C3 glomerulopathy in a patient with a history of post-infectious glomerulonephritis

Post-infectious glomerulonephritis (PIGN) is an immune complex mediated glomerular injury occurring because of an infection, most commonly with group A beta-hemolytic streptococcus in children. C3 glomerulopathy (C3G) is a distinct clinicopathological entity occurring secondary to dysregulation of alternate complement pathway encompassing both C3 glomerulonephritis (C3GN) and dense deposit disease (DDD). While most patients with PIGN attain complete remission with normalized complement levels by 6-8 weeks after presentation, patients with C3G continue to have hypocomplementemia with high rates of progressive kidney disease. Here, we report a patient diagnosed with dense deposit disease after his initial presentation with PIGN three years prior. While current literature continues to explore the overlapping and distinguishing features of PIGN and C3G, including how underlying defects in the alternate complement pathway may commonly contribute to both diseases, this case further exemplifies the importance of recognizing the clinico-pathogenic features of PIGN and C3G in pediatric patients with glomerulonephritis.

Giants Hiding in Small Places: A Case of New Onset Heart Failure, Atrioventricular Block, and Ventricular Arrhythmias

Woman with new-onset heart failure, atrioventricular block, and ventricular tachycardia found to have giant cell myocarditis.

Surgical Outcomes of Infective Native Aortoiliac Aneurysms in a Chilean Academic Center

BACKGROUND

Infective native aortic aneurysms (INAAs), formerly called mycotic aneurysms, remain an uncommon disease with significant heterogeneity among cases; hence, there is lack of solid evidence to opt for the best treatment strategy. The present study aims to describe a 20-year experience at a single institution treating this uncommon condition.

METHODS

Retrospective study of all patients treated for INAA at a single academic hospital in Santiago, Chile, between 2002 and 2022. Clinical characteristics are described, as well as operative outcomes per type of treatment. Nonparametric Mann-Whitney U-test or Kruskal-Wallis tests were performed when appropriate, and results were reported as median and ranges. Survival at given timeframes was determined by a Kaplan-Meier curve, with analysis performed through a Cox regression model.

RESULTS

During the study period, 1,798 patients underwent aortic procedures at our center, of which 35 (1.9%) were treated for INAA. Of them, 25 (71.4%) were male. One patient had 2 INAAs. Median age was 69.5 years (range: 34-89 years). Of the 36 INAAs, the most frequent location was the abdominal and thoracic aorta in 20 (55.5%) and 11 (30.5%) cases, respectively, followed by the iliac arteries in 4 (11.1%) cases. One (2.7%) patient presented a thoracoabdominal INAA. Overall, endovascular treatment associated with long-term antibiotics was used in 20 (57.1%) patients: 4 of them underwent hybrid treatment. Fifteen (42.8%) patients underwent direct aortic debridement followed by in situ or extra anatomic revascularization. There was a significant difference in age between both treatment strategies (a median of 76.5 years for endovascular versus a median of 57 years for open, P = 0.011). The median hospital stay was 15 days (range: 2-70 days). The early complications rate (<30 postoperative days) was 20% (n = 7). Early mortality rate (inhospital or before postoperative 30 days) was 14.2% (n = 5). Median follow-up was 33 months (range: 6-216 months). The overall survival rates at 1, 3, and 5 years were 69.9% (standard error [SE] 8.0), 61.7% (SE 9.8), and 50.9% (SE 11.8), respectively. Five-year survival rate of patients undergoing endovascular treatment compared with open approach was 45.9% (SE 15.1) versus 80.0% (SE 17.8), respectively (P = 0.431). There were no significant differences in survival between open and endovascular treatment, hazard ratio 3.58 (confidence interval 95%: 0.185-1.968, SE ± 0.45 P = 0.454).

CONCLUSIONS

Patients treated by endovascular approach were older than patients treated by open approach. Even though, the open group had a higher 5-year survival rate than the endovascular group, not statically significance differences were found between treatments.

An Unusual Presentation of Metastatic BK Virus-Associated Urothelial Carcinoma Arising in the Allograft, Persisting After Transplant Nephrectomy

We report a 32-year-old male 14 years post-living-related kidney transplant presenting with new-onset hematuria and BK viremia. He was found to have BK virus-associated urothelial carcinoma originating in the renal allograft with locally advanced disease and metastases to multiple sites. He also developed acute T-cell-mediated rejection in the setting of immunosuppression reduction for BK viremia prior to undergoing transplant nephrectomy. Eight months following transplant nephrectomy and immunosuppression cessation, distant metastases persisted with partial response to chemotherapy and immunotherapy. Here, we discuss this unique presentation and compare it with other BK virus-associated allograft carcinomas reported in the literature, in addition to discussing evidence for the role of BK virus in oncogenesis.

Transfemoral Access to Implant Iliac Branch Devices After Previous Aortic Grafts

OBJECTIVE

To report on the outcomes of patients undergoing an iliac branch device implantation after previous open or endovascular aorto-biliac repair, using exclusively femoral access for catheterization and delivery of the covering stent to the hypogastric artery.

METHODS

Single-center retrospective study in which all patients in whom an iliac branch device was implanted after previous open or endovascular aorto-biliac repair were identified. Patients in whom the hypogastric artery catheterization and delivery of the bridging cover stent were achieved via exclusive femoral access were included. Different techniques were used based on surgeon preference. Technical success and access-related complications, as well as iliac branch device endoleak or occlusions during follow-up, were evaluated.

RESULTS

From 2015 to 2021, 28 patients with a prior open or endovascular aorto-biliac repair underwent 34 iliac branch device implantations. Most (71%) had juxtarenal or thoracoabdominal aortic aneurysms, 82% had common iliac artery aneurysms, and 25% had hypogastric artery aneurysms. Bilateral iliac branch device implantations were performed in 21% of the patients, and in 26% of cases, landing in the superior gluteal artery was obtained. An "up-and-over" technique from the contralateral groin was used in 65% of the cases, and a steerable sheath in 35%. Technical success was 94%, with no complications related to access or technique to catheterize and deliver the stents in the hypogastric artery. The cohort had 20% of major complications, with 3 perioperative deaths. Kaplan-Meier estimated an iliac branch device freedom from occlusion and endoleak was 92% and 83% at 2 years.

CONCLUSIONS

The implantation of an iliac branch device over previous aortic or open endografts involving the aortic bifurcation is feasible and safe. We suggest using a femoral approach as the primary access of choice.

CLINICAL IMPACT

In this study we present 28 patients with previous aortoiliac grafts in which iliac branch devices were performed as a subsequent step.We demonstrated the feasibility of the technique despite the difficulty of crossing a neobifurcation, with a steep angle, without complications associated with the technique. Based on our experience, we recommend transfemoral access as the first option for bypassing the hypogastric artery stent, preserving upper extremity access and its possible complications.

