Clinicopathological Results of Percutaneous Transplant Kidney Biopsy as a Marker of Graft Survival in Georgia

Kidney transplantation remains the preferred treatment for patients with kidney failure. Living-donor kidney transplantation has been an established treatment in Georgia, with a population of 3.7 million. From 1995 to 2023, four hundred thirty-three kidney transplant recipients were listed in the national transplant e-records system. Among them, 330 received grafts from living-related donors (76% of all kidney transplants). The rest received the graft abroad from cadaver donors.

This retrospective study aimed to explore long-term graft and patient survival based on the national kidney biopsy registry and governmental dialysis and transplant e-records system data. We included both living-related and deceased transplant recipients in the study. Data of 128 kidney graft recipients were extracted from the kidney biopsy registry and the national transplant e-records system between 1 January 2013 and 31 August 2023. Among them, 116 were living-related transplant recipients. For categorical variables, the Chi-square test was used for unilabiate comparisons. Cox regression analysis was performed, and the results were presented as hazard ratio (HR) and 95% confidence intervals (CI).

Out of the 128 patients, 35% were female and 65% were male. The median age at biopsy was 35 years (IQR: 28–47). The median time between transplantation and the first biopsy was 30 months (IQR: 7–66). However, 10% of the biopsies were performed within 1 month, and 90% within 113 months from transplantation. The follow-up time after biopsy was 25 months (IQR 5–56). All histological diagnoses were grouped into nine diagnostic categories, as described in Table 1.The main indication for kidney transplant biopsy was proteinuria (15%) and a decrease of GFR (85%).

Table 1: Characteristics of kidney transplant recipients (N=128) who underwent a renal transplant biopsy between 2013and 2023

Rejection was diagnosed in 39.6% (51/128) of patients. The rejections were further divided into subcategories, where acute T-cell-mediated rejection was noted in 29 (22.7%) of all rejection types: Chronic TCMR 1 (0.79%), Chronic Active TCMR 7 (5.56%) Active ABMR 10 (7.94%) Chronic ABMR. 4(3.17%) Chronic active ABMR 4 (3.17%),Combined Active ABMR and Acute TCMR 0, and Combined Chronic ABMR and Chronic TCMR 1 (0.79%)The most prevalent biopsy diagnosis among living donors and deceased donors is chronic changes, including IFTA (52.6% and 58.3%), followed by rejection (39.5% and 41.7%), and glomerular disease (24.6% and 33.3%). FSGS was 13 and IgA nephropathy was 9. The least prevalent diagnosis among living donors is minor abnormalities (0.9%). Among deceased donors, we have not seen any infections or TIN, as well as minor abnormalities.

Patients suvaival.  

There were 15 patients (11.7%) who died during the follow-up. The median age of these patients at biopsy time was 33 years (IQR 29–50). The most common causes of death among all patients were infection (41%), and cardiovascular disease (29%).

The risk for graft loss was significantly higher for patients with glomerular diseases than for all other diagnoses. The most common causes of death among all patients were infection (41%), and cardiovascular disease (29%).