Abstract

BACKGROUND Convalescent plasma may reduce mortality in patients with viral respiratory diseases, and is being investigated as a potential therapy for coronavirus disease 2019 (COVID-19). A thorough understanding of the current body of evidence regarding benefits and risks of this intervention is required. OBJECTIVES To assess the effectiveness and safety of convalescent plasma transfusion in the treatment of people with COVID-19; and to maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS To identify completed and ongoing studies, we searched the World Health Organization (WHO) COVID-19 Global literature on coronavirus disease Research Database, MEDLINE, Embase, Cochrane COVID-19 Study Register, and the Epistemonikos COVID-19 L*OVE Platform. We searched monthly until 03 March 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs) evaluating convalescent plasma for COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)), as well as studies evaluating standard immunoglobulin. DATA COLLECTION AND ANALYSIS We followed standard Cochrane methodology. To assess bias in included studies we used RoB 2. We used the GRADE approach to rate the certainty of evidence for the following outcomes: all-cause mortality at up to day 28, worsening and improvement of clinical status (for individuals with moderate to severe disease), hospital admission or death, COVID-19 symptoms resolution (for individuals with mild disease), quality of life, grade 3 or 4 adverse events, and serious adverse events. MAIN RESULTS In this fourth review update version, we included 33 RCTs with 24,861 participants, of whom 11,432 received convalescent plasma. Of these, nine studies are single-centre studies and 24 are multi-centre studies. Fourteen studies took place in America, eight in Europe, three in South-East Asia, two in Africa, two in western Pacific and three in eastern Mediterranean regions and one in multiple regions. We identified a further 49 ongoing studies evaluating convalescent plasma, and 33 studies reporting as being completed. Individuals with a confirmed diagnosis of COVID-19 and moderate to severe disease 29 RCTs investigated the use of convalescent plasma for 22,728 participants with moderate to severe disease. 23 RCTs with 22,020 participants compared convalescent plasma to placebo or standard care alone, five compared to standard plasma and one compared to human immunoglobulin. We evaluate subgroups on detection of antibodies detection, symptom onset, country income groups and several co-morbidities in the full text. Convalescent plasma versus placebo or standard care alone Convalescent plasma does not reduce all-cause mortality at up to day 28 (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.92 to 1.03; 220 per 1000; 21 RCTs, 19,021 participants; high-certainty evidence). It has little to no impact on need for invasive mechanical ventilation, or death (RR 1.03, 95% CI 0.97 to 1.11; 296 per 1000; 6 RCTs, 14,477 participants; high-certainty evidence) and has no impact on whether participants are discharged from hospital (RR 1.00, 95% CI 0.97 to 1.02; 665 per 1000; 6 RCTs, 12,721 participants; high-certainty evidence). Convalescent plasma may have little to no impact on quality of life (MD 1.00, 95% CI -2.14 to 4.14; 1 RCT, 483 participants; low-certainty evidence). Convalescent plasma may have little to no impact on the risk of grades 3 and 4 adverse events (RR 1.17, 95% CI 0.96 to 1.42; 212 per 1000; 6 RCTs, 2392 participants; low-certainty evidence). It has probably little to no effect on the risk of serious adverse events (RR 1.14, 95% CI 0.91 to 1.44; 135 per 1000; 6 RCTs, 3901 participants; moderate-certainty evidence). Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces or increases all-cause mortality at up to day 28 (RR 0.73, 95% CI 0.45 to 1.19; 129 per 1000; 4 RCTs, 484 participants; very low-certainty evidence). We are uncertain whether convalescent plasma reduces or increases the need for invasive mechanical ventilation, or death (RR 5.59, 95% CI 0.29 to 108.38; 311 per 1000; 1 study, 34 participants; very low-certainty evidence) and whether it reduces or increases the risk of serious adverse events (RR 0.80, 95% CI 0.55 to 1.15; 236 per 1000; 3 RCTs, 327 participants; very low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus human immunoglobulin Convalescent plasma may have little to no effect on all-cause mortality at up to day 28 (RR 1.07, 95% CI 0.76 to 1.50; 464 per 1000; 1 study, 190 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Individuals with a confirmed diagnosis of SARS-CoV-2 infection and mild disease We identified two RCTs reporting on 536 participants, comparing convalescent plasma to placebo or standard care alone, and two RCTs reporting on 1597 participants with mild disease, comparing convalescent plasma to standard plasma. Convalescent plasma versus placebo or standard care alone We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (odds ratio (OR) 0.36, 95% CI 0.09 to 1.46; 8 per 1000; 2 RCTs, 536 participants; very low-certainty evidence). It may have little to no effect on admission to hospital or death within 28 days (RR 1.05, 95% CI 0.60 to 1.84; 117 per 1000; 1 RCT, 376 participants; low-certainty evidence), on time to COVID-19 symptom resolution (hazard ratio (HR) 1.05, 95% CI 0.85 to 1.30; 483 per 1000; 1 RCT, 376 participants; low-certainty evidence), on the risk of grades 3 and 4 adverse events (RR 1.29, 95% CI 0.75 to 2.19; 144 per 1000; 1 RCT, 376 participants; low-certainty evidence) and the risk of serious adverse events (RR 1.14, 95% CI 0.66 to 1.94; 133 per 1000; 1 RCT, 376 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (OR 0.30, 95% CI 0.05 to 1.75; 2 per 1000; 2 RCTs, 1597 participants; very low-certainty evidence). It probably reduces admission to hospital or death within 28 days (RR 0.49, 95% CI 0.31 to 0.75; 36 per 1000; 2 RCTs, 1595 participants; moderate-certainty evidence). Convalescent plasma may have little to no effect on initial symptom resolution at up to day 28 (RR 1.12, 95% CI 0.98 to 1.27; 1 RCT, 416 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. This is a living systematic review. We search monthly for new evidence and update the review when we identify relevant new evidence. AUTHORS' CONCLUSIONS For the comparison of convalescent plasma versus placebo or standard care alone, our certainty in the evidence that convalescent plasma for individuals with moderate to severe disease does not reduce mortality and has little to no impact on clinical improvement or worsening is high. It probably has little to no effect on SAEs. For individuals with mild disease, we have very-low to low certainty evidence for most primary outcomes and moderate certainty for hospital admission or death. There are 49 ongoing studies, and 33 studies reported as complete in a trials registry. Publication of ongoing studies might resolve some of the uncertainties around convalescent plasma therapy for people with asymptomatic or mild disease.

