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Evrimler S, Yip-Schneider MT, Swensson J, Soufi M, Muraru R, Tirkes T, Schmidt CM, Akisik F. Magnetic resonance imaging-derived fat fraction predicts risk of malignancy in intraductal papillary mucinous neoplasm. Abdom Radiol (NY) 2021; 46:4779-4786. [PMID: 34086091 DOI: 10.1007/s00261-021-03146-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Assess the relationship between MRI-derived pancreatic fat fraction and risk of malignancy in intraductal papillary mucinous neoplasm (IPMN). METHODS MRIs of patients with IPMN who underwent pancreaticoduodenectomy were analyzed. IPMN with low-grade dysplasia (n = 29) were categorized as low-risk while IPMN at high risk of malignancy consisted of those with high-grade dysplasia/invasive carcinoma (n = 33). Pancreatic fat-fraction (FFmean) was measured using the 2-point Dixon-method. Images were evaluated for the high-risk stigmata and worrisome features according to the revised 2017 Fukuoka consensus criteria. Data on serum CA19-9, Diabetes Mellitus (DM) status, body mass index (BMI), and histological chronic pancreatitis were obtained. RESULTS A significant difference in FFmean was found between the high-risk IPMN (11.45%) and low-risk IPMN (9.95%) groups (p = 0.027). Serum CA19-9 level (p = 0.021), presence of cyst wall enhancement (p = 0.029), and solid mass (p = 0.008) were significantly associated with high-risk IPMN. There was a significant correlation between FFmean and mural nodule size (r = 0.36, p ˂ 0.01), type 2 DM (r = 0.34, p ˂ 0.01), age (r = 0.31, p ˂ 0.05), serum CA 19-9 (r = 0.30, p ˂ 0.05), cyst diameter (r = 0.30, p ˂ 0.05), and main pancreatic duct diameter (r = 0.26, p ˂ 0.05). Regression analysis revealed FFmean (OR 1.103, p = 0.035) as an independent predictive variable of high-risk IPMN. CONCLUSION FFmean is significantly associated with high-risk IPMN and an independent predictor of IPMN malignant risk. FFmean may have clinical utility as a biomarker to complement the current IPMN treatment algorithm and improve clinical decision making regarding the need for surgical resection or surveillance.
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Affiliation(s)
- Sehnaz Evrimler
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Radiology, Suleyman Demirel University School of Medicine, 32260, Isparta, Turkey
| | - Michele T Yip-Schneider
- Department of Surgery, Indiana University Health Pancreatic Cyst and Cancer Early Detection Center, Indianapolis, IN, 46202, USA
| | - Jordan Swensson
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Mazhar Soufi
- Department of Surgery, Indiana University Health Pancreatic Cyst and Cancer Early Detection Center, Indianapolis, IN, 46202, USA
| | - Rodica Muraru
- Center for Outcomes Research in Surgery, Indiana University School of Medicine, 545 Barnhill Drive, EH 106E, Indianapolis, IN, 46202, USA
| | - Temel Tirkes
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - C Max Schmidt
- Department of Surgery, Indiana University Health Pancreatic Cyst and Cancer Early Detection Center, Indianapolis, IN, 46202, USA
| | - Fatih Akisik
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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Frøkjær JB, Olesen SS, Drewes AM, Collins D, Akisik F, Swensson J. Impact of age on the diagnostic performance of pancreatic ductal diameters in detecting chronic pancreatitis. Abdom Radiol (NY) 2020; 45:1488-1494. [PMID: 32296897 DOI: 10.1007/s00261-020-02522-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE In the diagnosis of chronic pancreatitis (CP), definition of main pancreatic duct (MPD) dilation is challenging due to lack of commonly accepted normal values. This study assessed the diagnostic performance of MPD diameters to detect CP including the impact of age. METHODS 274 patients with ERCP-verified CP and 262 healthy controls were included. All had magnetic resonance cholangiopancreatography (MRCP) with measurement of MPD diameters in the pancreatic head, body, and tail. CP disease stage was defined as patients with and without functional (exocrine and/or endocrine) impairment. Diagnostic performance of MPD diameter and corresponding cut-offs values to diagnose CP were determined, including an age-stratified analysis. RESULTS In healthy controls, an effect of age on MPD diameters was seen for the pancreatic head (P < 0.001), body (P = 0.006), and tail (P = 0.03). Patients with CP had increased MPD diameter compared to controls (all segments P < 0.001). Increased pancreatic head MPD diameter was seen in patients with functional pancreatic impairment compared to patients without (P = 0.03). The diagnostic performance of MPD diameter to detect CP was high (all segments ROC-AUC > 0.92). The optimal pancreatic MPD diameter cut-off values for diagnosing CP were: < 40 years: 2.0(head) and 1.8(body) mm; 40-60 years: 2.4(head) and 2.1(body) mm; > 60 years: 2.7(head) and 2.1(body) mm. CONCLUSION Age is an important factor when evaluating the diameter of the pancreatic ductal system. Our findings challenge the existing reported thresholds for defining an abnormal duct diameter and point at age-stratified assessments as an integrated part of future imaging-based diagnostic and grading systems for CP.
