Renal Transplant Patients Research Articles

Management of Diverticulitis in Renal Transplant Patients.

Renal transplant patients presenting with diverticulitis remain a clinical challenge for health care professionals. Secondary to immunosuppression, renal transplant recipients are often considered for early operative intervention due to concerns for an unreliable physical exam and feared morbidity and mortality associated with non-operative management. This study aimed to evaluate trends in management of renal transplant patients with diverticulitis at a quaternary referral center. One hundred ninety-one renal transplant patients admitted to the hospital with diverticulitis were identified. Of this cohort, 71 (37%) underwent surgical resection, of which 20 (28%) were performed emergently. The overall 30-day operative mortality was 8% (6/71), of which there was a significant difference between emergent (25%, 5/20) and elective (2%, 1/51) groups (P = .006). Patients who underwent elective surgery were more likely to receive a minimally invasive approach (51%) and were significantly more likely to undergo stoma reversal (P = .006). Our study shows that not all renal transplants with diverticulitis will require operative intervention and many can be safely treated non-operatively. Elective resection and surgical management should be considered on an individual basis. Patients treated with elective resection were more likely to undergo a minimally invasive approach and restoration of intestinal continuity.

Revision ureteroneocystostomy in pediatric renal transplant patients for symptomatic vesicoureteral reflux and its effect on recurrent hospitalizations

Nearly 13,000 pediatric renal transplantations have been performed since 1987 with improving overall mortality and morbidity; however, graft infection remains a significant post-transplant concern. Recurrent urinary tract infections in pediatric patients with vesicoureteral reflux into their renal transplant can result in graft dysfunction, increased hospital cost, and impaired social and cognitive development due to time spent hospitalized. To evaluate the effect of revision ureteroneocystostomy on pediatric renal transplant patients with symptomatic vesicoureteral reflux in reducing hospitalizations and recurrent urinary tract infections. We retrospectively reviewed pediatric patients from 2002 through 2021 who underwent renal transplantation and required revision ureteroneocystostomy due to symptomatic vesicoureteral reflux. We analyzed the differences in days hospitalized, days hospitalized due to urinary tract infection, and treated urinary tract infections prior to and after revision ureteroneocystostomy. Ten patients requiring revision ureteroneocystostomy secondary to symptomatic vesicoureteral reflux were identified. There was no difference in the observation time between transplant to revision, and revision to last follow up (2.3 years (IQR 1.3-6.5) vs 1.7 years (IQR 1-6.7), p=0.4446). Overall, there was a significant decrease in the total number of hospitalization days (21.5 days (IQR 3-43) vs 5.5 days (IQR 0-9), p=0.006), total number of hospitalization days related to urinary tract infection (14.5 days (IQR 3-28) vs 0 days (IQR 0-3), p=0.008) and treated urinary tract infections (3.5 (IQR 3-6) vs 1 (IQR 0-2), p=0.019) following revision ureteroneocystostomy. The rate of hospitalization days for urinary tract infection was also significantly decreased following revision ureteroneocystostomy (7.15 per/year (IQR 0.4-11.75) vs 0 per/year (IQR 0-0.8), p=0.008). Symptomatic vesicoureteral reflux in pediatric transplant patients is difficult to manage and some patients will ultimately require surgery. There have been previous studies on the success of revision ureteroneocystostomy in treating reflux but no data on the reduction in hospitalizations associated with recurrent infections following the procedure. Limitations of this study are the small cohort size, retrospective nature, multi-surgeon study, and inherent selection bias due to evaluation of only surgical patients. Revision ureteroneocystostomy can limit the negative consequences of recurrent graft infections with reduction in hospitalization days and improved hospitalization rates due to urinary tract infections. The reduction in hospitalizations can greatly improve the cost of care along with quality of life for transplant patients and should be strongly considered in children with symptomatic vesicoureteral reflux who have failed conservative therapy.

Dawn of a new beginning- First renal transplant in patient with HIV in Nepal

Human immunodeficiency virus infection was traditionally considered an absolute contraindication for transplantation because of the concern that immunosuppression would accelerate HIV disease progression, resulting in increased mortality and a "waste" of organs. Since potent antiretroviral therapy became widely available in 1996, the prognosis of patients with HIV infection has dramatically improved. HIV-infected patients are now accepted recipients of both HIV-infected and HIV- uninfected donor organs in specialized transplant centers worldwide. However, due to stigma about the disease and lack of appropriate expertise, renal transplant in HIV patients has not been done in Nepal. Here, we report the first case of renal transplantation done in patient with HIV in Nepal. So, even in a resource limited setting like Nepal, HIV-positive ESRD patients with stable disease should be given the benefit of kidney transplantation as patient and graft survival are reasonably good with better quality of life.

