key: cord-0822541-g02ap06l
authors: Klapholz, Marc; Pentakota, Sri Ram; Zertuche, Juan-Pablo; McKenna, Marshall; Roque, Willy; Forsberg, Mark; Packer, Johnathan; Lal, Devika S; Dever, Lisa
title: Matched Cohort Study of Convalescent COVID-19 Plasma (CCP) Treatment in Severely or Life Threateningly Ill COVID-19 Patients
date: 2021-01-04
journal: Open Forum Infect Dis
DOI: 10.1093/ofid/ofab001
sha: 6592d7af22af0d38b88bc0f92348802ff6ac044e
doc_id: 822541
cord_uid: g02ap06l

BACKGROUND: The utility of convalescent COVID-19 plasma (CCP) in the current pandemic is not well defined. We sought to evaluate safety and efficacy of CCP in severely or life threateningly ill COVID-19 patients when matched with a contemporaneous cohort. METHODS: Patients with severe or life threatening COVID-19 were treated with CCP according to FDA criteria, prioritization by an interdisciplinary team and based on CCP availability. Individual-level matched controls (1:1) were identified from patients admitted during the prior month when no CCP was available. Safety outcome was freedom from adverse transfusion reaction and efficacy outcome a composite of death or worsening O2 support. Demographic, clinical and laboratory data were analyzed by univariate and multivariable regression analyses accounting for matched design. RESULTS: Study patients (N=94, 47 matched pairs) were 62% male with mean age of 58 and 98% (90/94) were minority (53% Hispanic, 45% Black, non-Hispanic) in our inner-city population. Seven-day composite and mortality outcomes suggested a non-significant benefit in CCP treated patients (adjusted hazard ratio (aHR), 0.70; 95% confidence interval (CI), 0.23 to 2.12; P=0.52; aHR, 0.23; 95% CI, 0.04 to 1.51; P=0.13, respectively). Stratification by pre-transfusion mechanical ventilation status showed no differences between groups. No serious transfusion reactions occurred. CONCLUSION: In this short-term matched cohort study, transfusion with CCP was safe and showed a non-significant association with study outcomes. Randomized and larger trials to identify appropriate timing and dosing of CCP in COVID-19 is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT04420988

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease , has infected over 13.7 million people around the world with close to 600,000 deaths. [1, 2] While numerous trials are underway for prevention and treatment of COVID-19 at present there are no proven therapeutic options for patients other than remdesivir which has demonstrated a decrease in length of hospitalizations [3, 4] .

Convalescent COVID-19 plasma (CCP) is plasma that is collected from individuals who have recovered from COVID-19 and have presumed or proven antibodies to SARS-CoV-2. CCP therapy may have the potential to limit the severity of illness in patients infected with SARS-CoV-2 and may also have efficacy in preventing infection in individuals at high risk for contracting SARS-CoV-2. [5] In the current pandemic, two reports from China on the use of CCP to treat patients with COVID-19 suggested improvement [6, 7] , whereas a third report on the use of CCP in an open label multicenter randomized study did not [8] . As per ClinicalTrials.Gov, worldwide there are currently close to 200 studies recruiting COVID-19 patients to examine effects of plasma in these patients. [9] Numerous trials have limited control groups or rely on data for controls from published RCTs [9, 10] .

Our study reports on the safety and efficacy of CCP in 47 COVID-19 patients who received CCP treatment and were matched 1:1 by individual-level matching to 47 contemporaneous COVID-19 control patients who were admitted to our hospital in the month prior when CCP was not available.

A c c e p t e d M a n u s c r i p t 5

We employed a retrospective matched cohort study design to assess short-term outcomes pertaining to the safety and efficacy of CCP treatment in severely or life threateningly ill COVID -19 patients. Our treatment patients comprised of COVID-19 hospitalized patients who received CCP treatment under eIND approvals and expanded access IND approvals for compassionate use [11] .

CCP treated patients were matched 1:1 using individual-level matching to contemporaneous non-CCP treated COVID-19 patients who were admitted to our center when CCP treatment was not yet available. Clinical criteria for severe or life threatening COVID-19 were defined per FDA criteria and included laboratory confirmed COVID-19. For severe disease one or more of the following: shortness of breath, respiratory frequency ≥ 30/min, blood oxygen saturation ≤ 93% on room air, partial pressure of arterial oxygen to fraction of inspired oxygen ratio < 300 or lung infiltrates > 50% within 24 to 48 hours. Life-threatening disease was defined as one or more of the following: respiratory failure, septic shock or multiple organ dysfunction or failure [11] .

