Dengue virus infection among renal transplant recipients in Singapore: a 15-year, single-centre retrospective review

INTRODUCTION

Dengue is a mosquito-borne viral infection endemic in Singapore. Its impact on renal transplantation is limited to small case series. We aimed to characterise the clinical presentation and outcomes of dengue infection among renal transplant recipients in Singapore.

METHODS

We conducted a 15-year retrospective review of dengue in renal transplant patients treated at Singapore General Hospital between January 2005 and October 2019. The diagnosis of dengue was made if there were a compatible clinical syndrome and a positive dengue diagnostic assay (dengue non-structural 1 antigen, immunoglobulin M or reverse transcriptase-polymerase chain reaction).

RESULTS

Of the 31 patients diagnosed with dengue, 18 (58.1%) were deceased donor recipients. The median age was 52 (interquartile range [IQR] 40-61) years; 16 (51.6%) were females. The median time to diagnosis was 99 (IQR 18-169) months from transplant. The most common clinical symptoms were fever (87.1%), myalgia (41.9%), gastrointestinal symptoms (38.7%) and headache (25.8%). Nineteen (61.3%) patients had dengue without warning signs, nine (29.0%) had dengue with warning signs, three (9.7%) had severe dengue and 30 (96.8%) were hospitalised. Seventeen (54.8%) patients had graft dysfunction, 16 (94.1%) of whom had recovery of graft function. One (3.2%) patient required dialysis and subsequently died. There were two cases of donor-derived infections (DDIs) with favourable outcomes.

CONCLUSION

Our experience with dengue in renal transplant recipients is concordant with published data. Although graft dysfunction is common, it is often transient with favourable outcomes. Outpatient management may be considered for mild infections. Although dengue DDIs are uncommon, more stringent donor screening may be considered in endemic regions.

Unrepresented human leucocyte antigen alleles in single-antigen bead assays: A single-centre cohort study

Human leucocyte antigen (HLA) alleles may generate antibodies that are undetectable by routine single-antigen beads (SABs) assays if their unique epitopes are unrepresented. We aimed to describe the prevalence and explore the potential impact of unrepresented HLA alleles in standard SAB kits in our cohort. All individuals who had undergone two-field HLA typing (HLA-A/B/C/DRB1/DQA1/-DQB1/-DPA1/-DPB1) from February 2021 to July 2023 were included. Two-field HLA-DRB3/4/5 typing was imputed. Each unrepresented allele was compared with the most similar represented allele in the standard LABScreen, LABScreen ExPlex (One Lambda) and the LIFECODES (Immucor) SAB kits. Differences in eplet expression (HLA Eplet Registry) were identified. Differences in three-dimensional molecular structures were visualized using generated models (SWISS-MODEL). Two-field HLA typing was performed for 116 individuals. Overall, 16.7% of all HLA alleles, found in 36.2% of individuals, were unrepresented by all SAB test kits. Four eplets, found in 12.9% of individuals, were unrepresented in at least 1 SAB kit. Non-Chinese individuals were more likely to have unrepresented HLA alleles and eplets than Chinese individuals. There were differences in HLA allele and eplet representation amongst the different SAB test kits. Use of supplementary SAB test kits may improve HLA allele and eplet representation. Although some HLA alleles were unrepresented, most epitopes were represented in current SAB kits. However, some unrepresented alleles may contain epitopes which may generate undetectable antibodies. Further studies may be needed to investigate the potential clinical impact of these unrepresented alleles and eplets, especially in certain ethnic populations or at-risk individuals.

Bat coronavirus was detected positive from insectivorous bats in Krau Wildlife Reserve Forest

Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.

Coronavirus disease 2019 in kidney transplant recipients: a systematic review and meta-analysis

Introduction

The clinical presentation and outcomes of coronavirus disease 2019 (COVID-19) in kidney transplant recipients (KTRs) have not been well studied.

Methods

We performed a meta-analysis to examine the presenting features, outcomes and the effect of treatment on outcomes of KTRs with COVID-19. Database search was performed up to 5 September 2020 through PubMed, Embase, Web of Science, Scopus and CENTRAL.

Results

Overall, 23 studies (1,373 patients) were included in the review and meta-analysis. The most common presenting symptoms included fever (74.0%, 95% confidence interval [CI] 65.3-81.1), cough (63.3%, 95% CI 56.5-69.6) and dyspnoea (47.5%, 95% CI 39.6-55.6). Pooled rates of mortality and critical illness were 21.1% (95% CI 15.3-28.4) and 27.7% (95% CI 21.5-34.8), respectively. Acute kidney injury occurred in 38.9% (95% CI 30.6-48.1) and dialysis was required in 12.4% (95% CI 8.3-18.0) of the cases.

Conclusion

Kidney transplant recipients with COVID-19 have a similar clinical presentation as the general population, but they have higher morbidity and mortality. It is uncertain whether high-dose corticosteroid or hydroxychloroquine reduces the risks of mortality in KTRs with COVID-19.