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Affiliation(s)
- Jens Brøndum Frøkjær
- Department of Radiology, Aalborg University Hospital, P.O. Box 365, 9100, Aalborg, Denmark.
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
| | - Søren Schou Olesen
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Asbjørn Mohr Drewes
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
- Mech-Sense, Department of Gastroenterology & Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - David Collins
- Department of Radiology, Indiana University, Indianapolis, USA
| | - Fatih Akisik
- Department of Radiology, Indiana University, Indianapolis, USA
| | - Jordan Swensson
- Department of Radiology, Indiana University, Indianapolis, USA
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Swensson J, Nagaraju S, O'Brien D, Tann M, Shah A, Mangus R, Powelson J, Fridell J. Contrast‐enhanced ultrasound of the transplant pancreas in the post‐operative setting. Clin Transplant 2019; 33:e13733. [DOI: 10.1111/ctr.13733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/02/2019] [Accepted: 10/14/2019] [Indexed: 12/16/2022]
Affiliation(s)
| | | | - Daniel O'Brien
- Indiana University School of Medicine Indianapolis Indiana
| | - Mark Tann
- Indiana University School of Medicine Indianapolis Indiana
| | - Angela Shah
- Indiana University School of Medicine Indianapolis Indiana
| | - Richard Mangus
- Indiana University School of Medicine Indianapolis Indiana
| | - John Powelson
- Indiana University School of Medicine Indianapolis Indiana
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Swensson J, Tirkes T, Tann M, Cui E, Sandrasegaran K. Differentiating IgG4-related sclerosing cholangiopathy from cholangiocarcinoma using CT and MRI: experience from a tertiary referring center. Abdom Radiol (NY) 2019; 44:2111-2115. [PMID: 30783729 DOI: 10.1007/s00261-019-01944-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE To compare the cross-sectional imaging findings of immunoglobulin G4-related sclerosing cholangiopathy (IgG4-SC) and cholangiocarcinoma (CCA). METHODS Retrospective search of radiology and pathology databases identified 24 patients with IgG4-SC and over 500 patients with CCA from January 2009 to December 2016. Patients with no pre-treatment imaging studies available on PACS, non-contrasted imaging only, presence of mass lesions, metastatic disease or biliary stents were excluded. 17 patients with IgG4-SC and a selected group of 20 (age and gender matched) patients with CCA were obtained. Images were blinded and independently reviewed by two radiologists. Differences in proportions and means between groups were analyzed using Fishers and Mann-Whitney tests, respectively. RESULTS Both readers identified a statistically significant difference in the presence of abrupt common bile duct narrowing between IgG4-SC and CCA (6.7% vs. 68.4%, p < 0.001; 33.3% vs. 75%, p = 0.019). No difference was seen in biliary wall thickening, wall enhancement, extrahepatic exclusive location of disease, or pancreatic duct dilation. Inter-observer variability was κ = 0.52. Total bilirubin and CA 19-9 were unable to differentiate between IgG4-SC and CCA. Serum IgG4 was positive in two of six IgG4-SC patients who were tested. CONCLUSION IgG4-SC and CCA share many clinical and imaging findings on CT and MRI. Abrupt bile duct cut sign strongly favors CCA. In the absence of this finding, IgG4-SC should be considered in the differential diagnosis in all cases of suspected extrahepatic CCA.
