The Banff 2015 Kidney Meeting Report: Current Challenges in Rejection Classification and Prospects for Adopting Molecular Pathology

The XIII Banff meeting, held in conjunction the Canadian Society of Transplantation in Vancouver, Canada, reviewed the clinical impact of updates of C4d-negative antibody-mediated rejection (ABMR) from the 2013 meeting, reports from active Banff Working Groups, the relationships of donor-specific antibody tests (anti-HLA and non-HLA) with transplant histopathology, and questions of molecular transplant diagnostics. The use of transcriptome gene sets, their resultant diagnostic classifiers, or common key genes to supplement the diagnosis and classification of rejection requires further consensus agreement and validation in biopsies. Newly introduced concepts include the i-IFTA score, comprising inflammation within areas of fibrosis and atrophy and acceptance of transplant arteriolopathy within the descriptions of chronic active T cell-mediated rejection (TCMR) or chronic ABMR. The pattern of mixed TCMR and ABMR was increasingly recognized. This report also includes improved definitions of TCMR and ABMR in pancreas transplants with specification of vascular lesions and prospects for defining a vascularized composite allograft rejection classification. The goal of the Banff process is ongoing integration of advances in histologic, serologic, and molecular diagnostic techniques to produce a consensus-based reporting system that offers precise composite scores, accurate routine diagnostics, and applicability to next-generation clinical trials.

Banff '09 meeting report: antibody mediated graft deterioration and implementation of Banff working groups

The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v-lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics-technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

The impact of c4d pattern and donor-specific antibody on graft survival in recipients requiring indication renal allograft biopsy

We examined the pattern of PTC C4d by immunohistochemistry and DSA in 297 kidney recipients with indication biopsies, and evaluated their predictive value for graft survival. Median biopsy time was 5.1 months posttransplant. Patients were followed for 17.9 +/- 9.4 months postbiopsy. An 18.5% had focal and 15.2% had diffuse C4d, with comparable graft survival (adjusted graft failure HR: 2.3, p = 0.001; HR:1.9, p < 0.02, respectively). 31.3% were DSA+, 19.5% class I and 22.9% class II DSA. Only those with class II DSA had worse outcome (adjusted HR:2.5, p = 0.001 for class II only; HR:2.7, p < 0.001 for class I/II DSA). Among patients with <10%C4d, 23.9% had DSA, compared to 68.9% with diffuse staining. For patients biopsied in first-year posttransplant presence of DSA, regardless of C4d positivity in biopsy, was a poor prognostic factor (adjusted graft failure HR: 4.2, p < 0.02 for C4d-/DSA+; HR:4.9, p = 0.001 for C4d+/DSA+), unlike those biopsied later. We have shown that focal C4d had similar impact on graft survival as diffuse pattern. During the first-year posttransplant either class I or II DSA, and afterward only class II DSA were associated with worse graft survival. DSA was predictive of worse outcome regardless of C4d for patients biopsied in first year and only with C4d positivity afterward, supporting the importance of assessment of both DSA and C4d pattern in biopsy.

Positive cross-match living donor kidney transplantation: longer-term outcomes

The long-term graft outcomes after positive cross-match (PXM) living donor kidney transplantation (LDKT) are unknown and the descriptive published data present short-medium term results. We conducted a retrospective cohort study of LDKT with PXM by flow cytometry performed at our center during February 1999 to October 2006, compared to a control group, matched 1:1 for age, sex, race, retransplantation and transplant year. The PXM group was treated with a course of plasmapheresis/low-dose intravenous immunoglobulin (IVIg) preoperatively, and OKT3 or thymoglobulin induction. Both groups (n = 41 each) were comparable except for duration of end-stage renal disease (ESRD), induction, HLA mismatch and panel-reactive antibody (PRA). During the period of up to 9 years, 14 PXM and 7 controls lost their grafts (p < 0.04). Graft survival rates at 1 and 5 years were 89.9% and 69.4% for PXM group and 97.6% and 80.6% for the controls, respectively. PXM was associated with higher risk of graft loss (HR 2.6, p = 0.04; 95%CI 1.03-6.4) (t(1/2)= 6.8 years), but not with patient survival (HR 1.96, p = 0.29; 95%CI 0.6-7.0) or 1-year serum creatinine (beta= 0.06, p = 0.59 for ln (SCr); 95% CI -0.16 to 0.28). These results suggest that despite the favorable short-term results of PXM LDKT after PP/IVIg conditioning, medium-long-term outcomes are notably worse than expected, perhaps comparable to non-ECD deceased donor kidney transplantation (KT).

