COVID-19 clinical manifestations and treatment strategies among solid-organ recipients: A systematic review of cases

A review of the clinical characteristics and management of immunosuppressed patients living with HIV or solid organ transplants infected with SARS-CoV-2 omicron variants

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron strain was first detected in South Africa in November 2021. Although clinical responses to SARS-CoV-2 depend on host immunity, it remains uncertain how immunosuppression affects subsequent coronavirus disease 2019-related (COVID-19-related) incidence, severity, and mortality, especially with respect to the omicron strain. Conversely, immunosuppressants are often thought to predispose to infection. To explore the associations between host immunity and infection with SARS-CoV-2 omicron variants, here we discuss two groups of immunosuppressed patients: organ transplant recipients, who generally receive exogenous immunosuppressants, and Human Immunodeficiency Virus (HIV)-infected patients, who often have disease-related immunosuppression. In summarizing the clinical features and prognoses of HIV-infected patients and human organ transplant recipients infected with SARS-CoV-2 omicron variants, we provide new insights into the pathogenesis of omicron SARS-CoV-2 and provide a framework for the management of these patients now and in the future.

Clinical Course, Nosocomial, and Opportunistic Infections Among Kidney Transplant Recipients with COVID-19: A Retrospective Single Center Study

BACKGROUND

We report the results of an observational study, analyzing the clinical course of kidney transplant patients hospitalized for COVID-19 and comparing it with a control to determine if outcomes, nosocomial, and opportunistic infections were different between groups.

METHODS

An observational, retrospective, case-control, single-center study, including a group of kidney transplant adults diagnosed with COVID-19, from March 2020 to April 2022. Transplant patients hospitalized for COVID-19 comprised the cases. The control group consisted of non-transplanted adults, without immunosuppressive treatment, hospitalized for COVID-19, and matched by age, sex, and month at diagnosis of COVID-19. Study variables were collected, including demographic/clinical, epidemiologic, clinical/biological at diagnosis, evolutive, and outcome variables.

RESULTS

Fifty-eight kidney transplant recipients were included. Thirty required hospital admission. Ninety controls were included. Transplant recipients had a higher frequency of intensive care unit (ICU) admission, ventilatory support, and death. The relative risk for death was 2.45. When adjusted by baseline estimated glomerular filtration rate (eGFR) and comorbidity, only the risk for opportunistic infection remained high. Variables independently associated with death were dyslipidemia, eGFR at admission, MULBSTA score, and ventilatory support. Pneumonia by Klebsiella oxytoca was the most frequent nosocomial infection. Pulmonary aspergillosis was the most frequent opportunistic infection overall. Pneumocystosis and cytomegalovirus colitis were more frequent among transplant patients. The relative risk for opportunistic infection in this group was 1.88. Baseline eGFR, serum interleukin 6 level, and coinfection were independently associated with it.

CONCLUSIONS

Evolutive course of COVID-19 requiring hospitalization in renal transplant recipients was primarily determined by comorbidity and baseline kidney function. At equal comorbidity and renal function, there were no differences in mortality, ICU admission, nosocomial infection, and hospital stay. However, the risk for opportunistic infection remained high.

A Comprehensive Comparison of Clinical Presentation and Outcomes of Kidney Transplant Recipients with COVID-19 during Wave 1 versus Wave 2 at a Tertiary Care Center, India