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Affiliation(s)
- Jordan Swensson
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd Room 0663, Indianapolis, IN, 46202, USA.
| | - Temel Tirkes
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd Room 0663, Indianapolis, IN, 46202, USA
| | - Mark Tann
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd Room 0663, Indianapolis, IN, 46202, USA
| | - Enming Cui
- Department of Radiology, Jiangmen Central Hospital, 23 Haibang Street, Pengjiang District, Jiangmen, 529030, Guangdong, People's Republic of China
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Wang Q, Swensson J, Hu M, Cui E, Tirkes T, Jennings SG, Akisik F. Distribution and correlation of pancreatic gland size and duct diameters on MRCP in patients without evidence of pancreatic disease. Abdom Radiol (NY) 2019; 44:967-975. [PMID: 30600375 DOI: 10.1007/s00261-018-1879-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE To use MRCP to investigate age-related changes and gender differences of the pancreas and to correlate pancreatic gland size and duct diameter. METHODS In this institutional review, board-approved, HIPAA-compliant study, 280 patients (age 20-88 years) without a history of pancreatic or liver disease who had undergone MRI/MRCP from 2004 to 2015 were identified. The anteroposterior size and main duct diameter of the pancreatic head, body, and tail were measured. The pancreatic gland and duct sizes were compared between genders, and among seven age subgroups (20-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89). RESULTS The pancreatic head and body were significantly larger in males than females (head, p < 0.01; body, p = 0.03), while the tail and the duct diameters of the pancreatic head, body, and tail showed no gender difference. As the age of male participants increased, there was an associated increase in size of the pancreatic gland initially (largest at age 50-59 (body) and 60-69 (head)), followed by subsequent decline in size thereafter. Additionally, the pancreatic duct diameter was found to increase gradually. In females, the size of the pancreatic gland decreased, while the diameter of the pancreatic duct increased with age. Moderate positive correlation for gland size and strong positive correlation for duct diameter among different pancreatic regions were found. Weak negative correlation was found between gland size and duct diameter. CONCLUSIONS There are gender differences in the gland size of the pancreatic head and body. The pancreatic gland size increases until the sixth decade in males, with a more continuous decrease in gland size with age in females. Both males and females demonstrate a marked decrease in gland size after the eighth decade. The duct diameter increases with age in both males and females.
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Affiliation(s)
- Qiushi Wang
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhong Shan Er Road, Guangzhou, 510080, Guangdong, China
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
| | - Jordan Swensson
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
| | - Maoqing Hu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
- Department of Radiology, Jiangmen Central Hospital, No. 23 Haibang Street, Jiangmen, 529030, Guangdong, China
| | - Enming Cui
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
- Department of Radiology, Jiangmen Central Hospital, No. 23 Haibang Street, Jiangmen, 529030, Guangdong, China
| | - Temel Tirkes
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
| | - Samuel G Jennings
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA
| | - Fatih Akisik
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550 N University Blvd, Indianapolis, IN, 46202, USA.
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Tirkes T, Fogel EL, Sherman S, Lin C, Swensson J, Akisik F, Sandrasegaran K. Detection of exocrine dysfunction by MRI in patients with early chronic pancreatitis. Abdom Radiol (NY) 2017; 42:544-551. [PMID: 27660281 DOI: 10.1007/s00261-016-0917-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE To determine if T1-weighted MR signal of the pancreas can be used to detect early CP. METHODS A retrospective analysis was performed on 51 suspected CP patients, who had both secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) and an intraductal secretin stimulation test (IDST). There were 29 patients in normal and 22 patients in the low bicarbonate group. Bicarbonate level, total pancreatic juice volume, and excretory flow rate were recorded during IDST. Signal intensity ratio of pancreas (SIR), fat signal fraction, pancreatograms findings, and grade of duodenal filling were recorded on S-MRCP by two blinded radiologists. RESULTS There was a significant difference in the signal intensity ratio of the pancreas to spleen (SIRp/s) between the normal and low bicarbonate groups (p < 0.0001). A significant positive correlation was found between pancreatic fluid bicarbonate level and SIRp/s (p < 0.0001). SIRp/s of 1.2 yielded sensitivity of 77% and specificity of 83% for detection of pancreatic exocrine dysfunction (AUC: 0.89). CONCLUSION T1-weighted MR signal of the pancreas has a high sensitivity and specificity for the detection of parenchymal abnormalities related to exocrine dysfunction and can therefore be helpful in evaluation of suspected early CP.
