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215 citation(s) found for "Hać, Aleksandra".

Indications for cerebral revascularization for moyamoya syndrome in pediatric sickle cell disease determined by Delphi methodology
Robert, Adam , Adelson, P. David, Lang, Shih‐Shan , Grabb, Paul A. , Greene, Stephanie , Leonard, Jeffrey, Magge, Suresh N. , Marupudi, Neena I. , Sillero, Rafael de Oliveira , Smith, Edward R. , Smith, Jodi L. , Strahle, Jennifer M. , Vadivelu, Sudhakar , Wellons, John C. , Wrubel, David, Hatem, Asmaa, Moody, C, Han, Sabrina H. , Millican, Nicklaus , Dain, Aleksandra S. , Beslow, Lauren A. , Aldana, Philipp R. , Montaser, Alaa, Smith, Edward , Hanel, Ricardó A. , Johnston, James M. , Piatt, Joseph H. , Hatem, Asmaa, Montaser, Alaa S. , Pederson, John M.

Journal of Neurosurgery: Pediatrics | July 24, 2024 | Volume: 34 | Issue: 4 | Pages: 402-413

10.3171/2024.5.peds2426 | PMID 39029127 Get It

OBJECTIVE Cerebral revascularization surgery (CRS) has been used to prevent stroke in children with sickle cell disease (SCD) and cerebral vasculopathy (e.g., moyamoya syndrome). While results suggest that it may be an effective treatment, surgical indications have not been well defined. This study sought to determine indications for offering revascularization surgery in centers with established sickle cell programs in the US. METHODS Three sequential surveys utilizing the Delphi methodology were administered to neurosurgeons participating in the Stroke in Sickle Cell Revascularization Surgery study. Respondents were presented with clinical scenarios of patients with SCD and varying degrees of ischemic presentation and vasculopathy, and the group’s agreement to offer surgical revascularization was measured. Consensus was defined as ≥ 75% similar responses. RESULTS The response rate to all 3 surveys was 100%. Seventeen neurosurgeons from 16 different centers participated. The presence of moyamoya collaterals (MMCs) and arterial stenosis matching an ischemic distribution yielded the strongest recommendations to offer surgery. There was consensus to offer revascularization in the presence of MMCs and at least 50% arterial stenosis matching an ischemic distribution. In contrast, there was no consensus to offer revascularization with 50%–70% stenosis not matching an ischemic presentation in the absence of MMCs. The presence of the ivy sign in the distribution of the stenotic artery also contributed to the consensus to offer surgery in certain scenarios. CONCLUSIONS There were several clinical scenarios that attained consensus to offer surgery; the strongest was moderate to severe arterial stenosis that matched the distribution of ischemic presentation in the presence of MMCs. Radiological findings of decreased cerebral flow or perfusion also facilitated attaining consensus to offer surgery. The findings of this study reflect expert opinion about questions that deserve prospective clinical research. Determination of indications for CRS can guide clinical practice and aid the design of prospective studies.
IFTA Foci Density: An Unrecognized Highly Prognostic Measurement of Fibrosis in Kidney Transplant Biopsies
Đenić, Aleksandar , Rule, Andrew D., Park, Walter D. , Smith, Byron H. , Mejia, Mateo Velasquez , Kukla, Aleksandra , Grande, Joseph P. , Smith, Byron , Denic, Aleksandar , Park, Walter , Rule, Andrew D. , Stegall, Mark D.