Data comparing the clinical spectrum of COVID-19 in kidney transplant recipients (KTRs) during the first and second waves of the pandemic in India is limited. Our single-center retrospective study compared the clinical profile, mortality, and associated risk factors in KTRs with COVID-19 during the 1st wave (1^st February 2020 to 31^st January 2021) and the second wave (1^st March-31^st August 2021). 156 KTRs with PCR confirmed SARS-CoV-2 infection treated at a tertiary care hospital in New Delhi during the 1st and the second waves were analyzed. The demographics and baseline transplant characteristics of the patients diagnosed during both waves were comparable. Patients in the second wave reported less frequent hospitalization, though the intensive care unit (ICU) and ventilator requirements were similar. Strategies to modify immunosuppressants such as discontinuation of antinucleoside drugs with or without change in calcineurin inhibitors and the use of steroids were similar during both waves. Overall patient mortality was 27.5%. The demographics and baseline characteristics of survivors and nonsurvivors were comparable. A higher percentage of nonsurvivors presented with breathing difficulty, low SpO₂, and altered sensorium. Both wave risk factors for mortality included older age, severe disease, ICU/ventilator requirements, acute kidney injury (AKI) needing dialysis, Chest Computerized Tomographic (CT) scan abnormalities, and higher levels of inflammatory markers particularly D-dimer and interleukin-6 levels. Conclusions. KTRs in both COVID-19 waves had similar demographics and baseline characteristics, while fewer patients during the second wave required hospitalization. The D-dimer and IL-6 levels are directly correlated with mortality.

SARS-CoV-2 Vaccines: Safety and Immunogenicity in Solid Organ Transplant Recipients and Strategies for Improving Vaccine Responses

Purpose of Review

While solid organ transplant (SOT) recipients are at the highest risk for severe complications and increased mortality from COVID19 disease, their vaccination against SARS-CoV-2 remains challenging due to fear of immune-mediated adverse events and suboptimal immune response. Our current review is aimed to summarize current knowledge about the safety and efficacy of SARS-CoV-2 vaccines, describe factors that are correlated with immune response, and discuss strategies to improve vaccine immunogenicity in SOT recipients.

Recent Findings

SARS-CoV-2 vaccines are safe in SOT recipients and not related to rejection or other major adverse events. The immune response to two doses of vaccine is suboptimal and correlated to age and magnitude of immunosuppression. Administration of a third vaccine dose brings to significant amplification of immune response.

Summary

This review strengthens the existing recommendation of vaccination by three doses of vaccine in all SOT recipients and completion of vaccination before transplantation if possible.

Viral infections in lung transplantation

Viral infections account for up to 30% of all infectious complications in lung transplant recipients, remaining a significant cause of morbidity and even mortality. Impact of viral infections is not only due to the direct effects of viral replication, but also to immunologically-mediated lung injury that may lead to acute rejection and chronic lung allograft dysfunction. This has particularly been seen in infections caused by herpesviruses and respiratory viruses. The implementation of universal preventive measures against cytomegalovirus (CMV) and influenza (by means of antiviral prophylaxis and vaccination, respectively) and administration of early antiviral treatment have reduced the burden of these diseases and potentially their role in affecting allograft outcomes. New antivirals against CMV for prophylaxis and for treatment of antiviral-resistant CMV infection are currently being evaluated in transplant recipients, and may continue to improve the management of CMV in lung transplant recipients. However, new therapeutic and preventive strategies are highly needed for other viruses such as respiratory syncytial virus (RSV) or parainfluenza virus (PIV), including new antivirals and vaccines. This is particularly important in the advent of the COVID-19 pandemic, for which several unanswered questions remain, in particular on the best antiviral and immunomodulatory regimen for decreasing mortality specifically in lung transplant recipients. In conclusion, the appropriate management of viral complications after transplantation remain an essential step to continue improving survival and quality of life of lung transplant recipients.

Immunosuppressants in Liver Transplant Recipients With Coronavirus Disease 2019: Capability or Catastrophe?-A Systematic Review and Meta-Analysis

Background: The probable impact of a maintenance immunosuppressant (IS) on liver transplant (LT) recipients with coronavirus disease 2019 (COVID-19) remains unexplored. Our specific aim was to approximate the prognosis of LT recipients with COVID-19 on the standard maintenance IS.

Method: We searched separate databases for the qualified studies in between December 2019 and June 25, 2021. Ultimately, a meta-analysis was carried out using a fixed-effect or random-effect model based on the heterogeneity.

