Impact of COVID-19 on liver transplant recipients during the first pandemic wave, in a tertiary hospital, in Northeastern Brazil

Worldwide, transplant programs have suffered a setback during the coronavirus disease 2019 (COVID-19) pandemic and most have temporarily suspended their transplant activities. . We identified 36 liver transplant patients who tested positive for COVID-19. The cases were confirmed by the nucleic acid test (RT-PCR). Epidemiological, demographic, clinical, laboratory, management and outcome data were obtained from the patients’ medical records. Fourteen patients (38.9%) required admission to the Intensive Care Unit and/or invasive ventilatory support (severe cases). The mean age of these severe cases was 63.8 years. Regarding the time since the transplant, 71.4% (10/14 patients) had undergone the procedure less than one year before. The immunosuppressive therapy was reduced in patients who required Intensive Care Unit. A total of 12 cases (12/14, 85.7%) required invasive ventilatory support. Eight cases (8/14, 57.1%) required renal replacement therapy. In this group of patients, nine died (64.3 %). In turn, 22 patients had mild to moderate symptoms of COVID-19, not requiring invasive ventilatory support or admission to the Intensive Care Unit. The mean age in these patients was 56.5 years and comorbidities were present in 15 (68.2%) of the cases. In this group, only five patients (5/22, 22.7%) required hospitalization due to complications and there were no deaths This report describes the results of COVID-19 infection in a very specific population, suggesting that liver transplant patients have a significant higher risk of progressing to severeCOVID-19 , with a mortality rate among critically-ill patients above that of the general population.

Development and validation of a simple web-based tool for early prediction of COVID-19-associated death in kidney transplant recipients

This analysis, using data from the Brazilian kidney transplant (KT) COVID-19 study, seeks to develop a prediction score to assist in COVID-19 risk stratification in KT recipients. In this study, 1379 patients (35 sites) were enrolled, and a machine learning approach was used to fit models in a derivation cohort. A reduced Elastic Net model was selected, and the accuracy to predict the 28-day fatality after the COVID-19 diagnosis, assessed by the area under the ROC curve (AUC-ROC), was confirmed in a validation cohort. The better calibration values were used to build the applicable ImAgeS score. The 28-day fatality rate was 17% (n = 235), which was associated with increasing age, hypertension and cardiovascular disease, higher body mass index, dyspnea, and use of mycophenolate acid or azathioprine. Higher kidney graft function, longer time of symptoms until COVID-19 diagnosis, presence of anosmia or coryza, and use of mTOR inhibitor were associated with reduced risk of death. The coefficients of the best model were used to build the predictive score, which achieved an AUC-ROC of 0.767 (95% CI 0.698-0.834) in the validation cohort. In conclusion, the easily applicable predictive model could assist health care practitioners in identifying non-hospitalized kidney transplant patients that may require more intensive monitoring. Trial registration: ClinicalTrials.gov NCT04494776.

Temporal Reduction in COVID-19-Associated Fatality Among Kidney Transplant Recipients: The Brazilian COVID-19 Registry Cohort Study

Data from the general population suggest that fatality rates declined during the course of the pandemic. This analysis, using data extracted from the Brazilian Kidney Transplant COVID-19 Registry, seeks to determine fatality rates over time since the index case on March 3rd, 2020. Data from hospitalized patients with RT-PCR positive SARS-CoV-2 infection from March to August 2020 (35 sites, 878 patients) were compared using trend tests according to quartiles (Q1: <72 days; Q2: 72–104 days; Q3: 105–140 days; Q4: >140 days after the index case). The 28-day fatality decreased from 29.5% (Q1) to 18.8% (Q4) (p_for-trend = 0.004). In multivariable analysis, patients diagnosed in Q4 showed a 35% reduced risk of death. The trend of reducing fatality was associated with a lower number of comorbidities (20.7–10.6%, p_for-trend = 0.002), younger age (55–53 years, p_for-trend = 0.062), and better baseline renal function (43.6–47.7 ml/min/1.73 m², p_for-trend = 0.060), and were confirmed by multivariable analysis. The proportion of patients presenting dyspnea (p_for-trend = 0.001) and hypoxemia (p_for-trend < 0.001) at diagnosis, and requiring intensive care was also found reduced (p_for-trend = 0.038). Despite possible confounding variables and time-dependent sampling differences, we conclude that COVID-19-associated fatality decreased over time. Differences in demographics, clinical presentation, and treatment options might be involved.