Abstract

BACKGROUND Convalescent plasma may reduce mortality in patients with viral respiratory diseases, and is being investigated as a potential therapy for coronavirus disease 2019 (COVID-19). A thorough understanding of the current body of evidence regarding benefits and risks of this intervention is required. OBJECTIVES To assess the effectiveness and safety of convalescent plasma transfusion in the treatment of people with COVID-19; and to maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS To identify completed and ongoing studies, we searched the World Health Organization (WHO) COVID-19 Global literature on coronavirus disease Research Database, MEDLINE, Embase, Cochrane COVID-19 Study Register, and the Epistemonikos COVID-19 L*OVE Platform. We searched monthly until 03 March 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs) evaluating convalescent plasma for COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)), as well as studies evaluating standard immunoglobulin. DATA COLLECTION AND ANALYSIS We followed standard Cochrane methodology. To assess bias in included studies we used RoB 2. We used the GRADE approach to rate the certainty of evidence for the following outcomes: all-cause mortality at up to day 28, worsening and improvement of clinical status (for individuals with moderate to severe disease), hospital admission or death, COVID-19 symptoms resolution (for individuals with mild disease), quality of life, grade 3 or 4 adverse events, and serious adverse events. MAIN RESULTS In this fourth review update version, we included 33 RCTs with 24,861 participants, of whom 11,432 received convalescent plasma. Of these, nine studies are single-centre studies and 24 are multi-centre studies. Fourteen studies took place in America, eight in Europe, three in South-East Asia, two in Africa, two in western Pacific and three in eastern Mediterranean regions and one in multiple regions. We identified a further 49 ongoing studies evaluating convalescent plasma, and 33 studies reporting as being completed. Individuals with a confirmed diagnosis of COVID-19 and moderate to severe disease 29 RCTs investigated the use of convalescent plasma for 22,728 participants with moderate to severe disease. 23 RCTs with 22,020 participants compared convalescent plasma to placebo or standard care alone, five compared to standard plasma and one compared to human immunoglobulin. We evaluate subgroups on detection of antibodies detection, symptom onset, country income groups and several co-morbidities in the full text. Convalescent plasma versus placebo or standard care alone Convalescent plasma does not reduce all-cause mortality at up to day 28 (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.92 to 1.03; 220 per 1000; 21 RCTs, 19,021 participants; high-certainty evidence). It has little to no impact on need for invasive mechanical ventilation, or death (RR 1.03, 95% CI 0.97 to 1.11; 296 per 1000; 6 RCTs, 14,477 participants; high-certainty evidence) and has no impact on whether participants are discharged from hospital (RR 1.00, 95% CI 0.97 to 1.02; 665 per 1000; 6 RCTs, 12,721 participants; high-certainty evidence). Convalescent plasma may have little to no impact on quality of life (MD 1.00, 95% CI -2.14 to 4.14; 1 RCT, 483 participants; low-certainty evidence). Convalescent plasma may have little to no impact on the risk of grades 3 and 4 adverse events (RR 1.17, 95% CI 0.96 to 1.42; 212 per 1000; 6 RCTs, 2392 participants; low-certainty evidence). It has probably little to no effect on the risk of serious adverse events (RR 1.14, 95% CI 0.91 to 1.44; 135 per 1000; 6 RCTs, 3901 participants; moderate-certainty evidence). Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces or increases all-cause mortality at up to day 28 (RR 0.73, 95% CI 0.45 to 1.19; 129 per 1000; 4 RCTs, 484 participants; very low-certainty evidence). We are uncertain whether convalescent plasma reduces or increases the need for invasive mechanical ventilation, or death (RR 5.59, 95% CI 0.29 to 108.38; 311 per 1000; 1 study, 34 participants; very low-certainty evidence) and whether it reduces or increases the risk of serious adverse events (RR 0.80, 95% CI 0.55 to 1.15; 236 per 1000; 3 RCTs, 327 participants; very low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus human immunoglobulin Convalescent plasma may have little to no effect on all-cause mortality at up to day 28 (RR 1.07, 95% CI 0.76 to 1.50; 464 per 1000; 1 study, 190 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Individuals with a confirmed diagnosis of SARS-CoV-2 infection and mild disease We identified two RCTs reporting on 536 participants, comparing convalescent plasma to placebo or standard care alone, and two RCTs reporting on 1597 participants with mild disease, comparing convalescent plasma to standard plasma. Convalescent plasma versus placebo or standard care alone We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (odds ratio (OR) 0.36, 95% CI 0.09 to 1.46; 8 per 1000; 2 RCTs, 536 participants; very low-certainty evidence). It may have little to no effect on admission to hospital or death within 28 days (RR 1.05, 95% CI 0.60 to 1.84; 117 per 1000; 1 RCT, 376 participants; low-certainty evidence), on time to COVID-19 symptom resolution (hazard ratio (HR) 1.05, 95% CI 0.85 to 1.30; 483 per 1000; 1 RCT, 376 participants; low-certainty evidence), on the risk of grades 3 and 4 adverse events (RR 1.29, 95% CI 0.75 to 2.19; 144 per 1000; 1 RCT, 376 participants; low-certainty evidence) and the risk of serious adverse events (RR 1.14, 95% CI 0.66 to 1.94; 133 per 1000; 1 RCT, 376 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (OR 0.30, 95% CI 0.05 to 1.75; 2 per 1000; 2 RCTs, 1597 participants; very low-certainty evidence). It probably reduces admission to hospital or death within 28 days (RR 0.49, 95% CI 0.31 to 0.75; 36 per 1000; 2 RCTs, 1595 participants; moderate-certainty evidence). Convalescent plasma may have little to no effect on initial symptom resolution at up to day 28 (RR 1.12, 95% CI 0.98 to 1.27; 1 RCT, 416 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. This is a living systematic review. We search monthly for new evidence and update the review when we identify relevant new evidence. AUTHORS' CONCLUSIONS For the comparison of convalescent plasma versus placebo or standard care alone, our certainty in the evidence that convalescent plasma for individuals with moderate to severe disease does not reduce mortality and has little to no impact on clinical improvement or worsening is high. It probably has little to no effect on SAEs. For individuals with mild disease, we have low certainty evidence for our primary outcomes. There are 49 ongoing studies, and 33 studies reported as complete in a trials registry. Publication of ongoing studies might resolve some of the uncertainties around convalescent plasma therapy for people with asymptomatic or mild disease.

