Search

Previous work has shown that Secretory-IgA (SIgA) binding to the intestinal microbiota is variable and may regulate host inflammatory bowel responses. Nevertheless, the impact of the SIgA functional binding to the microbiota remains largely unknown in preterm infants whose immature epithelial barriers make them particularly susceptible to inflammation. Here, we investigated SIgA binding to intestinal microbiota isolated from stools of preterm infants

Background Alport Syndrome and IgA Nephropathy (IgAN) are both disorders that can cause hematuria. Alport syndrome is most commonly an X-linked disease, caused by COL4A5 mutation. Mutations of COL4A3 and COL4A4 on chromosome two are also common causes of Alport syndrome. IgAN is the most common glomerulonephritis worldwide. Though IgAN is usually sporadic, an estimated 15% of cases have an inheritable component. These cases of Familal IgA Nephropathy (FIgAN) can have mutations on genes which are known to cause Alport Syndrome. Case presentation We report a case of a 27-year-old man with strong family history of renal disease, who presented with hematuria and new non-nephrotic range proteinuria. Physical exam showed no abnormalities. His creatinine remained persistently elevated, and renal ultrasound exhibited bilaterally increased echogenicity consistent with Chronic Kidney Disease. Twenty-four-hour urinary collection revealed non-nephrotic range proteinuria of 1.4 g, with otherwise negative workup. On biopsy, he had IgA positive immunofluorescent staining as well as moderate interstitial fibrosis and tubular atrophy. Electron microscopy showed a basket-weave pattern of thickening and splitting of the lamina densa-consistent with Alport Syndrome, as well as mesangial expansion with electron-dense deposits -consistent with IgAN. Conclusions Mutations of COL4A5 on the X chromosome, as well as mutations of COL4A3 and COL4A4 on chromosome 2, can cause both Alport Syndrome and FIgAN. Genome wide association studies identified certain Angiotensin Converting Enzyme gene polymorphisms as independent risk factors for progression of IgAN. Our Presentation with this co-occurring pathology suggests a new paradigm where Alport Syndrome and FIgAN may represent manifestations of a single disease spectrum rather than two disparate pathologies. Appreciating hematuria through this framework has implications for treatments and genetic counseling. Further genome wide association studies will likely increase our understanding of Alport Syndrome, FIgAN, and other causes of hematuria.

Rho guanine nucleotide exchange factors (RhoGEFs) regulate Rho GTPase activity and cytoskeletal and cell adhesion dynamics. βPix, a CDC42/RAC family RhoGEF encoded by ARHGEF7, is reported to modulate human colon cancer cell proliferation and postwounding restitution of rat intestinal epithelial monolayers. We hypothesized that βPix plays a role in maintaining intestinal epithelial homeostasis. To test this hypothesis, we examined βPix distribution in the human and murine intestine and created mice with intestinal epithelial-selective βPix deletion [βPix(flox/flox)/Tg(villin-Cre); Arhgef7 CKO mice]. Using Arhgef7 conditional knockout (CKO) and control mice, we investigated the consequences of βPix deficiency in vivo on intestinal epithelial and enteroid development, dextran sodium sulfate-induced mucosal injury, and gut permeability. In normal human and murine intestines, we observed diffuse cytoplasmic and moderate nuclear βPix immunostaining in enterocytes. Arhgef7 CKO mice were viable and fertile, with normal gross intestinal architecture but reduced small intestinal villus height, villus-to-crypt ratio, and goblet cells; small intestinal crypt cells had reduced Ki67 staining, compatible with impaired cell proliferation. Enteroids derived from control mouse small intestine were viable for more than 20 passages, but those from Arhgef7 CKO mice did not survive beyond 24 h despite addition of Wnt proteins or conditioned media from normal enteroids. Adding a Rho kinase (ROCK) inhibitor partially rescued CKO enteroid development. Compared with littermate control mice, dextran sodium sulfate-treated βPix-deficient mice lost more weight and had greater impairment of intestinal barrier function, and more severe colonic mucosal injury. These findings reveal βPix expression is important for enterocyte development, intestinal homeostasis, and resistance to toxic injury. NEW & NOTEWORTHY To explore the role of βPix, a guanine nucleotide exchange factor encoded by ARHGEF7, in intestinal development and physiology, we created mice with intestinal epithelial cell Arhgef7/βPix deficiency. We found βPix essential for normal small intestinal epithelial cell proliferation, villus development, and mucosal resistance to injury. Moreover, Rho kinase signaling mediated developmental arrest observed in enteroids derived from βPix-deficient small intestinal crypts. Our studies provide insights into the role Arhgef7/βPix plays in intestinal epithelial homeostasis.