High mortality among kidney transplant recipients diagnosed with coronavirus disease 2019: Results from the Brazilian multicenter cohort study

BACKGROUND

Kidney transplant (KT) recipients are considered a high-risk group for unfavorable outcomes in the course of coronavirus disease 2019 (COVID-19).

AIM

To describe the clinical aspects and outcomes of COVID-19 among KT recipients.

METHODS

This multicenter cohort study enrolled 1,680 KT recipients diagnosed with COVID-19 between March and November 2020, from 35 Brazilian centers. The main outcome was the 90-day cumulative incidence of death, for the entire cohort and according to acute kidney injury (AKI) and renal replacement therapy (RRT) requirement. Fatality rates were analyzed according to hospitalization, intensive care unit (ICU) admission, and mechanical ventilation (MV) requirement. Multivariable analysis was performed by logistic regression for the probability of hospitalization and death.

RESULTS

The median age of the recipients was 51.3 years, 60.4% were men and 11.4% were Afro-Brazilian. Comorbidities were reported in 1,489 (88.6%), and the interval between transplantation and infection was 5.9 years. The most frequent symptoms were cough (54%), myalgia (40%), dyspnea (37%), and diarrhea (31%), whereas the clinical signs were fever (61%) and hypoxemia (13%). Hospitalization was required in 65.1%, and immunosuppressive drugs adjustments were made in 74.4% of in-hospital patients. ICU admission was required in 34.6% and MV in 24.9%. In the multivariable modeling, the variables related with the probability of hospitalization were age, hypertension, previous cardiovascular disease, recent use of high dose of steroid, and fever, dyspnea, diarrhea, and nausea or vomiting as COVID-19 symptoms. On the other hand, the variables that reduced the probability of hospitalization were time of COVID-19 symptoms, and nasal congestion, headache, arthralgia and anosmia as COVID-19 symptoms. The overall 90-day cumulative incidence of death was 21.0%. The fatality rates were 31.6%, 58.2%, and 75.5% in those who were hospitalized, admitted to the ICU, and required MV, respectively. At the time of infection, 23.2% had AKI and 23.4% required RRT in the follow-up. The cumulative incidence of death was significantly higher among recipients with AKI (36.0% vs. 19.1%, P < 0.0001) and in those who required RRT (70.8% vs. 10.1%, P < 0.0001). The variables related with the probability of death within 90 days after COVID-19 were age, time after transplantation, presence of hypertension, previous cardiovascular disease, use of tacrolimus and mycophenolate, recent use of high dose of steroids, and dyspnea as COVID-19 symptom. On the other hand, the variables that reduced the risk of death were time of symptoms, and headache and anosmia as COVID-19 symptoms.

CONCLUSION

The patients diagnosed with COVID-19 were long-term KT recipients and most of them had some comorbidities. One in every five patients died, and the rate of death was significantly higher in those with AKI, mainly when RRT was required.

Exploring the causes of the high incidence of delayed graft function after kidney transplantation in Brazil: a multicenter study

This retrospective multicenter (n = 18) cohort study evaluated the incidence, risk factors, and the impact of delayed graft function (DGF) on 1-year kidney transplant (KT) outcomes. Of 3992 deceased donor KT performed in 2014-2015, the incidence of DGF was 54%, ranging from 29.9% to 87.7% among centers. Risk factors (_{lower-bound-95%CI} OR _{upper-bound-95%CI} ) were male gender (_1.066 1.249_1.463 ), diabetic kidney disease (_1.053 1.296_1.595 ), time on dialysis (_1.005 1.007_1.009 ), retransplantation (_1.035 1.397_1.885 ), preformed anti-HLA antibodies (_1.011 1.383_1.892 ), HLA mismatches (_1.006 1.066_1.130 ), donor age (_1.011 1.017_1.023 ), donor final serum creatinine (sCr) (_1.239 1.317_1.399 ), cold ischemia time (CIT) (_1.031 1.043_1.056 ), machine perfusion (_0.401 0.542_0.733 ), and induction therapy with rabbit antithymocyte globulin (rATG) (_0.658 0.800_0.973 ). Duration of DGF > 4 days was associated with inferior renal function and DGF > 14 days with the higher incidences of acute rejection, graft loss, and death. In conclusion, the incidence and duration of DGF were high and associated with inferior graft outcomes. While late referral and poor donor maintenance account for the high overall incidence of DGF, variability in donor and recipient selection, organ preservation method, and type of induction agent may account for the wide variation observed among transplant centers.