Frequencies and Association of CYP3A5 Polymorphism With Tacrolimus Concentration Among Renal Transplant Recipients in Vietnam

This study aims to investigate the frequencies and association of CYP3A5 polymorphism with tacrolimus concentration among renal transplant recipients in Vietnam. Sixty-eight kidney transplant recipients were included in this study from the department of nephrology and dialysis, Military Hospital 103. Blood samples were collected for monitoring of tacrolimus levels and determination of CYP3A5 genetic polymorphism. A total of 68 patients studied. The CYP3A5*3*3, CYP3A5*1*3, and CYP3A5*1*1 genotypes were detected in 48 (70.6%), 16 (23.5%), and 4 (5.9%), respectively. Tacrolimus concentrations were much lower in CYP3A5 expressors than in CYP3A5 nonexpressors on the first day, month 1, 3, 6, and 12 (5.98 ± 1.05 vs 6.57 ± 1.03, P=.03; 5.79 ± 1.13 vs 6.82 ± 1.05, P < .001; 4.76 ± 1.48 vs 6.73 ± 1.09, P < .001; 4.29 ± 1.64 vs 6.46 ± 1.23, P < .001; 4.20 ± 1.36 vs 6.04 ± 1.26, P < .001), respectively. Notably, the concentration/dose ratio in the CYP3A5 expressors was lower than in CYP3A5 nonexpressors at time points of follow up (P < .001). However, there were no significant differences in the age, sex, HLA mismatch, type of donors, acute rejection, and creatinine levels at time points between group of CYP3A5 expressors and those of CYP3A5 nonexpressors. In conclusion, this research indicated the significant association of CYP3A5 genetic polymorphism with daily dose and tacrolimus concentrations in renal transplant recipients. This study provided a closer step to individualize the dose of tacrolimus in renal transplant patients in Vietnam.

Nomogram based on high-frequency shear wave elastography (SWE) to evaluate chronic changes after kidney transplantation.

To construct a nomogram with high-frequency shear wave elastography (SWE) as a noninvasive method to accurately assess chronic changes in renal allografts. A total of 191 renal transplantation patients (127 cases in the training group and 64 cases in the verification group) were included in this study. All patients received conventional ultrasound and high-frequency SWE examination, followed directly by biopsy the next day. The chronic changes were divided into mild, moderate, and severe. Multivariate logistic analyses were used to select significant variables, which were used to develop the nomogram. Nomogram models were assessed by receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). The cutoff value of SWE in mild, moderate, and severe chronic changes was 18.9, 22.5, and 27.6 kPa, respectively. The areas under the curve (AUCs) of SWE in the differential diagnosis of mild and moderate to severe chronic changes and mild to moderate and severe chronic changes were 0.817 and 0.870, respectively. Multivariate analysis showed that time since transplantation, proteinuria, glomerular filtration rate, echogenicity, and SWE were independent diagnostic factors for moderate to severe chronic changes (all p < 0.05); thus, a nomogram was successfully developed. The AUCs of the nomogram in the training and validation groups were 0.905 and 0.938, respectively. The high agreement between the model predictions and the actual observations was confirmed by calibration plot and DCA. Based on SWE, the nomogram provided an insightful and applicable tool to evaluate chronic changes in renal allografts. • In kidney transplantation, compared with acute changes, chronic changes are significantly correlated with cortical stiffness. • SWE shows good performance in identifying mild to moderate and severe chronic changes, with an AUC of 0.870. • Time since transplantation, proteinuria, glomerular filtration rate, echogenicity, and SWE are independent diagnostic factors for moderate to severe chronic changes in renal allografts.

Analysis of Cross-sectional and Longitudinal HLA and Anti-viral Responses After COVID Infection in Renal Allograft Recipients: Differences and Correlates.

