title: Elevated tricuspid regurgitant jet velocity in subgroups of thalassemia patients: insight into pathophysiology and the effect of splenectomy.
abstract: A high tricuspid regurgitant jet velocity (TRV) signifies a risk for or established pulmonary hypertension (PH), which is a serious complication in thalassemia patients. The underlying pathophysiology in thalassemia subgroups and potential biomarkers for early detection and monitoring are not well defined, in particular as they relate to spleen removal. To better understand some of these unresolved aspects, we examined 76 thalassemia patients (35 non-transfused), 25 splenectomized non-thalassemia patients (15 with hereditary spherocytosis), and 12 healthy controls. An elevated TRV (>2.5 m/s) was found in 25/76 (33 %) of the patients, confined to non-transfused or those with a late start of transfusions, including patients with hemoglobin H-constant spring, a finding not previously described. These non or late-transfused patients (76 % splenectomized) had significantly increased platelet activation (sCD40L), high platelet count, endothelial activation (endothelin-1), and hemolysis (LDH, plasma-free Hb), while hypercoagulable and inflammatory markers were not significantly increased. The same markers were increased in the seven patients with confirmed PH on cardiac catheterization, suggesting their possible role for screening patients at risk for PH. A combination of hemolysis and absence of spleen is necessary for developing a high TRV, as neither chronic hemolysis in the non-splenectomized thalassemia patients nor splenectomy without hemolysis, in the non-thalassemia patients, resulted in an increase in TRV.
authors.affiliation: Department of Hematology-Oncology, Children's Hospital and Research Center Oakland, Oakland, CA, USA, tsinger@mail.cho.org.
authors.forename: Sylvia T
authors.initials: ST
authors.lastname: Singer
authors.forename: Frans
authors.initials: F
authors.lastname: Kuypers
authors.forename: Jeffery
authors.initials: J
authors.lastname: Fineman
authors.forename: Ginny
authors.initials: G
authors.lastname: Gildengorin
authors.forename: Sandra
authors.initials: S
authors.lastname: Larkin
authors.forename: Nancy
authors.initials: N
authors.lastname: Sweeters
authors.forename: Howard
authors.initials: H
authors.lastname: Rosenfeld
authors.forename: Gregory
authors.initials: G
authors.lastname: Kurio
authors.forename: Annie
authors.initials: A
authors.lastname: Higa
authors.forename: Michael
authors.initials: M
authors.lastname: Jeng
authors.forename: James
authors.initials: J
authors.lastname: Huang
authors.forename: Elliott P
authors.initials: EP
authors.lastname: Vichinsky
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013156:Splenectomy / Q000379:methods; D013789:Thalassemia / Q000097:blood / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014262:Tricuspid Valve Insufficiency / Q000097:blood / Q000503:physiopathology* / Q000601:surgery*; D055815:Young Adult