Defining the molecular correlate of arteriolar hyalinosis in kidney disease progression by integration of single cell transcriptomic analysis and pathology scoring

Arteriolar hyalinosis in kidneys is an independent predictor of cardiovascular disease, the main cause of mortality in chronic kidney disease (CKD). The underlying molecular mechanisms of protein accumulation in the subendothelial space are not well understood. Using single cell transcriptomic data and whole slide images from kidney biopsies of patients with CKD and acute kidney injury in the Kidney Precision Medicine Project, the molecular signals associated with arteriolar hyalinosis were evaluated. Co-expression network analysis of the endothelial genes yielded three gene set modules as significantly associated with arteriolar hyalinosis. Pathway analysis of these modules showed enrichment of transforming growth factor beta / bone morphogenetic protein (TGFβ / BMP) and vascular endothelial growth factor (VEGF) signaling pathways in the endothelial cell signatures. Ligand-receptor analysis identified multiple integrins and cell adhesion receptors as over-expressed in arteriolar hyalinosis, suggesting a potential role of integrin-mediated TGFβ signaling. Further analysis of arteriolar hyalinosis associated endothelial module genes identified focal segmental glomerular sclerosis as an enriched term. On validation in gene expression profiles from the Nephrotic Syndrome Study Network cohort, one of the three modules was significantly associated with the composite endpoint (> 40% reduction in estimated glomerular filtration rate (eGFR) or kidney failure) independent of age, sex, race, and baseline eGFR, suggesting poor prognosis with elevated expression of genes in this module. Thus, integration of structural and single cell molecular features yielded biologically relevant gene sets, signaling pathways and ligand-receptor interactions, underlying arteriolar hyalinosis and putative targets for therapeutic intervention.

Fiber Optic RealShape (FORS) Technology for Endovascular Navigation in Severe Tortuous Vessels

PURPOSE

The purpose of this study was to describe the use of a wire and catheters embedded with optical fiber (Fiber Optic RealShape [FORS]) to catheterize tortuous target vessels avoiding radiation.

TECHNIQUE

A virtual biplane vies was simulated coupling traditional x-ray system, preoperative CT scan, and FORS system to treat an isolated hypogastric aneurysm. Despite the complex anatomy, catheterization of all target vessels was possible in 12 minutes with 19 seconds of fluoroscopy time (Radiation Exposure 3.8 mGy×cm²). A minimal invasive endovascular exclusion of the aneurysm was achieved through selective coil-embolization of the iliolumbar artery and implantation of balloon expandable covered stents, thus preserving the perfusion of the superior gluteal artery.

CONCLUSION

FORS guidance allowed catheterization of a target vessel with challenging anatomy with a low radiation exposure.

True Idiopathic Brachial Artery Aneurysm Treated With a Saphenous Vein Graft

Purpose: The objective of this study is to report a case of a 65-year-old woman who presented with pallor and pain of her left arm secondary to a true arterial brachial aneurysm, which was successfully treated with saphenous vein bypass and embolization of the aneurysm sac. A review of the literature is also presented. Case report: A 65-year-old woman presented with an acute onset of pallor and pain of her left forearm, and hand. On physical examination, there was a pulsatile mass at the forearm. A doppler ultrasound showed a fusiform aneurysmal dilatation of the brachial artery of 23 mm of diameter. A dynamic contrast-enhanced MRI angiogram confirmed a fusiform dilation of the distal brachial artery. The patient was scheduled for open repair. A fusiform 20 x 60 mm aneurysm of the distal brachial artery extending to the cubital fossa was found and a brachial artery to radial and ulnar arteries bypass with interposed reverse right saphenous vein was created. Embolization of the aneurysm sac was performed using Gelita-spon ® (Gelita Medical, Eberbach, Germany). A final angiogram showed an adequate perfusion through the bypass to the hand, and no contrast in the aneurysmal sac. Postoperative course was uneventful with discharge on the fourth postoperative day. Conclusion: Revascularization with autologous saphenous vein graft and exclusion of the aneurysm with local embolization is a good treatment alternative in a patient with symptomatic brachial aneurysm with distal embolization.

Extrinsic venous compression secondary to spine osteophytes

OBJECTIVE

This study aims to report two cases of symptomatic extrinsic compression of the inferior vena cava and left iliac vein caused by vertebral osteophytes.

METHODS

We present two case reports of extrinsic venous compression by vertebral osteophytes. Both cases were endovascularly treated, with a successful outcome. A review of the literature of this unusual condition is also presented.

RESULTS

The first patient is an 80-year-old woman who presented to the vascular surgery clinic with bilateral lower extremity edema and pain. A computed-tomography angiography (CTA) revealed extrinsic compression of the inferior vena cava from enlarged osteophytes. Venography and intravascular ultrasound were performed, confirming the diagnosis. A self-expanding venous stent was successfully deployed in the inferior vena cava relieving the extrinsic compression. The edema resolved the following day and was discharged without complications. The second patient is a 61-year-old male that presented to the emergency department with a left iliofemoral deep venous thrombosis. CTA showed left iliac vein compression by a lumbar osteophyte. Percutaneous thrombectomy was successfully achieved and an expanding stent was deployed covering the entire lesion. One month after the procedure the patient died from COVID-19-associated respiratory failure.

CONCLUSION

Osteophytes must be considered when dealing with extrinsic venous compression, especially in elderly people.

Variables Associated With Response to Therapy in Patients With Interstitial Pneumonia With Autoimmune Features

BACKGROUND/OBJECTIVE

We have limited knowledge regarding characteristics of patients with interstitial pneumonia with autoimmune features (IPAF) that are associated with response to immunosuppression. In this study, we used published IPAF criteria to characterize features associated with response to treatment.

METHODS

We conducted a single-center medical records review study of 63 IPAF patients to evaluate for serological, clinical, and morphological characteristics that are associated with response to immunosuppression. Response was defined as % relative functional vital capacity decline of less than 10% and absence of death or lung transplant within the first year of continuous immunosuppressive therapy. Nonparametric measures of association and multivariate logistic regression were used to evaluate the relationship between baseline characteristics and immunosuppressive response.

RESULTS

There was a trend of greater progression among men, ever smokers, those negative for antisynthetase antibodies, and those with usual interstitial pneumonia radiographic pattern, but no statistically significant relationship was found between baseline serological, clinical, or morphological features and response to immunosuppression. Patients on combination therapy with mycophenolate mofetil and prednisone had less disease progression (p = 0.018) than those on regimens that did not include both of these medications.

CONCLUSIONS

In our cohort, baseline clinical assessment did not identify which patients with IPAF will respond to immunosuppressive therapy. Combination therapy with mycophenolate mofetil and prednisone was associated with lack of disease progression in our IPAF patients, including in IPAF-usual interstitial pneumonia. Further studies are needed to evaluate which IPAF patients would benefit from immunosuppressive therapy, antifibrotic therapy, or a combination of both.

Complement Blockade in Recipients Prevents Delayed Graft Function and Delays Antibody-mediated Rejection in a Nonhuman Primate Model of Kidney Transplantation

BACKGROUND

Complement activation in kidney transplantation is implicated in the pathogenesis of delayed graft function (DGF). This study evaluated the therapeutic efficacy of high-dose recombinant human C1 esterase inhibitor (rhC1INH) to prevent DGF in a nonhuman primate model of kidney transplantation after brain death and prolonged cold ischemia.

METHODS

Brain death donors underwent 20 h of conventional management. Procured kidneys were stored on ice for 44-48 h, then transplanted into ABO-compatible major histocompatibility complex-mismatched recipients. Recipients were treated with vehicle (n = 5) or rhC1INH 500 U/kg plus heparin 40 U/kg (n = 8) before reperfusion, 12 h, and 24 h posttransplant. Recipients were followed up for 120 d.