Background Deceased-donor kidney quality pretransplantation is considered critical for future graft function. Assessment of donor kidney quality considers clinical and histologic variables. Several models that incorporate a variety of these factors have been proposed to predict long-term graft survival. Methods We compared the performance metrics of 4 scoring systems models---the Maryland Aggregate Pathology Index, Banff, Remuzzi, and Leuven---for predicting renal allograft survival. In this retrospective cohort study, we analyzed 173 renal allografts that underwent preoperative baseline biopsy. Donor demographics and donor baseline histopathology data were collected and correlated with graft survival posttransplant. Results Among the 4 scoring systems, none were significantly associated with posttransplant graft survival or early graft function. The Maryland Aggregate Pathology Index scoring system had better predictive capacity in receiver operating characteristic curve analysis; however, the utility as a predictor of graft survival was only slightly better than chance. Baseline histologic features were individually analyzed, and it was found that none were associated with graft survival in this cohort. Among donor demographics, none were significantly associated with graft survival. Conclusions In our study none of the 4 previously proposed predictive models were associated with graft survival after transplantation. Further studies are needed to define new models with stronger predictive value for graft outcome that could help minimize organ discards.

Salivary duct carcinoma of the parotid gland is a highly aggressive epithelial malignancy morphologically resembling high-grade, invasive, and in situ breast carcinoma. It can occasionally present with variable morphology making it diagnostically challenging in cases with unusual morphological components. Ancillary testing, particularly androgen receptor (AR) positivity on immunohistochemistry, can be very helpful in cases that demonstrate extensive squamous morphology, since AR positivity is uncommon in both the primary salivary gland and metastatic squamous cell carcinomas to the parotid. In this report, we describe a case of salivary duct carcinoma that showed only a squamous cell carcinoma component on the initial primary tumor site biopsy, as well as in subsequent contralateral neck lymph node and skin metastases. Apart from the variable morphology, the typical salivary duct and squamous cell carcinoma tumor components also showed significant immunohistochemical differences, including differential staining of human epidermal growth factor receptor 2/neu. The associated diagnostic pitfalls, distinct immunoprofiles of the tumor components, helpful adjuncts for making the correct diagnosis, and associated therapeutic implications are discussed.

Rats exposed to hypobaria equivalent to what occurs during aeromedical evacuation within a few days after isolated traumatic brain injury exhibit greater neurologic injury than those remaining at sea level. Moreover, administration of excessive supplemental O2 during hypobaria further exacerbates brain injury. This study tested the hypothesis that exposure of rats to hypobaria following controlled cortical impact (CCI)-induced brain injury plus mild hemorrhagic shock worsens multiple organ inflammation and associated mortality. In this study, at 24 h after CCI plus hemorrhagic shock, rats were exposed to either normobaria (sea level) or hypobaria (=8,000 ft altitude) for 6 h under normoxic or hyperoxic conditions. Injured rats exhibited mortality ranging from 30% for those maintained under normobaria and normoxia to 60% for those exposed to 6 h under hypobaric and hyperoxia. Lung histopathology and neutrophil infiltration at 2 days postinjury were exacerbated by hypobaria and hyperoxia. Gut and kidney inflammation at 30 days postinjury were also worsened by hypobaric hyperoxia. In conclusion, exposure of rats after brain injury and hemorrhagic shock to hypobaria or hyperoxia results in increased mortality. Based on gut, lung, and kidney histopathology at 2 to 30 days postinjury, increased mortality is consistent with multi-organ inflammation. These findings support epidemiological studies indicating that increasing aircraft cabin pressures to 4,000 ft altitude (compared with standard 8,000 ft) and limiting excessive oxygen administration will decrease critical complications during and following aeromedical transport.

Use of granulocyte colony-stimulating factor (G-CSF) has been associated with side effects including reports of acute glomerulonephritis (GN), almost all of which have been immune complex associated. There is one prior report of pauci-immune GN in a child, but was negative for ANCA (anti-neutrophilic cytoplasmic antibodies). We describe the first case of ANCA-positive pauci-immune GN exacerbated by the use of G-CSF for peripheral blood stem cell (PBSC) donation in a patient with no prior history of vasculitis. Given the use of G-CSF in PBSC donation and neutropenias associated with various conditions, it is important that both the nephrologist and the hematologist are aware of the renal risks associated with its use.

Introduction Routine C4d staining in renal transplantation has stimulated its use in kidney biopsies with glomerulonephritis (GN). Methodical description on staining patterns in the native kidney is not available. Methods We retrospectively evaluated C4d staining in formalin-fixed paraffin-embedded sections from 519 native kidney biopsies (bx) with and without glomerular disease. Results Strong C4d staining was consistently present in immune-complex GN, including lupus nephritis (LN) (n = 68), membranous GN (n = 24), membranoproliferative glomerulonephritis (MPGN) pattern (n = 22), fibrillary GN (n = 3), and proliferative GN with monoclonal IgG (n = 3). C4d stained all cases of postinfectious GN (n = 7) amyloidosis (n = 20) and C1q GN (n = 3). In contrast, IgA nephropathy (IgAN) (n = 34), was negative in 62% of bx, with the rest staining variably. The E1 Oxford classification score correlated with capillary wall C4d staining (P = 0.05). C4d marked the glomerular and arteriolar lesions in thrombotic microangiopathy (TMA; n = 16), the glomerular sclerotic segments in focal segmental glomerulosclerosis (FSGS; n = 77), and marked areas of necrosis in crescentic GN (n = 21). In diabetic glomerulopathy (n = 70), C4d marked advanced insudative lesions but was negative otherwise. C4d weakly stained the mesangium, or was negative in normal biopsies (n = 13), minimal change disease (MCD; n = 21), thin basement membrane disease (n = 20), Alport (n = 3), IgM nephropathy (n = 2), C3 glomerulopathy (n = 5), acute interstitial nephritis (n = 12), acute tubular necrosis (n = 22), ischemic glomerulopathy/nephrosclerosis (n = 23), and other miscellaneous processes (n = 14). Staining in tubular basement membranes and peritubular capillaries was most common in lupus. Conclusion Based on reliable staining in lupus and membranous GN, C4d staining is potentially useful as a screening and diagnostic tool, if only paraffin-embedded tissue is available. Knowledge of C4d staining patterns in normal and pathological tissues enhances its diagnostic value., Graphical abstract