Abstract

CONTEXT Studies comparing initial therapy for multisystem inflammatory syndrome in children (MIS-C) provided conflicting results. OBJECTIVE To compare outcomes in MIS-C patients treated with intravenous immunoglobulin (IVIG), glucocorticoids, or the combination thereof. DATA SOURCES Medline, Embase, CENTRAL and WOS, from January 2020 to February 2022. STUDY SELECTION Randomized or observational comparative studies including MIS-C patients <21 years. DATA EXTRACTION Two reviewers independently selected studies and obtained individual participant data. The main outcome was cardiovascular dysfunction (CD), defined as left ventricular ejection fraction < 55% or vasopressor requirement ≥ day 2 of initial therapy, analyzed with a propensity score-matched analysis. RESULTS Of 2635 studies identified, 3 nonrandomized cohorts were included. The meta-analysis included 958 children. IVIG plus glucocorticoids group as compared with IVIG alone had improved CD (odds ratio [OR] 0.62 [0.42-0.91]). Glucocorticoids alone group as compared with IVIG alone did not have improved CD (OR 0.57 [0.31-1.05]). Glucocorticoids alone group as compared with IVIG plus glucocorticoids did not have improved CD (OR 0.67 [0.24-1.86]). Secondary analyses found better outcomes associated with IVIG plus glucocorticoids compared with glucocorticoids alone (fever ≥ day 2, need for secondary therapies) and better outcomes associated with glucocorticoids alone compared with IVIG alone (left ventricular ejection fraction < 55% ≥ day 2). LIMITATIONS Nonrandomized nature of included studies. CONCLUSIONS In a meta-analysis of MIS-C patients, IVIG plus glucocorticoids was associated with improved CD compared with IVIG alone. Glucocorticoids alone was not associated with improved CD compared with IVIG alone or IVIG plus glucocorticoids.

Abstract

We conducted this systematic review and meta-analysis to evaluate the existing evidence and to quantitatively synthesise evidence on the impact of therapeutic plasma exchange (TPE) on severe COVID-19 patients. This systematic review and meta-analysis protocol was prospectively registered on PROSPERO (CRD42022316331). We systemically searched six electronic databases (PubMed, Scopus, Web of Science, ScienceDirect, clinicaltrial.gov, and Cochrane Central Register of Controlled Trials) from inception until 1 June 2022. We included studies comparing patients who received TPE versus those who received the standard treatment. For risk of bias assessment, we used the Cochrane risk of bias assessment tool, the ROBINS1 tool, and the Newcastle Ottawa scale for RCTs, non-RCTs, and observational studies, respectively. Continuous data were pooled as standardized mean difference (SMD), and dichotomous data were pooled as risk ratio in the random effect model with the corresponding 95% confidence intervals (CI). Thirteen studies (one randomized controlled trials (RCT) and 12 non-RCTs) were included in the meta-analysis, with a total of 829 patients. There is a moderate-quality evidence from one RCT that TPE reduces the lactic dehydrogenase (LDH) levels (SMD -1.09, 95% CI [-1.59 to -0.60]), D-dimer (SMD -0.86, 95% CI [-1.34 to -0.37]), and ferritin (SMD -0.70, 95% CI [-1.18 to -0.23]), and increases the absolute lymphocyte count (SMD 0.54, 95% CI [0.07-1.01]), There is low-quality evidence from mixed-design studies that TPE was associated with lower mortality (relative risk 0.51, 95% CI [0.35-0.74]), lower IL-6 (SMD -0.91, 95% CI [-1.19 to -0.63]), and lower ferritin (SMD -0.51, 95% CI [-0.80 to -0.22]) compared to the standard control. Among severely affected COVID-19 patients, TPE might provide benefits such as decreasing the mortality rate, LDH, D-dimer, IL-6, and ferritin, in addition to increasing the higher absolute lymphocyte count. Further well-designed RCTs are needed.