Banff 07 classification of renal allograft pathology: updates and future directions

The 9th Banff Conference on Allograft Pathology was held in La Coruna, Spain on June 23-29, 2007. A total of 235 pathologists, clinicians and scientists met to address unsolved issues in transplantation and adapt the Banff schema for renal allograft rejection in response to emerging data and technologies. The outcome of the consensus discussions on renal pathology is provided in this article. Major updates from the 2007 Banff Conference were: inclusion of peritubular capillaritis grading, C4d scoring, interpretation of C4d deposition without morphological evidence of active rejection, application of the Banff criteria to zero-time and protocol biopsies and introduction of a new scoring for total interstitial inflammation (ti-score). In addition, emerging research data led to the establishment of collaborative working groups addressing issues like isolated 'v' lesion and incorporation of omics-technologies, paving the way for future combination of graft biopsy and molecular parameters within the Banff process.

Early withdrawal of calcineurin inhibitors and rescue immunosuppression with sirolimus-based therapy in renal transplant recipients with moderate to severe renal dysfunction

Mammalian Target-of-Rapamycin inhibitors (mTOR inhibitors) can be used to replace the calcineurin inhibitors (CNIs) to prevent progression in chronic kidney disease (CKD) following organ transplantation. Discontinuation of tacrolimus in 136 recipients of kidney transplants with progressive renal dysfunction significantly decreased the rate of loss of estimated glomerular filtration rate (eGFR, mL/min/1.73 m(2)) (pre-intervention vs. post-intervention slopes, -0.013 vs. -0.002, p < 0.0001). Discontinuation of tacrolimus was associated with a sustained and significant improvement in graft function (pre-eGFR vs. post-eGFR; 26.0 +/- 1.1 vs. 47.4 +/- 2.1, p < 0.0001) in 74% of patients. This intervention was ineffective if the mean and (median) values of creatinine (mg/dL) and eGFR were 3.8 +/- 0.2 (3.4) and 18.4 +/- 1.9 (22.4), respectively, at the time of conversion therapy. During the follow-up (range, 1.5-34.6, months), a total of 13 patients had their first acute rejection following the conversion therapy, an annual incidence of less than 10% and none of these episodes resulted in graft loss. The salutary effects of sirolimus therapy following discontinuation of tacrolimus in patients with moderate to severe graft dysfunction due to allograft nephropathy even in high-risk patients improves kidney function and prevents acute rejection.

Cost efficiency in the prospective diagnosis and follow-up of polyomavirus allograft nephropathy

Evaluation of urine cytology (UC) for decoy cells and quantitative determinations of viruria (urine viral load [UPCR])and viremia (viral load in blood [VLB]) have been proposed as surrogate markers of polyomavirus allograft nephropathy (PVAN). In this study, we present the experience with the concurrent evaluation of UC, UPCR, and VLB in 349 patients (940 sets of samples). Results were correlated with each other and with a previous, concurrent, or subsequent biopsy diagnosis of PVAN. Patients were followed up for a mean of 27 months posttransplantation. We conclude that both UC and UPCR are useful for screening of renal transplant recipients. Simultaneous performance of both UC and UPCR does not add useful clinical information. In patients with positive UC, performance of UPCR, however, can allow for the distinction between BK and JC polyoma viruses. Quantitative measurement of viremia is not indicated in patients lacking viruria because no patients with PVAN present with this combination of findings. In patients with viruria, a positive viremia strongly correlates with PVAN. Rationale selection of screening protocols based on the current knowledge of the infection and tailored to the available laboratory capabilities in each transplantation center can optimize the use of resources.

Fatal disseminated adenoviral infection associated with thrombotic thrombocytopenic purpura after allogeneic bone marrow transplantation

Adenoviruses are increasingly recognized as a significant cause of morbidity and mortality in immunocompromised patients. We report on a patient who, approximately 4 weeks after allogeneic stem cell transplantation, developed fever, new liver lesions and thrombotic microangiopathy. Adenovirus type 2 was isolated from blood and urine samples. Liver biopsy showed parenchymal necrosis with intranuclear viral inclusion bodies. Immunohistochemistry was positive for adenovirus. In addition, on electron microscopy the morphologic pattern was highly suggestive of adenovirus. The patient died on post-transplant day 40. The relatively early post-transplant presentation of disseminated adenoviral disease and its possible association with a TTP-like picture are rather unusual after allogeneic transplantation.