Kidney360 | July 18, 2024 | Volume: 5 | Issue: 9 | Pages: 1341-1349

10.34067/kid.0000000000000514 | PMID 39024036 Get It

Key Points Morphometry allows for a more prognostic multidimensional quantification of interstitial fibrosis and tubular atrophy (IFTA) in kidneys than does visual inspection. The density of IFTA foci is determined by dividing the number of contiguous IFTA patches in the kidney cortex by the area of cortex. Higher density of IFTA foci significantly predicted renal allograft failure beyond %IFTA and other biopsy and clinical characteristics. Background Contraction of interstitial fibrosis and tubular atrophy (IFTA) may cause %IFTA to under-represent the severity of nephron loss. Higher density of IFTA foci is an important predictor of progressive CKD in native kidneys independent of %IFTA. Methods We studied kidney transplant recipients transplanted between 2000 and 2013 who had a 5-year surveillance kidney biopsy and subsequent follow-up. Banff ci score (interstitial fibrosis) was obtained from the pathology reports. After digitizing the biopsies, we traced cortex area and each distinct IFTA focus on a single trichrome-stained section. Percent IFTA area and IFTA foci density (count of IFTA foci/cortex area) were calculated. Cox models assessed the risk of death-censored graft failure after the 5-year biopsy with Banff ci score, morphometric %IFTA, and IFTA foci density. Results There were 58 death-censored allograft failures among 835 kidney recipients during the 5 years of follow-up. Biopsies from grafts that failed had higher mean Banff ci score (1.5 versus 0.7, P < 0.0001), %IFTA (22.6% versus 7.0%, P < 0.0001), and IFTA foci density (1.3/mm 2 versus 0.4/mm 2 , P < 0.0001). After adjusting for other Banff scores or clinical variables, Banff ci did not correlate with allograft failure, but both higher %IFTA (hazard ratio = 1.56, P < 0.0001) and higher IFTA foci density (hazard ratio = 2.34, P < 0.0001) did. All but four allograft failures by 10 years had biopsies in the top quartile of either %IFTA or IFTA foci density at 5 years. A model using just these two morphometric measures without clinical characteristics resulted in a c-statistic of 0.891 with respect to allograft failure. Conclusions Morphometric characterization of IFTA foci density is a strong predictor of death-censored allograft failure not captured in current Banff classification for grading of kidney fibrosis.
Distinct transcriptional alterations distinguish Lewy body disease from Alzheimer’s disease
Olney, Kimberly C. , Rabichow, Benjamin E. , Wojtas, Aleksandra, DeTure, Michael , McLean, Pamela J. , Dickson, Dennis W. , Chang, Rui , Ross, Owen A. , Fryer, John Denis , Wojtas, Aleksandra M, Dickson, Dennis W , Ross, Owen A , McLean, Pamela J

Brain | June 25, 2024 | Volume: 148 | Issue: 1 | Pages: 69-88

10.1093/brain/awae202 | PMID 38916996 Get It

Abstract Lewy body dementia and Alzheimer's disease (AD) are leading causes of cognitive impairment, characterized by distinct but overlapping neuropathological hallmarks. Lewy body disease (LBD) is characterized by α-synuclein aggregates in the form of Lewy bodies as well as the deposition of extracellular amyloid plaques, with many cases also exhibiting neurofibrillary tangle (NFT) pathology. In contrast, AD is characterized by amyloid plaques and neurofibrillary tangles. Both conditions often co-occur with additional neuropathological changes, such as vascular disease and TDP-43 pathology. To elucidate shared and distinct molecular signatures underlying these mixed neuropathologies, we extensively analysed transcriptional changes in the anterior cingulate cortex, a brain region critically involved in cognitive processes. We performed bulk tissue RNA sequencing from the anterior cingulate cortex and determined differentially expressed genes (q-value &lt;0.05) in control (n = 81), LBD (n = 436), AD (n = 53) and pathological amyloid cases consisting of amyloid pathology with minimal or no tau pathology (n = 39). We used gene set enrichment and weighted gene correlation network analysis to understand the pathways associated with each neuropathologically defined group. LBD cases had strong upregulation of inflammatory pathways and downregulation of metabolic pathways. The LBD cases were further subdivided into either high Thal amyloid, Braak NFT, or low pathological burden cohorts. Compared to the control cases, the LBD cohorts consistently showed upregulation for genes involved in protein folding and cytokine immune response, as well as downregulation of fatty acid metabolism. Surprisingly, concomitant tau pathology within the LBD cases resulted in no additional changes. Some core inflammatory pathways were shared between AD and LBD but with numerous disease-specific changes. Direct comparison of LBD cohorts versus AD cases revealed strong enrichment of synaptic signalling, behaviour and neuronal system pathways. Females had a stronger response overall in both LBD and AD, with several sex-specific changes. Overall, the results identify genes commonly and uniquely dysregulated in neuropathologically defined LBD and AD cases, shedding light on shared and distinct molecular pathways. Additionally, the study underscores the importance of considering sex-specific changes in understanding the complex transcriptional landscape of these neurodegenerative diseases.
Mesangial Expansion by Morphometry at 5 y After Kidney Transplantation: Incidence, Risk Factors, and Association With Graft Loss
Đenić, Aleksandar , Buglioni, Alessia , Túrkevi-Nagy, Sándor , Mejia, Mateo Velasquez , Subramani, Rashmi , Kukla, Aleksandra , Diwan, Tayyab S. , Grande, Joseph P. , Denic, Aleksandar , Smith, Byron H. , Park, Walter D. , Stegall, Mark D.