RESULTS

Of vehicle-treated recipients, 80% (4 of 5) developed DGF versus 12.5% (1 of 8) rhC1INH-treated recipients (P = 0.015). rhC1INH-treated recipients had faster creatinine recovery, superior urinary output, and reduced urinary neutrophil gelatinase-associated lipocalin and tissue inhibitor of metalloproteinases 2-insulin-like growth factor-binding protein 7 throughout the first week, indicating reduced allograft injury. Treated recipients presented lower postreperfusion plasma interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and IL-18, lower day 4 monocyte chemoattractant protein 1, and trended toward lower C5. Treated recipients exhibited less C3b/C5b-9 deposition on day 7 biopsies. rhC1INH-treated animals also trended toward prolonged mediated rejection-free survival.

CONCLUSIONS

Our results recommend high-dose C1INH complement blockade in transplant recipients as an effective strategy to reduce kidney injury and inflammation, prevent DGF, delay antibody-mediated rejection development, and improve transplant outcomes.

Physician-Modified Endograft With Inner Branches for the Treatment of Complex Aortic Urgencies

PURPOSE

To describe the use of physician-modified endograft (PMEG) with the exclusive use of inner branches or in combination with fenestrations for the urgent treatment of complex aortic aneurysms.

TECHNIQUE

We present two urgent cases. A patient with a 6.8 cm saccular juxtarenal aneurysm and another patient with a contained rupture of the thoracoabdominal aorta right above the celiac trunk (CT). In both cases, a Cook Zenith TX2 thoracic endograft was back-table modified, in the first case by adding three fenestrations and one inner branch for the left renal artery to improve sealing due to its partial involvement in the aneurysm and, in the second case, with the use of two inner branches for the CT and superior mesenteric artery. Both procedures were successful, with uneventful postoperative courses and complete aneurysm exclusion on postoperative CT angiography.

CONCLUSION

Use of PMEGs with inner branches is feasible for urgent repair in complex aortic anatomy.

One-Year Results of ZBIS Iliac Branch Device With an Off-Label Connection Limb

PURPOSE

The purpose of this article is to study 1-year results of Zenith branch iliac endovascular graft (ZBIS) with the off-label use of a 13 mm spiral Z limb to connect to the aortic main body.

MATERIALS AND METHODS

A retrospective review from 2015 to 2019 of all iliac branch devices (IBDs) was performed at 1 institution that were connected to an aortic main body with a 13 mm spiral Z limb and had at least 1-year follow-up with computed tomography (CT). Primary endpoints are freedom from ZBIS separation from the connection limb, endoleak (EL), or reintervention at 1 year. Secondary endpoints are primary and secondary ZBIS patency, presence of any EL, and aortic reinterventions.

RESULTS

Of 149 IBDs implanted in this period, 45 ZBIS in 35 patients were connected with a 13 mm limb and had a 1-year CT; 97% of patients had common iliac artery (CIA) aneurysms, 7% of patients had hypogastric artery (HA) aneurysms, and 30% of patients had bilateral ZBIS implantation. Technical success was 98%. In 84% of cases, the Advanta V12 was used as the HA mating stent; 56% of patients had an EL, mostly type II, which resolved spontaneously in 70% at 1 year, and 9% of ZBIS required reinterventions at 1 year (2 for thrombosis, 2 for type Ic EL from HA mating stent). One-year ZBIS primary patency and secondary patency were 96% and 100%, respectively. No EL was noted to be related to the 13 mm connection limb. No migration or separation of the devices occurred.

CONCLUSIONS

The use of 13 mm spiral Z limb to connect a ZBIS with the main body in our series yields a high technical success rate and good 12-month outcomes without device separation or migration.

Utility of Bronchoalveolar Lavage and Transbronchial Biopsy in Patients with Interstitial Lung Disease

PURPOSE

Bronchoalveolar lavage and transbronchial biopsy can be a useful tool in the evaluation of interstitial lung disease (ILD), but patient selection for this procedure remains poorly defined. Determining clinical characteristics that help with patient selection for bronchoscopy may improve confidence of ILD classification while limiting potential adverse outcomes associated with surgical lung biopsy. The purpose of this study is to identify factors that were associated with change in multidisciplinary ILD diagnosis (MDD) before and after incorporation of BAL and TBBx data.

METHODS

We conducted a retrospective cohort study of ILD patients at a single center who underwent bronchoscopy in the diagnostic workup of ILD. We performed sequential MDD both pre- and post-bronchoscopy to calculate the frequency of change in diagnosis after incorporating information from BAL and TBBx and identify features associated with change in diagnosis.

RESULTS

245 patients were included in the study. Bronchoscopy led to a change in diagnosis in 58 patients (23.7%). The addition of TBBx to BAL increased diagnostic yield from 21.8 to 34.1% (p = 0.027). Identification of antigen, HRCT scan inconsistent with UIP, and absence of a pre-bronchoscopy diagnosis of CTD-ILD or IPAF were associated with a change in diagnosis after bronchoscopy.

CONCLUSION

Our study suggests clinical features that may assist with patient selection for bronchoscopy. We suggest bronchoscopy in patients with identified antigen or an HRCT that is consistent with a non-IPF diagnosis. Appropriate patient selection for bronchoscopy may improve ILD diagnostic confidence and avoid potential complications from more invasive and higher risk procedures.

Phase II Study of Ensituximab, a Novel Chimeric Monoclonal Antibody, in Adults with Unresectable, Metastatic Colorectal Cancer

PURPOSE

Patients with metastatic colorectal cancer refractory to chemotherapy have limited treatment options. Ensituximab (NEO-102) is a novel chimeric mAb targeting a variant of MUC5AC with specificity to colorectal cancer.

PATIENTS AND METHODS

Single-arm, phase II trial assessed the efficacy and safety of ensituximab in patients with advanced, refractory cancer who expressed MUC5AC antigen in tumor tissue. Ensituximab was administered intravenously every 2 weeks with 3 mg/kg as recommended phase II dose (RP2D). A minimum sample size of 43 patients was required on the basis of the assumption that ensituximab would improve median overall survival (OS) by 7 months using a one-sided significance level of 10% and 80% power. Written informed consent was obtained from all patients.

RESULTS

Sixty-three patients with advanced, refractory colorectal cancer were enrolled and 53 subjects were treated in phase II arm. Median age was 58 years and 46% of the patients were female. Among 57 evaluable patients, median OS was 6.8 months. No responses were observed, and stable disease was achieved in 21% of the patients. The most common treatment-related adverse events (AE) at RP2D included fatigue (38%), anemia (30%), nausea (15%), vomiting (11%), increased bilirubin (9%), constipation (8%), decreased appetite (6%), and diarrhea (6%). Serious AEs at least possibly related to ensituximab occurred in 4 patients and included anemia, nausea, increased bilirubin, and hypoxia. No patients discontinued treatment due to drug-related AEs.

CONCLUSIONS

Ensituximab was well tolerated and demonstrated modest antitumor activity in patients with heavily pretreated refractory colorectal cancer.

Does Tumor FDG-PET Avidity Represent Enhanced Glycolytic Metabolism in Non-Small Cell Lung Cancer?

BACKGROUND

In non-small cell lung cancer (NSCLC), 18fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) assists in diagnosis, staging, and evaluating treatment response. One variable of FDG-PET, the maximum standard uptake value (SUVm), is considered an objective measure of glucose uptake. However, little is known about the fate of glucose in FDG-avid lung tumors in vivo. This study used stable glucose isotope tracing to determine whether the SUVm predicts glycolytic metabolism or other glucose fates in tumors.