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Affiliation(s)
- Temel Tirkes
- Department of Radiology and Clinical Sciences, Indiana University School of Medicine, 550 N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA.
| | - Evan L Fogel
- Division of Gastroenterology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Stuart Sherman
- Division of Gastroenterology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chen Lin
- Department of Radiology and Clinical Sciences, Indiana University School of Medicine, 550 N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA
| | - Jordan Swensson
- Department of Radiology and Clinical Sciences, Indiana University School of Medicine, 550 N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA
| | - Fatih Akisik
- Department of Radiology and Clinical Sciences, Indiana University School of Medicine, 550 N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA
| | - Kumaresan Sandrasegaran
- Department of Radiology and Clinical Sciences, Indiana University School of Medicine, 550 N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA
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Swensson J, McMahan L, Rase B, Tahir B. Curricula for Teaching MRI Safety, and MRI and CT Contrast Safety to Residents: How Effective Are Live Lectures and Online Modules? J Am Coll Radiol 2015; 12:1093-6. [DOI: 10.1016/j.jacr.2015.04.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 04/08/2015] [Indexed: 10/23/2022]
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Wu GD, Gochi E, Jin YS, Swensson J, Starnes VA, Cramer DV. Maturation of xenoantibody gene expression during the humoral immune response of rats to hamster xenografts. Xenotransplantation 2001; 8:291-302. [PMID: 11737855 DOI: 10.1034/j.1399-3089.2001.00136.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Immunoglobulin isotype switching represents an important component of antibody maturation in the development of humoral immune responses. We have recently conducted a series of studies in a nonimmunosuppressed rodent model to define the kinetics of xenoantibody production and seek evidence for the maturation of xenoantibody Ig gene expression by xenograft recipients. LEW rats were transplanted with hamster cardiac xenografts and the grafts were allowed to remain in situ for prolonged immune stimulation of the host. Anti-hamster antibodies were examined at days 4, 8, 21, 28 and 40 post-transplantation. cDNA libraries specific for rat mu or gamma heavy chains were constructed from B lymphocytes of the xenograft recipients at day 4 and day 21 post-transplantation. Selected cDNA clones encoding the Ig V(H)HAR family of genes from each group were sequenced and analyzed for the presence of somatic mutations. We found that the reactivity of xenoantibodies examined with flow cytometry underwent sequential changes in which IgM titers peaked at day 8 post-transplantation (PTx) and returned to low levels after 21 days. IgG titers started to increase at about one week PTx and peaked at 21-28 days. All the IgG isotypes (IgG1, 2a, 2b and 2c) were differentially involved in the IgG responses. Serum passive transfer experiments demonstrated that IgM antibody fractions separated from sera at day 4 post-transplantation were capable of causing hyperacute rejection (HAR) of hamster xenografts, whereas IgM fractions from days 21-40 failed to cause HAR (N = 7, MST = 4 days), a pattern that was consistent with a rise in total xenoreactive IgM levels at days 4-8 and a fall to low levels at 21 days post-transplantation. IgG-containing fractions separated from day 21-40 antisera caused HAR (N = 7, MST = 36 min) whereas IgG fractions from day 8 sera failed to induce graft rejection. Genetic analysis of the rearranged VH genes from 10 cDNA clones demonstrated that the Ig mu (n = 5) and gamma (n = 5) chain clones used the same family of VH genes (V(H)HAR family) to encode their antibody binding activity. The majority (80%) of the IgM clones were present in their original germline configuration. In contrast, the nucleotide sequences from IgG clones manifested an increase in the numbers of replacement mutations in the CDR region of the Ig heavy chain genes, providing evidence for a potential role for somatic mutation in the maturation of IgG xenoantibody responses as the humoral response matures with time post-transplantation.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Heterophile/biosynthesis
- Antibodies, Heterophile/genetics
- Antibodies, Heterophile/immunology
- B-Lymphocytes/immunology
- Cricetinae
- DNA, Complementary/genetics
- Gene Expression Regulation/immunology
- Gene Rearrangement, B-Lymphocyte, Heavy Chain
- Genes, Immunoglobulin
- Graft Rejection/genetics
- Graft Rejection/immunology
- Heart Transplantation/immunology
- Immunization, Passive
- Immunoglobulin Class Switching
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/genetics
- Immunoglobulin G/immunology
- Immunoglobulin M/biosynthesis
- Immunoglobulin M/genetics