Transplantation Direct | June 17, 2024 | Volume: 10 | Issue: 7 | Pages: e1652

10.1097/txd.0000000000001652 | PMID 38881746 Get It

Background. Mesangial expansion (ME) is an understudied histologic lesion in renal allografts. The current Banff mm score is not reproducible and may miss important ME features. The study aimed to improve the quantification of ME using morphometry, assess changes over time, and determine its association with allograft loss. Methods. We studied ME in 1-y and 5-y surveillance biopsies in 835 kidney transplants performed between January 2000 and December 2013. ME was assessed using the Banff mm score by a central pathologist and by morphometry. We derived 3 different morphometric measures: (1) %ME mm (%glomeruli with ME in ≥2 lobules, like Banff mm); (2) %MEany (%glomeruli with any ME lesion); and (3) %ME area (sum of all ME areas/all glomerular tuft areas). Unadjusted and adjusted Cox models assessed the risk of death-censored allograft loss. Results. From 1- to 5-y biopsies, the mean Banff mm score increased from 0.18 to 0.34, whereas %ME mm increased from 2.5% to 13.3%. Banff mm score had modest correlations with morphometric ME measures. Moderate-severe %ME mm was present in 20.1% of 5-y biopsies, whereas only 6.6% of Banff mm scores were. In general, higher ME on both 1- and 5-y biopsies was associated with a deceased donor, older recipient age, recipient diabetes/obesity (present in >50% of severely affected biopsies), higher hemoglobin A1c at 5 y posttransplant, and recurrent kidney disease. Higher ME on 5-y biopsies was associated with delayed graft function. A higher Banff mm score at 1-y biopsy and morphometry ME measures at 5-y biopsy were associated with rejection during the first year posttransplant. Morphometric ME measures were associated with allograft loss independent of Banff scores and all clinical characteristics, including kidney function and recurrent disease. The model with %MEany had the highest c-statistic (0.872). Conclusions. Banff mm score underestimates the pervasiveness of ME in 5-y biopsies. ME is common and associated with alloimmune and nonalloimmune causes of graft loss.
Concurrent RB1 Loss and BRCA Deficiency Predicts Enhanced Immunologic Response and Long-term Survival in Tubo-ovarian High-grade Serous Carcinoma
Saner, Flurina A.M. , Takahashi, Kazuaki , Budden, Timothy , Pandey, Ahwan , Ariyaratne, Dinuka , Zwimpfer, Tibor A. , Meagher, Nicola S. , Twomey, Laura , Hoang, Therese, Group, for the Australian Ovarian Cancer Study, Christie, Elizabeth L. , Kang, Eun-Young , Nelson, Gregg , Riggan, Marjorie J. , Alsop, Jennifer , Beckmann, Matthias W. , Boros, Jessica , Brand, Alison H. , Carney, Michael E. , Coulson, Penny , Courtney‐Brooks, Madeleine , Cushing‐Haugen, Kara L. , El‐Bahrawy, Mona , Gayther, Simon A. , Hartmann, Arndt , Hendley, Joy , Jimenez-Linan, Mercedes , Jones, Michael E. , Kluz, Tomasz , Koziak, Jennifer