Clinical and morphological characteristics of biopsy-proven kidney graft rejection in Latvia

Research output: Contribution to journalMeeting Abstractpeer-review

Abstract

Background and Aims: Kidney transplantation is a treatment for many patients with end stage renal disease leading to increased
quality of life. In last decades results in kidney transplantation have been improving, but allograft rejection remains an important
clinical problem. Graft biopsy remains the gold standard to assess the cause of kidney transplant status. This study aimed to determine
clinical and histopathological characteristics, treatment and short-term outcomes of biopsy-proved kidney graft rejection in Latvia.
Method: In this retrospective observational study all kidney allograft biopsies performed in Pauls Stradins Clinical University Hospital
from January 2014 till December 2022 was reviewed. Biopsies with rejection, ≥7 glomeruli, patients ≥18 years old were included. Acute
rejection was diagnosed according to clinical, laboratory and biopsy-proven acute rejection (BPAR) histological criteria. BPAR was
classified and subdivided using Banff criteria. All recipients universally received either depleting or non-depleting induction therapy.
Most of the patient (82%) for maintenance immunosuppression (MI) received triple therapy with calcineurin inhibitor, mycophenolate
mofetil, and prednisone, others—in different combinations with above and mammalian target of rapamycin (mTOR), azathioprine.
Graft function was evaluated according to glomerular filtration rate (GFR), calculated with the CKD-EPI Creatinine, 2021 equation.
Treatment strategies, laboratory data at the time of biopsy and after 1 year follow-up were analysed. Repeated-control biopsies after
receiving therapy were excluded. Data were analysed using descriptive statistics and T-test.
Results: From all 523 biopsies, further included and analysed were 153 (total 146 patients). 58% were males, average patient age was
45.5 years. Most 84% of the grafts were from deceased, 8%—living donors. Mean time from transplantation to biopsy was 32 months.
Acute antibody-mediated rejection (AAMR) was diagnosed in 41% cases, chronic-active antibody mediated (CAAMR)—25%, followed
by mixed 16%, acute cellular (ACR) 10% and borderline 8% rejection. Besides augmented MI for almost all patients, pulse steroids (GCS)
were the most commonly 70% administered treatment, followed by plasma exchange 59% (PEX), rituximab (RTX) 50%, immunoglobulins (IG) 24% and anti-thymocyte globulin (ATG) 10% in different, mostly non-homogenous combinations. Non adherence, advanced
fibrotic changes in biopsy and serious comorbidities were the main reasons patients did not receive specific treatment besides intensified MI. The most favourable outcomes were in ACR where mean allograft GFR increased +20.7 ml/min after one year, compared
to the worst outcome CAAMR group where GFR decreased −4.7 ml/min (p = 0.03). In ACR group 92% graft function stayed the same
or improved, moreover 54% graft function increased ≥20% from baseline; similarly in mixed and AAMR group GFR increase ≥20%
were for 45% and 48%, compared to CAAMR where it was only for 6% of patient. Furthermore, the CAAMR group was with the most
patients (48%) who returned to dialysis or died. In AAMR and mixed rejection groups mean GFR changes were close +13.4 ml/min
and +12.9 ml/min (p = 0.95). There were no statistically significant associations between treatment outcomes in PEX+RTX+GCS vs
PEX+RTX+GCS+IG in the AAMR group (p = 0.382). Overall, 3.9% of patients died.
Conclusion: Overall BPAR prevalence between kidney graft biopsies was high (29%). Antibody mediated rejection was diagnosed most
often with least favourable short-term outcomes in CAAMR group. Despite various improvements in immunosuppression, CAAMR
remains a serious cause of transplant dysfunction or loss.
Original languageEnglish
Article number#2859
Pages (from-to)i2657-i2657
Number of pages1
JournalNephrology Dialysis Transplantation
Volume39
Issue numberSuppl. 1, May 2024
Publication statusPublished - May 2024
Event61st European Renal Association (ERA) Congress: Inspiring Kidney Care - Stockholm, Sweden
Duration: 23 May 202326 May 2023

Field of Science*

  • 3.2 Clinical medicine

Publication Type*

  • 3.3. Publications in conference proceedings indexed in Web of Science and/or Scopus database

Fingerprint

Dive into the research topics of 'Clinical and morphological characteristics of biopsy-proven kidney graft rejection in Latvia'. Together they form a unique fingerprint.

Cite this