Immune monitoring of prevalent kidney transplant recipients using Torque Teno Virus: Protocol for a single-centre prospective cohort study

INTRODUCTION

Kidney transplant recipients (KTRs) suffer from immunosuppression-related adverse events (iRAEs), such as infections and malignancy from chronic immunosuppression, but are also at risk of graft loss from rejection with underimmunosuppression. Biomarkers that predict both iRAEs and rejection while allowing individualisation of immunosuppression exposure are lacking. Although plasma viral DNA levels of torque teno virus (TTV), a widely prevalent, non-pathogenic virus, have been shown to predict both iRAE and rejection in newly transplanted KTRs within the first year after transplant, its role for prevalent KTRs on stable immunosuppression is less clear.This study aims to determine the prognostic value of TTV levels for severe infections (defined as infections requiring hospitalisation) in prevalent KTRs on stable immunosuppression for at least 3 months and compare it against that of other commonly available biomarkers. The study also aims to explore the relationship between TTV levels and factors affecting the 'net state of immunosuppression' as well as other clinical outcomes.

METHODS AND ANALYSIS

This is a single-centre, prospective, observational cohort study of 172 KTRs on stable immunosuppression for more than 3 months. TTV levels will be measured using the TTV R-GENE kit upon recruitment when study subjects are admitted and when kidney allograft biopsies are performed. Subjects will be monitored for iRAEs and rejection for at least 12 months. The relationship between TTV load and clinical outcomes such as severe infections will be analysed and compared against that from other common biomarkers and previously published predictive scores.

ETHICS AND DISSEMINATION

The study was approved by the SingHealth Centralised Institutional Review Board (2023/2170). The results will be presented at conferences and submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05836636.

Safely navigating kidney transplantation during the COVID-19 pandemic: the Singapore General Hospital's experience

Background

The coronavirus disease 2019 (COVID-19) pandemic curtailed transplant activities worldwide, driven by concerns about increased COVID-19-related mortality among kidney transplant recipients (KTRs), infections originating from donors, and decreased availability of surgical and intensive care resources as healthcare resources are reallocated for pandemic response. We examined the outcomes of KTRs at our center before and during the COVID-19 pandemic.

Methods

We conducted a retrospective single-center cohort study examining the characteristics and outcomes of patients undergoing kidney transplantation during two periods January 1, 2017 to December 31, 2019 (pre-COVID-19 era) and January 1, 2020 to June 30, 2022 (COVID-19 era). We reviewed perioperative and COVID-19 infection-related outcomes in both groups.

Results

A total of 114 transplants were performed during the pre-COVID-19 era, while 74 transplants were conducted during the COVID-19 era. No differences in baseline demographics were observed. Additionally, there were no significant differences in perioperative outcomes, except for a longer cold ischemia time during the COVID-19 era. However, this did not result in an increased incidence of delayed graft function. Among the KTRs infected with COVID-19 during the pandemic era, no severe complications such as pneumonia, acute kidney injury, or death were reported.

Conclusions

With the global transition to an endemic phase of COVID-19, it is imperative to revitalize organ transplant activities. Effective containment workflow, good vaccination uptake, and prompt COVID-19 treatment are essential to ensure that transplants can proceed safely.

Knowledge of COVID-19 and associated factors among kidney transplant recipients and donors in Singapore

Background

Effective interventions during the coronavirus disease 2019 (COVID-19) pandemic require an understanding of patients' knowledge and perceptions that influence their behaviour. Our study assessed knowledge of COVID-19 among kidney transplant recipients and donors, hitherto unevaluated.

Methods

We conducted a cross-sectional survey among 325 kidney transplant recipients and 172 donors between 1 May 2020 and 30 June 2020. The survey questionnaire assessed knowledge levels of COVID-19, sociodemographic data, health status, psychosocial impact of COVID-19 and precautionary behaviours during the pandemic.

Results

The mean COVID-19 knowledge score of the study population was 7.5 (standard deviation: 2.2) out of 10. The mean score was significantly higher among kidney recipients compared to kidney donors (7.9 [1.9] vs. 6.7 [2.6]; P <0.001). Younger age (21-49 vs. ≥50 years) and higher education (diploma and higher vs. secondary and lower) were associated with significantly higher knowledge scores in donors, but not among recipients (P-interactions ≤0.01). In both kidney recipients and donors, financial concerns and/or social isolation were associated with lower knowledge levels.

Conclusions

Concerted efforts are needed to improve COVID-19 knowledge in kidney transplant recipients and donors, particularly older donors, donors with lower education and patients with financial concerns or feelings of social isolation. Intensive patient education may mitigate the impact of education levels on COVID-19 knowledge levels.