M. , Kristjansdottir, Björg , Le, Nhu D. , Lener, Marcin , Lester, Jenny , Mateoiu, Constantina , Oršulić, Sandra , Ruebner, Matthias , Schoemaker, Minouk J. , Shah, Mitul , Sharma, Raghwa , Shvetsov, Yurii B. , Soong, T. Rinda , Sukumvanich, Paniti , Talhouk, Aline , Anglesio, Michael S. , Fasching, Peter A. , Goodman, Marc T. , Huntsman, David G. , Kelemen, Linda E. , Menon, Usha , Pharoah, Paul D.P. , Schildkraut, Joellen M. , Goode, Ellen L. , Ramus, Susan J. , Bowtell, David D.L. , Garsed, Dale W. , Fereday, Sian , Twomey, Laura , Pishas, Kathleen I , Hoang, Therese , Bolithon, Adelyn , Traficante, Nadia , Alsop, Kathryn , Christie, Elizabeth L , Kang, Eun-Young , Nelson, Gregg S , Ghatage, Prafull , Lee, Cheng-Han , Riggan, Marjorie J , Alsop, Jennifer , Beckmann, Matthias W. , Boros, Jessica , Brand, Alison H , Brooks-Wilson, Angela R , Carney, Michael E , Coulson, Penny , Courtney-Brooks, Madeleine , Cushing-Haugen, Kara L , Cybulski, Cezary , El-Bahrawy, Mona A , Elishaev, Esther , Erber, Ramona , Gayther, Simon A , Gentry‐Maharaj, Aleksandra , Gilks, C. Blake , Harnett, Paul R , Harris, Holly R , Hartmann, Arndt , Hein, Alexander , Hendley, Joy , Hernandez, Brenda Y , Jakubowska, Anna , Jimenez-Linan, Mercedes , Jones, Michael E , Kaufmann, Scott H , Kennedy, Catherine J , Kluz, Tomasz , Koziak, Jennifer M , Kristjansdottir, Björg , Le, Nhu D , Lener, Marcin , Lester, Jenny , Lubinski, Jan , Mateoiu, Constantina , Orsulic, Sandra , Ruebner, Matthias , Schoemaker, Minouk J , Shah, Mitul , Sharma, Raghwa , Sherman, Mark E , Shvetsov, Yurii B , Soong, T Rinda , Steed, Helen , Sukumvanich, Paniti , Talhouk, Aline , Taylor, Sarah E , Vierkant, Robert A , Wang, Chen , Widschwendter, Martin , Wilkens, Lynne R , Winham, Stacey J , Anglesio, Michael S , Berchuck, Andrew , Brenton, James D , Campbell, Ian G , Cook, Linda S. , Doherty, Jennifer A , Fasching, Peter A , Fortner, Renée T , Goodman, Marc T , Gronwald, Jacek , Huntsman, David G , Karlan, Beth Y , Kelemen, Linda E , Menon, Usha , Modugno, Francesmary , Pharoah, Paul D P , Schildkraut, Joellen M , Sundfeldt, Karin , Swerdlow, Anthony J , Goode, Ellen L , Fazio, Anna de , Köbel, Martin , Ramus, Susan J , Bowtell, David D , Garsed, Dale W , Ariyaratne, Dinuka , Pandey, Ahwan , Fereday, Sián , Traficante, Nadia , Group, for the Australian Ovarian Cancer Study, Alsop, Kathryn , Lee, Cheng‐Han , Brooks‐Wilson, Angela , Cybulski, Cezary , Elishaev, Esther , Harnett, Paul R. , Harris, Holly R. , Hein, Alexander , Hernandez, Brenda Y. , Jakubowska, Anna , Kaufmann, Scott H. , Kennedy, Catherine J. , Lubiński, Jan , Sherman, Mark E. , Steed, Helen , Vierkant, Robert A. , Wang, Chen , Widschwendter, Martin , Wilkens, Lynne R. , Winham, Stacey J. , Berchuck, Andrew , Brenton, James D. , Campbell, Ian , Doherty, Jennifer A. , Fortner, Renée T. , Gronwald, Jacek , Karlan, Beth Y. , Modugno, Francesmary , Swerdlow, Anthony J. , DeFazio, Anna , Köbel, Martin