Yersinia enterocolitica causes a severe enteric infection in infants and young children. There is no vaccine approved for use in humans. We investigated the immunogenicity and protective capacity of Yersinia YopB, a conserved type III secretion system protein, alone or combined with LcrV in adult mice immunized intranasally. YopB or LcrV (5 μg) administered with the Escherichia coli double mutant heat-labile toxin (dmLT) adjuvant afforded modest (10–30%) protection against lethal Y. enterocolitica oral infection. The combination of YopB and LcrV (5 μg each) dramatically improved vaccine efficacy (70–80%). Additionally, it afforded complete protection against Y. pestis pulmonary infection. Immunization with YopB/LcrV+dmLT resulted in Ag-specific serum IgG, systemic and mucosal Ab-secreting cells, as well as IFN-γ, TNF-α, IL-2, IL-6, IL-17A, and KC production by spleen cells. Serum Abs elicited by YopB/LcrV+dmLT had enhanced bactericidal and opsonophagocytic killing activity. After Y. enterocolitica challenge, YopB/LcrV+dmLT–vaccinated mice exhibited intact intestinal tissue, active germinal centers in mesenteric lymph nodes, IgG+ and IgA+ plasmablasts in the lamina propria, and Abs in intestinal fluid. On the contrary, complete tissue destruction and abscesses were seen in placebo recipients that succumbed to infection. Mice immunized as infants with YopB+dmLT or LcrV+dmLT achieved 60% protection against lethal Y. enterocolitica infection, and vaccine efficacy increased to 90–100% when they received YopB/LcrV+dmLT. YopB+dmLT also afforded substantial (60%) protection when administered intradermally to infant mice. YopB/LcrV+dmLT is a promising subunit vaccine candidate with the potential to elicit broad protection against Yersinia spp.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040 . 1

Background Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive biomarker for the early detection of organ transplant rejection and other causes of graft injury. For nonrejection renal injuries, there is little information about the performance characteristics of this biomarker. We highlight some of the possible causes of kidney injury that may arise in patients with normal dd-cfDNA levels. Methods We performed a retrospective analysis of solitary renal transplant cases between January 2017 and November 2019. Those who had an abnormal laboratory or pathological finding within 1 mo of a normal dd-cfDNA test were selected. Subgroups were stratified for those who had normal or abnormal/rising serum creatinine, and differences between the groups were analyzed. Results Of 414 individuals who received a kidney transplant, 24 (7.5%) had a total of 41 normal dd-cfDNA values and 51 abnormal laboratory tests or histologic findings. The most common graft-injuring event was BK virus viremia (24 of 51). Other abnormal findings included urinary traction infections (n = 4), CMV viremia (n = 4), and biopsies demonstrating antibody-mediated rejection (AMR) (n = 2), T cell-mediated rejection (n = 1), focal segmental glomerulosclerosis (n = 2), nondonor-specific antibody chronic AMR (n = 1), and interstitial fibrosis and tubular atrophy (n = 7). Subgroup analysis of those with normal dd-cfDNA and normal/stable versus abnormal/rising creatinine showed that BK virus viremia was the most common abnormal finding in both groups at 53% and 38% respectively. On biopsy, 1 case of acute T cell-mediated rejection (1B and 2B) was seen with normal/stable creatinine, whereas 1 of nonspecific C4d focally positive and 1 of nondonor-specific antibody AMR were seen with abnormal/rising creatinine. Conclusions Low levels of serum dd-cfDNA do not preclude detection of active graft-injuring events and that subclinical injuries may be developing. Context is important in the interpretation of dd-cfDNA, so renal biopsy remains a part of the diagnostic pathway for allograft dysfunction and maintenance of allograft health.

