Is there any correlation between pathologic changes for acute rejection in kidney transplantation (Banff 97) and graft function?

How Should Acute T-cell Mediated Rejection of Kidney Transplants Be Treated: Importance of Follow-up Biopsy

Background.

Limited published data exist to guide patient monitoring after the treatment of T-cell mediated rejection (TCMR) of kidney allografts.

Methods.

We reviewed the kidney function and histological outcomes after treatment of 163 first episodes of biopsy-proven TCMR between January 1‚ 2015‚ and July 31‚ 2020.

Results.

Of the 146 patients treated with steroid pulse alone, complete histological response was seen in 83% of patients with borderline rejection, 82.5% with grade 1A, 67% with grade 1B, and 50% with grade IIA. Of the 17 patients treated with steroids plus antithymocyte globulin, the complete histological response rate was 100% with grade 1A, 75% with grade 1B, 100% with grade IIA, and 57% with grade IIB. Among the patients with complete response as assessed by kidney function, 14% only had a partial or no response histologically. Among patients with no kidney function response, 68% had a complete response histologically.

Conclusion.

We thus find that responses based on kidney function alone do not correlate well with histological responses. If further treatment had been based solely on changes in estimated glomerular filtration rate, a significant number of patients would have been subsequently undertreated or overtreated. These results support the use of protocol follow-up biopsies after the treatment of TCMR.

Allograft outcomes of treated children with kidney transplant who developed plasma cell-rich acute rejection (PCAR): A single center's experience

INTRODUCTION

PCAR is a rare form of ACR that may compromise renal allografts. This review evaluates the outcomes of a protocol used to treat PCAR (Study group), and compares these outcomes with a matched cohort with ACR (Control group).

METHODS

A retrospective analysis of 138 of pRTRs who underwent renal allograft biopsies between January 2008 and November 2016.

RESULTS

Seven biopsies revealed in situ hybridization of EBER-negative PCAR (5%). Three Study group pRTRs lost their grafts within 3 months after rejection (43%). None of the Control group pRTRs lost their graft during this period. At the time of rejection, eGFR was different between the Control and Study groups (27.0 ± 19.9 mL/min per m² vs 40.0 ± 10.6 mL/min/1.73 m² , respectively; P < 0.05). Among Study group pRTRs with functioning allografts (n = 4), treatment resulted in an increase in eGFR from nadir levels (27.0 ± 19.9 vs 55.6 ± 18.3 mL/min/1.73 m² , P < 0.05). In the Study group, complications included neutropenia, BK and EBV viremia, and infusion-related hypotension and hypertension.

SUMMARY

(a) Graft loss in Study group while remaining high (43%) was lower than that reported in the published pediatric literature. (b) Our protocol was associated with improvement in eGFR in all surviving pRTRs within the Study group. (c) No life-threatening complications or malignancy were reported during the observation period.

Acute cellular rejection treatment outcomes stratified by Banff grade in pediatric kidney transplant

INTRODUCTION

There are limited data to guide optimal treatment strategies for acute cellular rejection (ACR) based on Banff grade for pediatric kidney transplant recipients. This report reviews a large pediatric transplant center's experience with ACR.

MATERIALS AND METHODS

A retrospective analysis of pediatric kidney transplant recipients at our center from 2007 to 2014 was performed. Primary outcomes were incidence of graft failure and graft function one year following ACR based on Banff grade and treatment received.

RESULTS

A total of 204 patients were reviewed, of which 65 received rejection treatment with either an oral steroid cycle (n = 16), intravenous steroid pulse (n = 28), or anti-thymocyte globulin (rATG, n = 21). Overall, patients received rATG for treatment of more severe rejection associated with impaired graft function and as a group experienced statistically significant improvements in eGFR over the year following treatment, though most did not regain baseline graft function.

DISCUSSION

Our data suggest that rATG is partially effective in treating ACR, but our study was underpowered to determine the effect of different treatments based on Banff grade. Since there is limited literature to guide clinical treatment of ACR in children, large transplant centers should collaborate to evaluate outcomes and establish evidence-based practice.

Efficacy of Acute Cellular Rejection Treatment According to Banff Score in Kidney Transplant Recipients: A Systematic Review

Supplemental digital content is available in the text.

Background

The poor prognosis classically associated with Banff grade 2 acute cell-mediated rejection (CMR) may be due to unrecognized antibody-mediated damage. We thus performed a systematic review of the literature to determine the rate of response to treatment in kidney transplant recipients with pure CMR, stratified by Banff class.