Background.Characterization of anti-HLA versus anti-severe acute respiratory syndrome coronavirus 2 (anti–SARS-CoV-2) immune globulin isotypes in organ transplant recipients after coronavirus disease 2019 (COVID-19) infection has not been reported. We aimed to determine changes in anti-HLA antibodies in renal transplant patients with COVID-19 and compare the immunoglobulin and epitope-binding pattern versus anti–SARS-CoV-2 antibodies.Methods.This is a cross-sectional study of 46 kidney transplant recipients including 21 with longitudinal sampling. Using a semi-quantitative multiplex assay, we determined immunoglobulin (Ig) M, IgA, IgG, and IgG1-2-3-4 antibodies against Class I and Class II HLA, and 5 SARS-CoV-2 epitopes including the nucleocapsid protein and multiple regions of the spike protein.Results.Fourteen of 46 (30%) patients had donor-specific anti-HLA antibodies (donor-specific antibody [DSA]), 12 (26%) had non-DSA anti-HLA antibodies and 45 (98%) had anti–SARS-CoV-2 antibodies. Most DSAs targeted HLA-DQ (71%), with a dominant IgG isotype and IgG1 subtype prevalence (93%), and/or IgG3 (64%), followed by IgG2 (36%). Comparatively, there was a higher prevalence of IgA (85% versus 14%, P = 0.0001) and IgM (87%, versus 36%, P = 0.001) in the anti–SARS-CoV-2 antibody profile, when compared to DSAs, respectively. Anti–SARS-CoV-2 antibody profile was characterized by increased prevalence of IgM and IgA, when compared to DSAs. The median calculated panel reactive antibody before COVID-19 diagnosis (24%) tended to decrease after COVID-19 diagnosis (10%) but it was not statistically significant (P = 0.1).Conclusions.Anti-HLA antibody strength and calculated panel reactive antibody in kidney transplant recipients after COVID-19 do not significantly increase after infection. Although the IgG isotype was the dominant form in both HLA and SARS-CoV-2 antigens, the alloimmune response had a low IgA pattern, whereas anti–SARS-CoV-2 antibodies were high IgA/IgM.

342.3: Outcome Analysis of Patients With Genetic Mutations of Complement Regulatory Proteins in Relation to Incidence of Post Renal Transplant Thrombotic Microangiopathy

Introduction: Thrombotic Microangiopathy is an occlusive disorder of microvasculature characterized by thrombocytopenia, systemic or intrarenal platelet aggregation, thrombus formation and hemolytic anemia caused by fragmentation of erythrocytes due to the disturbed microvasculature. TMA developing after renal transplantation can be categorized into either De novo TMA, developing for the first time without any evidence of the disease before the transplant or recurrent TMA where native kidneys have failed due to TMA and recur after kidney transplantation. The contribution of complement regulatory gene (CRG) mutation to post-transplant Thrombotic Microangiopathy (TMA) in Indian kidney transplant recipients (KTR) is unknown. This is a study to determine the association of CRG on post-transplant TMA and graft failure. Methods: A Single Centre, Prospective Observational Cohort Study was undertaken in renal transplant recipients. All live and Deceased donor renal allograft recipients who underwent transplantation from 1st December 2019 onwards till 31st December 2020 were recruited and were followed up for 1 year beyond the last enrolment. Genetic testing was performed with MLPA and Clinical exome sequencing. Results: 78 KTRs with a mean age of 37.09 ± 13.23 years were enrolled. The Native cause of kidney disease in 55 (70.5%) patients was undetermined and 23 (29.5%) had established cause of chronic kidney disease. 58 (74.4%) were males and 20 (25.6%) were females. CRG mutation was seen in 48/78 (61.5%) KTRs. The allele frequency of the CRG mutation was seen in 48/78 (61.53%) of which duplication of CFHR gene was predominantly seen in 40/78 (51.2%) patients. CRG mutation in this cohort was seen more in the younger age group patients. There was no gender predominance for patients with CRG mutation. None of the patients had a mutation for CFH, CFI, CFB, C3, THBD, DGKE genes. One patient had a mutation for the PLG gene. The incidence of post-transplant TMA was seen in 4/78 (5.12%) patients. Mutation related to aHUS was seen in 2 patients. There was no significant difference in serum creatinine levels of patients with or without CRG mutation at the end of 1 year. Conclusion: The prevalence of CRG mutation in our KTR cohort was high and is associated with post-transplant TMA in 50% of patients with de novo TMA. The graft outcome at the end of 1 year was similar in patients with mutation and those without mutation. This study suggests that the presence of CRG mutation should not preclude renal transplantation in patients with ESRD.

