Beyond prevention: Unveiling the benefits of triple vaccination on COVID-19 severity and resource utilization in solid organ transplant recipients

OBJECTIVE

Despite the widespread reduction in COVID-19-related morbidity and mortality attributed to vaccination in the general population, vaccine efficacy in solid organ transplant recipients (SOTR) remains under-characterized. This study aimed to investigate clinically relevant outcomes on double and triple-vaccinated versus unvaccinated SOTR with COVID-19.

STUDY DESIGN AND SETTING

A retrospective propensity score-matched cohort study was performed utilizing data from the US Collaborative Network Database within TriNetX (n = 117,905,631). We recruited vaccinated and unvaccinated (matched controls) SOTR with COVID-19 over two time periods to control for vaccine availability: December 2020 to October 2022 (bi-dose, double-dose vaccine effectiveness) and December 2020 to April 2023 (tri-dose, triple-dose vaccine effectiveness). A total of 42 factors associated with COVID-19 disease severity were controlled for including age, obesity, diabetes, and hypertension. We monitored 30-day outcomes including acute respiratory failure, intubation, and death following a diagnosis of COVID-19.

RESULTS

Subjects were categorized into two cohorts based on the two time periods: bi-dose cohort (vaccinated, n = 462; unvaccinated, n = 20,998); tri-dose cohort (vaccinated, n = 517; unvaccinated, n = 23,061).Compared to unvaccinated SOTR, 30-day mortality was significantly lower for vaccinated subjects in both cohorts: tri-dose (2.0% vs 7.5%, HR = 0.22 [95% CI: 0.11, 0.46]); bi-dose (3.7% vs 8.2%, HR = 0.43 [95% CI: 0.24, 0.76]). Hospital admission rates were similar between bi-dose vaccinated and unvaccinated subjects (33.1% vs 28.6%, HR = 1.2 [95% CI: 0.95, 1.52]). In contrast, tri-dose vaccinated subjects had a significantly lower likelihood of hospital admission (29.4% vs 36.6%, HR = 0.74 [95% CI: 0.6, 0.91]). Intubation rates were significantly lower for triple-vaccinated- (2.3% vs 5.2%, p < 0.05), but not double-vaccinated subjects (3.0% vs 5.2%, p > 0.05).

CONCLUSION

In solid organ transplant recipients with COVID-19, triple vaccination, but not double vaccination, against SARS-CoV-2 was associated with significantly less hospital resource utilization, decreased disease severity, and fewer short-term complications. These real-world data from extensively matched controls support the protective effects of COVID-19 vaccination with boosters in this vulnerable population.

Assessing quality of life in solid organ transplant recipients: A systematic review of the development, content, and quality of available condition- and transplant-specific patient-reported outcome measures

PURPOSE

We aimed to identify the condition- and transplant-specific patient-reported outcome measures (PROMs) available to measure quality of life (QoL) in solid organ transplant (SOT) recipients, examine their development and content, and critically appraise the quality of their measurement properties, to inform recommendations for clinical and research use.

METHODS

We systematically searched MEDLINE, Embase, CINAHL, PsycINFO, Cochrane CENTRAL, and Scopus from inception to 27th January 2023. Search hits were screened for eligibility by two independent reviewers; papers reporting the development and/or validation of condition- and transplant-specific PROMs measuring QoL in adult SOT recipients were considered eligible. We abstracted and synthesised data on PROM characteristics, development (item generation and/or reduction), and content (QoL dimensions). Quality appraisal and synthesis were informed by the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines, and included methodological and quality assessment of measurement properties, GRADE levels of evidence, feasibility and interpretability.

RESULTS

We identified 33 papers reporting 26 QoL PROMs validated in SOT recipients (kidney n = 10 PROMs; liver n = 6; lung n = 3; heart n = 2; pancreas n = 1; multiple organs n = 4). Patient discussions (n = 17 PROMs) and factor analysis (n = 11) were the most common item generation and reduction techniques used, respectively. All PROMs measured ≥3 of nine QoL dimensions (all measured emotional functioning); KDQoL-SF and NIDDK-QA measured all nine. Methodological quality was variable; no PROM had low evidence or better for all measurement properties. All PROMs were COSMIN recommendation category 'B', primarily because none had sufficient content validity.

CONCLUSIONS

There are many condition- and transplant-specific QoL PROMs validated in SOT recipients, particularly kidney. These findings can help inform PROM selection for clinicians and researchers. However, caution is required when adopting measures, due to the substantial heterogeneity in development, content, and quality. Each PROM has potential but requires further research to be recommendable. Greater consideration of patient and professional involvement in PROM development in this setting is needed to ensure sufficient content validity.