Funder: Fondazione Pisa, Pisa, Italy; Id: http://dx.doi.org/10.13039/100007368, Funder: Tuscany Region, Italy; Id: http://dx.doi.org/10.13039/501100009888, Funder: Pisa University Hospital, Pisa, Italy, Funder: University of Pisa, Pisa, Italy; Id: http://dx.doi.org/10.13039/501100007514, The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Background. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive plasma biomarker to evaluate for transplant allograft rejection. The relationship between infectious complications in kidney allografts and dd-cfDNA has received cursory attention in prior publications. Methods. Retrospective review of all renal transplant recipients who underwent dd-cfDNA testing between November 2017 and August 2019. Results. We report on 7 cases in whom infections affecting the transplanted kidney were associated with elevation in dd-cfDNA without concomitant rejection or elevation in serum creatinine. Five patients had BK viremia, and 2 patients had urinary tract infection associated with elevated dd-cfDNA levels. Conclusions. These observations suggest that elevations in dd-cfDNA are not specific to kidney allograft rejection and can be associated with infections affecting the transplanted kidney. This biomarker may be valuable in evaluating infectious complications of kidney allografts.

Summary Immune escape contributes to viral persistence, yet little is known about human polyomaviruses. BK-polyomavirus (BKPyV) asymptomatically infects 90% of humans but causes premature allograft failure in kidney transplant patients. Despite virus-specific T cells and neutralizing antibodies, BKPyV persists in kidneys and evades immune control as evidenced by urinary shedding in immunocompetent individuals. Here, we report that BKPyV disrupts the mitochondrial network and membrane potential when expressing the 66aa-long agnoprotein during late replication. Agnoprotein is necessary and sufficient, using its amino-terminal and central domain for mitochondrial targeting and network disruption, respectively. Agnoprotein impairs nuclear IRF3-translocation, interferon-beta expression, and promotes p62/SQSTM1-mitophagy. Agnoprotein-mutant viruses unable to disrupt mitochondria show reduced replication and increased interferon-beta expression but can be rescued by type-I interferon blockade, TBK1-inhibition, or CoCl2-treatment. Mitochondrial fragmentation and p62/SQSTM1-autophagy occur in allograft biopsies of kidney transplant patients with BKPyV nephropathy. JCPyV and SV40 infection similarly disrupt mitochondrial networks, indicating a conserved mechanism facilitating polyomavirus persistence and post-transplant disease., Graphical Abstract, Highlights • BK polyomavirus agnoprotein disrupts mitochondrial membrane potential and network • Agnoprotein impairs nucleus IRF3 translocation and interferon-β expression • Agnoprotein facilitates innate immune evasion during the late viral replication phase • Damaged mitochondria are targeted for p62/SQSTM1 autophagy, Biological Sciences; Immunology; Virology; Cell Biology

Emphysematous gastritis (EG) is a rare and potentially lethal process caused by invasive, gas-producing bacteria leading to inflammation and gas dissection of the stomach. The most common etiologic agents are Clostridium infections, but other organisms, including enterobacteria, staphylococcus, and fungi have also been identified. We report the first case of EG due to Sarcina ventriculi in a solid organ transplant recipient, who presented with epigastric pain and vomiting. The patient had a history of type 1 diabetes mellitus (DM) with recurrent episodes of ketoacidosis and systemic diabetic complications, including severe gastroparesis. CT scan studies demonstrated EG with venous air, and endoscopy showed severe gastritis and ulcerations. In the gastric biopsies, abundant Sarcina ventriculi were noted in areas of mucosal/submucosal necrosis. Antibiotic treatment was instituted at admission, and subsequent endoscopy demonstrated the disappearance of Sarcina, with some improvement of the gastric inflammation; however, the patient developed septic shock with multiorgan failure and expired. This case highlights the need to consider other infectious etiologies in transplant patients, in addition to the well-known opportunistic infections.

Pancreas transplant longevity is limited by immune rejection, which is diagnosed by graft biopsy using the Banff Classification. The histological criteria for antibody-mediated rejection (AMR) are poorly reproducible and inconsistently associated with outcome. We hypothesized that a 34-gene set associated with antibody-mediated rejection in other solid organ transplants could improve diagnosis in pancreas grafts. The AMR 34-gene set, comprising endothelial, natural killer cell and inflammatory genes, was quantified using the NanoString platform in 52 formalin-fixed, paraffin-embedded pancreas transplant biopsies from 41 patients: 15 with pure AMR or mixed rejection, 22 with T cell-mediated rejection/borderline and 15 without rejection. The AMR 34-gene set was significantly increased in pure AMR and mixed rejection (P = .001) vs no rejection. The gene set predicted histological AMR with an area under the receiver operating characteristic curve (ROC AUC) of 0.714 (P = .004). The AMR 34-gene set was the only biopsy feature significantly predictive of allograft failure in univariate analysis (P = .048). Adding gene expression to DSA and histology increased ROC AUC for the prediction of failure from 0.736 to 0.770, but this difference did not meet statistical significance. In conclusion, assessment of transcripts has the potential to improve diagnosis and outcome prediction in pancreas graft biopsies.