P16.15: HLA Genetic Frequency in Renal Transplantation Patients, Dead by COVID-19

P16.15: HLA Genetic Frequency in Renal Transplantation Patients, Dead by COVID-19

242.7: Influence of CYP3A5 Polymorphisms on Tacrolimus Dosing in Renal Transplant Recipients

Introduction: Tacrolimus is a commonly used immunosuppressant after kidney transplantation it has narrow theraupetic range and demonstrates wide interindividual variability in pharmacokinetics leading to potential under immunosuppression or tacrolimus toxicity genetic polymorphism in CYP3A5 enzyme expression contributes to differences in tacrolimus bioavailibility between individuals. Aim of the study: Ti evaluate pharmacogenomic effect of CYP3A5 gene polymorphisms on tacrolimus dosing in renal transplant recipients. Materials and Methods: Present study we investigated pharmacogenomics associations of common CYP3A5 polymorphisms with requirements of tacrolimus in renal transplant patients: □INCLUSION CRITERIA - 50 patients on tacrolimus based triple immunosuppression were genotyped for cyp3A5 polymorphism most allels- *1/*1,*1/*3,*3/*3 alleles. □EXCLUSION CRITERIA- those patients on CYP inducers or inhibitors were excluded demographic data, weight based tacrolimus doses, serum tacrolimus level at 1 month, 3 months 1 year and present tacrolimus trough level were collected. Data was statistically analysed. Results: Mean age of the recipients was 33.41+/-10.2,72% were males mean tacrolimus level at 1 month was 8ng/ml (7-10ng/ml) at 1 month post transplant cyp *1/*1 was 5.75+_0.95,tac level in cyp3a5 *1/*3 was 9.52∔_1.42,CYP3A5*3/*3 -10.26+_1.02 with significant P VALUE <0.01 among patients with high tac level 36% were poor metabolisers,50% intermediate metabolizers,none of the extensive metabolisers had higher tacrolimus level. At>3 months of transplantation tac level in cyp3a5 *1/*1 was 5.75∔0.95, cyp3a5 *1/*3 was 6.33∓1.17, cyp3a5 *3/*3 was 6.78∔-0.8 with significant P value < 0.01. 56% developed tac toxicity - 84%(*3/*3) poor metabolisers, 14.3% in intermediate *1/*3 metabolisers.125 developed rejections in first three months of transplant,90.755 were extensive metabolisers Discussion: Tacrolimus toxicity as well as rejection due to sub theraupetic levels influence graft outcomes. bioavailibility of tacrolimus varies widely due to gene polymorphisms of CYP3A5 gene. CYP3A5*1/*1 had lower tac level in blood resulting higher rates of rejection requiring 1.5 to 2 times higher dose compared to poor metabolisersand intermediate metabolizers. Poor metabolizers *3/*3 had tacrolimus related toxicity at similar dose adjusted tac levels, indicating lower dose for maintanence (0.06mg/kg). Conclusion: Genotyped based dosing may improve achievement of theraupetic drug concentrations with reduced drug related complications in the era of personalised medicine.

P8.051: Corticosteroids Withdrawal in Renal Grafted Patients: Follow-up and Outcome

Introduction: Corticosteroids are powerful antiinflamatory with immunosuppressant effects utilized in maintenance therapy following kidney transplantation and are associated with a higher rate of side events in comparison with protocols involving early corticosteroid withdrawl. The present paper reports the results of cessation of steroids in stable maintenance renal transplant patients. Patients and methods: One hundred sixty seven deceased kidney grafted patients (54% men), aged 57.5±12.4 years, with follow-up of 84 months and steroids withdrawl period of 60 months (1-198) follow-up steroid free were studied. Etiology of end stage renal disease was secondary to Glomerulonephritis 31%, Diabetes 22%, Policystic disease 14%, Tubulointerstitial nephropathy 13%, Vascular 5%, Unknown 17%. The patients were on Prednisone 5-10 mg dairy combined with Cyclosporine 50-150 mg/Tacrolimus 0.5-6 mg, associate to Mycophenolate Mophetyl 250-2.000 mg, Sodium Micophenolate, 360-900 mg or Azatioprine 50-75 mg, and Everolimus 1-4 mg. Steroids were diminished gradually in three months period and some patients receibe monotherapy only. Results: Basal serum creatinine was 1.54±0.6mg/dl and after five years followup 1.4±0.5 mg/dl. Basal blood glucose concentration was 130±12 mg/dl and after five years 109±0.8mg/dl. Weight was maintained. At 5 years, graft and patient survival were 100%. There was no acute rejection after steroids withdrawl. After withdrawl blood pressure control was achieved with less antihypertensive drugs. Lipids diminished slightly with less cholesterol-lowering drugs. Conclusion: Corticosteroids could be withdrawn safely in stable renal transplant patients and avoid morbidity and adverse events related to chronic utilization improving survival and quality of life.

