Abstract 2014

Poster Board I-1036

Introduction:

Clinical manifestations of blood hypercoagulability, such as pulmonary arterial hypertension (PAH) and ischemic stroke, are well known in patients with thalassemia. We herein present evidence that the hypercoagulable state in β-Thalassemia disease patients is to a significant extent the result of prior splenectomy.

Patients and Methods:

One hundred and ten clinically stable hemoglobin E/β-Thalassemia outpatients, on no medication aside from folic acid and who received no blood transfusion in the preceding 4 weeks were studied. All gave written informed consent, and study protocol was approved by the institution ethics committee on studies in humans (#0774/2548). Echocardiogram was used to estimate systolic PA pressure (SPAP). Clinical features and laboratory data were stratified according to the presence or absence of the spleen, and statistical analysis was done by STATA version 10 (Stata Corp, Texas), considering a P value <0.05 as statistically significant.

Results:

Of the 110 patients, 61 were asplenic and females comprised 51% in both groups. Selected statistically significant results are shown in the table.

ResultsAsplenic (61 Patients)Non-splenectomized (49 Patients)P value
Age at 1st transfusion (median) 4.7 years 17 years <0.001 
Total transfusions (median) 35 units PRBC 13 units PRBC 0.005 
Systolic pulmonary artery pressure 37.1 +/- 14.6 mm Hg 28.8 +/- 7.6 mm Hg <0.001 
Cardiomegaly 50.9% 27.3% 0.013 
Extramedullary hematopoiesis 50.9% 27.3% 0.013 
RBC count 3.19 +/- 0.57 × 106/μL 3.87 +/- 1.09 × 106/μL <0.001 
Corrected reticulocyte count (median) 5.2% 1.4% <0.001 
Nucleated RBC (median) 581/100 WBCs 5/100 WBCs <0.001 
Corrected WBC count 9.72 +/- 4.2 × 103/μL 6.71 +/- 2.3 × 103/μL <0.001 
Platelet count 726 +/- 215 × 103/μL 243 +/- 115 × 103/μL <0.001 
Serum ferritin (median) 1,892 ng/mL 1,050 ng/mL 0.001 
ALT (median) 65.5 u/L 44.5 u/L 0.004 
AST (median) 64 u/L 36 u/L 0.001 
Free hemoglobin (median) 4.2 mg/dL 2.5 mg/dL 0.001 
C-reactive protein (high sens) (median) 2.7 mg/L 1.2 mg/L 0.012 
Thrombin-antithrombin complexes 3.5 μg/L 1.1 μg/L <0.001 
Soluble P-selectin 113.4 +/- 31.2 ng/mL 56.4 +/- 32.1 ng/mL <0.001 
Soluble E-selectin 43.3 +/- 21.5 ng/mL 29.5 +/- 18.4 ng/mL 0.003 
ResultsAsplenic (61 Patients)Non-splenectomized (49 Patients)P value
Age at 1st transfusion (median) 4.7 years 17 years <0.001 
Total transfusions (median) 35 units PRBC 13 units PRBC 0.005 
Systolic pulmonary artery pressure 37.1 +/- 14.6 mm Hg 28.8 +/- 7.6 mm Hg <0.001 
Cardiomegaly 50.9% 27.3% 0.013 
Extramedullary hematopoiesis 50.9% 27.3% 0.013 
RBC count 3.19 +/- 0.57 × 106/μL 3.87 +/- 1.09 × 106/μL <0.001 
Corrected reticulocyte count (median) 5.2% 1.4% <0.001 
Nucleated RBC (median) 581/100 WBCs 5/100 WBCs <0.001 
Corrected WBC count 9.72 +/- 4.2 × 103/μL 6.71 +/- 2.3 × 103/μL <0.001 
Platelet count 726 +/- 215 × 103/μL 243 +/- 115 × 103/μL <0.001 
Serum ferritin (median) 1,892 ng/mL 1,050 ng/mL 0.001 
ALT (median) 65.5 u/L 44.5 u/L 0.004 
AST (median) 64 u/L 36 u/L 0.001 
Free hemoglobin (median) 4.2 mg/dL 2.5 mg/dL 0.001 
C-reactive protein (high sens) (median) 2.7 mg/L 1.2 mg/L 0.012 
Thrombin-antithrombin complexes 3.5 μg/L 1.1 μg/L <0.001 
Soluble P-selectin 113.4 +/- 31.2 ng/mL 56.4 +/- 32.1 ng/mL <0.001 
Soluble E-selectin 43.3 +/- 21.5 ng/mL 29.5 +/- 18.4 ng/mL 0.003 
Conclusions:

In comparison with non-splenectomized hemoglobin E/β-Thalassemia patients, asplenic ones have higher SPAP, more severe hemolysis, more liver impairment and chronic iron overload, significant chronic low grade inflammation, and evidence of coagulation activation. Splenectomy should be more judiciously applied than heretofore, and if performed, measures to blunt or prevent a subsequent hypercoagulable and inflammatory state, which could lead to PAH should be initiated.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.

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