Results: In a total of eight studies and 509 LT recipients with COVID-19, the pooled rates of severity and mortality during all the combined immunosuppressive therapies were 22.4 and 19.5%, respectively. Our study sufficiently showed that an immunosuppressive therapy in LT recipients with COVID-19 was significantly associated with a non-severe COVID-19 [odds ratio (OR): 11.49, 95% CI: 4.17–31.65; p < 0.001] and the survival of the patients (OR: 17.64, 95% CI: 12.85–24.22; p < 0.001). Moreover, mammalian target of rapamycin inhibitor (mTORi) typically had the lowest rate of severity and mortality compared to other ISs such as calcineurin inhibitors (CNIs), steroids, and antimetabolites, i.e., severity (13.5 vs. 21.1, 24.7, and 26.3%) and mortality (8.3 vs. 15, 17.2, and 12.1%), respectively. Contrary to the general opinions, our meta-analysis showed comorbidities such as diabetes, hypertension, cardiopulmonary disorders, chronic kidney disease (CKD), age >60, the duration of LT to the diagnosis of COVID-19, primary disease for LT, and obesity were not significantly associated with the severity and mortality in LT recipients with COVID-19 under an immunosuppressive therapy. However, our pooled analysis found that LT recipients with COVID-19 and without comorbidities have a less severe disease and low mortality rate compared to those with both COVID-19 and comorbidities.

Conclusions: In conclusion, LT recipients with COVID-19 undergoing immunosuppressive therapies are not significantly associated with the severity and mortality. Therefore, taking the risk of organ rejection into a key consideration, a complete withdrawal of the IS may not be wise. However, mycophenolate mofetil (MMF) might be discontinued or replaced from an immunosuppressive regimen with the CNIs- or mTORis-based immunosuppressive therapy in some selected LT recipients with COVID-19, depending upon the severity of the disease.

Mortality risk factors of COVID-19 infection in kidney transplantation recipients: a systematic review and meta-analysis of cohorts and clinical registries

Kidney transplantation recipients (KTR) with coronavirus disease 2019 (COVID-19) are at higher risk of death than general population. However, mortality risk factors in KTR are still not clearly identified. Our objective was to systematically analyze published evidence for risk factors associated with mortality in COVID-19 KTR. Electronic databases were searched for eligible studies on 1 August 2021. All prospective and retrospective studies of COVID-19 in KTR were considered eligible without language restriction. Since data in case reports and series could potentially be subsets of larger studies, only studies with ≥ 50 patients were included. Random-effects model meta-analysis was used to calculate weighted mean difference (WMD) and pooled odds ratio (OR) of factors associated with mortality. From a total 1,137 articles retrieved, 13 were included in the systematic review and meta-analysis comprising 4,440 KTR. Compared with survivors, non-survivors were significantly older (WMD 10.5 years, 95% CI 9.3-11.8). KTR of deceased donor were at higher risk of death (OR 1.73, 95% CI 1.10-2.74). Comorbidities including diabetes mellitus, cardiovascular disease, and active cancer significantly increased mortality risk. KTR with dyspnea (OR 5.68, 95% CI 2.11-15.33) and pneumonia (OR 10.64, 95% CI 3.37-33.55) at presentation were at higher mortality risk, while diarrhea decreased the risk (OR 0.61, 95% CI 0.47-0.78). Acute kidney injury was associated with mortality (OR 3.24, 95% CI 1.36-7.70). Inflammatory markers were significantly higher in the non-survivors, including C-reactive protein, procalcitonin, and interleukine-6. A number of COVID-19 mortality risk factors were identified from KTR patient characteristics, presenting symptoms, and laboratory investigations. KTR with these risk factors should receive more intensive monitoring and early therapeutic interventions to optimize health outcomes.