P11.06: HTK vs WISCONSIN and Delayed Renal Graft Function

Introduction: Preservation solutions are beneficial for solid organ transplants, being an important factor in the development of delayed graft function (RFI), being associated with a reduction in graft survival after one year. Objectives: To compare the use of histidine-tryptophan-ketoglutarate (HTK) solution vs University of Wisconsin solution with the development of renal graft function delay (RFI). Material and Method: Observational (Cross Sectional), retrospective and analytical study. Renal transplant patients with cadaveric donors were included during the period between January 2017 and December 2021.T test was used for independent samples and Chi2 2x2 for categorical variables. An alpha value of ≤ 0.05 was determined for statistical significance. Results: 82 kidney transplant recipients were retrospectively compared with cadaveric, preserved HTK (n=49) and UW (n=33) donors. The mean age of the donors was 40 years. The incidence of RFI was 56%. In the Student test analysis, statistical significance was observed in donor age (37,31 vs 42,52 p=.035), donor BMI (25,78 vs 29,46p=.000), pre-ablation creatinine (0,94 vs 1,18 p=.014) and pre-ablation urea (28,86 vs 39,74 p=.006) and renal RFI. In the CHI2 analysis, the use of HTK solution (KANTRILEX/ CUSTOPLEX) was associated with 40.2% renal RFI development (p=.012) (OR 3.17 95% CI 1.26-7.95), compared to UW solution (14.6%) (p=.007) (OR 0.28 CI 95% 0.11-0.71). Conclusion: In our study, it was observed that the use of HTK solution was associated with a higher risk of renal RFI compared to UW solution.

Oral 32 - A prospective illustrative study on the endoscopic approaches for treating obstructive kidney stone disease in renal transplant patients

Oral 32 - A prospective illustrative study on the endoscopic approaches for treating obstructive kidney stone disease in renal transplant patients

314.4: How Did the Omicron Wave Impact Kidney Transplant Recipients? A Comparative Analysis From a Prospective Cohort Single-Center Study

Introduction: The first two years of the SARS-CoV-2 pandemic were marked by an unprecedented impact on the survival of the kidney transplant patient worldwide, a population that accumulates risk factors for worse outcomes and has reduced vaccine response. However, from the end of 2021, the pandemic acquired new nuances, with the broad availability of booster doses of the vaccine – in Brazil, since 08/26/2021 – and the emergence of the Omicron variant, more infectious but possibly less lethal. The aim of our study was to describe how the new era of the pandemic differed from the previous one in a large cohort of renal transplant patients being followed up at a single center. Methods: This single-center prospective cohort study included kidney transplant recipients with confirmed COVID-19 between 03/20/2020 and 02/15/2022. The outcomes of interest were incidence of confirmed SARS-CoV-2 infection, need for hospitalization, mechanical ventilation, dialysis and COVID-19 associated death within 28 days from the onset of symptoms. For the present analysis, we arbitrarily separated the patients into two eras, named “Era 1” (03/20/2020 to 12/02/2021) and “Era 2” (12/17/2021 to 02/15/2022), considering the emergence of the Omicron variant in Brazil at the end of the year 2021 and that there were no cases registered between 12/02/2021 and 12/17/2021. Genetic sequencing to identify the variants was not available in the center. Results: Among the 10,497 kidney transplant recipients in follow up, there were 3,327 cases of confirmed COVID-19 in the entire observation period. There was an increase in the incidence rate from 0.3 cases/1000patients-day in Era 1 to 1.72 cases/1000patients-day in Era 2, and the sharp increase in the number of cases in the last Era is demonstrated in Figure 1. There was no difference in the median age (51 [IQR 42-60] years versus 50 [IQR 40-61] years, p=0.447) or in the proportion of male patients (60.4% versus 58.5%, p=0.294) between the two Eras. There was a significant decrease in the rate of hospitalization (57.5%% versus 29.2%, p<0.0001), need for mechanical ventilation (29.9% versus 16.3%, p<0.0001), dialysis (25.6%% versus 9.1%, p<0.0001) and COVID-19 related death (26.9% versus 10%, p<0.0001, as demonstrated in Figure 1). Conclusion: There was a clear change in the dynamics of the pandemic from December 2021 among renal transplant patients, with higher incidence and lower severity of COVID-19, possibly due, but not limited to, booster vaccination and lower pathogenicity of the Omicron variant.