Actinic Keratosis in Solid Organ Transplant Recipients: A Medical Literature Review

Pharmacological immunosuppression in solid organ transplant recipients is a significant risk factor in the occurrence of actinic keratosis (AK) and later progression into squamous cell carcinomas (SCC). Treating clinical and preclinical lesions is mandatory in this group of patients due to the high changes of progression into SCC. On the other hand, prevention of AK should be considered because it plays a crucial role. Several studies have been published on immunocompetent patients, as well as on the management and prevention of AK, but not on immunosuppressed patients. This review aims to summarize the current knowledge on the management and prevention measures of AK in solid organ transplant recipients.

[Translated article] Actinic Keratosis in Solid Organ Transplant Recipients: A Medical Literature Review

Pharmacological immunosuppression in solid organ transplant recipients is a significant risk factor in the occurrence of actinic keratosis (AK) and later progression into squamous cell carcinomas (SCC). Treating clinical and preclinical lesions is mandatory in this group of patients due to the high changes of progression into SCC. On the other hand, prevention of AK should be considered because it plays a crucial role. Several studies have been published on immunocompetent patients, as well as on the management and prevention of AK, but not on immunosuppressed patients. This review aims to summarize the current knowledge on the management and prevention measures of AK in solid organ transplant recipients.

Cryptococcemia in pancreas-kidney transplant patient

Solid organ transplant recipients have a higher risk of developing invasive fungal infections (IFIs) due to immunosuppressive therapy. Cryptococcosis is the third most commonly occurring invasive fungal infection in solid organ transplant (SOT) recipients. Cryptococcemia is associated with high mortality rate. We present a case of cryptococcemia in a 31-year-old female with a pancreas-kidney transplant who was admitted to hospital for the management of a suspected Hemodialysis catheter-related bloodstream infection (CRBSI).

Humoral immune responses against SARS-CoV-2 Spike variants after mRNA vaccination in solid organ transplant recipients

Although SARS-CoV-2 mRNA vaccination has been shown to be safe and effective in the general population, immunocompromised solid organ transplant recipients (SOTRs) were reported to have impaired immune responses after one or two doses of vaccine. In this study, we examined humoral responses induced after the second and the third dose of mRNA vaccine in different SOTR (kidney, liver, lung, and heart). Compared to a cohort of SARS-CoV-2 naïve immunocompetent health care workers (HCWs), the second dose induced weak humoral responses in SOTRs, except for the liver recipients. The third dose boosted these responses but they did not reach the same level as in HCW. Interestingly, although the neutralizing activity against Delta and Omicron variants remained very low after the third dose, Fc-mediated effector functions in SOTR reached similar levels as in the HCW cohort. Whether these responses will suffice to protect SOTR from severe outcome remains to be determined.

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Two doses of mRNA vaccine elicit weak humoral responses in transplant recipients

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A boost increases these responses, but below those of the general population

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Robust Fc effector functions but weak neutralization is observed after the boost

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Neutralizing activity is particularly poor against variants of concern

Immune Response to COVID-19 and mRNA Vaccination in Immunocompromised Individuals: A Narrative Review

Immunocompromised individuals are at high risk of poor coronavirus disease 2019 (COVID-19) outcomes and demonstrate a lower immune response to COVID-19 vaccines, including to the novel mRNA vaccines that have been shown to elicit high neutralizing antibody levels. This review synthesized available data on the immune response to COVID-19 and critically assessed mRNA COVID-19 vaccine immunogenicity in this vulnerable subpopulation. Patients with various immunocompromising conditions exhibit diverse responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19 severity and mortality, and available vaccines elicit lower immune responses, particularly in solid organ transplant recipients. Strategies to improve vaccine responses in immunocompromised individuals are being implemented in vaccine recommendations, including the use of a third and fourth vaccine dose beyond the two-dose series. Additional doses may enhance vaccine effectiveness and help provide broad coverage against emerging SARS-CoV-2 variants. Continued investigation of vaccines and dosing regimens will help refine approaches to help protect this vulnerable subpopulation from COVID-19.

Central Nervous System Infections in Solid Organ Transplant Recipients: Results from the Swiss Transplant Cohort Study

OBJECTIVES

To describe the epidemiology and clinical presentation of central nervous system (CNS) infections in solid organ transplant (SOT) recipients in the current era of transplantation.

METHODS

Patients from the Swiss Transplant Cohort Study (STCS) transplanted between 2008 and 2018 were included with a median follow-up of 3.8 years. Epidemiological, microbiological, and clinical data were extracted from the STCS database and patients' medical records. We calculated incidence rates and 90-day survival of transplant recipients with CNS infection.