The Impact of Hypothermic Pulsatile Machine Perfusion Versus Static Cold Storage: A Donor-Matched Paired Analysis in a Scenario of High Incidence of Delayed Kidney Graft Function

BACKGROUND The present study analyzed the impact of hypothermic pulsatile machine perfusion (MP) following a long period of static cold (SC) storage in the peculiar Brazilian scenario of high incidence of delayed graft function (DGF), despite good donor characteristics. MATERIAL AND METHODS A retrospective analysis, with a 1-year follow-up, of 206 recipients of donor-matched paired kidneys was performed. Of the 206 donor kidneys, 103 were maintained exclusively in static cold storage (SC group) and 103 were kept on machine perfusion after a period of SC preservation (MP group). All donors were brain dead. RESULTS Only 4.9% of the kidneys were from expanded-criteria donors. Static cold ischemia time (CIT) in the SC group was 20.8±4.1 hours vs. 15.8±6.2 hours in the MP group (P<0.001). Dynamic CIT in the MP group was 12.3±5.7 hours. MP significantly reduced DGF incidence (29.1% vs. 55.3%, P<0.001), and this effect was confirmed in multivariable analysis (OR, 1.115; 95% CI, 1.033-1.204, P=0.001). No differences were observed between the groups with regard to DGF duration, length of hospital stay, incidence of primary nonfunction and acute rejection, graft loss, death, or renal function. CONCLUSIONS In this Brazilian setting, MP following a long period of SC preservation was associated with reduced DGF incidence in comparison with SC storage without MP.

The immunohistochemical expression of von Willebrand factor, T-cadherin, and Caveolin-1 is increased in kidney allograft biopsies with antibody-mediated injury

BACKGROUND

There are only a few reports evaluating the applicability of endothelial-damage markers analysis by immunohistochemistry (IHC) in kidney allograft samples. This study analyzed the expression of Caveolin-1 (Cav), von Willebrand factor (Vwf), and T-cadherin (Cad) in kidney biopsies and their association with antibody-mediated injury.

METHODS

In this retrospective study, 114 cases with antibody-mediated changes (Banff, 2020) and 72 with interstitial fibrosis/tubular atrophy were selected. IHC for Cav, Vwf and Cad was performed and evaluated according to their qualitative expression in peritubular capillaries. The cases were grouped according to the presence of microvascular inflammation (MVI), donor-specific antibodies (DSA), C4d positivity and antibody-mediated rejection (AMR). A level of significance < 0.05 was adopted.

RESULTS

Vwf expression was associated with MVI (p < 0.001), DSA (p = 0.016), C4d (p < 0.001) and AMR (p < 0.001), and was higher in DSA+/C4d+ cases despite MVI (p < 0.001). The expression of Cad correlated with MVI (p = 0.015), C4d (p = 0.005) and AMR (p = < 0.001). Cad was more expressed in chronic AMR compared with acute/active cases (p = 0.001). Cav expression was associated with MVI (p = 0.029) and AMR (p = 0.016) and was also higher in chronic AMR (p = 0.049). A combined score of Vwf and Cad was higher in AMR when compared with C4d without rejection and IF/TA cases (p < 0.001).

CONCLUSION

Vwf, Cad and Cav expression shows association with antibody-mediated injury and may be helpful to support AMR diagnosis.

