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Development of de novo HLA donor specific antibodies (HLA-DSA), HLA antibodies (HLA-Ab) and allograft rejection post blood transfusion in kidney transplant recipients

Jalalonmuhali M, Carroll RP, Tsiopelas E, Clayton P, Coates PT

Hum Immunol, 2020 Jul;81(7):323-329.
PMID: 32327243 DOI: 10.1016/j.humimm.2020.04.002

BACKGROUND: Blood transfusion during the post-operative period of kidney transplantation is common as part of a life-saving procedure, especially in the event of acute blood loss. However, there have been conflicting opinions since the pre-cyclosporine era. The risk of sensitization post-transfusion remains the main limiting factor following transfusion in kidney transplant recipients. Thus, the objective of this study is to assess the development of de novo HLA-DSA, HLA-Ab and allograft rejection post blood transfusion.
METHODOLOGY: This is a retrospective cohort study recruiting all kidney transplant recipients in South Australia from January 2010 till December 2018. Following that, the incidence of blood transfusion within one week post-operatively were traced (transfusion group). The outcomes were compared with all other transplant recipients (non-transfusion group). Recipient's demographic, donor characteristics and immunological risk profiles were obtained from the transplant unit database, while the biopsy report, history of blood transfusion, latest serum creatinine and follow-up status was gathered from the electronic medical system (OASIS). The HLA-DSA and HLA-Ab results were collected from the NOMS database. Finally, the survival data were merged with the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry for South Australia recipients graft survival.
RESULTS: A total of 699 patients were eligible for analysis. The mean age was 50.64 ± 13.23 years old. There were more elderly (>65 years old) and females who needed transfusion. The majority had glomerulonephritis as the primary disease. There was no statistical difference in donor characteristics, cold ischemic time and immunological risk between the transfusion and non-transfusion group. There was no difference in the development of de novo HLA-DSA, HLA-Ab and rejection episodes between the group and the results were consistent in a model adjusted for all potential confounders. Median graft survival in days between the transfusion vs non-transfusion group was 1845 IQR (961,2430) and 1250 IQR (672,2013).
CONCLUSION: Blood transfusion under strong immunosuppressive cover within a one-week post-operative period is safe with no significant association with the development of de novo HLA-DSA, HLA-Ab or clinical rejection.

Matched MeSH terms: Graft Rejection/immunology
Proactive treatment of angiotensin receptor antibodies in kidney transplantation with plasma exchange and/or candesartan is safe and associated with excellent graft survival at 4 years: A single centre Australian experience

Carroll RP, Deayton S, Emery T, Munasinghe W, Tsiopelas E, Fleet A, et al.

Hum Immunol, 2019 Aug;80(8):573-578.
PMID: 31014826 DOI: 10.1016/j.humimm.2019.04.005

High levels of angiotensin receptor antibodies (ATRab) are associated with acute cellular and humoral rejection, vascular occlusion, de novo human leucocyte antigen donor specific antibody (HLA DSA) and poor graft survival in kidney transplant recipients (KTR). Since 2015 we proactively managed patients "at risk" (AR) with ATRab >17 U/ml with perioperative plasma exchange (PLEX) and/or angiotensin receptor blockade (ARB). 44 patients were treated with this protocol. 265 KTR with ATRab ≤17 U/ml deemed "low risk" (LR) were transplanted under standard conditions. PLEX and ARB were not associated with increased risk of: delayed graft function requiring haemodialysis (HDx), hyperkalaemia >5.5 mmol/l requiring HDx, and the combined clinical end-point of severe hypotension, blood transfusion and re-operation for bleeding. Rejection rates were similar at 90 days: 8/44 (18%) in the AR group and 36/265 (14%) in the LR group (p = 0.350). Death censored graft survival was the same between the AR and LR groups with a 94% 48-month graft survival - hazard ratio (log-rank) 1.16 [95% CI 0.2-5.8] p = 0.844. Proactive treatment of ATRab >17 U/ml with PLEX and/or ARB is not associated with increased rates of perioperative complications and comparable rates of rejection and death censored graft survival at 4 years compared to KTR <17 U/ml ATRab.

Matched MeSH terms: Graft Rejection/immunology*
Prevalence of AT1R antibody (AT1R-Ab) among Malaysian multi-ethnic population

Jalalonmuhali M, Caroll R, Deayton S, Emery T, Humphreys I, Lim SJ, et al.

Hum Immunol, 2020 Dec;81(12):679-684.
PMID: 32736900 DOI: 10.1016/j.humimm.2020.07.005

BACKGROUND: Angiotensin II type 1 receptor antibody (AT1R-Ab) is a non-HLA antibody that has been reported to cause antibody-mediated rejection and graft loss in kidney transplantation. The prevalence of positive AT1R-Ab varies between 8% and 18% in different regions. Thus, this study aims to determine the prevalence of AT1R-Ab among the Malaysian population.
METHODOLOGY: All sera for AT1R-Ab were collected at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The sera were centrifuged and kept refrigerated at -80 °C before being transported to the South Australian Transplantation and Immunogenetics Laboratory (SATIS). Enzyme-linked immunosorbent assay kit (One Lambda) was used for the detection of AT1R-Ab, and it was performed according to the manufacturer's instructions. The level of >17.1 U/mL was considered to be AT1R-Ab positive; 10.0-17.1 U/mL at risk, and <10.0 U/mL negative.
RESULTS: A total of 115 samples were collected from 99 patients pre and post-kidney transplant recipients. From the pre-transplant sera (n = 68) 17.7% were positive, 35.3% were at risk and 47.0% were negative. The positive AT1R-Ab cohort were relatively younger, with a mean age of 34.7 ± 8.3 years old and statistically significant, with a p-value of 0.028. Among the sera that were tested positive, 19.0% were from the Chinese ethnicity, 6.7% from Malay and 16.7% from Indian. There was no difference in the rejection episodes, persistent or de novo HLA-DSA, and graft function between the group (AT1R-Ab negative vs AT1R-Ab at risk and positive) and the results were consistent in a model adjusted for all potential confounders.
CONCLUSION: The prevalence of positive (>17.1 U/mL) pre-transplant AT1R-Ab was 17.7% and 35.3% were at risk (10.0-17.1 U/mL) in our pre-transplant cohort.