METHODS

In this prospective Institutional Review Board-approved clinical trial, 52 untreated potentially resectable confirmed NSCLC patients underwent FDG-PET computed tomography. During the surgical procedure, the patients were infused with 13C-labeled glucose. Blood, tumor, and normal lung samples were analyzed by mass spectrometry to determine 13C enrichment in glycolytic intermediates. These values were compared with clinical variables, including SUVm, maximum tumor diameter, stage, grade, and MIB-1/Ki67 proliferation index.

RESULTS

For each patient, 13C enrichment in each metabolite was compared between tumor and adjacent lung. Although all tumors metabolized glucose, SUVm did not correlate with glycolytic intermediate labeling. Rather, SUVm correlated with markers indicating the use of other respiratory substrates, including lactate, and with the proliferation index.

CONCLUSIONS

SUVm does not correlate with glycolytic metabolism in human NSCLC but does correlate with the proliferation index, suggesting that SUVm predicts glucose use by pathways other than glycolysis. These pathways may offer alternative therapeutic targets, including biosynthetic pathways required for cell proliferation. The research techniques in this study offer the opportunity to understand the relationships between SUVm, tumor metabolism, and therapeutic vulnerabilities in human NSCLCs.

Typical and atypical carcinoid tumors of the lung: a clinicopathological correlation of 783 cases with emphasis on histological features

We present 783 surgical resections of typical and atypical carcinoid tumors of the lung identified in the pathology files of 20 different pathology departments. All cases were critically reviewed for clinical and pathological features and further correlated with clinical outcomes. Long-term follow-up was obtained in all the patients and statistically analyzed to determine significance of the different parameters evaluated. Of the histopathological features analyzed, the presence of mitotic activity of 4 mitoses or more per 2 mm², necrosis, lymphatic invasion, and lymph node metastasis were identified as statistically significant. Tumors measuring 3 cm or more were also identified as statistically significant and correlated with clinical outcomes. Based on our analysis, we consider that the separation of low- and intermediate-grade neuroendocrine neoplasms of the lung needs to be readjusted in terms of mitotic count as the risk of overgrading these neoplasms exceeds 10% under the current criteria. We also consider that tumor size is an important feature to be considered in the assessment of these neoplasms and together with the histological grade of the tumor offers important features that can be correlated with clinical outcomes.

A Cellular Anatomy of the Normal Adult Human Prostate and Prostatic Urethra

A comprehensive cellular anatomy of normal human prostate is essential for solving the cellular origins of benign prostatic hyperplasia and prostate cancer. The tools used to analyze the contribution of individual cell types are not robust. We provide a cellular atlas of the young adult human prostate and prostatic urethra using an iterative process of single-cell RNA sequencing (scRNA-seq) and flow cytometry on ~98,000 cells taken from different anatomical regions. Immunohistochemistry with newly derived cell type-specific markers revealed the distribution of each epithelial and stromal cell type on whole mounts, revising our understanding of zonal anatomy. Based on discovered cell surface markers, flow cytometry antibody panels were designed to improve the purification of each cell type, with each gate confirmed by scRNA-seq. The molecular classification, anatomical distribution, and purification tools for each cell type in the human prostate create a powerful resource for experimental design in human prostate disease.

Using single-cell RNA sequencing, immunofluorescence, and flow cytometry, Henry et al. create a cellular anatomy of the normal human prostate and provide the tools to identify, isolate, and localize every cell type. They identify two additional epithelial cell types enriched in the prostatic urethra and proximal prostatic ducts.

Telomere length and genetic variant associations with interstitial lung disease progression and survival

Leukocyte telomere length (LTL), MUC5B rs35705950 and TOLLIP rs5743890 have been associated with idiopathic pulmonary fibrosis (IPF).In this observational cohort study, we assessed the associations between these genomic markers and outcomes of survival and rate of disease progression in patients with interstitial pneumonia with autoimmune features (IPAF, n=250) and connective tissue disease-associated interstitial lung disease (CTD-ILD, n=248). IPF (n=499) was used as a comparator.The LTL of IPAF and CTD-ILD patients (mean age-adjusted log-transformed T/S of -0.05±0.29 and -0.04±0.25, respectively) is longer than that of IPF patients (-0.17±0.32). For IPAF patients, LTL <10th percentile is associated with faster lung function decline compared to LTL ≥10th percentile (-6.43% per year versus -0.86% per year; p<0.0001) and worse transplant-free survival (hazard ratio 2.97, 95% CI 1.70-5.20; p=0.00014). The MUC5B rs35705950 minor allele frequency (MAF) is greater for IPAF patients (23.2, 95% CI 18.8-28.2; p<0.0001) than controls and is associated with worse transplant-free IPAF survival (hazard ratio 1.92, 95% CI 1.18-3.13; p=0.0091). Rheumatoid arthritis (RA)-associated ILD (RA-ILD) has a shorter LTL than non-RA CTD-ILD (-0.14±0.27 versus -0.01±0.23; p=0.00055) and higher MUC5B MAF (34.6, 95% CI 24.4-46.3 versus 14.1, 95% CI 9.8-20.0; p=0.00025). Neither LTL nor MUC5B are associated with transplant-free CTD-ILD survival.LTL and MUC5B MAF have different associations with lung function progression and survival for IPAF and CTD-ILD.

Bile Cast Nephropathy: A Pathologic Finding with Manifold Causes Displayed in an Adult with Alcoholic Steatohepatitis and in a Child with Wilson's Disease

Bile cast nephropathy (BCN) is seen in patients who have acute kidney injury and severe hyperbilirubinemia due to a wide range of hepatobiliary system diseases. Findings seen by renal biopsy include acute tubular injury with necrotic and sloughed epithelial cells, yellow-green pigment within tubular epithelial cells, and pigmented granular casts. Hall's special stain for bile turns these casts green. In recent years, BCN has been described in a small number of case reports and clinical studies primarily in the setting of severe liver dysfunction. We present 2 diverse cases of BCN. The first involves an adult with hepatorenal syndrome secondary to alcoholic steatohepatitis and early cirrhosis. Second, we describe the first reported case of BCN in a child with fulminant hepatic failure due to Wilson's disease. Our cases expand the spectrum of causative diseases, and they provide further evidence that BCN is a distinct pathologic entity which may be found in both adult and pediatric patients with a variety of severe liver diseases.

An Empirical Approach Leveraging Tumorgrafts to Dissect the Tumor Microenvironment in Renal Cell Carcinoma Identifies Missing Link to Prognostic Inflammatory Factors

By leveraging tumorgraft (patient-derived xenograft) RNA-sequencing data, we developed an empirical approach, DisHet, to dissect the tumor microenvironment (eTME). We found that 65% of previously defined immune signature genes are not abundantly expressed in renal cell carcinoma (RCC) and identified 610 novel immune/stromal transcripts. Using eTME, genomics, pathology, and medical record data involving >1,000 patients, we established an inflamed pan-RCC subtype (IS) enriched for regulatory T cells, natural killer cells, TH1 cells, neutrophils, macrophages, B cells, and CD8+ T cells. IS is enriched for aggressive RCCs, including BAP1-deficient clear-cell and type 2 papillary tumors. The IS subtype correlated with systemic manifestations of inflammation such as thrombocytosis and anemia, which are enigmatic predictors of poor prognosis. Furthermore, IS was a strong predictor of poor survival. Our analyses suggest that tumor cells drive the stromal immune response. These data provide a missing link between tumor cells, the TME, and systemic factors.Significance: We undertook a novel empirical approach to dissect the renal cell carcinoma TME by leveraging tumorgrafts. The dissection and downstream analyses uncovered missing links between tumor cells, the TME, systemic manifestations of inflammation, and poor prognosis. Cancer Discov; 8(9); 1142-55. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 1047.