Abstract

AIM: We aimed to study the effect of COVID-19 on the in-hospital outcomes of percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). METHOD A systematic literature search was performed in 2nd February 2022 updated in 12(th) December 2022 for recruiting relevant papers. The effect size was computed via the odds ratio (OR) for dichotomous data or standardized mean difference (SMD) for continuous data along with the 95% confidence interval (95%CI). RESULTS After the screening of 1075 records, we found 11 relevant papers that included 2018 COVID-19 patients and negative controls 21207. ACS patients with COVID-19 had a significant higher mortality rate (OR: 4.95; 95%CI: 3.92-6.36; p <0.01), long hospital stay (days) 19 (SMD: 1.17; 95%CI: 0.92-1.42; p <0.01) and reduced post TIMI 3 score (OR: 0.55; 95%CI: 0.41-0.73; p <0.01) rather than controls. However, we found no significant differences in terms of thrombus aspiration prevalence (OR: 1.88; 95%CI: 0.97-3.65; p =0.06) or door to balloon time (SMD: 0.11; 95%CI: -0.43-0.66; p =0.7). CONCLUSION Despite that we found a significant association between COVID-19 and high mortality, more length of hospital stay and reduced post TIMI 3 score, in ACS patients after PCI, a rigorous analysis of the adjusted hazard ratio -that was absent in all the included studies- by further meta-analysis is recommended to confirm this association. However, close monitoring of COVID-19 in patients with a high risk of developing ACS, is recommended due to the associated hypercoagulability of COVID-19 infection.

Abstract

BACKGROUND Outpatient monoclonal antibodies are no longer effective and antiviral treatments for COVID-19 disease remain largely unavailable in many countries worldwide. Although treatment with COVID-19 convalescent plasma is promising, clinical trials among outpatients have shown mixed results. METHODS We conducted an individual participant data meta-analysis from outpatient trials to assess the overall risk reduction for all-cause hospitalizations by day 28 in transfused participants. Relevant trials were identified by searching MEDLINE, Embase, MedRxiv, World Health Organization, Cochrane Library, and Web of Science from January 2020 to September 2022. RESULTS Five included studies from four countries enrolled and transfused 2,620 adult patients. Comorbidities were present in 1,795 (69%). The virus neutralizing antibody dilutional titer levels ranged from 8 to 14,580 in diverse assays. 160 (12.2%) of 1315 control patients were hospitalized, versus 111 (8.5%) of 1305 COVID-19 convalescent plasma treated patients, yielding a 3.7% (95%CI: 1.3%-6.0%; p=.001) absolute risk reduction and 30.1% relative risk reduction for all-cause hospitalization. The hospitalization reduction was greatest in those with both early transfusion and high titer with a 7.6% absolute risk reduction (95%CI: 4.0%-11.1%; p=.0001) accompanied by at 51.4% relative risk reduction. No significant reduction in hospitalization was seen with treatment > 5 days after symptom onset or in those receiving COVID-19 convalescent plasma with antibody titers below the median titer. CONCLUSIONS Among outpatients with COVID-19, treatment with COVID-19 convalescent plasma reduced the rate of all-cause hospitalization and may be most effective when given within 5 days of symptom onset and when antibody titer is higher.

Abstract

PURPOSE Different modalities of treatment have been suggested in the treatment for post COVID-19 olfactory dysfunction (OD). Starting with lifestyle modification, smoking cessation, for example, was shown to improve the symptoms for patients with OD. Intranasal and oral corticosteroids have been described in the literature for the treatment of OD. In this review, we are looking at a novel intervention using platelet-rich plasma injection into the nasal cleft for treatment of post COVID-19 infection olfactory dysfunction. METHODS A literature search was done using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 Guidelines, the databases of PMC, Medline, CINAHL, Wiley online library were searched from their year of inception until February 2023. Search terms were used and included a combination of the following keywords; "platelet-rich plasma", "platelet rich plasma", "PRP", "Anosmia", "olfactory dysfunction" and "COVID". RESULTS The four studies in this review included a total of 238 adult patients who presented with olfactory dysfunction. The studies were heterogenic in terms of follow up period which was not long enough through all the included studies. Additionally, different protocol of injecting was seen in different studies. CONCLUSION Injecting PRP for treatment of COVID-19 induced olfactory dysfunction is a safe technique with what seems like promising initial results with low complication rate. However, there are not enough studies assessing its effectiveness compared to other treatment modalities. Further randomized controlled trials with shared protocol are needed to establish further understanding of its role in treatment of COVID-19 induced OD.