COVID-19 vaccine acceptance among kidney transplant recipients in Singapore

Introduction

A successful vaccination programme forms the cornerstone of controlling coronavirus disease 2019 (COVID-19). The unprecedented speed of COVID-19 vaccine development and lack of long-term data have raised fears regarding its safety and efficacy. Vaccine hesitancy can undermine the uptake, and hence success of the vaccination programme. Given the high complication rates of COVID-19 infections in kidney transplant recipients, it is particularly important to identify and address vaccine hesitancy in this population.

Methods

We conducted a cross-sectional survey among kidney transplant recipients attending transplant clinic between 5 April and 5 May 2021. The survey assessed attitudes towards COVID-19, willingness/hesitancy towards COVID-19 vaccination, vaccination concerns and prompts to vaccination. This was scored on a Likert scale with scores ranging from 'strongly disagree' - 1 point to 'strongly agree' - 5 points.

Results

One hundred and one completed responses were captured. Of these, 86% respondents reported to agree or strongly agree to vaccination. This was despite significant concerns of allograft rejection (mean score 4.12, standard deviation [SD] 0.97) and decreased immunosuppressant efficacy (mean score 4.14, SD 0.96) with vaccination. Multivariable model showed a positive association with transplant vintage of ≥ 5 years (median 2.41), lower educational levels of secondary school or less (median 5.82) and healthcare provider advocacy (median 1.88) in predicting vaccine acceptance.

Conclusions

Vaccine acceptance rate was high among kidney transplant recipients. Vaccine hesitancy remains a concern in those with a transplant vintage of less than 5 years and those with tertiary educational level. Healthcare provider advocacy is important in improving vaccine acceptance rates.

An outpatient model of care for COVID-19 infected kidney transplant patients - The hospital-at-home

BACKGROUND

The COVID-19 pandemic is protracted and episodic surges from viral variants continue to place significant strain on healthcare systems. COVID-19 vaccines, antiviral therapy and monoclonal antibodies have significantly reduced COVID-19 associated morbidity and mortality. Concurrently, telemedicine has gained acceptance as a model of care and a tool for remote monitoring. These advances allow us to safely transit our inpatient-based care for COVID-19 infected kidney transplant recipients (KTRs) to a hospital-at-home (HaH) model of care.

METHODS

KTRs with PCR-proven COVID-19 infection were triaged by teleconsult and laboratory tests. Suitable patients were enrolled into the HaH. Remote monitoring via teleconsults were conducted daily until patients were de-isolated based on a time-based criterion. Monoclonal antibodies were administered in a dedicated clinic where indicated.

RESULTS

Eighty-one KTRs with COVID-19 were enrolled into the HaH between February and June 2022, 70 (86.4%) completed HaH recovery without complications. Eleven (13.6%) patients required inpatient hospitalization for medical issues (n = 8) and weekend monoclonal antibody infusion (n = 3). Patients requiring inpatient hospitalization had longer transplant vintage (15 years vs. 10 years, p = .03), anaemia (haemoglobin 11.6 g/dL vs. 13.1 g/dL, p = .01), lower eGFR (39.8 vs. 62.9 mL/min/1.73 m² , p < .05) and lower RBD levels (<50 AU/mL vs. 1435 AU/mL, p = .02). HaH saved 753 inpatient patient-days with no deaths observed. Hospital admission rates from the HaH programme was 13.6%. Patients who required inpatient care had direct access admission without utilization of emergency department resources.

CONCLUSION

Selected KTRs with COVID-19 infection can be safely managed in a HaH programme; alleviating strain on inpatient and emergency healthcare resources.

Regional citrate anticoagulation vs systemic heparin anticoagulation for double-filtration plasmapheresis

INTRODUCTION

Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients.

METHODS

A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center.

RESULTS

A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P = .10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P = .04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P = .03).

CONCLUSION

Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.

Bariatric Surgery in Kidney Transplant Candidates and Recipients: Experience at an Asian Center

Background

Kidney transplant (KT) candidates and recipients with obesity experience more frequent complications such as infection, poorer allograft outcomes, diabetes, and mortality, limiting their eligibility for transplantation. Bariatric surgery (BS) is not commonly performed among KT patients given concerns about immunosuppression absorption, wound healing, infections, and graft outcomes. Its role has not been described before in an Asian KT patient setting.

Methods

A retrospective review of patients who underwent BS at the largest KT center in Singapore from 2008 to 2020 was conducted. Metabolic outcomes, immunosuppression doses, graft outcomes, and mortality were studied.

Results

Seven patients underwent BS and KT (4 underwent BS before KT, 3 underwent BS after KT; 4 underwent sleeve gastrectomy, 3 underwent gastric bypass). Mean total weight losses of 23.8% at 1 year and 18.6% at 5 years post-BS were achieved. Among the five patients with diabetes, glycemic control improved after BS. There were no deaths in the first 90 days or graft loss in the first year after KT and BS. Patients who underwent BS after KT had no significant changes in immunosuppression dose.

Conclusion

BS can be safely performed in KT recipients and candidates and results in sustainable weight losses and improvements in metabolic comorbidities. Although no major complications were observed in our study, close monitoring of this complex group of patients is imperative.

