in terms of demographic characteristics, severe COVID-19-associated risk factors, and co-drug use. Wid-19 combined Percentage of patients with hypoxia and combined use of hydroxychloroquine. (Both were variables included in the adaptation model) were lower in the higher titration groups.

Main result

A correlation model between anti-SARS-COV-2 antibody levels in liquefied plasma and mortality risk.

Deaths within 30 days after plasma transfusion occurred in 26.9% of all patients (830 out of 3082 patients; 95% Confidence Intervals [CI]This primary outcome event occurred in 29.6% (166 out of 561 patients) in the low-titer group, 27.4% (549 from 2006 patients) in the medium-titer group and 22.3% (115 out of 515. In the high-titer group, the high-titer group had a lower risk of death within 30 days after transfusion than in the low-titer group (relative risk, 0.75; 95% CI, 0.61 to 0.93) (Table 2). Additional analyzes were adjusted according to the demographic characteristics of the patient. (Age, status, weight and race) and clinical features (Invasive ventilator exposure, combination therapy, and hypoxia) to assess the overall effect of anti-SARS-COV-2 IgG antibody levels on mortality risk within 30 days. After blood transfusion (Schedule S1 in the supplementary annex), modified version. (As defined in Table 2) In general, a similar relationship was shown – relative risk of mortality was lower in plasma transfusion patients with high levels of anti-SARS-CoV-2 IgG antibodies (Model 2, relative risk of 0.79. [95% CI, 0.65 to 0.96]And season 3 [with additional adjustment], Relative risk, 0.82 [95% CI, 0.67 to 1.00]) (Table 2The findings of a sensitivity analysis at which patients were excluded when exited were qualitatively similar to these findings.

Subgroup analysis

Characteristics of Covid-19 infected patients who were not mechanically ventilated and those receiving Plasma recovered according to Anti – SARS-CoV-2 IgG levels.

Among 3082 patients in 2014, the patients did not receive a ventilator prior to transfusion. Table 3 Significant patient characteristics of a subgroup of non-ventilated patients stratified by anti-SARS-CoV-2 IgG antibody levels in the subgroup of non-ventilated patients died within 30. Days after plasma transfusion in 81 of 365 patients (22.2%; 95% CI, 18.2 to 26.7) in the low-titer group, 251 of 1297 (19.4%; 95% CI, 17.3 to 21.6) in the medium- group. titer and 50 of 352 patients (14.2%; 95% CI, 10.9 to 18.2) in the high-titer group; Table S4 lists these results in a subgroup of patients receiving mechanical ventilation. In a subgroup of ventilator-treated patients, death was 30 days after plasma transfusion in 80 of 183 patients (43.7%; 95% CI, 36.7 to 51.0) in the low-titer group 277 of 666. People (41.6%; 95% CI, 37.9 to 45.4) in the medium-titer group and 64 of 158 patients (40.5; 95% CI, 33.2 to 48.3) in the high-titer group. The balance between the three antibody groups

In a fully adjusted relative risk regression model, mortality risk within 30 days after high-titer plasma transfusion was observed in patients who did not receive a ventilator prior to blood transfusion. (Relative risk 0.66; 95% CI, 0.48 to 0.91) No mortality effect was observed in patients receiving ventilator prior to blood transfusion. (Relative risk 1.02; 95% CI, 0.78 to 1.32)

Table S2 presents a relative regression to total risk, with or without modification, for the patient’s demographic characteristics, anti-SARS-CoV-2 IgG antibody levels, clinical features, and study time intervals, including all three models. (Basic model, model 2, and model 3) for the subgroup of ventilated patients, Table S3 shows the relative regression-risk for the subgroup of ventilated patients.

Risk of death within 30 days of convalescent plasma replacement.

The wild plots of mortality risk were associated with moderate antibody levels versus low antibody levels (Panel A) and high versus low antibody levels (Panel B). Subgroups were 12 specific categories at the time of the study in Year 2020 Patient age and ventilator support in convalescent blood transfusion patients It represents an estimated risk of mortality in patients receiving convalescent plasma with IgG signal-to-cut ratios in the range 4.62 to 18.45 (medium titration) or greater than 18.45 (high titration). Compared to the relative risk of the patient In plasma subjects with an IgG signal-to-cut ratio lower than 4.62 (low titer), the overall estimate from all subgroups is based on the Mantel – Haenszel estimator. Table S5 shows sample size and mortality in Each subgroup 𝙸 95% confidence interval bar

These findings are further supported by stratified data analysis methods, which provide direct analytical control for critical variables associated with mortality risk. (Exposure to invasive ventilator and study period) (Figure 2The combined (or general) relative risk of mortality in all patients within 30 days after plasma transfusion in the high-titer group compared to the low-titer group was 0.80 (95% CI, 0.65 to 0.97). (Figure 2Figure S1 shows the risk of mortality within 7 days following required convalescent plasma with this stratified data analysis method.

Exploratory analysis

In the group of patients receiving ventilator prior to blood transfusion, the number of days between COVID-19 diagnosis and convalescent plasma transfusion was 10.0 ± 7.7.This is almost twice the average number of days for those who did not receive a ventilator. (5.4 ± 4.8) The mortality rate that did not improve within 30 days of transfusion was reduced in patients receiving blood transfusions within 3 days of diagnosis of COVID-19 (approximately 22.2%. ; 95% CI, 19.9 to 24.8), greater than those who received blood transfusions 4 or more days after the diagnosis of COVID-19 (approximately 29.5%; 95% CI, 27.6 to 31.6) in the model. 3. Transfusion status by day binary classification to transfusion resulted in a 1.18 death risk (95% CI, 1.04 to 1.35) in patients who received blood transfusions 4 or more days after. Diagnosed This effect dose was lower than observed in patients previously exposed to the third generation of ventilator (Relative risk 2.16; 95% CI, 1.90 to 2.46).

A trained gradient stimulator was used to assess the relationship between the major variables associated with mortality risk within 30 days after plasma transfusion and mortality at 30 days. An exploration of how this machine learning technique links key variables to predicting mortality.

In the first method, a variable significance plot is created for each variable included in the model (Fig. S2). The “significance” of the variable is a relative number that improves forecasts in terms of its position in the decision tree. (Where more observations are categorized higher in the decision tree) and the number of times used. Collection of trees The main variables at 30-day mortality risk were age, evidence of an advanced clinical course of Covid-19, such as exposure to invasive ventilator and intensive care unit (ICU) admission. And anti-SARS-COV-2 antibody levels according to variable order of importance.

The second method used to explore the relationship between a given variable and mortality prediction is by using partial dependence schemes. A partial dependency plot was shown that after adjusting for all other variables included in the model, anti-SARS-CoV-2 IgG antibody levels remained inversely correlated with mortality risk, Figure S3. Shows a similar partial dependence plot for the primary analysis model in which the antibody level was treated as a continuous variable using a natural spline with four evenly spaced knots in this model. Some dependencies for the overall sample are closely aligned with the patterns observed in the Gradient Engine model. Inverse correlations to antibody levels were again found in non-ventilator patients and no clear correlation was found in these patients.


Source link