Borderline changes in the banff schema: rejection or no rejection?

Three-month course of intragraft transcriptional changes in kidney allografts with early histological minimal injury - a cohort study

The tubulitis with/without interstitial inflammation not meeting criteria for T-cell-mediated rejection (minimal allograft injury) is the most frequent histological findings in early transplant biopsies. The course of transcriptional changes in sequential kidney graft biopsies has not been studied yet. Molecular phenotypes were analyzed using the Molecular Microscope^® Diagnostic System (MMDx) in 46 indication biopsies (median 13 postoperative days) diagnosed as minimal allograft injury and in corresponding follow-up biopsies at 3 months. All 46 patients with minimal injury in early biopsy received steroid pulses. MMDx interpreted indication biopsies as no-rejection in 34/46 (74%), T-cell-mediated rejection (TCMR) in 4/46 (9%), antibody-mediated rejection in 6/46 (13%), and mixed rejection in 2/46 (4%) cases. Follow-up biopsies were interpreted by MMDx in 37/46 (80%) cases as no-rejection, in 4/46 (9%) as TCMR, and in 5/46 (11%) as mixed rejection. Follow-up biopsies showed a decrease in MMDx-assessed acute kidney injury (P = 0.001) and an increase of atrophy-fibrosis (P = 0.002). The most significant predictor of MMDx rejection scores in follow-up biopsies was the tubulitis classifier score in initial biopsies (AUC = 0.84, P = 0.002), confirmed in multivariate binary regression (OR = 16, P = 0.016). Molecular tubulitis score at initial biopsy has the potential to discriminate patients at risk for molecular rejection score at follow-up biopsy.

Practice Patterns in the Treatment and Monitoring of Acute T Cell-Mediated Kidney Graft Rejection in Canada

Background

One of the goals of the Canadian National Transplant Research Program (CNTRP) is to develop novel therapies for acute rejection that could positively affect graft outcomes with greater efficacy or less toxicity. To develop innovative management strategies for kidney graft rejection, new modalities need to be compared with current clinical practices. However, there are no standardized practices concerning the management of acute T cell-mediated rejection (TCMR).

Objectives

To describe clinicians' practice patterns in the diagnosis, treatment, and monitoring of acute TCMR in Canada.

Design

Survey.

Setting Patients/Participants

Canadian transplant nephrologists and transplant surgeons involved in the management of acute TCMR.

Methods and Measurements

We developed an anonymous, web-based survey consisting of questions related to the diagnosis, treatment, and monitoring of TCMR. The survey was disseminated on 3 occasions between June and October 2016 through the Canadian Society of Transplantation (CST) kidney group electronic mailing list.

Results

Forty-seven respondents, mostly transplant nephrologists (97%), originating from at least 18 of the 25 Canadian centers offering adult or pediatric kidney transplantation, participated in the study. Surveillance biopsies were used by 28% of respondents to screen for kidney graft rejection. High-dose steroids were used by most of the respondents to treat clinical and subclinical Banff grade 1A and 1B rejections. Nine percent (95% confidence interval [CI]: 1-17) of practitioners used lymphocyte-depleting agents as the first-line approach for the treatment of Banff grade 1B acute rejection. Eighteen percent (95% CI: 7-29) and 36% (95% CI: 8-65) of respondents reported that they would not use high-dose steroids for treating clinical and subclinical borderline rejections, respectively. Seventy percent (95% CI: 54-83) of respondents answered that there was no indication to assess histological response to treatment independent of the change in kidney function.

Limitations

The limitations of this study are its limited sample size and the low representation of pediatric specialists.

Conclusions

There is heterogeneity regarding the use of surveillance biopsies, treatment of borderline rejection, and modalities to monitor treatment response among transplant physicians. Our results illustrate the current state of practice patterns across Canada and can be used to inform the design of future trials.

Borderline Changes on Dysfunctional Renal Allograft Biopsies: Clinical Relevance in a Living Related Renal Transplant Setting

OBJECTIVES

Our aim was to determine the clinical significance of borderline lymphocytic infiltrates on indicated renal allograft biopsies in a living related renal transplant setting.

MATERIALS AND METHODS

The study was conducted at the histopathology department of Sindh Institute of Urology and Transplantation. A retrospective review of 421 renal transplant patients was conducted from October 2007 to September 2008 to identify patients in whom a histologic diagnosis of borderline changes was made on dysfunctional renal allograft biopsies. Demographic, clinical, and laboratory data; biopsy findings; treatments given; and responses to treatment were collected and analyzed. Standard biopsy indications determined the need for graft biopsies. Biopsies were reported according to Banff criteria.