Immune escape contributes to viral persistence, yet little is known about human polyomaviruses. BK-polyomavirus (BKPyV) asymptomatically infects 90% of the human population, but causes early allograft failure in 10% of kidney transplants. Despite inducing potent virus-specific T-cells and neutralizing antibodies, BKPyV persists in the kidneys and regularly escapes from immune control as indicated by urinary shedding in immunocompetent individuals. Here, we report that BKPyV disrupts the mitochondrial network and its membrane potential when expressing the 66aa-long agnoprotein during late replication. Agnoprotein impairs nuclear IRF3-translocation, interferon-βexpression, and promotes p62-mitophagy in vitro and in kidney transplant biopsies. Agnoprotein-mutant viruses unable to disrupt mitochondria show reduced replication, which can be rescued by type-I-interferon-blockade, TBK1-inhibition, or CoCl2treatment. Agnoprotein is necessary and sufficient, using its amino-terminal and central domain for mitochondrial targeting and disruption, respectively. JCPyV- and SV40-infection similarly disrupt the mitochondrial network indicating a conserved mechanism facilitating polyomavirus persistence and post-transplant disease.

Active maintenance of beta-cell identity through fine-tuned regulation of key transcription factors ensures beta-cell function. Tacrolimus, a widely used immunosuppressant, accelerates onset of diabetes after organ transplantation, but underlying molecular mechanisms are unclear. Here we show that tacrolimus induces loss of human beta-cell maturity and beta-cell failure through activation of the BMP/SMAD signaling pathway when administered under mild metabolic stress conditions. Tacrolimus-induced phosphorylated SMAD1/5 acts in synergy with metabolic stress-activated FOXO1 through formation of a complex. This interaction is associated with reduced expression of the key beta-cell transcription factor MAFA and abolished insulin secretion, both in vitro in primary human islets and in vivo in human islets transplanted into high-fat diet-fed mice. Pharmacological inhibition of BMP signaling protects human beta-cells from tacrolimus-induced beta-cell dysfunction in vitro. Furthermore, we confirm that BMP/SMAD signaling is activated in protocol pancreas allograft biopsies from recipients on tacrolimus. To conclude, we propose a novel mechanism underlying the diabetogenicity of tacrolimus in primary human beta-cells. This insight could lead to new treatment strategies for new-onset diabetes and may have implications for other forms of diabetes.

Novel tools are needed to improve diagnostic accuracy and risk prediction in BK virus nephropathy (BKVN). We assessed the utility of intragraft gene expression testing for these purposes. Eight hundred genes were measured in 110 archival samples, including a discovery cohort of native kidney BKVN (n = 5) vs pure T cell-mediated rejection (TCMR; n = 10). Five polyomavirus genes and seven immune-related genes (five associated with BKVN and two associated with TCMR) were significantly differentially expressed between these entities (FDR < 0.05). These three sets of genes were further evaluated in samples representing a spectrum of BK infection (n = 25), followed by a multicenter validation cohort of allograft BKVN (n = 60) vs TCMR (n = 10). Polyomavirus 5-gene set expression reliably distinguished BKVN from TCMR (validation cohort AUC = 0.992), but the immune gene sets demonstrated suboptimal diagnostic performance (AUC ≤ 0.720). Within the validation cohort, no significant differences in index biopsy gene expression were identified between BKVN patients demonstrating resolution (n = 35), persistent infection (n = 14) or de novo rejection (n = 11) 6 months following a standardized reduction in immunosuppression. These results suggest that, while intragraft polyomavirus gene expression may be useful as an ancillary diagnostic for BKVN, assessment for concurrent TCMR and prediction of clinical outcome may not be feasible with current molecular tools.

Pathological evaluation of whole pancreas transplants (WPnTx) is necessary for the accurate determination of the cause of graft dysfunction, graft failure, and graft insufficiency. In the early posttransplantation period, histological studies are essential to differentiate idiopathic graft thrombosis from thrombosis secondary to acute allograft rejection, most likely representing an aggressive form of antibody-mediated rejection (ABMR). Clinical manifestations of graft dysfunction have overall poor specificity. Histological studies are necessary to differentiate acute rejection from other causes of graft injury and are furthermore required to differentiate acute T-cell-mediated rejection (TCMR) from ABMR, which are treated differently. Equally important is the accurate identification of the various types of islet cell pathology, including calcineurin inhibitor toxicity and development of recurrent type 1 diabetes mellitus. Histological studies are also shedding light on the contribution of type 2 diabetes mellitus to graft dysfunction/insufficiency. This chapter includes a discussion of the Banff grading schema, as well as the various nonrejection-related pathological processes affecting WPnTx. In addition, the contribution of pathological evaluation in various other clinicopathological settings is presented.

