{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/137532"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/137532","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Plasma ADAMTS13 activity in dogs with severe thrombocytopenia and presumed immune thrombocytopenia","abstract":"Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is an important cause of thrombocytopenia in immune thrombotic thrombocytopenic purpura (iTTP). This disease can be difficult to differentiate from immune thrombocytopenia (ITP) in people. Further evaluation of other disease entities such as iTTP-like disease is warranted in subsets of dogs with ITP due to the variability in bleeding tendencies without correlation to platelet counts and poor response to treatment. Hypotheses: Dogs with severe thrombocytopenia and presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs. Additionally, bleeding assessment scores, such as the DOGiBAT, negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with severe thrombocytopenia and presumed ITP and 40 healthy control dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity is significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP.","abstract_html":"Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is an important cause of thrombocytopenia in immune thrombotic thrombocytopenic purpura (iTTP). This disease can be difficult to differentiate from immune thrombocytopenia (ITP) in people. Further evaluation of other disease entities such as iTTP-like disease is warranted in subsets of dogs with ITP due to the variability in bleeding tendencies without correlation to platelet counts and poor response to treatment. Hypotheses: Dogs with severe thrombocytopenia and presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs. Additionally, bleeding assessment scores, such as the DOGiBAT, negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with severe thrombocytopenia and presumed ITP and 40 healthy control dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity is significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP.","abstract_has_math":false,"creators":["Travis, Sierrah D."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Biomedical and Veterinary Sciences","degree_department":"Biomedical and Veterinary Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Wilkinson, Ashley"],"committee_members":["DeMonaco, Stefanie Marie","Bolton, Timothy","Keebaugh, Audrey Elizabeth"],"year":2025,"date_issued":"2025-08-18","date_published":"2025-08-18","updated_at":"2026-07-22T22:19:41Z","subjects":["ADAMTS-13","thrombocytopenia","von Willebrand factor","platelets","canine"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:44430"],"render_values":[{"text":"vt_gsexam:44430","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/137532","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Wilkinson, Ashley"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["DeMonaco, Stefanie Marie","Bolton, Timothy","Keebaugh, Audrey Elizabeth"]},{"key":"dc:contributor.department","label":"Department","values":["Biomedical and Veterinary Sciences"]},{"key":"dc:creator","label":"Author","values":["Travis, Sierrah D."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-08-19T08:00:47Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-08-19T08:00:47Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-08-18"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biomedical and Veterinary Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ADAMTS-13","thrombocytopenia","von Willebrand factor","platelets","canine"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:44430"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/137532"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is an important cause of thrombocytopenia in immune thrombotic thrombocytopenic purpura (iTTP). This disease can be difficult to differentiate from immune thrombocytopenia (ITP) in people. Further evaluation of other disease entities such as iTTP-like disease is warranted in subsets of dogs with ITP due to the variability in bleeding tendencies without correlation to platelet counts and poor response to treatment. Hypotheses: Dogs with severe thrombocytopenia and presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs. Additionally, bleeding assessment scores, such as the DOGiBAT, negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with severe thrombocytopenia and presumed ITP and 40 healthy control dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity is significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is the cause of immune thrombotic thrombocytopenic purpura (iTTP). This can be difficult to differentiate from immune thrombocytopenia (ITP) as both disease processes involve thrombocytopenia, or decreased platelet counts. Dogs with ITP, the most common acquired primary hemostatic disorder in this species, have bleeding tendencies that do not correlate with the severity of the thrombocytopenia. Moreover, the reported mortality rate in dogs with