Procurement Biopsies Can Predict Unfavorable Outcomes in Kidneys With Low MAPI Score Values

BACKGROUND

There are few reports about the usefulness of Maryland Aggregate Pathology Index (MAPI) score in procurement biopsies. This study aimed to evaluate the association between histopathological analysis according to MAPI and unfavorable outcomes in the first year after kidney transplantation (KT).

METHODS

This retrospective study included deceased-donor KT patients whose grafts were biopsied before transplantation and had low MAPI scores (<8) in frozen sections (FSs). Paraffin sections (PSs) were analyzed after KT. MAPI parameters were global glomerulosclerosis in more than 15% (2 patients), periglomerular fibrosis (4 patients), wall-lumen ratio of arteries >0.5 (2 patients), arteriolar hyalinosis (4 patients), and interstitial scar (3 patients). Multivariable models were used to analyze risk factors for delayed graft function (DGF), prolonged DGF, inferior renal function, and graft loss (P < .05).

RESULTS

One hundred fifty-nine KTs were included. Donors (n = 120) were predominantly men (70%) and young adults (37.68 ± 12.50 years old) who suffered a traumatic death (55.8%). Recipients were predominantly men (62.26%) and adults (45.70 ± 15.80 years old) with kidney disease of unknown etiology (39.6%). Low rates of agreement between FS and PS were observed for all MAPI criteria, with kappa values ranging from 0.28 to 0.51. Using FS, no histologic parameter was independently associated with outcomes. After adjustment, glomerulosclerosis was an independent risk factor for prolonged DGF (odds ratio = 6.18: 95% confidence interval, 1.27-30.18) and wall-lumen ratio >0.5 for inferior renal function at 1 year (odds ratio = 4.08; 95% confidence interval, 1.21-13.76).

CONCLUSION

Procurement biopsies can be useful to predict inferior outcomes even in kidneys with low MAPI scores.

Lessons from SARS-CoV-2 screening in a Brazilian organ transplant unit

Protecting immunosuppressed patients during infectious disease outbreaks is crucial. During this novel coronavirus disease 2019 pandemic, preserving “clean areas” in hospitals assisting organ transplant recipients is key to protect them and to preserve transplantation activity. Evidence suggests that asymptomatic carriers might transmit the SARS‐CoV‐2, challenging the implementation of transmission preventive strategies. We report a single‐center experience using universal SARS‐CoV‐2 screening for all inpatients and newly admitted patients to an Organ Transplant Unit located in a region with significantly high community‐based transmission.

The impact of deceased donor maintenance on delayed kidney allograft function: A machine learning analysis

Background

This study evaluated the risk factors for delayed graft function (DGF) in a country where its incidence is high, detailing donor maintenance-related (DMR) variables and using machine learning (ML) methods beyond the traditional regression-based models.

Methods

A total of 443 brain dead deceased donor kidney transplants (KT) from two Brazilian centers were retrospectively analyzed and the following DMR were evaluated using predictive modeling: arterial blood gas pH, serum sodium, blood glucose, urine output, mean arterial pressure, vasopressors use, and reversed cardiac arrest.

Results

Most patients (95.7%) received kidneys from standard criteria donors. The incidence of DGF was 53%. In multivariable logistic regression analysis, DMR variables did not impact on DGF occurrence. In post-hoc analysis including only KT with cold ischemia time<21h (n = 220), urine output in 24h prior to recovery surgery (OR = 0.639, 95%CI 0.444–0.919) and serum sodium (OR = 1.030, 95%CI 1.052–1.379) were risk factors for DGF. Using elastic net regularized regression model and ML analysis (decision tree, neural network and support vector machine), urine output and other DMR variables emerged as DGF predictors: mean arterial pressure, ≥ 1 or high dose vasopressors and blood glucose.

Conclusions

Some DMR variables were associated with DGF, suggesting a potential impact of variables reflecting poor clinical and hemodynamic status on the incidence of DGF.