Utility of Bronchoalveolar Lavage and Transbronchial Biopsy in Patients with Hypersensitivity Pneumonitis

INTRODUCTION

Making the diagnosis of HP is challenging due to a lack of consensus criteria and variability of both pathologic and radiographic findings. The purpose of this retrospective study was to determine the diagnostic utility of the combination of BAL lymphocyte count and TBBX in patients with HP.

METHODS

We conducted a retrospective cohort study of all patients with a MDD diagnosis of HP at a single center.

RESULTS

155 patients were included in the study. 49% of patients who underwent BAL had a lymphocyte count > 20, 42% had a lymphocyte count > 30, and 34% had lymphocyte count > 40%. The median BAL lymphocyte count was higher in inflammatory HP compared to fibrotic HP. The addition of TBBX to BAL significantly increased the diagnostic yield regardless of the BAL lymphocyte cutoff used. The yield of bronchoscopy with TBBX and BAL when a lymphocyte count > 40% was used as a cutoff was 52%.

CONCLUSIONS

Our study suggests that the combination of TBBX with BAL significantly increases the likelihood that the procedure will provide adequate additional information to allow a confident MDD diagnosis of HP and may reduce the need for SLB in the diagnostic workup of HP.

Proliferative Glomerulonephritis with Monoclonal Immunoglobulin G Lambda Deposits: Report of the First Pediatric Case

Proliferative glomerulonephritis with monoclonal immunoglobulin G deposits (PGNMID) is a recently described, uncommon renal disorder which is considered a monoclonal gammopathy of renal significance. Although some patients will have a detectable monoclonal spike, overt hematologic malignancy is found in only a minority. Most patients with PGNMID are over the age of 50 years, and to our knowledge no cases have been reported in children or adolescents. Renal biopsy shows variable histologic patterns by light microscopy, with membranoproliferative and membranous patterns being most common. Immunofluorescence microscopy demonstrates restriction to a single immunoglobulin G heavy chain isotype and a single light chain subtype. Electron microscopy reveals granular, unorganized deposits. We report a rare pediatric case which occurred in a 17-year-old female. The rarity of this entity in the adult population has not permitted a standard treatment regimen to be established. Our adolescent patient was treated with multiple treatment regimens including prednisone, mycophenolate mofetil, rituximab, bortezomib, and daratumumab. Our case demonstrates that awareness of this disorder by pediatric nephrologists and pathologists is vital to guide accurate disease classification, prognosis, and treatment.

Lactate Metabolism in Human Lung Tumors

Cancer cells consume glucose and secrete lactate in culture. It is unknown whether lactate contributes to energy metabolism in living tumors. We previously reported that human non-small-cell lung cancers (NSCLCs) oxidize glucose in the tricarboxylic acid (TCA) cycle. Here, we show that lactate is also a TCA cycle carbon source for NSCLC. In human NSCLC, evidence of lactate utilization was most apparent in tumors with high ¹⁸fluorodeoxyglucose uptake and aggressive oncological behavior. Infusing human NSCLC patients with ¹³C-lactate revealed extensive labeling of TCA cycle metabolites. In mice, deleting monocarboxylate transporter-1 (MCT1) from tumor cells eliminated lactate-dependent metabolite labeling, confirming tumor-cell-autonomous lactate uptake. Strikingly, directly comparing lactate and glucose metabolism in vivo indicated that lactate's contribution to the TCA cycle predominates. The data indicate that tumors, including bona fide human NSCLC, can use lactate as a fuel in vivo.

Guidelines for the management of a brain death donor in the rhesus macaque: A translational transplant model

Introduction

The development of a translatable brain death animal model has significant potential to advance not only transplant research, but also the understanding of the pathophysiologic changes that occur in brain death and severe traumatic brain injury. The aim of this paper is to describe a rhesus macaque model of brain death designed to simulate the average time and medical management described in the human literature.

Methods

Following approval by the Institutional Animal Care and Use Committee, a brain death model was developed. Non-human primates were monitored and maintained for 20 hours after brain death induction. Vasoactive agents and fluid boluses were administered to maintain hemodynamic stability. Endocrine derangements, particularly diabetes insipidus, were aggressively managed.

Results

A total of 9 rhesus macaque animals were included in the study. The expected hemodynamic instability of brain death in a rostral to caudal fashion was documented in terms of blood pressure and heart rate changes. During the maintenance phase of brain death, the animal’s temperature and hemodynamics were maintained with goals of mean arterial pressure greater than 60mmHg and heart rate within 20 beats per minute of baseline. Resuscitation protocols are described so that future investigators may reproduce this model.

Conclusion

We have developed a reproducible large animal primate model of brain death which simulates clinical scenarios and treatment. Our model offers the opportunity for researchers to have translational model to test the efficacy of therapeutic strategies prior to human clinical trials.

The MUC5B promoter polymorphism and telomere length in patients with chronic hypersensitivity pneumonitis: an observational cohort-control study

BACKGROUND

Patients with hypersensitivity pneumonitis are at risk of developing pulmonary fibrosis, which is associated with reduced survival. In families with multiple affected members, individuals might be diagnosed as having idiopathic pulmonary fibrosis (IPF) or chronic (fibrotic) hypersensitivity pneumonitis, which suggests these disorders share risk factors. We aimed to test whether the genomic risk factors associated with the development and progression of IPF are also associated with the development of fibrosis and reduced survival in people with chronic hypersensitivity pneumonitis.

METHODS

We did an observational study of two independent cohorts of patients with chronic hypersensitivity pneumonitis, one from the University of California San Francisco, CA, USA (UCSF), and one from the University of Texas Southwestern, TX, USA (UTSW). We measured two common single-nucleotide polymorphisms associated with IPF (MUC5B rs35705950 and TOLLIP rs5743890) and telomere length in peripheral blood leucocytes, and assessed their associations with chronic hypersensitivity pneumonitis risk, survival, and clinical, radiographic, and pathological features. We compared findings with those in patients with IPF from the UCSF and UTSW cohorts, and healthy controls from the European population of the 1000 Genomes Project Phase 3, version 1.

FINDINGS

The cohorts included 145 patients from UCSF and 72 from UTSW. The minor allele frequency (MAF) was greater for MUC5B rs35705950 in patients with chronic hypersensitivity pneumonitis than in healthy controls (24·4% in UCSF and 32·3% in UTSW vs 10·7%, both p<0·0001), but not for TOLLIP rs5743890. The MAFs were similar to those for IPF (UCSF 33·3%, p=0·09; UTSW 32·0%, p=0·95). In the combined UCSF and UTSW chronic hypersensitivity pneumonitis cohort, we saw associations between extent of radiographic fibrosis and MUC5B rs35705950 minor alleles (adjusted odds ratio [OR] 1·91, 95% CI 1·02-3·59, p=0·045) and short telomere length (adjusted OR per unit change in mean natural logarithm-transformed ratio of telomere repeat copy number to single gene copy number 0·23, 0·09-0·59, p=0·002). Telomere length less than the tenth percentile for age was also significantly associated with reduced survival (log-rank p=0·006).

INTERPRETATION

The associations between MUC5B rs35705950 and short telomere length with extent of fibrosis, histopathological features of usual interstitial pneumonia, and reduced survival in patients with chronic hypersensitivity pneumonitis suggest shared pathobiology with IPF, and might help to stratify risk.

FUNDING

National Institutes of Health and Nina Ireland Program for Lung Health.