Cardiac evaluation for end-stage kidney disease patients on the transplant waitlist: a single-center cohort study

Background

Cardiac evaluation before deceased donor kidney transplant (DDKT) remains a matter of debate. Data on Asian countries and countries with prolonged waiting times are lacking. This study aimed to assess the outcomes of patients referred for DDKT after a cardiac evaluation at an Asian tertiary transplant center.

Methods

This single-center retrospective review analyzed patients who were referred for waitlist placement and underwent cardiac stress testing between January 2009 and December 2015. Patients with cardiac symptoms were excluded. The primary outcome was three-point major adverse cardiovascular events (MACE), a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death.

Results

Of 468 patients referred for DDKT, 198 who underwent cardiac stress testing (myocardial perfusion studies in 159 patients and stress echocardiography in 39 patients) were analyzed. MACE occurred in 20.7% of the patients over a median follow-up of 4.6 years. Cardiac stress tests were positive for ischemia in 19.7% of the patients. Coronary angiography was performed in 63 patients, including 29 patients with diabetic kidney disease and negative cardiac stress tests. Significant coronary artery disease (CAD) was detected in 27 patients (42.8%), of whom 18 underwent revascularization. MACE was associated with significant CAD on coronary angiography in the multivariable analysis. Cardiac stress test results were not associated with MACE. Amongst diabetic patients who had negative cardiac stress tests, 37.9% had significant CAD on coronary angiography.

Conclusions

The cardiovascular disease burden is significant amongst DDKT waitlist candidates. Pretransplant cardiac screening may identify patients with significant CAD at higher risk of MACE.

Complications of Percutaneous Kidney Allograft Biopsy: Systematic Review and Meta-analysis

BACKGROUND

Kidney biopsy is important to guide the management of allograft dysfunction but has a risk of complications. This review aimed to determine the incidence and risk factors of complications after kidney allograft biopsy.

METHODS

This is a systematic review and meta-analysis of randomized controlled trials, cohort studies, or case-control studies indexed on PubMed, Embase, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry, and ClinicalTrials.gov, limited to the English language, from January 2000 to December 2020, including adult and pediatric kidney allograft biopsies. Primary outcomes were gross hematuria, bleeding requiring transfusion, and major complications (requiring interventions such as blood transfusion or surgical or radiological interventions).

RESULTS

The review included 72 studies (40 082 biopsies). The quality of included studies was suboptimal. Pooled rates of gross hematuria, bleeding requiring transfusion, and major complications were 3.18% [95% confidence interval (95% CI), 2.31-4.19], 0.31% (95% CI, 0.15-0.52) and 0.89% (95% CI, 0.61-1.22), respectively. Gross hematuria rates were lower in high-income compared with middle-income countries (2.59% versus 6.44%, P < 0.01) and biopsies performed by radiology as compared with nephrology departments (1.25% versus 3.71%, P < 0.01). Blood transfusion rates were lower in pediatrics than adults (0.0% versus 0.65%, P < 0.01). Major complications were lower in biopsies performed by specialists as compared with trainees (0.02% versus 3.64%, P < 0.01). Graft loss and mortality were extremely rare. Limitations included missing data, few randomized controlled trials, and possible publication bias.

CONCLUSIONS

The risk of complications after kidney allograft biopsy was low. Given the low quality of included studies, risk factors for complications should be further examined in future studies.

Psychological distress and associated factors among kidney transplant recipients and living kidney donors during COVID-19

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused significant psychological distress globally. Our study assessed the prevalence of psychological distress and associated factors during COVID-19 pandemic among kidney transplant recipients and kidney donors.

Methods

A cross-sectional survey of 497 participants (325 recipients and 172 donors) was conducted from 1st May to 30th June 2020 in Singapore. The survey questionnaire assessed knowledge levels of COVID-19, socio-demographic data, health status, psychosocial impact of COVID-19, and precautionary behaviors during the pandemic. Psychological distress was defined as having anxiety, depression, or stress measured by the validated Depression, Anxiety and Stress Scale-21. Linear regression analyses were used to assess factors associated with higher psychological distress.

Results

The prevalence of psychological distress was 14.3% (95% confidence interval: 11.5–17.6%) in the overall population; it was 12.8% (9.79–16.6%) in recipients and 13.4% (9.08–19.6%) in donors with no significant difference (P = 0.67). Younger age (21–49 vs. ≥50 years), unmarried status, non-Singapore citizen, worse health conditions, and worrying about physical and mental health were associated with higher psychological distress. Malays (versus Chinese), taking precautionary measures (hand sanitization), and receiving enough information about COVID-19 were associated with lower psychological distress. No interactions were observed between recipients and donors.

Conclusions

At least one in ten recipients and donors suffer from psychological distress during COVID-19 pandemic. Focused health education to younger adults, unmarried individuals, non-Singapore citizens, and those with poor health status could potentially prevent psychological distress in recipients and donors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02698-7.