Clinical Cancer Research | June 5, 2024 | Volume: 30 | Issue: 16 | Pages: 3481-3498

10.1158/1078-0432.ccr-23-3552 | PMID 38837893 Get It

Abstract Purpose: The purpose of this study was to evaluate RB1 expression and survival across ovarian carcinoma histotypes and how co-occurrence of BRCA1 or BRCA2 (BRCA) alterations and RB1 loss influences survival in tubo-ovarian high-grade serous carcinoma (HGSC). Experimental Design: RB1 protein expression was classified by immunohistochemistry in ovarian carcinomas of 7,436 patients from the Ovarian Tumor Tissue Analysis consortium. We examined RB1 expression and germline BRCA status in a subset of 1,134 HGSC, and related genotype to overall survival (OS), tumor-infiltrating CD8+ lymphocytes, and transcriptomic subtypes. Using CRISPR-Cas9, we deleted RB1 in HGSC cells with and without BRCA1 alterations to model co-loss with treatment response. We performed whole-genome and transcriptome data analyses on 126 patients with primary HGSC to characterize tumors with concurrent BRCA deficiency and RB1 loss. Results: RB1 loss was associated with longer OS in HGSC but with poorer prognosis in endometrioid ovarian carcinoma. Patients with HGSC harboring both RB1 loss and pathogenic germline BRCA variants had superior OS compared with patients with either alteration alone, and their median OS was three times longer than those without pathogenic BRCA variants and retained RB1 expression (9.3 vs. 3.1 years). Enhanced sensitivity to cisplatin and paclitaxel was seen in BRCA1-altered cells with RB1 knockout. Combined RB1 loss and BRCA deficiency correlated with transcriptional markers of enhanced IFN response, cell-cycle deregulation, and reduced epithelial–mesenchymal transition. CD8+ lymphocytes were most prevalent in BRCA-deficient HGSC with co-loss of RB1. Conclusions: Co-occurrence of RB1 loss and BRCA deficiency was associated with exceptionally long survival in patients with HGSC, potentially due to better treatment response and immune stimulation.
Positive Identification of Genetic Causes of FSGS Increases with Proper Patient Selection
Zand, Ladan , Erickson, Stephen B., Prochnow, Carri A., Ters, Mireille El , Kukla, Aleksandra , Greene, Eddie L., Hernandez, Loren P. Herrera , Sethi, Sanjeev , Miao, Jing , Vairo, Filippo Pinto e , Hogan, Marie C. , Bentall, Andrew , Fervenza, Fernando C.

Journal of the American Society of Nephrology | May 17, 2024 | Volume: 31 | Issue: 10S | Pages: 513-513

10.1681/asn.20203110s1513a Get It

Comparison of the pleiotropic effect of atorvastatin and rosuvastatin on postmenopausal changes in bone turnover: A randomized comparative study
Braszak-Cymerman, Anna , Walczak‐Gałęzewska, Marta , Ludziejewska, Aleksandra , Oduah, Mary-Tiffany , Bryl, Wiesław

Medicine | May 10, 2024 | Volume: 103 | Issue: 19 | Pages: e38122

10.1097/md.0000000000038122 | PMID 38728464 Get It

Background: Statins are the first-line treatment for dyslipidemia, which is a major modifiable risk factor for atherosclerotic cardiovascular disease. Studies have shown that in addition to the beneficial lipid-lowering effect, statins also exhibit a number of pleiotropic effects that may find application in other diseases, including osteoporosis. This study aimed to assess the effect of statins on bone turnover, as measured by the concentration of bone turnover markers, and to compare the effect of atorvastatin as a lipophilic statin and rosuvastatin as a hydrophilic statin. Methods: This study included 34 postmenopausal women aged < 65 years with newly diagnosed dyslipidemia requiring statin therapy. Patients were randomly assigned to receive a statin drug. Statins were initiated at standard doses of 5 to 10 mg of rosuvastatin and 20 mg of atorvastatin. The levels of C-terminal telopeptide of type I collagen as a bone resorption marker and N-terminal propeptide of procollagen type I as a marker of bone formation, lipid concentrations and other biochemical parameters were assessed at baseline and after 6 and twelve months of treatment. Results: There were no statistically significant differences between the levels of bone turnover markers before and 6 months after statin implementation ( P > .05) - for all patients or subgroups according to statin use. Analysis of the results showed that after 12 months, there was a statistically significant decrease in N-terminal propeptide of procollagen type I concentration in all subjects ( P = .004). By statin subgroup, a statistically significant decrease in N-terminal propeptide of procollagen type I was observed only in patients receiving rosuvastatin ( P = .012) and not in those receiving atorvastatin ( P = .25). Moreover, changes in bone turnover markers did not correlate with changes in lipid concentrations. Conclusions: These results may indicate the superiority of atorvastatin over rosuvastatin in inhibiting adverse changes in bone turnover in postmenopausal women. Confirmed by studies involving a larger population, the observed differences might find particular applications in clinical practice, and the choice of atorvastatin over rosuvastatin for women could be considered in the early postmenopausal period to reduce the risk of osteoporosis and subsequent osteoporotic fractures.
Highly Sensitized Candidates Remain at Risk for Microvascular Inflammation Even When Donor-specific Antibody Is Avoided: A Matched Cohort Study
Balakrishnan, Suryanarayanan, Alexander, Mariam P., Cornell, Lynn D. , Kukla, Aleksandra , Agrawal, Amogh, Stegall, Mark, Cornell, Lynn , Agrawal, Amogh , Gandhi, Manish J. , Bentall, Andrew , Stegall, Mark D. , Schinstock, Carrie A.