SARS-CoV-2 in Solid Organ Transplant Recipients: A Structured Review of 2020

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is challenging health systems all over the world. Particularly high-risk groups show considerable mortality rates after infection. In 2020, a huge number of case reports, case series, and consecutively various systematic reviews have been published reporting on morbidity and mortality risk connected with SARS-CoV-2 in solid organ transplant (SOT) recipients. However, this vast array of publications resulted in an increasing complexity of the field, overwhelming even for the expert reader.

METHODS

We performed a structured literature review comprising electronic databases, transplant journals, and literature from previous systematic reviews covering the entire year 2020. From 164 included articles, we identified 3451 cases of SARS-CoV-2-infected SOT recipients.

RESULTS

Infections resulted in a hospitalization rate of 84% and 24% intensive care unit admissions in the included patients. Whereas 53.6% of patients were reported to have recovered, cross-sectional overall mortality reported after coronavirus disease 2019 (COVID-19) was at 21.1%. Synoptic data concerning immunosuppressive medication attested to the reduction or withdrawal of antimetabolites (81.9%) and calcineurin inhibitors (48.9%) as a frequent adjustment. In contrast, steroids were reported to be increased in 46.8% of SOT recipients.

CONCLUSIONS

COVID-19 in SOT recipients is associated with high morbidity and mortality worldwide. Conforming with current guidelines, modifications of immunosuppressive therapies mostly comprised a reduction or withdrawal of antimetabolites and calcineurin inhibitors, while frequently maintaining or even increasing steroids. Here, we provide an accessible overview to the topic and synoptic estimates of expectable outcomes regarding in-hospital mortality of SOT recipients with COVID-19.

[SARS-CoV-2 Infections and Clinical Consequences in a Cohort of Solid Organ Transplant Recipients during the first Wave in Germany - a Single Centre Survey and a Case Report]

BACKGROUND

The SARS-CoV-2 pandemic has caused an unprecedented global health crisis, with exceptionally high mortality rates in high-risk groups of affected patients. It is alarming that a steadily increasing number of clinical reports on outcomes of COVID-19 in solid organ transplant (SOT) recipients suggests a detrimental impact linked to high overall mortality. However, systematic data on SARS-CoV-2 infections in SOT recipients in Germany are still scarce.

MATERIAL AND METHODS

We conducted a survey on SARS-CoV-2 infection status among 387 SOT recipients treated at our centre during the past 5 years - located in a severely affected region in Germany. The survey was sent out two months after the first SARS CoV-2 outbreak in our region had resulted in government-imposed lockdown measures.

RESULTS

An incidence rate of 0.4% SARS-CoV-2-positive SOT recipients was determined in our cohort, in line with reported local infection rates in the general population at this time. However, the only SARS CoV-2 infection known to us within this group of patients led to severe morbidity - resulting in prolonged mechanical ventilation, hospitalisation > 60 days and finally in irreversible loss of graft function.

CONCLUSION

Our data demonstrate that SOT recipients are at equal risk for SARS-CoV-2 infections when compared to the general population, while SARS-CoV-2 infections in SOT recipients seem to be associated with deleterious clinical consequences.

Long-term follow-up of SARS-CoV-2 recovered renal transplant recipients: A single-center experience from India

INTRODUCTION

Follow-up studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in kidney transplant recipients (KTR) are scarcely reported.

METHODS

We studied 142 hospitalized KTR for a median (interquartile range) follow-up of 9 (8-11) months who recovered from SARS-CoV-2 during May 2020 to Dec 2020. The outcomes were to assess persistent symptoms post-discharge; EuroQoL visual analogue score (EQ-VAS); EuroQoL 5-dimension score (E5-QD-5L) score and modified medical research dyspnea score (mMRC) at 1 month, 3-month, and beyond 6 months. Graft outcome was also analyzed.