RESULTS

Among 4762 patients, 42 episodes of CNS infection in 41 (0.8%) SOT recipients were identified, with an overall incidence rate of 2.06 per 1000 patient-years. Incidence of CNS infections was similar across all types of transplantations. Time to CNS infection onset ranged from 0.6 to 97 months after transplant. There were 22/42 (52.4%) cases of viral infections, 11/42 (26.2%) of fungal infections, 5/42 (11.9%) of bacterial infections and 4/42 (9.5%) of probable viral/bacterial etiology. Clinical presentation was meningitis/encephalitis in 25 cases (59.5%) and brain-space occupying lesions in 17 cases (40.5%). Twenty-three cases (60.5%) were considered opportunistic infections. Diagnosis were achieved mainly by brain biopsy/necropsy (15/42, 36%) or by cerebrospinal fluid analysis (20/42, 48%). Up to 40% of cases (17/42) had concurrent extra-neurological disease localizations. Overall, 90-day mortality rate was 29.0% (73.0% for fungal, 14.0% for viral and 11.0% for bacterial and probable infections, p<0.0001).

CONCLUSIONS

CNS infections were rare in the STCS, with viral meningoencephalitis being the most common disease. Fungal infections were associated with a high mortality.

Early remdesivir to prevent severe COVID-19 in recipients of solid organ transplant: a real-life study from Northern Italy

Objectives

The effectiveness of a 3-day course of remdesivir to prevent severe disease in patients with COVID-19 who received solid organ transplant (SOT) is unknown. We wanted to study the efficacy of this therapeutic option in patients with COVID-19 who received SOT in preventing both hospitalizations for outpatients and clinical worsening due to COVID-19 for those already hospitalized for other reasons.

Methods

This is a single-center, retrospective, observational study conducted in the Fondazione IRCSS Policlinico San Matteo of Pavia, Northern Italy. We extracted all the data of patients with COVID-19 receiving SOT who received and did not receive pre-emptive remdesivir between December 23, 2021, and February 26, 2022. We used a Cox proportional hazard model to assess whether receiving pre-emptive remdesivir was associated with lower rates of hospitalization.

Results

A total of 24 patients who received SOT were identified. Among these, seven patients (29, 1%) received pre-emptive remdesivir, whereas 17 (70, 9%) patients did not. Receiving remdesivir significantly reduced the hospitalization rate in outpatients who received SOT and the clinical worsening of the condition of already hospitalized patients who received SOT (hazard ratio 0.05; confidence interval [0.00–0.65], P-value = 0.01).

Conclusion

In our cohort of patients infected with SARS-CoV-2 who received SOT, pre-emptive remdesivir was effective in reducing the hospitalization rate due to COVID-19 and in preventing the clinical worsening of the condition of patients who received SOT who were hospitalized for reasons other than COVID-19.

Outcome of SARS-CoV-2 variant breakthrough infection in fully immunized solid organ transplant recipients

SARS-CoV-2 vaccination in solid organ transplant recipients is associated with suboptimal immune response and risk for breakthrough infection. It is not known whether they are at risk of severe post-vaccine breakthrough infections in the presence of SARSCoV-2 variant of concern. We describe a case series of four fully vaccinated solid organ transplant recipients who developed SARS-CoV-2 variants of concern breakthrough infections. Three patients received BNT162b2 mRNA (Pfizer-BioNTech) and one patient received ChAdOx1 (AZD12220) COVID-19 vaccines. The patients were infected with SARS-CoV-2 variants circulating in Saudi Arabia. Two patients were infected with Alpha variant and had severe pneumonia requiring intensive care admission and ventilatory support and subsequently died. The other two patients recovered; one patient was infected with Beta variant required low supplemental oxygen via nasal flow and the other patient was infected with Delta variant and required high supplemental oxygen nasal flow. Younger patients had a better outcome than older patients. Future large studies are required to confirm our observations and to compare the different vaccine efficacy among solid organ transplants in the era of SARS-CoV-2 variants of concern.

