1. Spleen neoangiogenesis in patients with myelofibrosis with myeloid metaplasia
- Author
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Ramaioli Isabella, Marchetti Monia, Viarengo G. Luca, Massa Margherita, Bazzan Mario, Giovanni Barosi, Necchi Vittorio, Campanelli Rita, Rosti Vittorio, Magrini Umberto, and Pecci Alessandro
- Subjects
Pathology ,medicine.medical_specialty ,education.field_of_study ,Myeloid ,business.industry ,medicine.medical_treatment ,Splenectomy ,Population ,CD34 ,Spleen ,Hematology ,medicine.disease ,Haematopoiesis ,medicine.anatomical_structure ,medicine ,Bone marrow ,education ,Myelofibrosis ,business - Abstract
Summary Neoangiogenesis is an integral component of bone marrow myeloproliferation in patients with myelofibrosis with myeloid metaplasia (MMM). As extramedullary haematopoiesis is a constitutive feature of MMM, we studied spleen neoangiogenesis by a computerized image analysis in MMM patients. Compared with five normal subjects, spleen CD34-staining capillary vascular density (CVD) was 2·1–3·03 times higher than the upper range of normal in six of the 15 (40%) MMM patients. CD8-staining sinusoidal vascular density (SVD) was constantly normal or lesser than normal and was inversely correlated with CVD (R = −0·53; P = 0·04). In MMM patients who did not receive cytoreductive or radiation therapy in the month before splenectomy (n = 9), the CVD was a significant determinant of spleen size (R = 0·88; P = 0·04). In MMM patients, the number of spleen CD34+ haematopoietic stem cells was increased from 1·2 to 98 times the upper limit of normal, and predicted the expansion of CVD (R = 0·57; P = 0·03). A population of cells expressing the CD34+/CD133+/VEGFR-2+ angiopoietic phenotype was present in the blood and spleen of five of seven patients. These results document that neoangiogenesis is an integral component of spleen re-localization of haematopoietic stem cells and suggest a cellular mechanism for spleen neoangiogenesis.
- Published
- 2004