Collaborative Brazilian pediatric renal transplant registry (CoBrazPed-RTx): A report from 2004 to 2018

The Brazilian collaborative registry for pediatric renal transplantation began in 2004 as a multicenter initiative aimed at analyzing, reporting, and disseminating the results of pediatric renal transplantation in Brazil. Data from all pediatric renal transplants performed from January 2004 to May 2018 at the 13 participating centers were analyzed. A total of 2744 pediatric renal transplants were performed in the thirteen participating centers. The median age at transplantation was 12.2 years, with the majority being male recipients (56%). The main underlying diseases were CAKUT (40.5%) and glomerulopathy (28%). 1981 (72%) of the grafts were from deceased donors (DD). Graft survival at one year (censored by death) was 94% in the live donor group (LD) and 91% in the DD group (log-rank test P < 0.01). The patient's survival at one and 5 years was 97% and 95% for the LD group and 96% and 93% for the DD group (log-rank test P = 0.02). The graft loss rate was 19% (n = 517), more frequently caused by vascular thrombosis (n = 102) and chronic graft nephropathy (n = 90). DD recipients had 1.6 (1.0-2.2) times greater chance of death and 1.5 (1.2-1.8) times greater chance of graft loss compared to LD recipients. The mortality rate was 5.4% (n = 148), mainly due to infection (n = 69) and cardiovascular disease (n = 28). The results of this collaborative pediatric renal transplant record are comparable to other international registries, although we still have a high infection rate as a cause of death.

Secondary hemophagocytic syndrome after renal transplantation: two case-reports

Hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH) is an infrequent and underdiagnosed condition caused by an overactive immune response, resulting in blood cells phagocytosis. After kidney transplantation (KTx), HLH is usually secondary (or reactive) to infectious and neoplastic processes and has a high mortality rate. No effective treatment is available for this condition. Usual procedures include detecting and treating the pathology triggering the immune system dysregulation, other than administration of intravenous human immunoglobulin (IVIG) and high doses of steroids, and plasmapheresis. The best protocol for maintenance immunosuppressive therapy is also unknown. This article presents two cases of post-KTx reactive HLH that underwent adjuvant IVIG treatment and obtained good clinical results. Despite the high morbidity and mortality associated with reactive HLH after KTx, the early and precise diagnosis and the administration of IVIG therapy along with the treatment of the triggering disease, was an effective strategy to control HLH.

The impact of everolimus in reducing cytomegalovirus events in kidney transplant recipients on steroid-avoidance strategy: 3-year follow-up of a randomized clinical trial

There is no evidence of whether everolimus (EVR) reduces cytomegalovirus (CMV) events in patients receiving steroid-free regimens. Besides, studies evaluating a tacrolimus (TAC) and EVR regimen are limited to 1-year follow-up. In this single-center prospective randomized trial, the incidence of CMV and 3-year efficacy and safety outcomes of EVR were compared to those of mycophenolate sodium (MPS) in a steroid-free regimen based on low-exposure TAC. Both groups received rabbit anti-thymocyte globulin (r-ATG) induction (6 mg/kg) and the steroids were withdrawn at day 7. Maintenance immunosuppression consisted of TAC (4-7 ng/ml until month 3 and 2-4 ng/ml thereafter) plus EVR (3-8 ng/ml) in the EVR group (n = 59); and TAC (4-7 ng/ml during all follow-up) plus MPS (1440 mg) in the MPS group (n = 56). The EVR group presented with a lower incidence of CMV events (18.6% vs. 50%, P = 0.001). No differences were observed in biopsy-proven acute rejection (6.8% vs. 3.6%, P = 0.680),graft loss (0.0% vs. 1.8%, P = 0.487),death (6.8% vs. 1.8%, P = 0.365), or estimated glomerular filtration rate at 36 months (61.1 ± 25.4 vs. 66.3 ± 24 ml/min/1.73 m² , P = 0.369). A higher proportion of patients discontinued MPS treatment (8.5% vs. 26.8%, P = 0.013) for safety issues. In conclusion, EVR was associated with lower rates of CMV events in patients induced with standard dose r-ATG and a maintenance steroid-free regimen based on TAC. This regimen effectively prevented acute rejection and demonstrated a more favorable safety profile. (ClinicalTrials.gov:NCT02084446).

Computed tomography angiography study of variations of the celiac trunk and hepatic artery in 100 patients

Objective

To describe the main anatomical variations of the celiac trunk and the hepatic artery at their origins.