39 An unusual case of lung mass, bacteraemia and CNS disease in a renal transplant patient

39 An unusual case of lung mass, bacteraemia and CNS disease in a renal transplant patient

POS-107 LONG TERM OUTCOMES OF RENAL TRANSPLANTATION WITH PRE- AND POST-TRANSPLANT TUBERCULOSIS

Tuberculosis (TB) is a common nemesis among dialysis and renal transplant (RT) patients in the Indian subcontinent. The impact of pre and post-transplant TB on graft and patient outcomes is inconspicuous. We aimed to study the influence of tuberculosis and its therapy on renal allograft outcomes on long term follow-up.

310.5: Torque teno virus Titre Changes Under Immunosuppression Reduction Protocol for BK Virus-Associated Nephropathy: A Single Centre Pilot Study

Introduction: In BK virus-associated nephropathy (BKVaN), balancing the risk of immunosuppression (IS) reduction with the potential benefits can be challenging. A common approach is to empirically stop antiproliferative agents in the first instance and reduce the dose of calcineurin inhibitors (CNIs) later. Torque Teno virus (TTV), a novel ubiquitous DNA virus, has emerged as a better predictor of IS burden in some studies. We examined the changes in BKV and TTV titres in response to IS reduction as part of BKVaN treatment. Method: 20 renal transplant patients with stored blood samples were included in the study cohort from a population transplanted between 2017-19, in remission from an episode of clinically significant BK viraemia. They received standard IS; tacrolimus, antiproliferative (mycophenolate mofetil/azathioprine) and weaning dose prednisolone. BKV and TTV titres, 30-day average tacrolimus concentration, the dose of antiproliferative and prednisolone were collected at 4-time points. These included the last negative BK PCR; the onset of viraemia; the peak BK titre and BK titre <500 copies/ml. TTV DNA was extracted from stored frozen plasma and PCR was performed with Thermofisher 7500 Fast platform and TTV R-GENE® kit. The relationships between the variables were assessed using a multivariable linear regression model. Data were collected from electronic patient records and analysed with R 4.0.3. Result: The log-transformed mean TTV titre at the 4 time points were 5.02 (2.07), 5.52 (1.74), 6.23 (2.14) and 4.56 (1.27) respectively. In the multivariable model, log-transformed BK virus titre increased by 0.25 for every 1 ng/mL increase in tacrolimus concentration (p 0.0008). However, every 1 log rise in TTV titre led to 0.57 (0.17) log copies increase in BKV titre (p 0.0009), once adjusted for tacrolimus concentration. The relationship between tacrolimus and BKV became statistically insignificant when TTV titre was added as a predictor variable. This implies that TTV titre is a more sensitive predictor of BK viral load than tacrolimus concentration. Although statistically significant, all changes in antiproliferative or prednisolone dose were unable to predict linear changes in BKV titres. 5 patients who lost their graft in the mean follow up of 2.8 years had significantly low TTV titres (p< 0.05) at baseline, indicating suboptimum IS burden. In this small cohort, there was no relationship between TTV titres and rejections (n=5) or de novo DSA (n=3). An ongoing adequately powered prospective study will address these questions more decisively.Conclusion: Our study demonstrates that TTV titres more accurately indicate the effect of IS/CNI changes on BK titre and demonstrates its potential as a sensitive assay to objectively guide IS modification compared to current empirical practice in the management of BKVaN. A randomised control trial is warranted comparing empirical practices to TTV titre guided adjustment of immunosuppressive medications.

