ABO blood group antigens are expressed on von Willebrand factor (VWF) and glycosylation patterns influence circulating VWF levels. The aim of this study was to examine the effect of ABO blood type on tissue-associated VWF protein levels. We selected 35 formalin-fixed paraffin-embedded pulmonary tissue blocks obtained at autopsy from decedents who died from pulmonary embolism with known ABO blood groups (O, A, B and AB phenotypes), prepared tissue microarrays (TMAs) and stained TMAs with antibodies to VWF and platelet/endothelial cell adhesion marker-1 (PECAM-1) as a marker of endothelial cells. A pixel count scoring algorithm was used to quantify VWF and PECAM-1 staining intensity in pulmonary arterioles in digitised images. Compared with type O, non-O individuals have a significantly higher amount of endothelial cell-associated VWF protein expression. VWF protein levels associated with pulmonary vascular endothelial cells is influenced by ABO antigenic determinants.
Histiocyte-rich pseudotumors (HRPT) developing postchemoradiation therapy are a florid response to treatment and reparative change. Although these are benign processes, clinically and radiologically, these may mimic recurrent/relapsed disease. We describe a case of an adult male with history of diffuse large B-cell lymphoma (DLBCL), status postchemoradiation therapy, who developed HRPT at the site of original involvement, mimicking relapse of disease on positron emission tomography/computed tomography (PET/CT) imaging. This is one of the few reported cases of posttreatment HRPT. This entity is important to point out the limitations of PET/CT imaging in patients with lymphomas and metastatic disease and stresses the importance of an excisional biopsy for determining relapse and the need for further treatment.
ABO blood group antigens are expressed on von Willebrand factor (VWF) and glycosylation patterns influence circulating VWF levels. Retrospective studies performed on patients with deep vein thromboses indicate that individuals with type O blood group have a decreased thrombotic risk secondary to lower von Willebrand factor (vWF) plasma levels compared to type A, B and AB (non‐O) individuals. We examined the effect of ABO blood type on tissue‐associated VWF protein and mRNA levels in formalin fixed paraffin‐embedded pulmonary tissue obtained at autopsy from decedents who died from pulmonary embolism with known ABO blood group phenotype (O, A, B or AB). Tissue microarrays were created and stained with antibodies to VWF and platelet/endothelial cell adhesion marker‐1 (PECAM‐1) as a marker of endothelial cells. A pixel count scoring algorithm was used to quantify VWF and PECAM‐1 staining intensity in pulmonary arterioles in digitized images. Compared with type O, non‐O individuals have a significantly higher amount of endothelial cell‐associated VWF protein expression. However, quantitate RT‐PCR showed that, when normalized to PECAM‐1, VWF transcripts were lower in type A individuals, compared to type O. In conclusion, VWF protein levels associated with pulmonary vascular endothelial cells are influenced by ABO antigenic determinants; however, protein levels are not regulated at the transcriptional level.
Support or Funding Information
Research was supported by funds provided by UAMS Department of Pathology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.