Abstract

The aim of this review was to update evidence for benefit of convalescent plasma transfusion (CPT) in patients with coronavirus disease 2019 (COVID-19). Databases were searched for randomized controlled trials (RCT) comparing CPT plus standard treatment versus standard treatment only in adults with COVID-19. Primary outcome measures were mortality and need for invasive mechanical ventilation (IMV). Twenty-Six RCT involving 19,816 patients were included in meta-analysis for mortality. Quantitative synthesis showed no statistically significant benefit of adding CPT to standard treatment (RR = 0.97, 95% CI = 0.92 to 1.02) with unimportant heterogeneity (Q(25) = 26.48, p = .38, I(2) = 0.00%). Trim-and-fill-adjusted effect size was unimportantly changed and level of evidence was graded as high. Trial sequential analysis (TSA) indicated information size was adequate and CPT was futile. Seventeen trials involving 16,083 patients were included in meta-analysis for need of IMV. There was no statistically significant effect of CPT (RR = 1.02, 95% CI = 0.95 to 1.10) with unimportant heterogeneity (Q(16) = 9.43, p = .89, I(2) = 3.30%). Trim-and-fill-adjusted effect size was trivially changed and level of evidence was graded as high. TSA showed information size was adequate and indicated futility of CPT. It is concluded with high level of certainty that CPT added to standard treatment of COVID-19 is not associated with reduced mortality or need of IMV compared with standard treatment alone. In view of these findings, further trials on efficacy of CPT in COVID-19 patients are probably not needed.

Abstract

BACKGROUND The clinical benefits of high-dose intravenous immunoglobulin (IVIg) in treating COVID-19 remained controversial. METHODS We systematically searched databases up to February 17, 2022, for studies examining the efficacy of IVIg compared to routine care. Meta-analyses were conducted using the random-effects model. Subgroup analysis, meta-regression, and trial series analysis w ere performed to explore heterogeneity and statistical significance. RESULTS A total of 4,711 hospitalized COVID-19 patients (1,925 IVIg treated and 2786 control) were collected from 17 studies, including five randomized controlled trials (RCTs) and 12 cohort studies. The application of IVIg was not associated with all-cause mortality (RR= 0.89 [0.63, 1.26], P= 0.53; I(2) = 75%), the length of hospital stays (MD= 0.29 [-3.40, 6.44] days, P= 0.88; I2 = 96%), the needs for mechanical ventilation (RR= 0.93 ([0.73, 1.19], P= 0.31; I2 = 56%), or the incidence of adverse events (RR= 1.15 [0.99, 1.33], P= 0.06; I2 = 20%). Subgroup analyses showed that overall mortality among patients with severe COVID-19 was reduced in the high-dose IVIg subgroup (RR= 0.33 [0.13, 0.86], P= 0.02, I(2) = 68%; very low certainty). CONCLUSIONS Results of this study suggest that severe hospitalized COVID-19 patients treated with high-dose IVIg would have a lower risk of death than patients with routine care. SYSTEMATIC REVIEW REGISTRATION https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021231040, identifier CRD42021231040.