RESULTS

Mean age was 26.92 ± 9.14 years (range, 10-45) for recipients and 38.46 ± 9.16 years (range, 19-50) for donors. Males were predominant among recipients (84.6% vs 15.4%), and females were predominant among donors (57.7% vs 42.3%). The best serum creatinine levels were 1.79 ± 1.15 mg/dL (range, 0.83-6.12). These were achieved after a median of 3 days (interquartile range, 2-7.25). Dysfunctional biopsies exhibiting borderline infiltrates were performed at a median duration of 5.5 days (interquartile range, 3-14.25). Mean serum creatinine at the time of biopsy was 2.34 ± 1.43 mg/dL (range, 1.25-8.25). The biopsies showed borderline cellular infiltrates (interstitial inflammation 1 [i1] and tubulitis 1 and [t1] lesions). All recipients except one received antirejection treatment (antithymocyte globulin, n = 5; escalation of mycophenolate mofetil dosage, n = 1; pulse steroids, n = 19); all recipients responded with a decline in serum creatinine toward baseline, with a mean serum creatinine of 1.31 ± 0.42 mg/dL (range, 0.40-2.71). This response was achieved at a median duration of 9.73 ± 5.32 days (range, 1-23) after starting treatment.

CONCLUSIONS

The borderline cellular infiltrates on dysfunctional renal allograft biopsies signify evolving phases of acute cellular rejection. These infiltrates responded favorably to antirejection treatment in our setting.

Four-Year Analyses of Renal Graft Biopsies: A Single-Center Pathology Experience

OBJECTIVES

Kidney transplant is the best treatment for patients with end-stage renal disease. Long-term graft survival depends on the protection of renal allograft function. Renal allograft biopsy is the most important method for examining an allograft function. Biopsy provides critical information, enabling diagnosis and grading of pathologic changes, prediction of response to therapy, and long-term graft prognosis.

MATERIALS AND METHODS

We reviewed the medical records of patients who underwent renal transplant from living and deceased donors at Baskent University Adana Teaching and Research Hospital between 2010 and 2014 and who had an indication for biopsy. Clinical characteristics and laboratory results of patients were recorded. Patient biopsy samples were examined according to the Banff 2009 classification.

RESULTS

Between 2010 and 2014, there were 175 renal transplants performed at our hospital, with 134 recipients (76.6%) having living-donor and 41 recipients (23.4%) having deceased-donor transplants. Fifty-one patients (29.1%) were children, and 124 patients (70.9%) were adults. We found that there were 123 biopsies made from 75 transplant patients over a 4-year period. When examined according to Banff 2009 criteria, the biopsy samples revealed acute T-cell-mediated rejection alone in 14.1% of the samples, acute antibody-mediated rejection in 4%, and a combination of the 2 rejections in 5.7%. Specific infections were detected in 12 patients. The graft nephrectomy rate was 5.1%.

CONCLUSIONS

This study investigated biopsy results, their relation with patient clinical status and 4-year survival rates, and our pathology experience and found that rejection and infection rates were similar to the literature. Our future studies with a longer follow-up and a larger sample size will likely provide more accurate information about graft survival and biopsy results.

Identification of lesions indicating rejection in kidney transplant biopsies: tubulitis is severely under-detected by conventional microscopy

BACKGROUND

In the current international Banff classification of kidney transplant rejection, tubulitis and intimal arteritis are regarded as the key histological features of acute rejection. Grade 1 tubulitis can sometimes be seen in biopsies that do not represent acute rejection; but in the case of intimal arteritis, just one lymphocyte can justify anti-rejection treatment. Our aim was to audit reliability and accuracy of recognizing tubulitis and intimal arteritis using the approach recommended by the Banff classification and correlate any discrepancies with subsequent graft function.

METHODS

This is a retrospective review of all kidney transplant biopsies reported as negative for rejection from 1 January 2009 to 31 December 2009 to assess the presence or absence of occult tubulitis and arteritis. Lymphocytes were immunostained with CD3, using Periodic Acid Schiff as a counterstain. Sections were reviewed to detect missed intimal arteritis and tubulitis. Discrepancies between the report and the immunostain results were analysed by biopsy type and broken down by the reporting pathologist. The graft function of any patient with missed lesions was checked to test for adverse impact on the patient.

RESULTS

'Missed' tubulitis was found in 68% of biopsies, but only two such cases subsequently developed biopsy-proven acute rejection. Only one case of missed intimal arteritis was found (1%) and the subsequent clinical course suggested that this was probably early rejection. There was no significant difference between the reporting pathologists.

CONCLUSIONS

We conclude that tubulitis is missed very frequently, but the Banff classification seems to be 'calibrated' to allow for this and it does not seriously affect the identification of clinically significant acute rejection. Immunostaining is therefore not indicated in routine practice because (by Banff criteria) it would result in over-diagnosis of rejection. Intimal arteritis can indicate acute rejection even if extremely mild.