Cytomegalovirus-associated pseudomembranous colitis in a kidney transplant recipient

Pseudomembranous colitis (PMC) is classically associated with Clostridium difficile infection. We report a rare case of cytomegalovirus (CMV)-associated PMC in a 52-year-old female patient who had undergone kidney transplantation more than 20 years ago and was on low dose prednisolone and ciclosporin. She presented with an acute history of fever, lethargy, vomiting and diarrhoea on admission. Computed tomography of the abdomen showed extensive colitis, and colonoscopy revealed extensive pseudomembrane formation. Multiple tests for Clostridium difficile and other common microbiological causes of colitis were negative. CMV DNAemia and colonic biopsies confirmed the diagnosis of CMV colitis. The patient responded to prompt CMV treatment, as demonstrated by clinical, endoscopic, and histological response. While CMV is a common pathogen in the solid organ transplant population that is familiar to most transplant physicians, it may present atypically as PMC. Here, we review the literature on CMV-associated PMC and its relevance to solid organ transplant recipients. To our knowledge, this is the first reported case of CMV-associated PMC in a kidney transplant recipient.

Regional Citrate Anticoagulation during Double-Filtration Plasmapheresis in Kidney Transplant Recipients: A Single-Center Retrospective Cohort Study

INTRODUCTION

Double-filtration plasmapheresis (DFPP) may be used for immunomodulation in kidney transplant (KTx). While DFPP reduces plasma product exposure, risk of circuit clotting merits adequate anticoagulation. Regional citrate anticoagulation (RCA) avoids the risks of systemic anticoagulation, but a protocol for RCA-DFPP is not previously widely described.

METHODS

We conducted a single-center retrospective cohort study involving adult (≥21 years old) KTx recipients who underwent RCA-DFPP from 2018 to 2020 to investigate efficacy and safety for an RCA protocol during DFPP in KTx recipients.

RESULTS

Fifty-one (85%) of 60 RCA-DFPP sessions in 17 patients completed without circuit clotting. Circuit clotting was associated with high post-filter ionized calcium (28 vs. 3.7%, odds ratio 10.1, 95% CI 1.1-89.4, p = 0.037). Hypo- and hypercalcemia developed in 5 (8.3%) and 8 (13.3%) sessions, respectively, but no adverse effects were noted despite severe hypocalcemia in one. There was no significant change in pre- and post-RCA-DFPP sodium, bicarbonate, albumin, and platelet levels. With regards DFPP procedure, prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) was observed following 38 (64.4%) and 12 (20.3%) sessions, respectively. Severely prolonged (>1.5 × upper limit normal) PT and aPTT were recorded in 2 sessions each. Expectedly, hypofibrinogenemia developed after 31 (51.7%) sessions: including 4 (6.7%) severe hypofibrinogenemia (<0.5 g/L). Two patients developed bleeding requiring blood product transfusion. The median total volume of fluids administered per session was 1.495 (1.373-1.612) L; post-RCA-DFPP significant weight gain of 0.5 (0-1.25) kg was noted. Diuretic was commenced or dose increased following 20 (33.3%) sessions for fluid balance management.

DISCUSSION/CONCLUSION

Protocol-based RCA for DFPP is feasible and safe in KTx recipients. However, DFPP-related coagulopathy can develop consequent to treatment; caution should be exercised for patients with bleeding risk. Close monitoring and management of the patients' electrolytes, especially hypocalcemia and hypomagnesemia, and fluid status is recommended.

A single-centre observational study comparing the impact of different cytomegalovirus prophylaxis strategies on cytomegalovirus infections in kidney transplant recipients

Background/objective:

Prevention of cytomegalovirus (CMV) infection is an important component of post kidney transplant care. We aimed to evaluate the impact of two different CMV prophylaxis protocols on the epidemiology and outcomes of CMV infections at our centre.

Methods:

This is a single-centre retrospective before/after observational study. Kidney transplant recipients who received Protocol 1, a valacyclovir- or valganciclovir-based regimen prescribed for one to three months based on the CMV risk status between 2004 and 2008, were compared to those who received Protocol 2, a valganciclovir-based regimen prescribed for three months and six months for those at moderate and high risk, respectively, between 2010 and 2014. The impact of different prophylaxis regimens on the incidence of CMV infections, disease, recurrent infections and onset of CMV infection at 24 months were reviewed.

Results:

There were 192 patients included; 106 patients received Protocol 1, 86 received Protocol 2. At 24 months, the incidence of CMV infection was 53.8% and 55.8% in Protocols 1 and 2, respectively ( p=0.884). The incidence rates of CMV disease and recurrent CMV infections were higher in Protocol 1, but this was not statistically significant. The median time to first CMV infection was significantly shorter in patients who received Protocol 1: 132 days (interquartile range (IQR) 125–139 days) versus 185 days (IQR 178–192 days), p=0.001. Both prophylaxis protocols were well tolerated.

