Donor Characteristics, Recipient Outcomes, and Histologic Findings of Kidney Allografts With Diffuse Donor-derived Glomerular Fibrin Thrombi

Abstract

Background. Limited data are available on whether donor kidneys with diffuse glomerular fibrin thrombi (GFT) are safe to use. In this study, the clinicopathologic characteristics of allografts with diffuse donor-derived GFT were examined. Methods. All deceased donor kidney transplant implantation biopsies from our institution between July 2011 and February 2018 with diffuse GFT were included. A control group for comparison consisted of all cases with implantation biopsies obtained during the study period without diffuse GFT. Clinical data were extracted from electronic medical records for all study patients, including donor information. Results. Twenty-four recipients received kidneys with diffuse GFT from 16 deceased donors. All donors died from severe head trauma. On average, 79% of glomeruli contained fibrin thrombi. Nineteen cases had subsequent biopsy; all revealed resolution of GFT. Compared with the control group, kidneys with diffuse GFT had longer cold ischemia time (34 versus 27 h), were more frequently pumped using machine perfusion (100% versus 81%), and recipients experienced a higher frequency of delayed graft function (58% versus 27%). Only 2 grafts with diffuse GFT failed within the first year. Overall graft survival was similar between the diffuse GFT group and control group. Conclusions. Deceased donor kidneys with diffuse GFT appear to be safe to use given that nearly 92% of recipients in this cohort who received such allografts experienced good clinical outcomes. Histologically, GFT demonstrated rapid resolution following transplantation. Interestingly, diffuse GFT only occurred in donors who suffered severe head trauma in this cohort, which may be a predisposing factor.

Aggravation of fibrin deposition and microthrombus formation within the graft during kidney transplantation

“…The occurrence of glomerular brin thrombi (GFT) has been investigated before, especially since GFT in preimplantation biopsies are sometimes used to accept or decline a deceased donor kidney offer. Incidences of GFT vary from 2.6-9.9% [11][12][13]. In our study GFT were present in 7.1% of the DDK.…”

“…The fact that the number of microthrombi/mm 2 is equal after reperfusion in both LDK biopsies and DDK biopsies, however, indicates that the majority of microthrombi develop upon reperfusion of the graft and to a lesser extend in the donor. This nding is clinically relevant since previous studies mainly focused on formation of microthrombi in preimplantation biopsies or its association with disseminated intravascular coagulation in the donor, assuming that microthrombi are donor-derived [9][10][11][12][13]. Our results show that this is not the case, as LDK derived from relatively healthy donors exhibit a steady development from 0.09 microthrombi/mm 2 in preimplantation biopsies to 1.19 microthrombi/mm 2 in reperfusion biopsies.…”

“…Two other studies nonetheless report that the majority of GFT resolve within 1 to 3 months after transplantation, and conclude that GFT do not in uence kidney function after transplantation or lead to more brosis or glomerulosclerosis [11,25]. A recent study [12] came to the same conclusion, although it is debatable whether their cut-off of < 50% brin thrombi positive glomeruli -compared to a study using 15% [26] does not underestimate the results. In other words, it is still unclear whether a kidney with 30% of glomeruli affected by brin thrombi will have a function similar to that of a kidney with 10% or 45%.…”

Aggravation of fibrin deposition and microthrombus formation within the graft during kidney transplantation

“…The fact that the number of microthrombi/mm 2 is equal after reperfusion in both LDK biopsies and DDK biopsies, however, indicates that the majority of microthrombi develop upon reperfusion of the graft and to a lesser extend in the donor. This finding is clinically relevant since previous studies mainly focused on formation of microthrombi in preimplantation biopsies or its association with disseminated intravascular coagulation in the donor, assuming that microthrombi are donor-derived [9][10][11][12][13] . Our results show that this is not the case, as LDK derived from relatively healthy donors exhibit a steady development from 0.09 www.nature.com/scientificreports/ microthrombi/mm 2 in preimplantation biopsies to 1.19 microthrombi/mm 2 in reperfusion biopsies.…”

“…The occurrence of glomerular fibrin thrombi (GFT) has been investigated before, especially since GFT in preimplantation biopsies are sometimes used to accept or decline a deceased donor kidney offer. Incidences of GFT vary from 2.6% to 9.9% [11][12][13] . In our study GFT were present in 7.1% of the DDK.…”