Abstract

BACKGROUND Hyperimmune immunoglobulin (hIVIG) contains polyclonal antibodies, which can be prepared from large amounts of pooled convalescent plasma or prepared from animal sources through immunisation. They are being investigated as a potential therapy for coronavirus disease 2019 (COVID-19). This review was previously part of a parent review addressing convalescent plasma and hIVIG for people with COVID-19 and was split to address hIVIG and convalescent plasma separately. OBJECTIVES To assess the benefits and harms of hIVIG therapy for the treatment of people with COVID-19, and to maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS To identify completed and ongoing studies, we searched the World Health Organization (WHO) COVID-19 Research Database, the Cochrane COVID-19 Study Register, the Epistemonikos COVID-19 L*OVE Platform and Medline and Embase from 1 January 2019 onwards. We carried out searches on 31 March 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs) that evaluated hIVIG for COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)), as well as studies that evaluated standard immunoglobulin. DATA COLLECTION AND ANALYSIS We followed standard Cochrane methodology. To assess bias in included studies, we used RoB 2. We rated the certainty of evidence, using the GRADE approach, for the following outcomes: all-cause mortality, improvement and worsening of clinical status (for individuals with moderate to severe disease), quality of life, adverse events, and serious adverse events. MAIN RESULTS We included five RCTs with 947 participants, of whom 688 received hIVIG prepared from humans, 18 received heterologous swine glyco-humanised polyclonal antibody, and 241 received equine-derived processed and purified F(ab')(2) fragments. All participants were hospitalised with moderate-to-severe disease, most participants were not vaccinated (only 12 participants were vaccinated). The studies were conducted before or during the emergence of several SARS-CoV-2 variants of concern. There are no data for people with COVID-19 with no symptoms (asymptomatic) or people with mild COVID-19. We identified a further 10 ongoing studies evaluating hIVIG. Benefits of hIVIG prepared from humans We included data on one RCT (579 participants) that assessed the benefits and harms of hIVIG 0.4 g/kg compared to saline placebo. hIVIG may have little to no impact on all-cause mortality at 28 days (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.43 to 1.44; absolute effect 77 per 1000 with placebo versus 61 per 1000 (33 to 111) with hIVIG; low-certainty evidence). The evidence is very uncertain about the effect on worsening of clinical status at day 7 (RR 0.85, 95% CI 0.58 to 1.23; very low-certainty evidence). It probably has little to no impact on improvement of clinical status on day 28 (RR 1.02, 95% CI 0.97 to 1.08; moderate-certainty evidence). We did not identify any studies that reported quality-of-life outcomes, so we do not know if hIVIG has any impact on quality of life. Harms of hIVIG prepared from humans hIVIG may have little to no impact on adverse events at any grade on day 1 (RR 0.98, 95% CI 0.81 to 1.18; 431 per 1000; 1 study 579 participants; low-certainty evidence). Patients receiving hIVIG probably experience more adverse events at grade 3-4 severity than patients who receive placebo (RR 4.09, 95% CI 1.39 to 12.01; moderate-certainty evidence). hIVIG may have little to no impact on the composite outcome of serious adverse events or death up to day 28 (RR 0.72, 95% CI 0.45 to 1.14; moderate-certainty evidence). We also identified additional results on the benefits and harms of other dose ranges of hIVIG, not included in the summary of findings table, but summarised in additional tables. Benefits of animal-derived polyclonal antibodies We included data on one RCT (241 participants) to assess the benefits and harms of receptor-binding domain-specific polyclonal F(ab´)(2) fragments of equine antibodies (EpAbs) compared to saline placebo. EpAbs may reduce all-cause mortality at 28 days (RR 0.60, 95% CI 0.26 to 1.37; absolute effect 114 per 1000 with placebo versus 68 per 1000 (30 to 156) ; low-certainty evidence). EpAbs may reduce worsening of clinical status up to day 28 (RR 0.67, 95% CI 0.38 to 1.18; absolute effect 203 per 1000 with placebo versus 136 per 1000 (77 to 240); low-certainty evidence). It may have some effect on improvement of clinical status on day 28 (RR 1.06, 95% CI 0.96 to 1.17; low-certainty evidence). We did not identify any studies that reported quality-of-life outcomes, so we do not know if EpAbs have any impact on quality of life. Harms of animal-derived polyclonal antibodies EpAbs may have little to no impact on the number of adverse events at any grade up to 28 days (RR 0.99, 95% CI 0.74 to 1.31; low-certainty evidence). Adverse events at grade 3-4 severity were not reported. Individuals receiving EpAbs may experience fewer serious adverse events than patients receiving placebo (RR 0.67, 95% CI 0.38 to 1.19; low-certainty evidence). We also identified additional results on the benefits and harms of other animal-derived polyclonal antibody doses, not included in the summary of findings table, but summarised in additional tables. AUTHORS' CONCLUSIONS We included data from five RCTs that evaluated hIVIG compared to standard therapy, with participants with moderate-to-severe disease. As the studies evaluated different preparations (from humans or from various animals) and doses, we could not pool them. hIVIG prepared from humans may have little to no impact on mortality, and clinical improvement and worsening. hIVIG may increase grade 3-4 adverse events. Studies did not evaluate quality of life. RBD-specific polyclonal F(ab´)(2) fragments of equine antibodies may reduce mortality and serious adverse events, and may reduce clinical worsening. However, the studies were conducted before or during the emergence of several SARS-CoV-2 variants of concern and prior to widespread vaccine rollout. As no studies evaluated hIVIG for participants with asymptomatic infection or mild disease, benefits for these individuals remains uncertain. This is a living systematic review. We search monthly for new evidence and update the review when we identify relevant new evidence.