- Immunoglobulin M/immunology
- Immunoglobulin Variable Region/genetics
- Male
- Mesocricetus
- Molecular Sequence Data
- Myocardium/immunology
- Myocardium/pathology
- Rats
- Rats, Inbred Lew
- Sequence Alignment
- Sequence Homology, Amino Acid
- Species Specificity
- Transplantation, Heterologous/immunology
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Affiliation(s)
- G D Wu
- Transplantation Research Laboratory, Department of Cardiothoracic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Nozawa S, Xing PX, Wu GD, Gochi E, Kearns-Jonker M, Swensson J, Starnes VA, Sandrin MS, McKenzie IF, Cramer DV. Characteristics of immunoglobulin gene usage of the xenoantibody binding to gal-alpha(1,3)gal target antigens in the gal knockout mouse. Transplantation 2001; 72:147-55. [PMID: 11468550 DOI: 10.1097/00007890-200107150-00028] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Natural antibodies that react with galactose-alpha(1,3)galactose [galalpha(1,3)gal] carbohydrate epitopes exist in humans and Old World primates because of the inactivation of the alpha1,3-galactosyltransferase (alpha1,3GT) gene in these species and the subsequent production of antibodies to environmental microbes that express the galalpha(1,3)gal antigen. The Gal knockout (Gal o/o) mouse, produced by homologous disruption of the alpha1,3GT gene, spontaneously makes anti-galalpha(1,3)gal antibodies and can be used to study the genetic control of humoral immune responses to this carbohydrate epitope. METHODS Six hybridomas that produce monoclonal antibodies (mAbs) to galalpha(1,3)gal were generated in Gal o/o mice. The mAbs were tested to characterize the binding activity with flow cytometry using pig aortic endothelial cells and ELISA with galalpha(1,3)gal carbohydrates. The VH and VK genes of these hybridomas were cloned, sequenced, and analyzed. RESULTS The mAbs showed distinct patterns of antibody binding to galalpha(1,3)gal antigens. The VH genes that encode the mAb binding activity were restricted to a small number of genes expressed in their germline configuration. Four of six clones used closely related progeny of the same VH germline gene (VH441). Comparison of the mouse gene VH441 to the human gene IGHV3-11, a gene that encodes antibody activity to galalpha(1,3)gal in humans, demonstrates that these two genes share a nonrandom distribution of amino acids used at canonical binding sites within the variable regions (complimentary determining regions 1 and 2) of their immunoglobulin VH genes. CONCLUSIONS These results demonstrate the similarity of the Gal o/o mice and humans in their immune response to galalpha(1,3)gal epitopes. Gal o/o mouse can serve as a useful model for examining the genetic control of antibody/antigen interactions associated with the humoral response to pig xenografts in humans.
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Affiliation(s)
- S Nozawa
- Transplantation Biology Research Laboratory, Division of Cardiothoracic Surgery, The Keck School of Medicine, University of Southern California, Los Angeles 90027, USA
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Kearns-Jonker M, Swensson J, Ghiuzeli C, Chu W, Osame Y, Starnes V, Cramer DV. The human antibody response to porcine xenoantigens is encoded by IGHV3-11 and IGHV3-74 IgVH germline progenitors. J Immunol 1999; 163:4399-412. [PMID: 10510381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Preformed and induced Ab responses present a major immunological barrier to the use of pig organs for human xenotransplantation. We generated IgM and IgG gene libraries established from lymphocytes of patients treated with a bioartificial liver (BAL) containing pig hepatocytes and used these libraries to identify IgVH genes that encode human Ab responses to pig xenoantigens. Genes encoded by the VH3 family are increased in expression in patients following BAL treatment. cDNA libraries representing the VH3 gene family were generated, and the relative frequency of expression of genes used to encode the Ab response was determined at days 0, 10, and 21. Ig genes derived from the IGHV3-11 and IGHV3-74 germline progenitors increase in frequency post-BAL. The IGHV3-11 gene encodes 12% of VH3 cDNA clones expressed as IgM Abs at day 0 and 32.4-39.0% of cDNA clones encoding IgM Abs in two patients at day 10. IGHV3-11 and IGHV3-74 genes encoding IgM Abs in these patients are expressed without evidence of somatic mutation. By day 21, an isotype switch occurs and IGHV3-11 IgVH progenitors encode IgG Abs that demonstrate somatic mutation. We cloned these genes into a phagemid vector, expressed these clones as single-chain Abs, and demonstrated that the IGHV3-11 gene encodes Abs with the ability to bind to the gal alpha (1,3) gal epitope. Our results demonstrate that the xenoantibody response in humans is encoded by IgVH genes restricted to IGHV3-11 and IGHV3-74 germline progenitors. IgM Abs are expressed in germline configuration and IgG Abs demonstrate somatic mutations by day 21.