Transplantation | April 5, 2024 | Volume: 108 | Issue: 9 | Pages: 1986-1993

10.1097/tp.0000000000005011 | PMID 38578704 Get It

Background. Microvascular inflammation (MVI) is a key feature of antibody-mediated rejection (AMR) among patients with HLA donor-specific antibody (DSA), but MVI at AMR thresholds (Banff glomerulitis [g] + peritubular capillaritis [ptc] score ≥ 2) without DSA has been increasingly recognized. We aimed to determine the incidence of MVI among highly sensitized kidney transplant recipients without DSA. Methods. We performed a single-center, retrospective, matched cohort study comparing outcomes of kidney transplant recipients with cPRA ≥90% with preexisting DSA (n = 49), cPRA ≥90% without preexisting DSA (n = 47), and matched controls with cPRA = 0 without preexisting DSA (n = 49). Controls were matched by age, donor type, and transplant date. Indication and surveillance biopsies combined with annual de novo DSA screening were obtained. Results. Kidney transplant recipients with a cPRA ≥90% and no evidence of preexisting or de novo DSA had a higher incidence of MVI (glomerulitis + peritubular capillaritis ≥ 2) than patients with cPRA = 0 [35% (17/49) versus 12% (6/49), P = 0.0003] over a median (interquartile range) follow-up of 5 (4–6) y posttransplant. Among this cPRA ≥90% group without DSA, MVI persisted in 54% of cases on follow-up biopsy (7/13), and 24% (4/13) of cases developed transplant glomerulopathy (Banff cg score > 0). Conclusions. Highly sensitized transplant recipients have a high incidence of persistent and progressive MVI, even without DSA. The mechanisms underlying these histologic features needs to be elucidated, but this information is important to consider when making decisions about transplantation among highly sensitized individuals.
Indications, Techniques, and Barriers for Pancreas Transplant Biopsy: A Consensus Perspective From a Survey of US Centers
Fleetwood, Vidya A. , Alhamad, Tarek , Maher, Kennan, Xiao, Huiling , Kukla, Aleksandra , Pavlakis, Martha , Alhamad, Tarek , Singh, Neeraj Kumar , Lentine, Krista L. , Woodside, Kenneth J. , Odorico, Jon S. , Axelrod, David A. , Fridell, Jonathan A. , Shokouh-Amiri, Hosein M. , Zibari, Gazi B. , Cooper, Matthew , Parsons, Ronald F.

Transplantation | March 12, 2024 | Volume: 108 | Issue: 7 | Pages: e129-e138

10.1097/tp.0000000000004960 | PMID 38467588 Get It

Background. Pancreas transplant biopsy practices for the diagnosis of rejection or other pathologies are not well described. Methods. We conducted a survey of staff at US pancreas transplant programs (March 22, 2022, to August 22, 2022) to assess current program practices and perceptions about the utility and challenges in the performance and interpretation of pancreas allograft biopsies. Results. Respondents represented 65% (76/117) of active adult pancreas transplant programs, capturing 66% of recent pancreas transplant volume in the United States. Participants were most often nephrologists (52%), followed by surgeons (46%), and other staff (4%). Pancreas allograft biopsies were performed mostly by interventional radiologists (74%), followed by surgeons (11%), nephrologists (8%), and gastroenterologists (1%). Limitations in the radiologist’s or biopsy performer’s comfort level or expertise to safely perform a biopsy, or to obtain sufficient/adequate samples were the two most common challenges with pancreas transplant biopsies. Pancreas transplant biopsies were read by local pathologists at a majority (86%) of centers. Challenges reported with pancreas biopsy interpretation included poor reliability, lack of reporting of C4d staining, lack of reporting of rejection grading, and inconclusive interpretation of the biopsy. Staff at a third of responding programs (34%) stated that they rarely or never perform pancreas allograft biopsies and treat presumed rejection empirically. Conclusions. This national survey identified significant variation in clinical practices related to pancreas allograft biopsies and potential barriers to pancreas transplant utilization across the United States. Consideration of strategies to improve program experience with percutaneous pancreas biopsy and to support optimal management of pancreas allograft rejection informed by histology is warranted.