ITP is 10-30% due to severe bleeding or lack of responsiveness to immunosuppressive therapy. Dogs with ITP have not been evaluated for plasma ADAMTS-13 deficiency. The presence of such a deficiency could demonstrate that a subset of dogs with presumed ITP have a different or more complex disease process. Hypotheses: Dogs with presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs and bleeding assessment scores (DOGiBAT) negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with presumed ITP and 40 healthy dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity was significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Plasma ADAMTS13 activity in dogs with severe thrombocytopenia and presumed immune thrombocytopenia"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Wilkinson, Ashley"],"dc:contributor.committeemember":["DeMonaco, Stefanie Marie","Bolton, Timothy","Keebaugh, Audrey Elizabeth"],"dc:contributor.department":["Biomedical and Veterinary Sciences"],"dc:creator":["Travis, Sierrah D."],"dc:date.accessioned":["2025-08-19T08:00:47Z"],"dc:date.available":["2025-08-19T08:00:47Z"],"dc:date.issued":["2025-08-18"],"dc:description.abstract":["Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is an important cause of thrombocytopenia in immune thrombotic thrombocytopenic purpura (iTTP). This disease can be difficult to differentiate from immune thrombocytopenia (ITP) in people. Further evaluation of other disease entities such as iTTP-like disease is warranted in subsets of dogs with ITP due to the variability in bleeding tendencies without correlation to platelet counts and poor response to treatment. Hypotheses: Dogs with severe thrombocytopenia and presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs. Additionally, bleeding assessment scores, such as the DOGiBAT, negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with severe thrombocytopenia and presumed ITP and 40 healthy control dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity is significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP."],"dc:description.abstractgeneral":["Background: In humans, deficiency of plasma ADAMTS-13, a von Willebrand factor cleaving enzyme, is the cause of immune thrombotic thrombocytopenic purpura (iTTP). This can be difficult to differentiate from immune thrombocytopenia (ITP) as both disease processes involve thrombocytopenia, or decreased platelet counts. Dogs with ITP, the most common acquired primary hemostatic disorder in this species, have bleeding tendencies that do not correlate with the severity of the thrombocytopenia. Moreover, the reported mortality rate in dogs with ITP is 10-30% due to severe bleeding or lack of responsiveness to immunosuppressive therapy. Dogs with ITP have not been evaluated for plasma ADAMTS-13 deficiency. The presence of such a deficiency could demonstrate that a subset of dogs with presumed ITP have a different or more complex disease process. Hypotheses: Dogs with presumed ITP have reduced plasma ADAMTS-13 activity compared to healthy dogs and bleeding assessment scores (DOGiBAT) negatively correlate with plasma ADAMTS-13 activity. Animals: Fifteen privately-owned dogs with presumed ITP and 40 healthy dogs enrolled in a separate study recruited from a hospital population. Methods: Prospective observational study. Dogs (≥ 1 year of age) with severe thrombocytopenia (≤20,000 platelets/uL) underwent diagnostic evaluation and were categorized as having presumed primary ITP (pITP) or potential secondary ITP (sITP). All dogs received a DOGiBAT score. Plasma ADAMTS-13 activity was assessed using the Diapharma® RUO Technozyme® ADAMTS-13 Activity ELISA kit. Wilcoxon rank sum test was used to determine if plasma ADAMTS-13 activity was significantly different in dogs with ITP compared to healthy controls. Spearman's rank correlation rho test was used to determine if plasma ADAMTS-13 activity correlates with DOGiBAT scores. Results: Dogs with severe thrombocytopenia and presumed ITP, the combination of presumed pITP and potential sITP, have reduced plasma ADAMTS-13 activity compared to healthy controls (P = 0.039). Individually, plasma ADAMTS-13 activity in dogs with presumed pITP or potential sITP is not different from healthy controls (P = 0.428, P = 0.095, respectively). Plasma ADAMTS-13 activity does not correlate with DOGiBAT scores (P = 0.069). Conclusions and clinical relevance: ADAMTS-13 deficiency may be a mechanism for thrombocytopenia in some dogs with severe thrombocytopenia presumptively diagnosed with ITP."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:44430"],"dc:identifier.uri":["https://hdl.handle.net/10919/137532"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["ADAMTS-13","thrombocytopenia","von Willebrand factor","platelets","canine"],"dc:title":["Plasma ADAMTS13 activity in dogs with severe thrombocytopenia and presumed immune thrombocytopenia"],"dc:type":["Thesis"],"thesis:degree_discipline":["Biomedical and Veterinary Sciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:41Z"}