416.3: Are HLA-A,B,DR and DQ-Mismatching Important for the Kidney Allocation Schemes?-UK Registry Data- an Artificial Intelligence Approach

Introduction: Currently, there is inconsistency among different kidney allocation systems for deceased donors and paired exchange schemes in terms of assessment for HLA-A,B,DR and DQ mismatch. The aim of our study is to assess the effect of HLA-A,B,DR and DQ mismatch on kidney transplant graft survival in the current era. Methodology: All renal transplant patients registered in the United Kingdom Transplant Registry database between January 2005 till January 2015 were retrospectively reviewed. Patients with complete data about HLA-A,D,DR and DQ mismatch were included. Follow up was till April 2021.Patient with complete dataset were included in the study. Recipients with multiple organ transplant, previous renal transplants, or those with missing data about HLA mismatch were excluded from the study. For survival analysis, we fit a penalised Cox model to the entire set of data. We obtained the estimated set of alphas using estimated cross-validated grid-search. The variables included in the penalised cox model donor, recipient and transplant factors in addition to the HLA mismatches. Then we determined the set of alpha for evaluation using optimized cross-validated grid-search. Moreover, we visualised how the coefficients changed for varying α using ridge regression model. The regression models were adjusted for recipient factors (age, sex, ethnicity, diabetes, body mass index), transplant factors (HLA mismatches, calculated reaction frequency, cold ischemia time, delayed graft function, induction, and maintenance immunotherapy) and donor factors (donor type, donor creatinine at time of retrieval, donor age). Results: Median follow-up was 7.5 years. Among living donor kidney transplant recipients (n=4782), Incremental increase in HLA-DR mismatch touched statistical significance and was associated with worse survival (Two HLA-DR: HR=1.31, P=0.05, 95%CI: 1.0-1.72; One HLA-DR mismatch: HR=1.21, P=0.05, 95%CI: 1.00-1.47). None of the other categories of HLA mismatches were associated with worse graft outcomes (P>0.05 for each category).Other factors that played an important role in determining graft survival were delayed graft function (P<0.01), black ethnicity (HR=1.88, 95%CI:1.45-2.51, p<0.01), and donor age (HR=1.02, P<0.01). Among deceased donor kidney transplant recipients (n=7996), None of the HLA mismatches were associated with worse graft survival (P>0.05 for each category of HLA mismatches). The factors that played an important role in determining graft survival were delayed graft function (HR=1.84, 95%CI: 1.67-2.03, P<0.01), black ethnicity (HR=1.42, 95%CI:1.21-1.65, p<0.01), donor age (HR=1.02, P<0.01), and recipient age (HR=0.99, P<0.01). Conclusion: In the current era, HLA-DR mismatches are associated with worse graft outcomes among living donor transplants. However, none of the HLA mismatches are associated with worse graft outcomes among deceased donor kidney transplant recipients. Other factors that play an important role in determining graft survival are delayed graft function, donor age and black ethnicity.

P8.152: Clinical Characteristics and Factors Related to Recurrent Cytomegalovirus Infection Post-kidney Transplant in Adult Patients at Cho Ray Hospital