SARS-CoV-2 infection was confirmed by real-time polymerase chain reaction (RT-PCR) assay.

We excluded patients who had a contraindication to transfusion (severe volume overload, history of anaphylaxis to blood products); severe multi-organ failure with hemodynamic instability requiring 

Informed consents were obtained from patients or their surrogates prior to transfusion.

The study protocol was approved by the Rutgers Institutional Review Board (IRB).

Following consent, a request was sent to the FDA for each patient for an eIND approval. Individual eINDs were used for the first 42 patients. Subsequently an expanded access IND was granted.

Monitoring of patients during and following their infusion followed our institution's blood bank transfusion protocol.

A cohort of COVID-19 patients admitted to our institution between March 11 th , 2020 and April 3 rd , 2020 prior to availability of CCP, were identified as contemporaneous controls and were matched to our CCP treated patients using individual-level matching. CCP became available as of mid-night of April 10 th , 2020. Treated and control patients were The study follow-up began with time from infusion of CCP. Exact date and time of CCP infusion was available for treated patients. For all matched controls study enrollment start time was assigned as 12:00 noon on the day they matched their respective treatment pairs' days spent on the same O2 support pre-transfusion. Duration of the same O2 support pre-transfusion was similar (+/-3 days) in 44/47 (94%) of the matched pairs. All study patients were followed for 7-days from infusion time and were assessed for change in levels of laboratory measures, O2 support, mortality or discharge.

For this study, we reviewed the first 95 consecutive COVID-19 patients who received CCP treatment at our center between April 11 th , 2020 and May 18 th , 2020. One patient did not satisfy inclusion criteria for expanded access and was excluded from further review. Out treatments changed rapidly during the study period. Initial regimens comprising of hydroxychloroquine, azithromycin, and doxycycline were soon found to be ineffective though they seemed initially promising. They were gradually replaced with IL-6 inhibitors as newer information became available.

Demographic, clinical, laboratory and treatment information of all CCP treated and for matched control patients was retrieved from the electronic medical record. All posttransfusion laboratory measures were obtained within 24-72 hours of CCP transfusion.

Changes in oxygen support were tracked daily from pre-transfusion (day 0) through day 7 post-transfusion. Date and time of discharge or death of study patients were also recorded. Study follow-up was limited to 7-days. The last control patient was enrolled on April 3 rd , 2020, providing the 7-day follow-up by April 10 th , 2020 when CCP became available at our institution. Drs. Klapholz and Pentakota had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Dr. Pentakota performed the data analyses.

We used means and standard deviations to describe normally distributed variables (age and BMI) and medians and interquartile ranges (Q1-Q3) to describe skewed continuous variables (all laboratory measures). Counts and proportions were used to describe categorical variables. First, to A c c e p t e d M a n u s c r i p t 10 assess the degree of success of our matching efforts we used standardized differences (std. diff.) to compare our treated and control patients. [12] Cut-off levels of 0.2, 0.5, and 0.8 were apriori determined to indicate small, medium, and large differences between the two groups. [12, 13] Second, univariate analyses using Wilcoxon signed rank test was performed to compare laboratory values including inflammatory markers. Additional univariate analyses comparing binary 7-day composite and mortality alone outcomes were performed using McNemar's test. For time-to-event analyses of 7-day composite, mortality alone, and worsening of O2 support outcomes, we used Cox proportional-hazards regression models to allow for additional adjustment of certain confounding variables. By employing a matching design, key confounding variables, such as, age, gender, race, ethnicity, specific O 2 support and duration of that O 2 support at time of transfusion (days) were already accounted for. Multivariable regression models accounted for additional confounding variables by including age in years, BMI, history of hypertension, history of diabetes mellitus, and usage of IL-6 inhibitors for anti-COVID-19 treatment in the models. Data on other comorbidities and treatments were available but were not included in the regression models due to small sample size, to avoid overfitting, and to reduce multi-collinearity. Hydoxychloroquine and doxycycline/azithromycin use was common in both treatment groups and balance achieved for other comorbidities through matching precluded their inclusion. Further, we did not include steroid and anti-coagulant treatments, which represented small and medium differences between the groups with limited impact on study outcomes in unadjusted models. Cox models were fit using "STRATA" option to take the matcheddesign into account with ties=BRESLOW option. Stratified analyses, limited to 7-day composite outcome, were performed among those who were and were not on a mechanical ventilator pretransfusion. All reported P values were two-sided and an alpha of 0.05 was considered to assess statistical significance. All data analyses were performed using SAS software version 9. Ninety-eight percent of our patients (92/94) were minority; 53.2% were Hispanic and 44.7% were Black non-Hispanic in both groups. (Table 1 ). One in five or 20% of study patients were on mechanical ventilation pre-transfusion.