RESULTS

The age of the cohort was 43 (34-69) years and COVID-19 severity ranged from asymptomatic (4%), mild (50%), moderate (35%) to severe (12%). The most common persistent symptom was fatigue which significantly decreased in the follow-up (n = 45 [32.3] vs. 10 [7.4] vs. 4 [2.9]; p-value = 0.001) at 1-month, 3-month, and beyond 6 months respectively. Decrement in the mean (standard deviation) EQ-VAS score from baseline was also improved (28.6 [13] vs. 10.4 [12.5] vs. 7.5 [12.0]; p-value = 0.012). There was significant improvement in all EQ-5D-5L scores in follow-up. There was no deterioration in mMRC scores during the follow-up (n = 4, 3% vs. 7, 5% vs. 3, 2%; p-value = 0.86). Cases requiring oxygen had significantly poorer overall scores initially, but there was no difference at 6 months. All 10 graft losses had oxygen requirement and chronic graft dysfunction at baseline.

CONCLUSION

Our initial assessment reports significant improvement in the quality of life in follow-up. The majority recovered from allograft dysfunction. Further research is warranted to study the full spectrum of follow-up.

The Immunology of SARS-CoV-2 Infection and Vaccines in Solid Organ Transplant Recipients

Since its outbreak in December 2019, the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), led to an enormous rise in scientific response with an excess of COVID-19-related studies on the pathogenesis and potential therapeutic approaches. Solid organ transplant (SOT) recipients are a heterogeneous population with long-lasting immunosuppression as a joining element. Immunocompromised patients are a vulnerable population with a high risk of severe infections and an increased infection-related mortality rate. It was postulated that the hyperinflammatory state due to cytokine release syndrome during severe COVID-19 could be alleviated by immunosuppressive therapy in SOT patients. On the other hand, it was previously established that T cell-mediated immunity, which is significantly weakened in SOT recipients, is the main component of antiviral immune responses. In this paper, we present the current state of science on COVID-19 immunology in relation to solid organ transplantation with prospective therapeutic and vaccination strategies in this population.

COVID-19 Severity and Mortality in Solid Organ Transplantation: Differences between Liver, Heart, and Kidney Recipients

The infection by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can generate a wide spectrum of clinical manifestations ranging from asymptomatic to severe respiratory and systemic disease with coagulation disorder named coronavirus disease 2019 (COVID-19). Patients with comorbidities have been identified as risk groups for severe COVID-19, also having a higher death risk. Previous reports have conflicting results regarding if solid organ transplant recipients present an increased risk for COVID-19. Nevertheless, previous investigations failed to distinguish between different organs received or made a longitudinal investigation on those patients. We recruited 39 solid organ transplant recipients: 25 kidney transplant recipients, 7 heart transplant recipients, and 7 liver transplant recipients and 25 age-matched non-transplant COVID-19 patients without comorbidities (control group) and compared daily laboratory data in addition to performing survival analysis. Heart and kidney transplant recipients presented an increase in several COVID-19 severity-associated biomarkers, such as neutrophil-to-lymphocyte ratio and thrombocytopenia, in comparison to the control group and liver transplant recipients. Heart and kidney transplant recipients also presented an increase in the need for intensive care and invasive mechanical ventilation during the disease’s course. Importantly, heart and kidney transplant recipients presented a higher mortality rate in comparison to liver transplant recipients and non-transplant recipients. In our cohort, heart and kidney transplant recipients presented a difference in clinical characteristics and survival rate in comparison to liver transplant recipients. Further investigation involving immune response to SARS-CoV-2 in solid organ recipients should consider and separate patients according to the organ grafted.

The Full Spectrum of COVID-19 Development and Recovery Among Kidney Transplant Recipients

BACKGROUND

Coronavirus disease 2019 (COVID-19) fatality rate is high among kidney transplant recipients. Among survivors, kidney outcomes, seroconversion, and persistence of viral shedding are unexplored.

METHODS

Single-center prospective cohort study including data from kidney transplant recipients with confirmed COVID-19 between March 20, 2020 and July 31, 2020. Outcomes were adjudicated until August 31, 2020 or the date of death.