Introduction: Cytomegalovirus (CMV) is one of the main causes of opportunistic infections after kidney transplantation. Manifestations of CMV disease in post renal transplantation patients are quite discreet, non-specific and difficult to diagnose early. Asymptomatic recurrent CMV infection has been reported remarkably to increase mortality rate and rejection incidence, and effect on graft survival. The recently follow-up and treatment procedures’ changes make it urgent to re-evaluate the incidence and the factors related to the risk of CMV recurrence as well as the clinical characteristics of CMV infection in postkidney transplantation patients. This helps to control the recurrence of CMV infection as well as to diagnose CMV disease early and treat it promptly and appropriately to reduce the mortality rate of patients after transplantation. Method: Objective 1: Retrospective cohort study of adult renal transplant recipients between January 1, 2015 and December 31, 2018. Objective 2: A cross - sectional descriptive study on 22 cases of CMV disease in post kidney transplant patients to present a review of the main clinical aspects of cytomegalovirus infection in renal transplants with a focus on clinical approach and its future perspectives. Results: Objective 1: A total of 365 patients who received a renal transplant at Cho Ray hospital in the study time period were reviewed for the presence of CMV infection occurring less than 540 days after transplant. The recurrent CMV infection was observed in 254 cases (69,6%), but only 3 patients (0,8%) developed CMV disease. Independent risk factors of CMV infection were HLA >80 (HR = 2,309, 95% CI 1,021 – 4,071, p = 0,044), daily oral Prednisone doses used <0,5 mg/kg/day (HR = 0,178, 95% CI 0,084 – 0,374, p <0,001), Tacrolimus whole blood trough concentration ≤10 µg/L (HR = 0,445, 95% CI 0,243 – 0,816, p = 0,009), Cyclosporine wole blood trough concentration >150 µg/L (HR = 4,25, 95% CI 1,97 – 9,2, p < 0,001). Objective 2: Male majority (2/3), with average age of 47,5 ± 4,5. Rate of symptomic recurrence CMV infection in the first 6 months, 6 - 12 months, 1 - 5 years, 5 - 10 years after transplant were 45,4%, 9,1%, 27,3% and 18,2% respectively. Common clinical manifestations are fever 59,1%, respiratory, renal and gastrointestinal manifestations 31,8%, 27,3% and 13,6%, respectively. Two cases of CMV retinitis with typical fundus lesions were treated with intraocular Ganciclovir, however, vision was not fully recovered. Lymphopenia <1.000 cells/mm3 was observed in most cases of CMV disease after kidney transplantation. Quantitative PCR of CMV DNA in plasma ranged from 375 – 6.533.850 copies/mL. 6 of 22 cases of PCR CMV DNA in plasma >4.000 copies/mL, of which 5 severe cases developed rapidlly progressive respiratory failure and 2 deaths. Conclusion: Recurrent CMV infection has a high rate in adult patients after kidney transplantation, so it is necessary to take initiactive for screening, monitoring and treating early to reduce mortality and protect the transplanted kidney. The appropriate dose of immunosuppressants plays an important role in the prevention of recurrent CMV infection and the successful treatment of disease due to it. Key words: Cytomegalovirus, Kidney transplantation, Post-transplant infection. * Deparment of Tropical diseases– Cho Ray Hospital ** Nephrology Surgery – Cho Ray Hospital Coresponding author: Tho A. N. Vo, Deparment of Tropical diseases– Cho Ray Hospital. Email: [email protected]. Mobile: 0983888841.

Surgery Is Underutilized in the Management of Tertiary Hyperparathyroidism.

Tertiary hyperparathyroidism (3HPT) is observed in up to 40% of renal transplant patients. Standard guidelines defining 3HPT and indications for operative intervention are not well described. We conducted a retrospective, single-institution cohort study of patients who underwent renal transplant between January 1, 2012 and January 30, 2018, with a minimum of 13-month follow-up and at least 1y of allograft function. We defined 3HPT as having elevated serum level parathyroid hormone (>88 pg/mL) after successful renal transplantation or multiple instances of elevated serum calcium starting at least 3mo after transplant. We compared graft failure rates after stratifying the cohort based on management strategy: expectant, medical management with cinacalcet, and parathyroidectomy. Out of the 381 transplanted patients with functional grafts at 1y, 178 patients (46.6%) were found to have 3HPT. One hundred twenty-nine patients (72.5%) were managed expectantly without medications, 35 patients (19.7%) were managed medically, and 14 patients (7.8%) were managed with parathyroidectomy. Twenty-two patients (17.1%) in the observation group had graft failure, 4 patients (11.4%) in the medically managed group had graft failure, and 0 patients in the surgery group had graft failure. Surgical intervention was associated with decreased renal allograft failure when compared to the combined cohort of nonoperative 3HPT patients (P=0.03). All patients who underwent parathyroidectomy were cured and did not have graft failure as of December 30, 2019. Calcium elevation, but not PTH elevation, was associated with referral for parathyroidectomy on multivariable logistic regression analysis (P<0.01). At our institution, the referral rate for parathyroidectomy among patients with 3HPT remains low. Parathyroidectomy was associated with high cure rates and reduced graft failure. Surgery may be underutilized in the management of 3HPT.

P16.18: Behavior of Anti- SARS-CoV-2 Antibodies in Renal Transplant Patients Vaccinated Prior to Transplantation

P16.18: Behavior of Anti- SARS-CoV-2 Antibodies in Renal Transplant Patients Vaccinated Prior to Transplantation