Role of Enterococcus faecalis surface protein Esp in the pathogenesis of ascending urinary tract infection

Enterococcus faecalis bacteria isolated from patients with bacteremia, endocarditis, and urinary tract infections more frequently express the surface protein Esp than do fecal isolates. To assess the role of Esp in colonization and persistence of E. faecalis in an animal model of ascending urinary tract infection, we compared an Esp(+) strain of E. faecalis to its isogenic Esp-deficient mutant. Groups of CBA/J mice were challenged transurethrally with 10(8) CFU of either the parent or mutant strain, and bacteria in the urine, bladder, and kidneys were enumerated 5 days postinfection. Significantly higher numbers of bacteria were recovered from the bladder and urine of mice challenged with the parent strain than from the bladder and urine of mice challenged with the mutant. Colonization of the kidney, however, was not significantly different between the parent and mutant strains. Histopathological evaluations of kidney and bladder tissue done at 5 days postinfection did not show marked histopathological changes consistent with inflammation, mucosal hyperplasia, or apoptosis, and there was no observable difference between the mice challenged with the parent and those challenged with the mutant. We conclude that, while Esp does not influence histopathological changes associated with acute urinary tract infections, it contributes to colonization and persistence of E. faecalis at this site.

Loss of Helicobacter pylori hemagglutination with serial laboratory passage and correlation of hemagglutination with gastric epithelial cell adherence

Adherence of Helicobacter pylori to gastric epithelial cells is thought to be important in the pathogenesis of infection and may be essential to maintain lifelong colonization. However, the factors responsible for adherence to gastric epithelial cells in vivo have not been characterized, and the significance of adherence to standard epithelial cell lines is unclear. Hemagglutination is also thought to be important in H. pylori adherence. However, no studies have clearly linked H. pylori hemagglutination or adherence to cultured epithelial cells to primary gastric epithelial cell adherence. Furthermore, it is not clear whether laboratory strains which have undergone multiple passages lose potential colonization factors. In this study, we examined the effect of serial laboratory passage on hemagglutination and correlated the hemagglutination characteristics of H. pylori strains to primary gastric cell adherence. Variable expression of hemagglutination was seen with serial laboratory passage of 15 strains. After 100 serial laboratory passages, all strains had lost hemagglutination activity. Hemagglutination was seen in association with adherence to primary gastric cells in vitro isolated from 2 patients. An association with ultrastructural intimate adherence was seen with HEp-2 cells, but not with gastric adenocarcinoma cells. Ultrastructural adherence was seen in corresponding antral biopsies of patients whose strains were hemagglutination positive, but hemagglutination was not associated with gastric inflammation. These data indicate that H. pylori hemagglutination is lost with serial passage and that hemagglutination may play a role in the attachment of H. pylori to gastric epithelial cells, but the role of adherence to chronic gastric inflammation is unclear.

Renal involvement of human parvovirus B19 in an immunocompetent host

Human parvovirus B19, which is most commonly known to cause erythema infectiosum in children, is also known to cause infection in adults, with complications ranging from a self-limited polyarthropathy in immunocompetent patients to hydrops fetalis in pregnant women, transient aplastic crises in patients with chronic hemolytic anemias, and chronic aplastic anemia in immunocompromised hosts. We describe a previously healthy immunocompetent woman who presented with manifestations of acute parvovirus B19 infection.

The role of cytotoxic necrotizing factor-1 in colonization and tissue injury in a murine model of urinary tract infection

Cytotoxic necrotizing factor-1 (CNF1) is commonly found in Escherichia coli isolates from patients with urinary tract infection (UTI). To determine whether CNF1 is an important UTI virulence factor we compared the ability of a clinical E. coli UTI isolate and a CNF1-negative mutant of that isolate to colonize and induce histological changes in the urinary tract in a murine model of ascending UTI. We found no evidence that the mutant strain was attenuated.

Gastrointestinal abnormalities in children with autistic disorder

OBJECTIVES

Our aim was to evaluate the structure and function of the upper gastrointestinal tract in a group of patients with autism who had gastrointestinal symptoms.

STUDY DESIGN

Thirty-six children (age: 5.7 +/- 2 years, mean +/- SD) with autistic disorder underwent upper gastrointestinal endoscopy with biopsies, intestinal and pancreatic enzyme analyses, and bacterial and fungal cultures. The most frequent gastrointestinal complaints were chronic diarrhea, gaseousness, and abdominal discomfort and distension.