RESULTS

There were 491 patients with COVID-19 among the 11 875 recipients in follow-up. The majority were middle aged with ≥1 comorbidities. Thirty-one percent were treated at home, and 69% required hospitalization. Among the hospitalized, 61% needed intensive care, 75% presented allograft dysfunction, and 46% needed dialysis. The overall 28-day fatality rate was 22% and among hospitalized patients it was 41%. Age (odds ratio, 3.08; 95% confidence interval, 1.86-5.09), diabetes mellitus (odds ratio, 1.69; 95% confidence interval, 1.06-2.72), and cardiac disease (odds ratio, 2.00; 95% confidence interval, 1.09-3.68) were independent factors for death. Among the 351 survivors, 19% sustained renal graft dysfunction, and there were 13 (4%) graft losses. Biopsy (n = 20) findings were diverse but decisive to guide treatment and estimate prognosis. Seroconversion was observed in 79% of the survivors and was associated with disease severity. Persistence of viral shedding was observed in 21% of the patients without detectable clinical implications.

CONCLUSIONS

This prospective cohort analysis confirms the high 28-day fatality rate of COVID-19, associated primarily with age and comorbidities. The high incidence of allograft dysfunction was associated with a wide range of specific histologic lesions and high rates of sequelae and graft loss. Seroconversion was high and the persistence of viral shedding deserves further studies.

Effect of Calcineurin Inhibitors and Mammalian Target of Rapamycin Inhibitors on the Course of COVID-19 in Kidney Transplant Recipients

Coronavirus disease 19 (COVID-19) has been an ongoing pandemic since December 2019. Unfortunately, kidney transplant recipients are a high-risk group during the disease course, and scientific data are still limited in this patient group. Beyond the dosage of immunosuppressive drugs, pharmacological immunosuppression may also alter the infection response in the COVID-19 course. The effects of immunosuppressive agents on the development and process of infection should not be decided only by determining how potent they are and how much they suppress the immune system; it is also thought that the direct effect of the virus, increased oxidative stress, and cytokine storm play a role in the pathogenesis of COVID-19 disease. There are data about immunosuppressive drugs like calcineurin inhibitors (CNI) or mammalian target of rapamycin inhibitors (mTORi) therapy related to their beneficial effects during any infection course. Limited data suggest that the use of CNI or mTORi may have beneficial effects on the process. In this hypothetical review, the probable impacts of CNI and mTORi on the pathogenesis of the COVID-19 were investigated.

Clinical Manifestations and Characterization of COVID-19 in Liver Transplant Recipients: A Systematic Review of Case Reports and Case Series

BACKGROUND

This systematic review is conducted to explore available information on clinical presentations, laboratory finding and outcomes of SARS-COV-2 in liver transplant patients.

METHODS

We searched four databases for relevant terms related to COVID-19 and liver transplantation and collected both case reports and case series on liver transplantation published up to the end of September 2020.

RESULTS

After initial screening of irrelevant articles, 25 studies were included and analyzed in this review. Among the 59 patients included, 78.3% were over 50 years old, and 71.6% were males. The majority of patients (93.3%) were hospitalized. The most common presenting symptoms were fever (72.9%) followed by dyspnea and cough (54.2%). The majority of patients revealed a high level of CRP (64.3%). Moreover, high level ALT, AST and ALP were reported in 64.3, 37.5, 30.5 and 22.2% of patients. A total, 9(15.3%), of cases died as a result of complications of COVID-19. Chest radiographs were reported in 72.9%(43/59) of cases that 94% demonstrated radiologic evidence of abnormality.

CONCLUSION

The results demonstrated that the most prevalent symptoms and signs were fever, dyspnea and cough. Moreover, most patients were males and hospitalized. The rate of mortality and high level of CRP, ALT/AST and ALP is similar within the non-immune suppressed and general population. However, early detection of high level of serum CRP, ALT/AST and ALP combined with a clinical COVID-19 symptom and finding of CT scan may be used as an index for the presence and severity of the disease.