Conclusion:

The incidence of CMV infection was similar in both protocols. Where valganciclovir is not available, valacyclovir may be considered over no prophylaxis. Post-prophylaxis CMV infections are not uncommon, and vigilance for it should be advocated.

197. Dengue Virus Infection Among Renal Transplant Recipients in Singapore: A 15-year Single Center Retrospective Review

Background

Dengue is a mosquito-borne viral infection endemic in Singapore. Its clinical course in the immunocompetent host is well characterised but its impact in renal transplantation is not well described. We aim to characterise the clinical presentation and outcomes of dengue virus infection in renal transplant recipients treated at a tertiary center in Singapore.

Methods

We conducted a 15 year retrospective review of dengue in renal transplant patients treated at Singapore General Hospital between January 2005 to October 2019. The diagnosis of dengue was made if there were a compatible clinical syndrome and a positive dengue diagnostic assay, either Dengue NS1 antigen, IgM or PCR.

Results

Thirty-two renal transplant patients were diagnosed with dengue, 18 (56.3%) were deceased donor recipients. The median age at time of diagnosis was 53 [IQR 42,61] years; 16 (50%) were males. The median time to diagnosis of dengue was 95.5 [IQR 15.0,95.5] months from transplant; and the median duration of clinical illness was 7 [IQR 5,7] days. The most common clinical symptoms were fever (84.4%), myalgia (40.6%), gastrointestinal symptoms (37.5%) and headache (25.0%). Based on the WHO 2009 dengue classification, 20 (62.5%) had dengue without warning signs, 9 (28.1%) had dengue with warning signs, and 3 (9.4%) had severe dengue; 19 (59.3%) had graft dysfunction and 1 (3.1%) required dialysis. Of the patients who had graft dysfunction, 18 (94.7%) had recovery of graft function at time of dengue resolution. Dengue mortality rate was 3.1%. There were 2 possible cases of donor derived dengue infections, occurring within 2 weeks of deceased donor transplantation.

Conclusion

Dengue in renal transplant is usually community acquired; donor derived infections are uncommon. The clinical presentation of dengue is similar to the immunocompetent host, however graft dysfunction is common and fluid management in this population is important. Severe dengue is less common.

Disclosures

All Authors: No reported disclosures

Impact of tacrolimus versus cyclosporine on one-year renal transplant outcomes: A single-centre retrospective cohort study

Background:

Calcineurin inhibitors are the cornerstone of maintenance immunosuppression after kidney transplant. While studies on predominantly Caucasian populations recommend tacrolimus over cyclosporine, the effects on Singapore’s local population remain unclear.

Objectives:

This study aimed to compare the impact of tacrolimus against cyclosporine on post-transplant outcomes in our local kidney transplant population.

Methods:

A single-centre retrospective chart review was conducted on ABO- and human leucocyte antigen (HLA)-compatible kidney transplantations between 1 January 2011 and 15 August 2018. Patients who received basiliximab induction, prednisolone, mycophenolate and either tacrolimus or cyclosporine were included and followed up for at least one year. Recipients of transplantations at other institutions or other immunosuppressive regimens were excluded. Patient and graft outcomes and adverse effects were collected.

Results:

Overall, 120 patients on tacrolimus and 49 on cyclosporine were included. Patients on tacrolimus were older. This group had more deceased donor transplants, a higher proportion with donor-specific antibodies (DSAs) present and more HLA mismatches. There were no differences in patient and graft survival, graft function and acute rejections at one year, despite adjusting for age, transplant type, presence of DSAs and total HLA mismatches. The tacrolimus group had more infectious admissions (odds ratio=0.27, 95% confidence interval 0.098–0.73, p=0.01) after adjusting for age, transplant type, HLA mismatches, presence of DSAs and acute rejections, with increased severity and more opportunistic infections. More patients on cyclosporine required a change to alternative immunosuppressants (p=0.003).

Conclusion:

Our study demonstrated comparable short-term post-transplant outcomes between cyclosporine and tacrolimus. Tacrolimus appears more tolerable but may be associated with infection risks.

Managing a Renal Transplant Programme During the COVID-19 Pandemic: Practical Experience from a Singapore Transplant Centre