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Affiliation(s)
- M Kearns-Jonker
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles 90033, USA.
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Gochi E, Wu GD, Wakiyama S, Kearns-Jonker M, Swensson J, Cramer DV. Genetic control of the humoral responses to xenografts. III. Identification of the immunoglobulin V(H) genes responsible for encoding rat immunoglobin G xenoantibodies to hamster heart grafts. Transplantation 1999; 68:15-24. [PMID: 10428261 DOI: 10.1097/00007890-199907150-00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND We have previously reported that the early phases of the immune response of rats to hamster xenografts are characterized by the production of IgM xenoantibodies encoded by a restricted group of Ig germline V(H) genes (V(H)HAR family). In the later phases of the reaction, an IgM to IgG isotype switch occurs and our study examines the structure of the rearranged V(H)HAR genes used to encode IgG antibodies after this isotype switch. METHODS A quantitative polymerase chain reaction was used to investigate the changes in the levels of V(H)HAR+ IgG mRNA seen after xenotransplantation. cDNA libraries specific for V(H)HAR+ Iggamma chain were established from total RNA extracted from splenocytes of naive rats and xenograft recipients of hamster hearts at days 4, 8, 21, and 28 posttransplantation. Colony filter hybridization was used to estimate the relative frequency of the use of individual V(H)HAR+ IgG subclasses. Selected IgG clones from day 21 cDNA libraries were sequenced and analyzed for VH-D-J(H) gene usage and antibody combining site structure. RESULTS The level of mRNA for V(H)HAR+ IgG increased 6-fold in xenograft recipients at day 21 post-transplantation when compared with naive animals. The relative frequency of isotype usage for V(H)HAR+ IgG1 antibodies alone increased from 22.3% at day 0 to 37.4% at day 21 PTx. Ten IgG clones from the day 21 cDNA libraries have been sequenced for the rearranged V(H)-D-J(H) genes. Thirty percent (3/10) of these IgG clones used V(H)HAR genes for the coding of heavy chain variable region with limited numbers of nucleic acid substitutions (>98% identity with their germline progenitors) although others demonstrated increased variation in nucleotide sequences (95-97% identity) when compared with germline V(H) genes. Analysis of the canonical binding site structure from the predicted amino acid sequences demonstrated that the majority of IgG clones (9/10) displayed a similar pattern of conserved configurations for their combining sites. CONCLUSIONS The change in IgM to IgG antibody production in the later stages of the humoral immune response of rats to hamster xenografts is associated with an IgM to IgG isotype switch and an increased production of antibodies of the IgG1 isotype. Rat anti-hamster IgG xenoantibodies continue to express the V(H)HAR family of V(H) genes, many in their original germline configuration, to encode antibody recognition of the hamster target antigens. There are, however, a majority of antibodies for which the V(H) genes express evidence of increased nucleic acid sequence variation when compared to currently available germline sequences. The source of this variation is not known but may represent the expression of as yet unidentified germline genes and/or the introduction of T cell-driven somatic mutations. Despite the appearance of this variation, the unusual level of conservation in key antigen binding sites within the V(H) region suggests the variation, independent of its origin, may have a limited influence on the restricted nature of the host antibody response to xenografts.