Immunosuppressant-induced cutaneous drug reactions in solid organ transplant recipients

Solid organ transplant recipients (SOTRs) are susceptible to various cutaneous side effects as a consequence of long-term immunosuppressive therapy. Skin cancers and infections are well-studied complications that can cause death and/or allograft rejection. Other cutaneous drug reactions, such as inflammatory manifestations, have a high prevalence but are rarely studied. We analyzed these manifestations' prevalence and their association with immunosuppressants in transplant recipients from a Brazilian tertiary center. Among 532 SOTRs followed at our dermatology clinic, 60 (11.3%) developed some cutaneous adverse reactions to the immunosuppressants, with a median age at transplantation of 50.5 years and a median life span posttransplantation of seven years. Acneiform eruption was the most common drug reaction found (21 patients, 30.4%), followed by diffuse non-scarring alopecia (16 patients, 23.1%), lymphedema (10 patients, 14.5%), gingival hyperplasia (7 patients, 10.1%), hypertrichosis (6 patients, 8.7%) and sebaceous hyperplasia (9 patients, 13.1%). Adequate immunosuppression is an essential prerequisite for successful organ transplantation. In the immediate post-transplant period, significant immunosuppression is needed, but after that, the complications of excessive immunosuppression outweigh the risk of organ rejection. SORTs may present with a broad spectrum of inflammatory and cosmetic findings due to immunosuppressants that can impair life quality.

The use of automated data extraction tools to develop a solid organ transplant registry: Proof of concept study of bloodstream infections

BACKGROUND

We created an electronic health record-based registry using automated data extraction tools to study the epidemiology of bloodstream infections (BSI) in solid organ transplant recipients. The overarching goal was to determine the usefulness of an electronic health record-based registry using data extraction tools for clinical research in solid organ transplantation.

METHODS

We performed a retrospective single-center cohort study of adult solid organ transplant recipients from 2010 to 2015. Extraction tools were used to retrieve data from the electronic health record, which was integrated with national data sources. Electronic health records of subjects with positive blood cultures were manually adjudicated using consensus definitions. One-year cumulative incidence, risk factors for BSI acquisition, and 1-year mortality were analyzed by Kaplan-Meier method and Cox modeling, and 30-day mortality with logistic regression.

RESULTS

In 917 solid organ transplant recipients the cumulative incidence of BSI was 8.4% (95% confidence interval 6.8-10.4) with central line-associated BSI as the most common source. The proportion of multidrug-resistant isolates increased from 0% in 2010 to 47% in 2015 (p = 0.03). BSI was the strongest risk factor for 1-year mortality (HR=8.44; 4.99-14.27; p<0.001). In 11 of 14 deaths, BSI was the main cause or contributory in patients with non-rapidly fatal underlying conditions.

CONCLUSIONS

Our study illustrates the usefulness of an electronic health record-based registry using automated extraction tools for clinical research in the field of solid organ transplantation. A BSI reduces the 1-year survival of solid organ transplant recipients. The most common sources of BSIs in our studies are preventable.

Pneumocystis jirovecii pneumonia in solid organ transplant recipients: a descriptive analysis for the Swiss Transplant Cohort

BACKGROUND

Descriptive data on Pneumocystis jirovecii pneumonia (PJP) in solid organ transplant recipients (SOTr) in the era of routine Pneumocystis-prophylaxis are lacking.

METHODS

All adult SOTr between 2008 and 2016 were included. PJP was diagnosed based on consensus guidelines. Early-onset PJP was defined as PJP within the first-year-post-transplant.

RESULTS

41/2842 SOTr (1.4%) developed PJP (incidence rate: 0.01/1000 person-days) at a mean of 493-days post-transplant: 21 (51.2%) early vs 20 (48.8%) late-onset PJP. 2465 (86.7%) SOTr received Pneumocystis-prophylaxis for a mean 316 days. PJP incidence was 0.001% and 0.003% (log-rank < 0.001) in SOTr with and without Pneumocystis-prophylaxis, respectively. PJP was an early event in 10/12 (83.3%) SOTr who did not receive Pneumocystis-prophylaxis and developed PJP, compared to those patients who received prophylaxis (11/29, 37.9%; P-value: 0.008). Among late-onset PJP patients, most cases (13/20, 65%) were observed during the 2nd year post-transplant. Age ≥65 years (OR: 2.4, P-value: 0.03) and CMV infection during the first 6 months post-SOT (OR: 2.5, P-value: 0.006) were significant PJP predictors, while Pneumocystis-prophylaxis was protective for PJP (OR: 0.3, P-value: 0.006) in the overall population. Most patients (35, 85.4%) were treated with trimethoprim-sulfamethoxazole for a mean 20.6 days. 1-year mortality was 14.6%.

CONCLUSIONS

In the Pneumocystis-prophylaxis-era, PJP remains a rare post-transplant complication. Most cases occurred post-PJP-prophylaxis-discontinuation, particularly during the second-year-post-transplant. Additional research may help identify indications for Pneumocystis-prophylaxis prolongation.