Matched MeSH terms: Graft Rejection/immunology*
Fulltext ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia

Gan CC, Jalalonmuhali M, Nordin NZ, Abdul Wahab MZ, Yahya R, Ng KP, et al.

Transplant Proc, 2021 Apr;53(3):856-864.
PMID: 33487455 DOI: 10.1016/j.transproceed.2020.10.038

Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.

Matched MeSH terms: Graft Rejection/immunology
Low Immunologic Risk Living Related Renal Transplant Using Very Low-Dose Antithymocyte Globulin as Induction Therapy: A Single Tertiary Hospital Experience

Jalalonmuhali M, Ng KP, Ong CS, Lee YW, Wan Md Adnan WAH, Lim SK

Transplant Proc, 2020 05 21;52(6):1709-1714.
PMID: 32448669 DOI: 10.1016/j.transproceed.2020.02.139

The aim of induction therapy in the management of kidney transplant is to reduce the incidence of acute rejection and delayed graft function after kidney transplant. The agent for induction therapy differs depending on the recipient risks. The regimen can be either polyclonal (rabbit antithymocyte globulin [rATG]) or monoclonal antibody (basiliximab). Basiliximab is commonly used in patients with low immunologic risk. However, to date we know that the use of rATG on T cell depletion is dose dependent and more potent antirejection therapy. Therefore, we would like to look at 1-year graft function of very low-dose rATG in low immunologic risk recipients. All low immunologic risk patients who received low-dose rATG (0.5 mg/kg of body weight daily) during transplant (day 0) and on days 1 and 2 were recruited. Their renal function, HLA donor-specific antibodies, lymphocyte counts, protocol biopsy results, and cytomegalovirus (CMV) polymerase chain reaction were monitored as per clinical practice. All 10 patients had immediate graft function. Low-dose rATG caused lymphocyte counts to deplete immediately on day 0, and the effect lasted about 1 month post-transplant. All the patients had stable graft function without any significance episode of rejection. Only one patient had de novo HLA-DQ antibody. It is good to know that without prophylaxis antiviral in CMV+ donor to CMV+ recipient, the incidence of CMV viremia is considerably low in our cohort. Very low-dose rATG is an effective induction immunosuppression in low immunologic risk patients with acceptable infection risk.

Matched MeSH terms: Graft Rejection/immunology
One-Year Outcomes of Living Related Kidney Transplant in Patients With Preformed HLA Donor-Specific Antibodies: A Single-Center Experience in Malaysia

Jalalonmuhali M, Ng KP, Mohd Shariff NH, Lee YW, Wong AH, Gan CC, et al.

Transplant Proc, 2020 05 21;52(6):1718-1722.
PMID: 32448671 DOI: 10.1016/j.transproceed.2020.02.140

The shortage of deceased donors led to an increase of living related renal transplant performed in the presence of donor-specific antibodies (DSAs) or ABO incompatibilities. There are various desensitization protocols that have been proposed. Here, we describe the outcome of these sensitized patients. This is a prospective cohort study recruiting all kidney transplant recipients from August 2016 until June 2018. Deceased donations, ABO incompatible patients, and sensitized patients who were not prescribed on our desensitization protocol were excluded. Recipients were screened for the presence of HLA-antibodies 1 month before transplant. Those with positive DSA will undergo flow cytometry (risk stratification). We are using a protocol that consisted of intravenous rituximab 200 mg (day -14), intravenous antithymocyte globulin 5mg/kg (day 0-4), plasma exchange post transplant for patients with mean fluorescent intensity (MFI) < 3000, and negative flow cytometry. Those patients with MFI ≥ 3000 or positive flow cytometry need extra cycles pretransplant. A total of 40 patients were recruited, and 20 were sensitized patients. Among the sensitized group 4 of 20 had flow cytometry crossmatch positive, while all had preformed HLA-DSA. A total of 8 of 20 had class I HLA-DSA, 11 of 20 had class II HLA-DSA, and 1of 20 was positive for both class I and II HLA-DSA. Mean immunodominant MFI was 2133.4 (standard deviation [SD], 4451.24) and 1383.7 (SD, 2979.02) for class I and class II, respectively. At 1 year, mean serum creatinine was 108.90 (SD, 25.95) and 118.42 (SD, 31.68) in sensitized and unsensitized patients, respectively. One of 20 unsensitized patients had Banff 1B rejection at 3 months, and there was no significant rejection in sensitized patients at 6 months and 1 year. There was no difference in the occurrence of de novo HLA-DSA between the groups. Desensitization protocols may help to overcome incompatibility barriers in living donor renal transplant. The combination of low-dose rituximab, antithymocyte globulin, and judicious use of plasma exchange has worked well for our cohort.

Matched MeSH terms: Graft Rejection/immunology*