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Affiliation(s)
- E Gochi
- Department of Cardiovascular Surgery, University of Southern California School of Medicine, Los Angeles 90033, USA
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Abstract
The Forssman antigen has been proposed to be a target for the xenograft reaction in selected species combinations, including the rat and mouse, which are Forssman-negative and -positive species respectively. The mouse represents an important experimental model for a variety of immune-mediated disease processes, and the availability of a simple, inexpensive target antigen could provide an important tool for studying a selected portion of the immunologic basis for the rejection of xenografts. We have examined the potential that antibodies directed against mouse Forssman antigen could cause the hyperacute rejection of mouse heart xenografts in naive rat recipients. The Forssman antibodies tested included rat anti-mouse (R-anti-M) antiserum, R-anti-M antiserum depleted of anti-Forssman (anti-F) antibodies, rat anti-sheep red blood cell (SRBC) antiserum containing anti-F antibodies and a rat monoclonal anti-F IgM antibody. Our results demonstrate that the R-anti-M antiserum at day 4 post transplantation displayed significant titers (1:512-4096) of hemagglutinating antibodies for SRBC and mild to moderate levels of IgM that specifically binds to Forssman glycolipid (GalNAcalpha1-3GalNAcbeta1-3Galalpha1-4Galbeta1- 4Glcbeta1-1ceramide) as measured by an enzyme-linked immunosorbent assay (ELISA). Passive transfer of the R-anti-M serum to rats receiving mouse cardiac grafts immediately after transplantation caused hyperacute rejection of the xenografts. Sequential immunoabsorption of R-anti-M sera with SRBCs resulted in total removal of the anti-Forssman activity (as defined by negative hemagglutination titer and minimal binding to Forssman glycolipid in ELISA). The anti-F Ab-depleted R-anti-M antisera, however, retained the capacity to induce hyperacute rejection of the mouse hearts [n = 6, median survival time (MST) 13 min] when passively transferred to rat recipients. Anti-Forssman antibodies induced by immunization of LEW rats with SRBCs or a rat anti-Forssman monoclonal antibody, mAb M.1.22.25, exhibited substantial anti-Forssman activity (hemagglutinating titer 1:512-4096 and moderate-to-strong binding to Forssman glycolipid in ELISA respectively). These antibodies also failed, however, to trigger hyperacute rejection of mouse cardiac xenografts. In conclusion, our results suggest that the rat anti-Forssman antibodies, including those stimulated by mouse cardiac xenografts, do not appear to play a role in the immediate (hyperacute) rejection of mouse heart xenografts.
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Affiliation(s)
- G D Wu
- Department of Cardiothoracic Surgery School of Medicine, University of Southern California, Los Angeles 90033, USA
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Wakiyama S, Cramer DV, Wu GD, Swensson J, Gochi E, Mendez R. Analysis of B cell subsets responsible for the production of anti-donor antibodies in hamster-to-rat xenorejection. Transplant Proc 1998; 30:1085-6. [PMID: 9636441 DOI: 10.1016/s0041-1345(98)00163-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S Wakiyama
- Transplantation Biology Research Laboratory, St. Vincent Medical Center, Los Angeles, California, USA
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Gochi E, Cramer DV, Wu GD, Kearns M, Swensson J, Wakiyama S, Mendez R. Genetic characteristics of anti-donor immunoglobulin G antibodies in the hamster-to-rat model of xenotransplantation. Transplant Proc 1998; 30:1089-90. [PMID: 9636443 DOI: 10.1016/s0041-1345(98)00165-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- E Gochi
- Transplantation Biology Research Laboratory, St. Vincent Medical Center, Los Angeles, California 90057, USA
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Baquerizo A, Mhoyan A, Shirwan H, Swensson J, Busuttil RW, Demetriou AA, Cramer DV. Xenoantibody response of patients with severe acute liver failure exposed to porcine antigens following treatment with a bioartificial liver. Transplant Proc 1997; 29:964-5. [PMID: 9123610 DOI: 10.1016/s0041-1345(96)00330-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A Baquerizo
- Transplantation Biology Research Laboratory, St Vincent Medical Center, Los Angeles, California, USA
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Börjesson L, Hassan AK, Swensson J, Torell LM. Comment on "Medium-range ordering in glasses: Comparison of Raman and diffraction measurements". Phys Rev Lett 1993; 70:4027. [PMID: 10054027 DOI: 10.1103/physrevlett.70.4027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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