Methods

In addition to a manual search, databases interrogated included Excerpta Medica Database (EMBASE), Medical Literature Analysis and Retrieval System Online (MEDLINE), Evidence-Based Medicine (EBM) databases, Central, PubMed and CINAHL. Studies providing functional and/or histological response rates to the treatment of CMR rejection by Banff class (1997 or more recent) were included.

Results

Among the 746 articles identified, 5 articles were included in the final review. Two studies excluded some, and 2 excluded all features of antibody-mediated rejection, while providing data on functional recovery. The absence of functional recovery was reported in 4% of borderline, 15% for Banff grade 1A and IB pooled, 0% to 25% of Banff grade 1B alone, 11% to 20% of Banff grade 2A, and 38% of Banff grade 2B rejections.

Conclusions

The rate of functional recovery of pure Banff IIA CMR overlapped with that of Banff grade 1 CMR, whereas Banff grade 2B showed worse prognosis. There was important heterogeneity in the definition of response to treatment and paucity of data describing the histological response to treatment stratified by Banff class. There is a pressing need to standardize outcome metrics for the reversibility of rejection in kidney transplant recipients in order to design high-quality trials for novel therapeutic alternatives.

Renal transplant biopsy specimen adequacy in a paediatric population

Updated guidelines on the diagnosis of acute allograft rejection including criteria for biopsy specimen adequacy were published in 1999. We sought to determine the adequacy of specimens in paediatric transplant patients and identify factors influencing adequacy. All renal transplant biopsies performed between 1998 and 2003 were classified as adequate (n =25), minimal (n =19) or inadequate (n =27) in accordance with the Banff 97 criteria, and the histological diagnoses were documented. The effect on specimen adequacy of grade of operator, method of sedation, age of child, needle gauge, number of cores and total core length was then investigated. Overall, a minimal or adequate specimen was obtained in 62% of cases. No histological diagnosis could be made in 30% of all specimens, just over half of which were inadequate. Higher rates of rejection were found in adequate (52%) than inadequate (33%) samples. The grade of operator (p =0.498), the age of the child at the time of biopsy (p =0.815) and type of sedation (p =0.188) did not affect adequacy. More than one core was obtained in 38 (54%) cases, and this was significantly associated with specimen adequacy (p <0.0005) as was longer total core length (p =0.002). Clinical features in isolation are not sufficient for the diagnosis of acute allograft rejection. Renal biopsy remains the gold standard and relies on adequate specimen collection. Our data shows that specimen adequacy according to the Banff 97 guidelines is achievable in children and that more than one core at the time of sampling significantly improves this achievement. Adequate sampling reduces the risk of an inconclusive histological diagnosis.

Predictive Value of Banff Score of Early Kidney Allograft Biopsies for 1-Year Graft Survival

The aim of this study was to evaluate the Banff score of early kidney allograft biopsies, taken during the first month after transplantation, seeking an association between early rejection and acute tubular necrosis. We analyzed data from 71 patients transplanted between 2000 and 2004 who had renal allograft biopsies performed within the first posttransplant month (23 women, 48 men), ages 18 to 67 years. All biopsies performed in cases of delayed or deteriorated graft function were graded according to the Banff' 97 classification. Twelve months after transplantation, 19 patients exhibited excellent renal function (group 1, serum creatinine concentration [Scr] < or = 1.5 mg/dL); 25 patients demonstrated preserved renal function (group II, Scr 1.51-1.99 mg/dL); and 19 patients showed deteriorated renal function (group III, Scr > or = 2.0 mg/dL). Eight recipients lost their grafts within 1 year after transplantation (group IV). The Banff index was defined as a sum of all components (value of glomerulitis ["g"] + interstitial inflammation ["i"] + tubulitis ["t"] + arteriolar hyaline thickening ["ah"] + intimal arteritis ["v"]). The deterioration of renal function was associated with a higher Banff index; patients who lost their grafts showed the highest values of this index. Scores of "v," "ah," and Banff index were positively correlated with serum creatinine concentrations at 28, 90, 180, and 360 days (P < .05). Glomerulitis ("g") was correlated with creatinine concentrations at 90 and 360 days (P < .05). Tubulitis ("t") and interstitial inflammation ("i") displayed no association with renal function at any time.