In our inner city, minority population there was a high burden of baseline comorbid conditions.

Overall, the prevalence of hypertension, diabetes and obesity were 55%, 33% and 49%, respectively (Table 1) . Renal function was preserved. Twenty-five percent of study patients had a smoking history. IL-6 inhibitors were administered more frequently in the treatment arm due to their wider usage per institutional protocols over time and despite matching differences in proportion receiving IL-6 inhibitors between the treatment (62%) and control (26%) groups remained (std. diff. =0.78). This One CCP treated patient, included in our analysis experienced a transient increase in temperature that resolved after the infusion was discontinued and acetaminophen administered.

Tests for both 7-day outcomes failed to show any statistically significant differences between the treatment groups. The incidence of composite outcome for worsening of O2 support (2-point deterioration of O2 support or being put on a mechanical ventilator or death) as of day 7 post-A c c e p t e d M a n u s c r i p t 13 transfusion was slightly less common in the treatment (14/47, 29 .8%) than the control (17/47, 36.2%) group (P=0.51). There was one less death in the treatment group (9/47, 19 .2%) compared to the control group (10/47, 21.3%).

Results from unadjusted and adjusted Cox proportional hazards regression models, both in the overall study population and stratified analyses by being on mechanical ventilator or not pretransfusion, are presented in Table 3 . The confounding effects of the variables employed to match were already minimized or accounted for during design phase by individual-level matching.

Additionally, in our multivariable regression models we accounted for age in years, BMI, history of hypertension and diabetes mellitus, and use of IL-6 inhibitors. Results from multivariable regression models examining the composite and mortality alone outcomes showed no significant difference between the treatment and control groups. In the overall population, for the 7-day composite outcome of worsening oxygen support and mortality, we observed a non-significant adjusted hazard ratio (aHR), 0.70; 95% confidence interval (CI), 0.23 to 2.12; P=0.52. Likewise, there were no differences between the groups for the 7-day mortality outcome (aHR, 0.23; 95% CI, 0.04 to 1.51; P=0.13). When the analyses were conducted among those not on ventilator at baseline for worsening O2 support we found that the risk of worsening of O2 support increased however nonsignificantly among CCP recipients (aHR, 2.38; 95% CI, 0.47-12.1; P=0.30). Similar to the overall analyses, stratified analyses by pre-transfusion mechanical ventilator status also did not show significant association between treatment group and 7-day composite outcome. See Table 3 In this non-randomized, open-label, physician directed, FDA guided clinical use of CCP for the treatment of severely or life threateningly ill COVID-19 patients as compared to a contemporaneous matched cohort when no CCP was available, no significant clinical benefit in either the composite for worsening oxygen support and mortality, or mortality alone was identified during the 7-day followup. . These observed results were seen despite greater burden of patients on worse oxygen support in the CCP arm compared to the control arm. Stratified analyses by pre-transfusion mechanical ventilator status also showed similar non-significant differences. The infusion of CCP was not associated with any identifiable serious adverse transfusion reactions.

We recognize this report is only on 47 matched-pairs with only one week of follow-up. This resulted from our definition of potential control patients as only those who had at least one week of data by April 10 th , 2020 when CCP became available. This design allowed for our strict adherence that data on contemporaneous matched controls be completely retrospective in nature vis-à-vis our CCP treated patients and eliminate any perceived treatment bias or potential violation of the intent of expanded access approval (i.e. no CCP was available for treatment during the period of follow up of the control patients). Nearly 60% of study patients remained hospitalized beyond 7 days. However, a longer term comparison between treatment and control arms is not possible with our study design since the majority of control patients after 7 days would increasingly cross over into the period where CCP became available.

Results from a large study of 5000 COVID-19 patients who received CCP as compassionate care suggested that CCP administration is relatively safe; but lack of controls precludes us from assessing CCP efficacy. [14] Seven-day mortality reported in this study was close to 15%, compared to close to A c c e p t e d M a n u s c r i p t 15 20% reported in our study. [14] The patients we treated were severely or life threateningly ill with high oxygen requirements and high levels of inflammatory markers. The high inflammatory markers are consistent with cytokine storm and may signify an advanced stage of disease where neutralizing antibodies may no longer be effective. [8, 15] Bullard et al have demonstrated that despite a positive PCR test result, the existence of replicating viable viruses beyond 8 th day from symptom onset is doubtful. [16] Infusion of CCP becomes futile when viable viruses cease to exist. In our study, the median interval from admission to initial CCP transfusion was 4 days i.e. for a majority of these patients the first CCP infusion might have occurred after more than 8 days from symptom onset and thereby rendering CCP treatment ineffectual. Similar reasons might have played a role in the WHO sponsored Solidarity trial, wherein the recently published interim results from the trial showed all four antiviral treatments (remdesivir, hydroxychloroquine, lopinavir, and interferon beta-1a) to be ineffective in hospitalized COVID-19 patients. [17] . Our treated and matched cohort were an inner city, minority population with a high prevalence of chronic comorbidities, which may have contributed to the higher mortality seen in the study patients. [18] .