Renal-Limited "Lupus-Like" Nephritis: How Much of a Lupus?

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by development of autoantibodies to nuclear and cytoplasmic antigens. A small subset of SLE patients who had the typical clinical features of SLE was reported to show persistently negative antinuclear antibody tests. Our report describes a 5-year-old male who presented with histopathological findings suggestive of lupus nephritis with no clinical signs or symptoms of SLE and negative autoantibodies. He was treated with corticosteroids, mycophenolate mofetil, and monthly intravenous cyclophosphamide. During the 2-year follow-up period, the proteinuria resolved and kidney function improved with continued negative autoantibody workup. This case presents a category of renal-limited “lupus-like” glomerulonephritis which can be challenging to treat and carries a poor prognosis.

Molecular pathogenesis of human prostate basal cell hyperplasia

BACKGROUND

Understanding the molecular pathogenesis of distinct phenotypes in human benign prostatic hyperplasia (BPH) is essential to improving therapeutic intervention. Current therapies target smooth muscle and luminal epithelia for relief of lower urinary tract symptoms (LUTS) due to BPH, but basal cell hyperplasia (BCH) remains untargeted. The incidence of has been reported at 8-10%, but a molecular and cellular characterization has not been performed on this phenotype.

METHODS

Using freshly digested tissue from surgical specimens, we performed RNA-seq analysis of flow cytometry-purified basal epithelia from 3 patients with and 4 patients without a majority BCH phenotype. qPCR was performed on 28 genes identified as significant from 13 non-BCH and 7 BCH specimens to confirm transcriptomic analysis. IHC was performed on several non-BCH and BCH specimens for 3 proteins identified as significant by transcriptomic analysis.

RESULTS

A total of 141 human BPH specimens were analyzed for the presence of BCH. Clinical characteristics of non-BCH and BCH cohorts revealed no significant differences in age, PSA, prostate volume, medical treatment, or comorbidities. Quantitation of cellular subsets by flow cytometry in 11 BCH patients vs. 11 non-BCH patients demonstrated a significant increase in the ratio of basal to luminal epithelia in patients with BCH (P <0.05), but no significant differences in the total number of leukocytes. RNA-seq data from flow cytometry isolated basal epithelia from patients with and without BCH were subjected to gene set enrichment analysis of differentially expressed genes, which revealed increased expression of members of the epidermal differentiation complex. Transcriptomic data were complemented by immunohistochemistry for members of the epidermal differentiation complex, revealing a morphological similarity to other stratified squamous epithelial layers.

CONCLUSIONS

Increased expression of epidermal differentiation complex members and altered epithelial stratification resembles the progression of other metaplastic diseases. These data provide insight into the plasticity of the human prostate epithelium and suggest a classification of basal cell hyperplasia as a metaplasia.

Improved imaging-pathology correlation with MR imaging-derived, 3D-printed, patient-specific whole-mount molds of the prostate

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Background: A critical requirement for imaging-pathology correlation is adequate image registration. Since the prostate is deformable, sectioning the gland in a plane similar to imaging is challenging. To improve the in vivo imaging and ex vivo histology image registration, 3D-printed, patient-specific, MRI-derived molds (PSMs) for whole-mount processing have been proposed. This study compared the anatomical registration of preoperative MRI and prostate whole-mounts obtained with PSMs versus conventional whole-mount sectioning (WMS). Methods: Based on an a priori power analysis, 50 men who underwent 3T prostate MRI followed by radical prostatectomy were included. Two blinded and independent readers (R1, R2) outlined the contours of the gland and of the tumor in the MRI using regions of interest (ROIs). These were compared with the ROIs from the whole-mount histology, the reference standard, using PSMs in the study group (n=25) or conventional WMS in the control group (n=25). The spatial overlap across the MRI and histology data sets was calculated using the Dice similarity coefficient (DSC) for the prostate overall and tumor. Results were compared using Wilcoxon rank sum test. Results: The MRI-histopathology anatomical registration for the prostate gland overall and the tumor were significantly superior with the use of PSMs than with the use of WMS for both readers (Table). Conclusions: The use of PSMs for prostate specimen whole-mount sectioning provides significantly superior anatomical registration of in vivo multiparametric MRI and ex vivo prostate whole-mounts than conventional WMS. The use of PSMs should facilitate the exchange of information across imaging and pathology required for research and patient care. [Table: see text]

Telomere-related lung fibrosis is diagnostically heterogeneous but uniformly progressive

Heterozygous mutations in four telomere-related genes have been linked to pulmonary fibrosis, but little is known about similarities or differences of affected individuals.115 patients with mutations in telomerase reverse transcriptase (TERT) (n=75), telomerase RNA component (TERC) (n=7), regulator of telomere elongation helicase 1 (RTEL1) (n=14) and poly(A)-specific ribonuclease (PARN) (n=19) were identified and clinical data were analysed.Approximately one-half (46%) had a multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF); others had unclassifiable lung fibrosis (20%), chronic hypersensitivity pneumonitis (12%), pleuroparenchymal fibroelastosis (10%), interstitial pneumonia with autoimmune features (7%), an idiopathic interstitial pneumonia (4%) and connective tissue disease-related interstitial fibrosis (3%). Discordant interstitial lung disease diagnoses were found in affected individuals from 80% of families. Patients with TERC mutations were diagnosed at an earlier age than those with PARN mutations (51±11 years versus 64±8 years; p=0.03) and had a higher incidence of haematological comorbidities. The mean rate of forced vital capacity decline was 300 mL·year^-1 and the median time to death or transplant was 2.87 years. There was no significant difference in time to death or transplant for patients across gene mutation groups or for patients with a diagnosis of IPF versus a non-IPF diagnosis.Genetic mutations in telomere related genes lead to a variety of interstitial lung disease (ILD) diagnoses that are universally progressive.

The defining pathology of the new clinical and histopathologic entity ACTA2-related cerebrovascular disease

INTRODUCTION

Smooth muscle cell contraction is an essential function of arteries and relies on the integrity of the actin-myosin apparatus. The tissue-specific α2-smooth muscle actin, encoded by ACTA2, is predominantly expressed in vascular smooth muscle cells. ACTA2 mutations predispose to development of aortic aneurysms and early onset coronary and cerebrovascular disease. Based on arteriographic findings, a distinct cerebrovascular disease has been proposed for ACTA2 heterozygous patients carrying the R179H mutation.

RESULTS

We present the first integrated analysis of a severely compromised patient with the R179H mutation and define the arterial pathology of ACTA2-related cerebrovascular disease. Histologically, striking morphological abnormalities were present in cerebral arteries of all sizes. Massive intimal smooth muscle cell proliferation, fragmentation of the elastic laminae and medial fibromuscular proliferation characterized large arteries whereas prominent vessel wall thickening, fibrosis and smooth muscle cell proliferation were unique changes in small arteries. The medial fibrosis and smooth muscle cell proliferation explain the characteristic radiologic appearance of "straight arteries" and suggest impaired function of mutant smooth muscle cells. Actin three-dimensional molecular modeling revealed critical positioning of R179 at the interface between the two strands of filamentous actin and destabilization of inter-strand bundling by the R179H mutation, explaining the severe associated phenotype.

CONCLUSIONS

In conclusion, these characteristic clinical and pathologic findings confirm ACTA2-related cerebrovascular disease as a new cerebrovascular disorder for which new therapeutic strategies need to be designed.