Materials and Methods

This was a prospective analysis of 100 consecutive computed tomography angiography studies of the abdomen performed during a one-year period. The findings were stratified according to classification systems devised by Sureka et al. and Michels.

Results

The celiac trunk was "normal" (i.e., the hepatogastrosplenic trunk and superior mesenteric artery originating separately from the abdominal aorta) in 43 patients. In our sample, we identified four types of variations of the celiac trunk. Regarding the hepatic artery, a normal anatomical pattern (i.e., the proper hepatic artery being a continuation of the common hepatic artery and bifurcating into the right and left hepatic arteries) was seen in 82 patients. We observed six types of variations of the hepatic artery.

Conclusion

We found rates of variations of the hepatic artery that are different from those reported in the literature. Our findings underscore the need for proper knowledge and awareness of these anatomical variations, which can facilitate their recognition and inform decisions regarding the planning of surgical procedures, in order to avoid iatrogenic intraoperative injuries, which could lead to complications.

Use of Thymoglobulin® (antithymocyte immunoglobulin) in renal transplantation: practical guide

The combination of immunosuppressive drugs is part of the treatment regimen of patients undergoing kidney transplantation (RT). Thymoglobulin®, a rabbit immunoglobulin directed against human thymocytes, is the most commonly agent used for induction therapy in RT in the US. In Brazil, Thymoglobulin® is approved by ANVISA for the use in patients who underwent kidney transplantation and despite being widely used, there are controversies regarding the drug administration. We prepared a systematic review of the literature, evaluating studies that used Thymoglobulin® for induction and for acute rejection treatment in patients undergoing RT. The review used the computadorized databases of EMBASE, LILACS and MedLine. Data were extracted from the studies concerning general features, methodological characteristics and variables analyzed in each study. From the results, a practical guide was prepared analyzing various aspects on the use of Thymoglobulin® in patients submitted to RT.

Dengue Fever Among Renal Transplant Recipients: A Series of 10 Cases in a Tropical Country

This is a case series of 10 consecutive renal allograft recipients, followed at a tertiary hospital in northeast Brazil, with a confirmed diagnosis of dengue. Five of the patients needed hospitalization. Half of them were males and age ranged from 19 to 60 years with a median of 38.2 years. They had been transplanted for a mean of 5 days to 166 months. Four patients developed dengue hemorrhagic fever (DHF). All patients had myalgia and headache. All of them, except one, had fever. Positive dengue serology (IgM) was found in all patients. No patient died. Dengue is an important infectious disease that can affect renal transplant recipients, mainly in endemic areas. Its presentation seems to be similar to that seen in immunocompetent patients.

Epidemiologic, clinical, diagnostic and therapeutic aspects of visceral leishmaniasis in renal transplant recipients: experience from thirty cases

BACKGROUND

Visceral leishmaniasis is a disease caused by the protozoan Leishmania sp. and is transmitted by Lutzomyia longipalpis (sand fly). In renal transplant recipients, visceral leishmaniasis causes severe damage to the liver, spleen, and hematopoietic system, as well as poor outcomes for patients with transplanted kidneys. This study describes the largest series of cases of visceral leishmaniasis in renal transplant recipients, providing important information about the diagnostic routines and therapeutic strategies in this patient population.

METHODS

A retrospective, descriptive study was performed to analyze the distribution and evaluate the extent of the epidemiologic, clinical, diagnostic and therapeutic aspects of 30 renal transplant recipients from endemic regions who presented with visceral leishmaniasis in the post-transplantation period.

RESULTS

In this study, visceral leishmaniasis was more frequent in men (80%). The mean age of presentation was 40 ± 10.5 years. The majority of patients worked in urban areas (66.7%), cohabitated with domestic animals (90%), and were from low-income households. In 73.3% of cases, diagnosis was made by direct isolation of Leishmania forms. Patients were treated with liposomal amphotericin, resulting in a high degree of disease remission (80%).

CONCLUSIONS

This study describes the largest series of visceral leishmaniasis in renal transplant recipients and expands clinical-epidemiological knowledge for transplantation teams to perform adequate disease management for this specific patient population.