Organ scaffold bioengineering is currently limited by the inability to effectively repopulate the scaffold with appropriately distributed functional cells. We examined the feasibility of a decellularized liver scaffold to support the growth and function of multilineage allogenic cells derived from either adult or neonatal liver cells. Cell slurries from neonatal and adult rat livers containing hepatocytes, cholangiocytes, and endothelial cells were introduced into decellularized adult rat liver scaffolds via the bile duct. Recellularized grafts were perfused with cell growth medium through the portal vein for 7 days. Concurrently, the same cell slurries were incubated on culture dishes. Albumin levels were measured from graft perfusates and cell culture media. Immunofluorescent assays were used to verify the colocalization of cholangiocytes, hepatocytes, endothelial cells, and Kupffer cells in the recellularized grafts by using anti-CK7, anti-hepatocyte antigen, anti-CD34, and anti-CD68, respectively. More robust albumin production was detected in the perfusate of scaffolds recellularized with a neonatal liver cell slurry compared with those with an adult liver cell slurry. The perfusates from all recellularized grafts showed increasing albumin concentration over 7 days; higher levels were detected in the constructs compared with the cell culture. Scaffolds seeded with a neonatal liver cell slurry showed the presence of hepatocytes, cholangiocytes, endothelial cells, and Kupffer cells. Results demonstrated the superiority of neonatal allogenic cells over adult cells of the same origin, possibly because of their pluripotent behavior. Liver bio-scaffolds supported the growth of four different liver cell lines. Recellularized grafts exhibited preserved functionality as demonstrated by albumin production, and constructs seeded with a neonatal cell slurry demonstrated proliferation on Ki-67 assay, thus representing a promising model for a transplantable construct.

Polyomavirus nephropathy (PVN) is a common viral infection of renal allografts, with biopsy-proven incidence of approximately 5%. A generally accepted morphologic classification of definitive PVN that groups histologic changes, reflects clinical presentation, and facilitates comparative outcome analyses is lacking. Here, we report a morphologic classification scheme for definitive PVN from the Banff Working Group on Polyomavirus Nephropathy, comprising nine transplant centers in the United States and Europe. This study represents the largest systematic analysis of definitive PVN undertaken thus far. In a retrospective fashion, clinical data were collected from 192 patients and correlated with morphologic findings from index biopsies at the time of initial PVN diagnosis. Histologic features were centrally scored according to Banff guidelines, including additional semiquantitative histologic assessment of intrarenal polyomavirus replication/load levels. In-depth statistical analyses, including mixed effects repeated measures models and logistic regression, revealed two independent histologic variables to be most significantly associated with clinical presentation: intrarenal polyomavirus load levels and Banff interstitial fibrosis ci scores. These two statistically determined histologic variables formed the basis for the definition of three PVN classes that correlated strongest with three clinical parameters: presentation at time of index biopsy, serum creatinine levels/renal function over 24 months of follow-up, and graft failure. The PVN classes 1–3 as described here can easily be recognized in routine renal biopsy specimens. We recommend using this morphologic PVN classification scheme for diagnostic communication, especially at the time of index diagnosis, and in scientific studies to improve comparative data analysis.

BACKGROUND The purpose of this study was to investigate whether lymphatic reconstitution and regeneration occurs after clinical facial transplantation using indocyanine green lymphography and immunohistochemical markers. METHODS Allograft skin biopsies at multiple posttransplant time points were stained with Lyve1 lymphatic antibody and other endothelial antibodies. Staining intensity was interpreted on a scale of none, mild, moderate, and strong by 2 investigators and consolidated by a third party for final interpretation. Standardized real-time lymphography was performed at various posttransplant time points to evaluate lymphatic reconstitution and regeneration. RESULTS Forty-two biopsies were evaluated at 15 different time points from posttransplant days 7 to 420. Strong Lyve1 staining was observed in 52.4%, moderate staining in 14.3%, and weak staining in 33.3% of biopsies. Strong staining was present on days 7, 10, 44, 79, 269, 402, and 420. Three lymphographic studies were conducted at 8.5, 30, and 35 months posttransplant. Initial drainage via distinct lymphatic channels with abrupt dermal splash and lymphostasis was observed at 8.5-month posttransplant. At 30- and 35-month posttransplant, communication of multiple lymphatic channels between donor tissue and recipient tissue was evident with distinct drainage into native recipient cervical lymph nodes. This correlated with ongoing clinical resolution of facial edema and was unaffected by 3 episodes of acute rejection. CONCLUSIONS These findings support ongoing lymphatic reconstitution between the donor facial allograft and recipient native tissue. Donor lymphatic regeneration begins after facial transplantation and continues long term. This mechanism may be responsible for the temporal and spatial process of lymphatic reconstitution with recipient lymphatic channels.

There is a lack of effective targeted therapies for the treatment of complement dependent diseases. We developed two recombinant Fc multimers, G207 and G211, with limited ability to interact with low/moderate affinity FcγRs, but with high avidity for C1q. These drugs effectively inhibited complement dependent cytotoxicity (CDC) in vitro, and prevented the deposition of C1q, C3b and MAC, on the surface of Ab-opsonized cells. Importantly, these inhibitory effects were both C1q dependent and independent. In order to determine the biologic relevance of our findings, we evaluated the clinical efficacy of these drugs in three different animal models, acute RBC hemolysis, anti-Thy-1 nephritis and passive Heymann's nephropathy (PHN), in which disease pathophysiology relies preferentially on complement activation. While G207 was protective in the anti-Thy-1 nephritis and PHN models, G211 was protective in all of the models tested and could effectively treat PHN. In the anti-Thy-1 nephritis model, G211 prevented the characteristic histologic changes associated with the disease and limited glomerular deposition of C3. Collectively, these data suggest that “complement preferential” Fc multimers offer a novel approach to the treatment of complement mediated diseases.

