{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T10:45:48Z","timestamp":1792147548877,"version":"4.4.0"},"reference-count":9,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Transfusion"],"abstract":"Abstract<\/jats:title>\n \n Background<\/jats:title>\n Chronic automated red cell exchange (RCE) reduces hemoglobin S (HbS) in patients with sickle cell disease (SCD), but procedural success varies across patients in ways standard exchange parameters do not explain. We introduce the Sickling Pressure Index (SPI), derived from each patient's daily rate of HbS rise (ROR) and daily rate of hematocrit fall (ROF).<\/jats:p>\n <\/jats:sec>\n \n Study Design and Methods<\/jats:title>\n \n This retrospective single\u2010center cohort study included 19 patients with SCD undergoing chronic automated RCE and contributing 115 procedures over 40\u2009months. ROR was calculated as the inter\u2010procedure rise in HbS% per day, ROF as the inter\u2010procedure hematocrit decline per day, and SPI as ROR\/ROF. Patients were classified as Low SPI (\n n<\/jats:italic>\n \u2009=\u20098) or High SPI (\n n<\/jats:italic>\n \u2009=\u200911). Group differences were assessed by Mann\u2013Whitney\n U<\/jats:italic>\n test, and procedure\u2010level target achievement by Fisher's exact test and generalized estimating equations (GEE).\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n High\u2010SPI patients had a significantly higher ROR (median 0.635 vs. 0.511 %HbS\/day;\n p<\/jats:italic>\n \u2009=\u2009.026) and lower ROF (0.068 vs. 0.129 %Hct\/day;\n p<\/jats:italic>\n \u2009=\u2009.002). The pre\u2010procedure HbS target was met at 70.8% (34\/48) of Low\u2010SPI encounters versus 47.6% (30\/63) of High\u2010SPI encounters (OR 2.67;\n p<\/jats:italic>\n \u2009=\u2009.020; GEE\u2010adjusted OR 2.65, 95% CI 1.07\u20136.59;\n p<\/jats:italic>\n \u2009=\u2009.036). Groups did not differ in exchange interval, fraction of cells remaining, or units transfused per day, though High\u2010SPI patients trended toward higher absolute RBC use per procedure (\n p<\/jats:italic>\n \u2009=\u2009.090).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n The SPI identifies patients with SCD on chronic RCE whose intrinsic HbS accumulation kinetics, rather than procedural factors, drive target failure. Calculable from routine apheresis data, the SPI may support individualized scheduling.<\/jats:p>\n <\/jats:sec>","DOI":"10.1111\/trf.70444","type":"journal-article","created":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T09:57:20Z","timestamp":1792144640000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The sickling pressure index predicts hemoglobin S target achievement during chronic red cell exchange in sickle cell disease"],"prefix":"10.1111","author":[{"given":"Austin","family":"Choi","sequence":"first","affiliation":[{"name":"Department of Pathology and Laboratory Medicine University of Miami Miller School of Medicine Miami Florida USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1506-3613","authenticated-orcid":false,"given":"Menatalla","family":"Nadim","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine University of Miami Miller School of Medicine Miami Florida USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7272-919X","authenticated-orcid":false,"given":"Nicholas","family":"Parisi","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine University of Miami Miller School of Medicine Miami Florida USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-1169-8861","authenticated-orcid":false,"given":"Yamac","family":"Akgun","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine University of Miami Miller School of Medicine Miami Florida USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,10,16]]},"reference":[{"issue":"2","key":"e_1_2_10_2_1","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1002\/jca.22043","article-title":"Guidelines on the use of therapeutic apheresis in clinical practice: evidence\u2010based approach from the Writing Committee of the American Society for Apheresis: the ninth special issue","volume":"38","author":"Connelly\u2010Smith L","year":"2023","journal-title":"J Clin Apher"},{"issue":"1","key":"e_1_2_10_3_1","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1182\/blood.V63.1.162.162","article-title":"Effect of transfusion therapy on arteriographic abnormalities and on recurrence of stroke in sickle cell disease","volume":"63","author":"Russell MO","year":"1984","journal-title":"Blood"},{"issue":"6","key":"e_1_2_10_4_1","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1016\/S0022-3476(95)70204-0","article-title":"Risk of recurrent stroke in patients with sickle cell disease treated with erythrocyte transfusions","volume":"126","author":"Pegelow CH","year":"1995","journal-title":"J Pediatr"},{"issue":"8","key":"e_1_2_10_5_1","doi-asserted-by":"crossref","first-page":"1554","DOI":"10.1182\/bloodadvances.2019001142","article-title":"American Society of Hematology 2020 guidelines for sickle cell disease: prevention, diagnosis, and treatment of cerebrovascular disease in children and adults","volume":"4","author":"DeBaun MR","year":"2020","journal-title":"Blood Adv"},{"issue":"4","key":"e_1_2_10_6_1","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1111\/trf.17797","article-title":"Using the daily rate of rise in hemoglobin S to manage RBC depletion\/exchange treatment in sickle cell disease","volume":"64","author":"Rogers K","year":"2024","journal-title":"Transfusion"},{"issue":"2","key":"e_1_2_10_7_1","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1182\/bloodadvances.2019001143","article-title":"American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support","volume":"4","author":"Chou ST","year":"2020","journal-title":"Blood Adv"},{"issue":"3","key":"e_1_2_10_8_1","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1038\/s41592-019-0686-2","article-title":"SciPy 1.0: fundamental algorithms for scientific computing in Python","volume":"17","author":"Virtanen P","year":"2020","journal-title":"Nat Methods"},{"issue":"12","key":"e_1_2_10_9_1","doi-asserted-by":"crossref","first-page":"2270","DOI":"10.1111\/trf.18044","article-title":"Post\u2010exchange neutrophil count, but not post\u2010hematocrit, predicts endogenous erythropoiesis in patients with sickle cell disease undergoing chronic red cell exchange","volume":"64","author":"Yurtsever N","year":"2024","journal-title":"Transfusion"},{"issue":"20","key":"e_1_2_10_10_1","doi-asserted-by":"crossref","first-page":"1317","DOI":"10.1056\/NEJM199505183322001","article-title":"Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia","volume":"332","author":"Charache S","year":"1995","journal-title":"N Engl J Med"}],"container-title":["Transfusion"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/trf.70444","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/trf.70444","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/trf.70444","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T09:57:21Z","timestamp":1792144641000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/trf.70444"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,16]]},"references-count":9,"alternative-id":["10.1111\/trf.70444"],"URL":"https:\/\/doi.org\/10.1111\/trf.70444","archive":["Portico"],"relation":{},"ISSN":["0041-1132","1537-2995"],"issn-type":[{"value":"0041-1132","type":"print"},{"value":"1537-2995","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,16]]},"assertion":[{"value":"2026-05-20","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-24","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-10-16","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"trf.70444"}}