RESULTS

Histologic examination in these 36 children revealed grade I or II reflux esophagitis in 25 (69.4%), chronic gastritis in 15, and chronic duodenitis in 24. The number of Paneth's cells in the duodenal crypts was significantly elevated in autistic children compared with non-autistic control subjects. Low intestinal carbohydrate digestive enzyme activity was reported in 21 children (58.3%), although there was no abnormality found in pancreatic function. Seventy-five percent of the autistic children (27/36) had an increased pancreatico-biliary fluid output after intravenous secretin administration. Nineteen of the 21 patients with diarrhea had significantly higher fluid output than those without diarrhea.

CONCLUSIONS

Unrecognized gastrointestinal disorders, especially reflux esophagitis and disaccharide malabsorption, may contribute to the behavioral problems of the non-verbal autistic patients. The observed increase in pancreatico-biliary secretion after secretin infusion suggests an upregulation of secretin receptors in the pancreas and liver. Further studies are required to determine the possible association between the brain and gastrointestinal dysfunctions in children with autistic disorder.

Treatment of severe esophageal Crohn's disease with infliximab

Esophageal ulceration with fistula is an uncommon manifestation of Crohn's disease. Typical presentation of symptomatic esophageal Crohn's disease may include dysphagia, odynophagia, weight loss, and chest discomfort. We present a patient with severe esophageal and skin involvement of Crohn's disease that was progressive despite conventional therapy including prednisone and 6-mercaptopurine. The diagnosis of Crohn's was based on the presence of typical clinical, endoscopic, and pathologic findings, including granulomas in the skin ulcer and the absence of infectious etiologies. The patient had a nearly complete resolution of her esophageal disease with a single infusion of infliximab.

Treatment of severe esophageal Crohn's disease with infliximab

Esophageal ulceration with fistula is an uncommon manifestation of Crohn's disease. Typical presentation of symptomatic esophageal Crohn's disease may include dysphagia, odynophagia, weight loss, and chest discomfort. We present a patient with severe esophageal and skin involvement of Crohn's disease that was progressive despite conventional therapy including prednisone and 6-mercaptopurine. The diagnosis of Crohn's was based on the presence of typical clinical, endoscopic, and pathologic findings, including granulomas in the skin ulcer and the absence of infectious etiologies. The patient had a nearly complete resolution of her esophageal disease with a single infusion of infliximab.

Iron deficiency anemia due to a Brunner's gland hamartoma

Brunner's gland hamartomas are rare benign duodenal tumors often discovered incidentally during endoscopy or on an upper gastrointestinal series. These tumors arise mainly in the duodenal bulb and can present with gastrointestinal bleeding or symptoms of intestinal obstruction. When symptomatic, surgical or endoscopic removal can be safely performed and the prognosis is very good. We describe a 63-year-old man presenting with iron deficiency anemia due to a large Brunner's gland hamartoma and review the endoscopic, radiologic, surgical, and pathologic findings.

Immunohistochemical demonstration of nerve fibers in pelvic adhesions

OBJECTIVE

To demonstrate the presence of nerve fibers in pelvic adhesions potentially capable of conducting pain stimuli.

METHODS

Pelvic adhesions from 17 patients, ten of whom had a history of pelvic pain, were examined histologically. Routine hematoxylin and eosin stains and immunoperoxidase stains for S100 protein, B lymphocytes, and T lymphocytes were performed. Mesothelial proliferation, presence of calcification and/or psammoma bodies, edema, vascularization, inflammation, fibroblastic proliferation, and collagenization were graded from 0 (absent) to 3 (extensive); their prevalences were compared between patients with and without pelvic pain.

RESULTS

Nerve fibers were present in specimens from ten of the 17 patients (five of ten patients with and five of seven without pain). There was no statistically significant difference in the numbers with nerve fibers or in the presence of mesothelial proliferation, calcification and/or psammoma bodies, edema, vascularization, inflammation, fibroblastic proliferation, or collagenization between the groups. In all cases, the infiltrating lymphocytes were T lymphocytes.

CONCLUSION

We were able to demonstrate the presence of nerve fibers in pelvic adhesions; however, their presence was not more prevalent among patients with pelvic pain. These findings support the concept that the formation of adhesions has different stages, with the final formation of mature connective tissue with its own vascularization and innervation.