Long-term clinicopathological studies of BK-associated nephropathy (PyVAN) are not available. We studied 206 biopsies (71 patients), followed 3.09 ± 1.46 years after immunosuppression reduction. The biopsy features (% immunostain for PyV large T ag + staining and inflammation ± acute rejection) were correlated with viral load dynamics and serum creatinine to define the clinicopathological status (PyVCPS). Incidence of acute rejection was 28% in the second biopsy and 50% subsequently (25% mixed T cell-mediated allograft rejection (TCMR) + antibody-mediated allograft rejection (AMR); rejection overall affected 38% of patients (>50% AMR). Graft loss was 15.4% (0.8-5.3 years after PyVAN); 76% had complete viral clearance (mean 28 weeks). The only predictors of graft loss were acute rejection (TCMR p = 0.008, any type p = 0.07), and increased "t" and "ci" in the second biopsy (p = 0.006 and 0.048). Higher peak viremia correlated with poorer viral clearance (p = 0.002). Presumptive and proven PyVAN had similar presentation, evolution, and outcome. Late PyVAN (>2 years, 9.8%) justifies BK viremia evaluation at any point with graft dysfunction and/or biopsy evaluation. This study describes the histological evolution of PyVAN and corresponding clinicopathological correlations. Although the pathological features overall reflect the viral and immunological interactions, the PyVAN course remains difficult to predict based on any single feature. Appropriate clinical management requires repeat biopsies and determination of the PyVCPS at relevant time points, for corresponding personalized immunosuppression adjustment.

Solid organ transplant recipients are at increased risk for developing malignancies. Polyomaviruses (PV) have been historically associated with experimental tumor development and recently described in association with renourinary malignancies in transplant patients. The aim of this study was to investigate the relationship between PV replication and smoking, and the development of malignant neoplasms in kidney transplant recipients.A retrospective case-control study was conducted for PV replication in all kidney biopsies and urine cytologies performed between 1998 and 2014 from kidney transplant recipients at the University of Maryland Medical Center. Polyomavirus-positive patients (n = 943) were defined as having any of the following: a kidney biopsy with PV associated nephropathy, any urine cytology demonstrating "decoy" cells, and/or significant polyomavirus BK viremia. Polyomavirus-negative matched patients (n = 943) were defined as lacking any evidence of PV replication. The incidence of malignancy (excluding nonmelanoma skin tumors) was determined in these 1886 patients and correlated with demographic data and history of smoking.There was a 7.9% incidence of malignant tumors after a mean posttransplant follow-up of 7.9 ± 5.4 years. Among all cancer subtypes, only bladder carcinoma was significantly associated with PV replication. By multivariate analysis, only PV replication and smoking independently increased the risk of bladder cancer, relative risk, 11.7 (P = 0.0013) and 5.6 (P = 0.0053), respectively.The findings in the current study indicate that kidney transplant recipients with PV replication and smoking are at particular risk to develop bladder carcinomas and support the need for long-term cancer surveillance in these patients.

T cell-mediated and antibody-mediated rejections are recognized as the main rejection pathways in pancreas transplantation. In comparison to other organs, rejection-related vascular lesions have not been described systematically yet. Tissue involvement in acute and chronic T cell-mediated and antibody-mediated rejections are very distinctive with respect to the epithelial components and the microvasculature, but have overlapping features regarding larger arterial branches. More specifically, the microvasculature (predominantly represented by the interacinar capillaries) which is targeted and potentially destroyed rapidly in acute antibody-mediated rejection is largely uninvolved in acute T cell-mediated rejection. In larger arteries, intimal arteritis and even arterial necrosis may be present in both types of rejection in the acute phase. Similarly in the chronic phase, both types of rejection can lead to transplant arteriopathy. Recognition of the distinctive, as well as common lesions is essential for accurate diagnosis. Future molecular studies will provide additional insight in mechanisms of vascular rejection in the pancreas.

// Kunrong Cheng 1, 2 , Aaron C. Shang 2 , Cinthia B. Drachenberg 3 , Min Zhan 1, 4 , Jean-Pierre Raufman 1, 2, 5 1 Veterans Affairs Maryland Healthcare System, Baltimore VA Medical Center, Baltimore, MD, USA 2 Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD, USA 3 Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA 4 Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA 5 Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, USA Correspondence to: Jean-Pierre Raufman, email: jraufman@medicine.umaryland.edu Keywords: colon neoplasia, metastases, muscarinic receptors, matrix metalloproteinase-1, receptor expression Received: November 30, 2016 Accepted: February 07, 2017 Published: February 18, 2017 ABSTRACT M3 muscarinic receptor (M3R) activation promotes colon cancer cell proliferation, migration, and invasion in vitro . Although over-expression of CHRM3 , the gene encoding M3R, is reported in primary colon cancers, expression of M3R itself has not been studied in colon neoplasia. We compared M3R expression in normal colon to colon adenomas, and primary and metastatic colon cancers. Compared to adjacent normal colon, CHRM3 expression was increased up to 128-fold in 10 of 18 consecutive surgical cancer specimens (56%) and associated with metastatic spread ( P < 0.05). To analyze M3R protein expression we interrogated 29 consecutive paraffin-embedded colon adenocarcinomas and adjacent normal colon using a specific anti-M3R antibody and immunoperoxidase staining. This revealed weak M3R expression in normal colonocytes, primarily on basolateral surfaces. In contrast, in 25 of 29 cancer tissues (86%) we observed both cytoplasmic and plasma membrane over-expression of M3R; compared to normal epithelium, mean M3R staining intensity was increased more than two-fold in colon cancer ( P < 0.001). M3R staining was also increased in 22 colon adenomas compared to adjacent normal colon ( P < 0.001). In contrast, M3R staining intensity was not increased in lymph node or liver metastases. These findings suggest M3R expression plays an important role in early progression and invasion of colon neoplasia but is less important once tumors have spread.