Elucidation of soft tissue flap histologic margins within a canine vocal fold

BACKGROUND

Histologic identification of implanted soft tissues in experimental animal models can be challenging, as donor tissue often strongly resembles the recipient bed. We have encountered this dilemma following implantation of a Composite Thyroid Ala Perichondrium flap (CTAP) into a vocal fold. The CTAP procedure is the first to utilize a vascularized flap for vocal fold reconstruction, making data to confirm or refute its viability critical. The current study evaluated several tissue stains to define precisely the histologic margins of CTAPs at two weeks post-implantation in a canine model.

METHODS

Initial testing exposed canine cadaveric tissues to four stains (tattoo ink, Congo red, 4'6-diamidino-2-phenylindole, and henna) across four time periods. Tattoo ink alone withstood histologic processing. An exposure of 1 minute adequately delineated CTAP boundaries. The study concluded with a canine in vivo evaluation of a CTAP exposed to tattoo ink for 1 minute. After a two-week recovery period, vocal folds were harvested and evaluated histologically.

RESULTS

Tattoo ink proved to be a safe and effective histologic marker in vivo, where the histologic margins of the implanted CTAP were clearly demarcated by a thin band of tattoo ink, soft tissue reactions were minimal, and interference with standard, special, or immunohistochemical stain assessments did not occur.

CONCLUSIONS

Tattoo ink provides a reliable means of demarcating a CTAP within a vocal fold and demonstrated that CTAPs survive transplantation. Further, tattoo ink demarcation may serve as a useful histologic marker for those wishing to assess tissue implants in other in vivo models.

The Aryl Hydrocarbon Receptor Influences Transplant Outcomes in Response to Environmental Signals

The aryl hydrocarbon receptor (AHR) is a cytosolic transcription factor with numerous endogenous and xenobiotic ligands, most notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Recent data suggests that TCDD may induce regulatory T cells, while a second AHR ligand, FICZ, promotes Th17 differentiation. The aim was to examine whether injection of recipient mice with either TCDD or FICZ altered skin allograft rejection in a fully mismatched model. TCDD or FICZ was given to recipient C57BL/6 mice intraperitoneally (IP). Twenty-four hr later, donor skin was grafted from BALB/c mice. An additional dose of FICZ was given on day 3. Treatment with TCDD delayed graft rejection for more than 4 weeks while FICZ treatment accelerated rejection by 1 - 2 days. In vivo exposure with TCDD led to a rise in the frequency of FoxP3(+) CD4(+) T cells in the spleen, while FICZ increased IL-17 secretion by splenocytes from treated animals. Activation of the AHR receptor by different AHR ligands in vivo resulted in opposing effects on skin graft survival. AHR serves as a sensor to environmental signals, with effects on the acquired immune system that may alter outcomes after organ transplantation. This model will be useful to further delineate direct effects of the environment on the immune system and outcomes of organ transplantation.

Local vascularized flaps for augmentation of Reinke's space

OBJECTIVES/HYPOTHESIS

The purpose of this study is to describe and test a novel surgical strategy for augmentation of Reinke's space using vascularized flaps: a thyroid ala perichondrium flap (TAP) and a composite thyroid ala perichondrium flap (CTAP) from the anterior larynx. We hypothesized that these specially designed vascularized flaps would remain viable once inset into the lamina propria, and that they would not disrupt rheologic, biomechanical, and histologic properties of the native vocal fold.

STUDY DESIGN

Experimental. In vivo canine model.

METHODS

The length and volume of test flaps harvested in six adult human cadaveric larynges were analyzed to determine suitability for use in augmentation in the lamina propria. Also, 12 beagles randomly underwent unilateral placement of either TAP or CTAP, which were designed in accordance with the human adult cadaveric experiments. Flap perfusion was measured before and after harvest with laser Doppler. After 1 month, the beagles were humanely sacrificed and their larynges subjected to aerodynamic and acoustic evaluation using an excised larynx apparatus. The vocal fold lamina propria of four larynges--two TAP and two CTAP--underwent rheologic evaluation using a simple-shear rheometer. The remaining eight larynges underwent quantitative histologic and immunohistochemical evaluation. The survival and complication (swallowing, airway, local wound) rates of all dogs were noted.

RESULTS

Initial studies with adult human cadaveric larynges established that TAP and CTAP possessed length and volume greater than native lamina propria. In the canine experiments, the perfusion change in the flaps was similar between flap groups. The damping ratio (ζ), dynamic viscosity (η'), elastic shear modulus (G'), and viscous shear modulus (G″) of treated and untreated native vocal folds were not statistically different. The glottic function measures of vocal efficiency, laryngeal resistance, jitter, shimmer, and harmonics-to-noise ratio (HNR) of treated and normal larynges were not statistically different. Similarly, the values for collagen, elastin, and glycosaminoglycans (GAGs) in treated and untreated vocal folds were not statistically different. Also, neither neochrondrogenesis nor neoosteogenesis was detected in any treated vocal fold. The values for vascular and cellular proliferation in treated and untreated vocal folds were not statistically different. All test dogs survived and had no complications related to swallowing, airway distress, or the local wound.

CONCLUSIONS

The test flaps described and tested in this study appear to have conceptually attractive features for augmentation of Reinke's space. When placed in an in vivo setting TAP and CTAP did not reveal unfavorable vascular, rheologic, aerodynamic, acoustic, or histologic characteristics. There was no unanticipated morbidity or mortality to the test animals. Long-term viability of these flaps is unknown. TAP and CTAP may open novel pathways for correction of glottic defects and may offer crossover opportunities with tissue engineering techniques.

Post-transplant DSA monitoring may predict antibody-mediated rejection in sensitized kidney transplant recipients

We examined whether changes in posttransplant highest intensity donor specific anti-HLA antibody specificity (DSAmax) measured by single antigen bead via Luminex (One Lambda, Inc.) were associated with antibody-mediated rejection (AMR). We conducted a retrospective analysis examining risk factors for AMR in 116 consecutive patients who underwent desensitization between 1/1/2009 and 9/1/2010. All patients had a negative flow cytometry crossmatch. The mean patient age at transplant was 46.4 +/- 4 years. The mean peak PRA (panel reactive antibody) and DSAmax at transplant were 40 +/- 6% and 894 +/- 150 mean fluorescent intensity (MFI), respectively. The mean time to rejection was 1.5 +/- 0.4 months. Cox regression analyses demonstrated that an increase in DSAmax by one week after transplant was significantly associated with AMR (pure or mixed). A rise in DSAmax greater than 500 MFI at 1 week was associated with a 2.6 times greater risk of rejection (HR 2.6, 95% CI 1.1 - 6.3, p = 0.02). We conclude that a rise in DSAmax at one week is an independent risk factor forAMR and that posttransplant DSA monitoring strategies may reduce the risk of AMR in sensitized patients.

Th1 and Th17 immunocompetence in humanized NOD/SCID/IL2rgammanull mice

We evaluated the immunocompetence of human T cells in humanized NOD-SCID interleukin (IL)-2r-gamma-null (hu-NSG) mice bearing a human thymic organoid, after multilineage reconstitution with isogeneic human leukocytes. Delayed type hypersensitivity (DTH) response was assessed by a direct footpad challenge of the immunized hu-NSG host, or by transfer of splenocytes from immunized hu-NSG, along with antigen, into footpads of C.B-17 scid mice (trans vivo [tv] DTH). Both methods revealed cellular immunity to tetanus toxoid (TT) or collagen type V (ColV). Immunohistochemical analysis of the swollen footpads revealed infiltration of human CD45(+) cells, including CD3(+) T cells, CD68(+) macrophages, and murine Ly6G(+) neutrophils. We observed a significant correlation between the percentage of circulating human CD4(+) cells and the direct DTH swelling response to TT. The tvDTH response to TT was inhibited by anti-interferon-gamma, whereas the tvDTH response to collagen V was inhibited by anti-IL-17 antibody, mimicking the cytokine bias of adult human T cells to these antigens. hu-NSG mice were also capable of mounting a B-cell response (primarily IgM) to TT antigen. The activation of either Th1- or Th17-dependent cellular immune response supports the utility of hu-NSG mice as a surrogate model of allograft rejection and autoimmunity.