Limitations of our study are several. Matched cohort design cannot account for unrecognized or unmeasured confounding variables. However, our treatment group had good precision with their control matches and controls were free of treatment bias. While positivity for antibodies to SARS-CoV-2 were documented using the NYSDOH Luminex based assay, titers were not available and may influence outcomes. [19] Plasma contains numerous other proteins including soluble clotting factors such as fibrinogen, factor XIII, von Willebrand factor (VWF) and vitamin K-dependent coagulation factors II, VII, IX, and X. Fibrinolytic proteins are also contained at normal physiologic concentrations [20, 21] . The effect of these other factors in our patient population who received treatment with CCP is unknown and may have contributed to observed outcomes. While concerns A c c e p t e d M a n u s c r i p t 16 exist for antibody dependent enhancement with antibody mediated worsening of infection in immune plasma therapy, we did not observe this in our population [22] . ABO blood groups may play a role in patients' outcomes in COVID-19. Non-peer reviewed data from China suggested that group O individuals had lower rates of infection and lower mortality compared to other ABO blood types [21, 23] . We do not have the complete ABO blood group types for our control group population (missing for 55%). However, blood type was not found to be statistically significantly associated with 7-day mortality in our treatment group with type A at 17%, type B at 29%, and type O at 18% mortality.

Convalescent plasma infused for severe or life threateningly ill COVID-19 inner city, minority patients appears to be safe. Comparison to a matched contemporaneous control cohort suggested improvement in the treated population for 7-day outcomes but was not statistically significant. Large, multicenter, randomized trials with CCP (alone or in combination with other anti-COVID-19 candidate drugs) that address timing relative to disease stage, and dosing or the use of CCP as a preemptive strategy for protection against SARS-CoV-2 infection in high risk patients appear to be warranted. M a n u s c r i p t 20 

COVID-19) pandemic, Numbers at a glance

Compassionate Use of Remdesivir for Patients with Severe Covid-19

Remdesivir for the Treatment of Covid-19 -Preliminary Report

The convalescent sera option for containing COVID-19

Convalescent plasma as a potential therapy for COVID-19

The feasibility of convalescent plasma therapy in severe COVID-19 patients: a pilot study

Effect of Convalescent Plasma Therapy on Time to Clinical Improvement in Patients With Severe and Life-threatening COVID-19: A Randomized Clinical Trial

Testing an Old Therapy Against a New Disease: Convalescent Plasma for COVID-19

CBER. Investigational COVID-19 Convalescent Plasma -Emergency INDs. Available at

Balance diagnostics for comparing the distribution of baseline covariates between treatment groups in propensity-score matched samples

Statistical Power Analysis for the Behavioral Sciences

Early safety indicators of COVID-19 convalescent plasma in 5,000 patients

Convalescent plasma or hyperimmune immunoglobulin for people with COVID-19: a living systematic review

Predicting infectious SARS-CoV-2 from diagnostic samples

Repurposed Antiviral Drugs for Covid-19 -Interim WHO Solidarity Trial Results

The Disproportionate Impact of COVID-19 on Racial and Ethnic Minorities in the United States

Convalescent plasma for COVID-19: Back to the future

Chapter 34 -Plasma Products

COVID-19 Convalescent Plasma: Now Is the Time for Better Science

Viral-Induced Enhanced Disease Illness

Relationship between the ABO Blood Group and the COVID-19 Susceptibility

A c c e p t e d M a n u s c r i p t 18 A c c e p t e d M a n u s c r i p t M a n u s c r i p t of that O2 support (+/-3 days) at time of initial convalescent plasma transfusion † Adjusted for age, BMI, hypertension, diabetes mellitus, and use of IL-6 inhibitors in models including overall study population; Adjusted for age, BMI, diabetes mellitus, and use of IL-6 inhibitors in models limited to O2 support worsening ; Age alone was adjusted for in stratified analyses