Objective To understand and overcome the challenges associated with moving life-urgent payloads using unmanned aircraft. Background data Organ transportation has not been substantially innovated in the last 60 years. Unmanned aircraft systems (UAS; ie, drones) have the potential to reduce system inefficiencies and improve access to transplantation. We sought to determine if UASs could successfully be integrated into the current system of organ delivery. Methods A multi-disciplinary team was convened to design and build an unmanned aircraft to autonomously carry a human organ. A kidney transplant recipient was enrolled to receive a drone-shipped kidney. Results A uniquely designed organ drone was built. The aircraft was flown 44 times (total of 7.38 hours). Three experimental missions were then flown in Baltimore City over 2.8 miles. For mission #1, no payload was carried. In mission #2, a payload of ice, saline, and blood tubes (3.8 kg, 8.4 lbs) was flown. In mission #3, a human kidney for transplant (4.4 kg, 9.7 lbs) was successfully flown by a UAS. The organ was transplanted into a 44-year-old female with a history of hypertensive nephrosclerosis and anuria on dialysis for 8 years. Between postoperative days (POD) 1 and 4, urine increased from 1.0 L to 3.6 L. Creatinine decreased starting on POD 3, to an inpatient nadir of 6.9 mg/dL. The patient was discharged on POD 4. Conclusions Here, we completed the first successful delivery of a human organ using unmanned aircraft. This study brought together multidisciplinary resources to develop, build, and test the first organ drone system, through which we performed the first transplant of a drone transported kidney. These innovations could inform not just transplantation, but other areas of medicine requiring life-saving payload delivery as well.

The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of bile acid–activated transcription factors and an important regulator of cell proliferation, apoptosis, and Wnt signaling. Down-regulated expression of FXR plays an important role in some malignancies such as colon cancer, and in rodent models of intestinal neoplasia, FXR knockout increases the size and number of colon tumors. These previous observations implicate FXR as a tumor suppressor, but the underlying molecular mechanisms are unclear. Employing complementary experimental approaches and using human colon cancer specimens, human and murine colon cancer cell lines, and FXR transgenic mice, here we identified an additional, potentially important role for FXR. We observed an inverse relationship between the expression of FXR and matrix metalloproteinase-7 (MMP7), a collagenase and signaling molecule consistently associated with colon cancer progression. We noted that FXR gene ablation increases MMP7 expression. Consistent with this finding, FXR overexpression and a dominant-negative FXR mutation reduced and augmented, respectively, MMP7 expression. Of note, MMP7 was the only MMP gene family member whose expression was down-regulated after FXR activation. FXR-mediated regulation of MMP7 transcription did not require heterodimerization with the retinoid X receptor (RXR), indicating that FXR represses MMP7 expression independently of RXR. Last, we uncovered that FXR suppresses MMP7 transcription by binding to a negative FXR-responsive element in the 5′ MMP7 promoter, an event that inhibited colon cancer cell proliferation and invasion. These findings identify the FXR-MMP7 axis as a potential therapeutic target for managing colon cancer.

We performed a prospective, 12-month, single-center, nonrandomized, open-label pilot study to investigate the use of belatacept therapy combined with alemtuzumab induction in renal allografts with preexisting pathology, as these kidneys may be more susceptible to additional toxicity when exposed to calcineurin inhibitors posttransplant. Nineteen belatacept recipients were matched retrospectively to a cohort of tacrolimus recipients on the basis of preimplantation pathology. The estimated glomerular filtration rate was not significantly different between belatacept and tacrolimus recipients at either 3 or 12 months posttransplant (59 vs 45, P = 0.1 and 56 vs 48 mL/min/1.72/m2 , P = 0.3). Biopsy-proven acute rejection rates at 12 months were 26% in belatacept recipients and 16% in tacrolimus recipients (P = 0.7). Graft survival at 1 year was 89% in both groups. Alemtuzumab induction combined with either calcineurin inhibitor or costimulatory blockade therapies resulted in similar acceptable one-year outcomes in kidneys with preexisting pathologic changes. Longer-term follow-up may be necessary to identify preferential strategies to improve outcomes of kidneys at a higher risk for poor function (ClinicalTrials.gov-NCT01496417).