Introduction: Coronavirus Disease 2019 (COVID-19) has significantly affected the way healthcare is delivered in Singapore. Healthcare services such as renal transplantation had to rapidly adjust and meet the needs to (1) protect patients and staff, (2) ramp up, conserve or redeploy resources while (3) ensuring that critical services remained operational. This paper aims to describe the experience of the renal transplant programme at the Singapore General Hospital (SGH) in responding to the risks and constraints posed by the pandemic. Methods and Materials: This is a review and summary of the SGH renal transplant programme’s policy and protocols that were either modified or developed in response to the COVID-19 Pandemic. Results: A multi-pronged approach was adopted to respond to the challenges of COVID-19. These included ensuring business continuity by splitting the transplant team into different locations, adopting video and tele-consults to minimise potential patient exposure to COVID-19, streamlining work processes using electronic forms, ensuring safe paths for patients who needed to come to hospital, ring-fencing and testing new inpatients at risk for COVID-19, enhancing precautionary measures for transplant surgery, ensuring a stable supply chain of immunosuppression, and sustaining patient and staff education programmes via video conferencing. Conclusions: Though the COVID-19 pandemic has reduced access to kidney transplantation, opportunities arose to adopt telemedicine into mainstream transplant practice as well as use electronic platforms to streamline work processes. Screening protocols were established to ensure that transplantation could be performed safely, while webinars reached out to empower patients to take precautions against COVID-19. Keywords: COVID-19, Nephrology, Public Health, Renal Transplant, Transplantation, Urology

Impact of pre-transplant biopsy on 5-year outcomes of expanded criteria donor kidney transplantation

AIM

Compared to Standard Criteria Donors (SCD), Expanded Criteria Donor (ECD) kidneys are associated with poorer outcomes, although pre-transplant biopsy may mitigate risks. This study assessed 5-year outcomes of deceased-donor kidney transplant recipients, comparing recipients of ECD allografts evaluated histologically to recipients of SCD and ECD kidneys assessed clinically.

METHODS

This is a single-centre retrospective study. From November 2005 to December 2009 (Era 1), donors were assessed clinically for suitability for kidney donation. From December 2009 to October 2017 (Era 2), kidneys from ECDs and diabetics underwent pre-transplant biopsy and were allocated based on Remuzzi score. Outcomes of Era 1 and 2 recipients were compared.

RESULTS

ECD kidney transplantation increased from 30.4% to 40.0% from Era 1 to 2. Univariable Cox regression, stratified by transplant era, found that 5-year graft loss was highest with Era 1 ECD (HR 2.5, 95% CI 1.1-5.5, P = .027) while graft loss for Era 2 ECD recipients was similar to SCD recipients. There was no difference in 5-year recipient survival. Amongst Era 1 ECD recipients, 51.2% experienced rejection compared to 30.8-41.5% for other subgroups. Five-year eGFR was higher with Era 2 ECD at 48.4 (33.3-60.7) ml/min/1.73 m² compared to 42.2 (35.8-57.3) ml/min/1.73 m² for Era 1 ECD. However, these differences were not statistically significant.

CONCLUSION

Introduction of pre-transplant biopsy assessment may be associated with improved outcomes of ECD kidney recipients such that they are now comparable to SCD kidney recipients, with benefits persisting over 5 years.

Managing a Renal Transplant Programme During the COVID-19 Pandemic: Practical Experience from a Singapore Transplant Centre

INTRODUCTION

Coronavirus Disease 2019 (COVID-19) has significantly affected the way healthcare is delivered in Singapore. Healthcare services such as renal transplantation had to rapidly adjust and meet the needs to (1) protect patients and staff, (2) ramp up, conserve or redeploy resources while (3) ensuring that critical services remained operational. This paper aims to describe the experience of the renal transplant programme at the Singapore General Hospital (SGH) in responding to the risks and constraints posed by the pandemic.

METHODS AND MATERIALS

This is a review and summary of the SGH renal transplant programme's policy and protocols that were either modified or developed in response to the COVID-19 Pandemic.

RESULTS

A multi-pronged approach was adopted to respond to the challenges of COVID-19. These included ensuring business continuity by splitting the transplant team into different locations, adopting video and tele-consults to minimise potential patient exposure to COVID-19, streamlining work processes using electronic forms, ensuring safe paths for patients who needed to come to hospital, ring-fencing and testing new inpatients at risk for COVID-19, enhancing precautionary measures for transplant surgery, ensuring a stable supply chain of immunosuppression, and sustaining patient and staff education programmes via video conferencing.

CONCLUSIONS

Though the COVID-19 pandemic has reduced access to kidney transplantation, opportunities arose to adopt telemedicine into mainstream transplant practice as well as use electronic platforms to streamline work processes. Screening protocols were established to ensure that transplantation could be performed safely, while webinars reached out to empower patients to take precautions against COVID-19.

Bleeding Complications and Adverse Events After Desmopressin Acetate for Percutaneous Renal Transplant Biopsy