Increase in proteinuria >200 mg/g after late rejection is associated with poor graft survival

BACKGROUND

There is no information on the effects of proteinuria on outcomes following rejection.

METHODS

We addressed this question in a retrospective study of 925 kidney transplant recipients between January 2003 and December 2007. Selection criteria were based on (i) biopsy proven diagnosis of a first episode of acute rejection, and (ii) available data on urine protein to creatinine (UPC) ratios at baseline (lowest serum creatinine before biopsy), time of biopsy and 1 month after biopsy. We examined the effects of a change in UPC (DeltaUPC = UPC 1 month after biopsy-baseline UPC) on outcomes.

RESULTS

We identified 82 patients with both acute rejection and available data on proteinuria. Mean time (+/-SE) to acute rejection was 19 +/- 2.3 months, and patients were followed up for 38.7 +/- 2.6 months after transplant. Median DeltaUPC was 200 mg/g (95% confidence interval 0.00 to 0.300). Forty-two patients had a DeltaUPC > or =200 (high proteinuria group). Baseline characteristics were similar between high and low proteinuria groups except for more induction therapy with interleukin-2 receptor blockade in the former (71 vs. 47%, P = 0.04). Patient with DeltaUPC > or =200 had higher rates of graft loss (26 vs. 15%, P = 0.01) or combined graft loss or death (38 vs. 20%, P = 0.002 by log-rank). In univariate and multivariate Cox regression analyses, DeltaUPC > or =200 mg/g, sirolimus therapy 1 month after rejection and re-transplant status were significant factors associated with death-censored graft loss (hazard ratio (HR) 4.4, 14.9 and 6.2, P < or = 0.008) or combined graft loss or patient death (HR 3.8, 6.5 and 3.9, P < or = 0.03). Conclusions. An increase in proteinuria > or =200 mg/g after late acute rejection is associated with poor graft and patient outcomes. Clinical trials are needed to determine whether post-rejection anti-proteinuric strategies improve outcomes.

Human NKT cells promote monocyte differentiation into suppressive myeloid antigen-presenting cells

NKT cells have been shown to promote peripheral tolerance in a number of model systems, yet the processes by which they exert their regulatory effects remain poorly understood. Here, we show that soluble factors secreted by human NKT cells instruct human peripheral blood monocytes to differentiate into myeloid APCs that have suppressive properties. NKT instructed monocytes acquired a cell surface phenotype resembling myeloid DCs. However, whereas control DCs that were generated by culturing monocytes with recombinant GM-CSF and IL-4 had a proinflammatory phenotype characterized by the production of IL-12 with little IL-10, NKT-instructed APCs showed the opposite cytokine production profile of high IL-10 with little or no IL-12. The control DCs efficiently stimulated peripheral blood T cell IFN-gamma secretion and proliferation, whereas NKT-instructed APCs silenced these T cell responses. Exposure to NKT cell factors had a dominant effect on the functional properties of the DCs, since DCs differentiated by recombinant GM-CSF and IL-4 in the presence of NKT cell factors inhibited T cell responses. To confirm their noninflammatory effects, NKT-instructed APCs were tested in an in vivo assay that depends on the activation of antigen-specific human T cells. Control DCs promoted substantial tissue inflammation; however, despite a marked neutrophilic infiltrate, there was little edema in the presence of NKT-instructed APCs, suggesting the inflammatory cascade was held in check. These results point to a novel pathway initiated by NKT cells that can contribute to the regulation of human antigen-specific Th1 responses.

Severe acute fibrinous and organizing pneumonia (AFOP) causing ventilatory failure: successful treatment with mycophenolate mofetil and corticosteroids

Acute fibrinous and organizing pneumonia (AFOP) has recently been identified as an unusual variant of acute lung injury. We describe a man with rapidly progressive lung disease who had AFOP detected via surgical lung biopsy. The patient acutely decompensated while in the hospital and required mechanical ventilation as well as a prolonged ICU stay. He responded poorly to initial treatment and progressively worsened, but he subsequently responded very well to combined therapy with mycophenolate mofetil and methylprednisolone. The combination of corticosteroids and mycophenolate may provide a safe and effective treatment strategy for severe forms of this newly defined pulmonary syndrome.

Unaltered graft survival and intragraft lymphocytes infiltration in the cardiac allograft of Cxcr3-/- mouse recipients

Previous studies showed that absence of chemokine receptor Cxcr3 or its blockade prolong mouse cardiac allograft survival. We evaluated the effect of the CXCR3 receptor antagonist MRL-957 on cardiac allograft survival, and also examined the impact of anti-CXCR3 mAb in human CXCR3 knock-in mice. We found only a moderate increase in graft survival (10.5 and 16.6 days, p < 0.05) using either the antagonist or the antibody, respectively, compared to control (8.7 days). We re-evaluated cardiac allograft survival with two different lines of Cxcr3(-/-) mice. Interestingly, in our hands, neither of the independently derived Cxcr3(-/-) lines showed remarkable prolongation, with mean graft survival of 9.5 and 10.8 days, respectively. There was no difference in the number of infiltrating mononuclear cells, expansion of splenic T cells or IFN-gamma production of alloreactive T cells. Mechanistically, an increased other chemokine receptor fraction in the graft infiltrating CD8 T cells in Cxcr3(-/-) recipients compared to wild-type recipients suggested compensatory T-cell trafficking in the absence of Cxcr3. We conclude Cxcr3 may contribute to, but does not govern, leukocyte trafficking in this transplant model.

Calcineurin inhibitor withdrawal after renal transplantation with alemtuzumab: clinical outcomes and effect on T-regulatory cells

To address the results of calcineurin inhibitor (CNI) withdrawal after alemtuzumab induction relative to CNI continuation, we performed a pilot randomized clinical trial in renal allograft recipients on CNI, a mycophenolic acid derivative and steroids after the first 2 months posttransplantation. Forty patients were randomized to taper off CNI or to maintain it, and followed for at least 1 year. Four patients in the withdrawal group were treated for acute rejection while no patient received antirejection treatment in the control group. Two control patients withdrew CNI due to nephrotoxicity. Estimated GFR was similar in both groups after 1 year. Flow cytometry of CD4(+)CD25(+)CTLA-4(+)FoxP3(+) regulatory T cells (Treg) demonstrated a significant increase in Treg percentages in the peripheral blood of alemtuzumab-treated patients on CNI early postransplant. Furthermore, the increased Treg percentages in the withdrawal cohort were unchanged at month 6 postenrollment, whereas they decreased significantly in those patients maintained on CNI. Patients withdrawn from CNI after alemtuzumab trend toward a higher rejection rate, but most patients can be weaned from a CNI using this regimen. With the exception of maintaining increased Treg levels, the benefits are not appreciable in this short follow-up, and a larger randomized trial is justified.