Introduction: Percutaneous renal biopsy remains critical for the workup of renal allograft dysfunction but is associated with the risk of bleeding. Prophylactic intravenous desmopressin has been proposed to reduce bleeding risk in native renal biopsies, but its efficacy in the renal transplant population is unclear and adverse events such as severe hyponatraemia have been reported. Materials and Methods: We conducted a single-centre retrospective cohort study involving adult (≥21 years old) renal transplant recipients with impaired renal function (serum creatinine ≥150 μmol/L) who underwent ultrasound-guided renal allograft biopsies from 2011‒2015 to investigate the effect of prebiopsy desmopressin on the risk of bleeding and adverse events. Results: Desmopressin was administered to 98 of 195 cases who had lower renal function, lower haemoglobin and more diuretic use.Postbiopsy bleeding was not significantly different between the 2 groups (adjusted odds ratio [OR] 0.79, 95% confidence interval [CI] 0.26‒2.43, P = 0.68) but desmopressin increased the risk of postbiopsy hyponatraemia (sodium [Na] <135 mmol/L) (adjusted OR 2.24, 95% CI 1.10‒4.59, P = 0.03). Seven cases of severe hyponatraemia (Na <125 mmol/L) developed in the desmopressin group, while none did in the non-desmopressin group. Amongst those who received desmopressin, risk of hyponatraemia was lower (OR 0.26, 95% CI 0.09‒0.72, P = 0.01) if fluid intake was <1 L on the day of biopsy. Conclusion: Prophylactic desmopressin for renal allograft biopsy may be associated with significant hyponatraemia but its effect on bleeding risk is unclear. Fluid restriction (where feasible) should be recommended when desmopressin is used during renal allograft biopsy. A randomised controlled trial is needed to clarify these outcomes. Key words: Adverse effects, Deamino arginine vasopressin, Haematoma, Haemorrhage, Hyponatraemia

Bleeding Complications and Adverse Events After Desmopressin Acetate for Percutaneous Renal Transplant Biopsy

INTRODUCTION

Percutaneous renal biopsy remains critical for the workup of renal allograft dysfunction but is associated with the risk of bleeding. Prophylactic intravenous desmopressin has been proposed to reduce bleeding risk in native renal biopsies, but its efficacy in the renal transplant population is unclear and adverse events such as severe hyponatraemia have been reported.

MATERIALS AND METHODS

We conducted a single-centre retrospective cohort study involving adult (≥21 years old) renal transplant recipients with impaired renal function (serum creatinine ≥150 µmol/L) who underwent ultrasound-guided renal allograft biopsies from 2011‒2015 to investigate the effect of prebiopsy desmopressin on the risk of bleeding and adverse events.

RESULTS

Desmopressin was administered to 98 of 195 cases who had lower renal function, lower haemoglobin and more diuretic use. Postbiopsy bleeding was not significantly different between the 2 groups (adjusted odds ratio [OR] 0.79, 95% confidence interval [CI] 0.26‒2.43, P = 0.68) but desmopressin increased the risk of postbiopsy hyponatraemia (sodium [Na] <135 mmol/L) (adjusted OR 2.24, 95% CI 1.10‒4.59, P = 0.03). Seven cases of severe hyponatraemia (Na <125 mmol/L) developed in the desmopressin group, while none did in the non-desmopressin group. Amongst those who received desmopressin, risk of hyponatraemia was lower (OR 0.26, 95% CI 0.09‒0.72, P = 0.01) if fluid intake was <1 L on the day of biopsy.

CONCLUSION

Prophylactic desmopressin for renal allograft biopsy may be associated with significant hyponatraemia but its effect on bleeding risk is unclear. Fluid restriction (where feasible) should be recommended when desmopressin is used during renal allograft biopsy. A randomised controlled trial is needed to clarify these outcomes.

The use of intravesical cidofovir for the treatment of adenovirus-associated haemorrhagic cystitis in a kidney transplant recipient

Adenovirus is an important cause of haemorrhagic cystitis in kidney transplant recipients. The optimal treatment for adenovirus-associated haemorrhagic cystitis (AAHC) is unknown. Intravenous cidofovir may be effective, but nephrotoxicity is a major concern. The use of intravesical cidofovir for viral haemorrhagic cystitis has been reported in haematopoietic stem cell transplant recipients and may be associated with a lower risk of nephrotoxicity, but its use has not been reported in kidney transplant recipients. We report the use of intravesical cidofovir for the treatment of AAHC in a kidney transplant recipients, along with a review of the literature.

The first epidemic of dengue hemorrhagic fever in the People's Republic of China

The first epidemic of dengue in China associated with significant severe and fatal hemorrhagic disease which met the World Health Organization case definition occurred on Hainan Island in 1985-1986. The epidemic began in Zhan County in September 1985, spread throughout the coastal areas, and ultimately involved 13 counties and cities of the island in 1986. The mosquito vector was Aedes aegypti. The morbidity associated with dengue infection on Hainan Island was 1,913 per 100,000 residents, with a case fatality rate of 0.25%. Severe disease was more prevalent in the 10-29-year-old age group. Principal clinical features in laboratory-confirmed cases were fever, osteoarthralgia, hemorrhage and/or shock, and thrombocytopenia. Complications such as acute intravascular hemolysis, diffuse intravascular coagulation, hemoconcentration, pleural effusion, altered mentality, and pneumonia were also observed. One hundred twenty-five isolates of dengue 2 virus were recovered from acute-phase serum samples from 278 patients, and 5 strains of this same virus serotype were isolated from 5 pools of adult Ae. aegypti.