title: ALK1 expression in oral lichen planus: a possible relation to microvessel density.
abstract: OBJECTIVE
  To assess the expression of activin receptor-like kinase 1 (ALK1) and investigate its possible relationship with microvessel density (MVD) in different forms of oral lichen planus (OLP) compared to controls' biopsies.
  
  
  METHODS
  Biopsies from 20 reticular/papular OLP (R/PLP), 20 atrophic/erosive OLP (A/ELP) patients, and 20 healthy subjects were immunohistochemically analyzed and statistically compared and correlated for ALK1 expression and MVD as assessed by CD34 expression.
  
  
  RESULTS
  All OLP specimens revealed the presence of positive cytoplasmic CD34 immunostaining in endothelial cells, with statistically high significant MVD in each of R/PLP (Median; M = 4.40) and A/ELP (M = 7.69) compared to controls (M = 1.16) (P < 0.001). Statistically significant MVD was found in A/ELP compared to R/PLP (P < 0.001). All control specimens revealed negative ALK1 immunostaining of the few inflammatory cells found, while 85% of A/ELP cases and 70% of R/PLP cases showed positively immunostained sections for ALK-1, with statistically significant higher ALK1 expression In A/ELP (M = 1.95) compared to R/PLP (M = 0.86) (P = 0.005). No significant correlation between CD34 and ALK1 was detected in R/PLP (r = 0.081), while a barely moderate positive correlation was found in A/ELP (r = 0.396).
  
  
  CONCLUSIONS
  ALK1 expression and MVD are increased in OLP, particularly in A/ELP type.
authors.affiliation: Oral Medicine, Diagnosis, Periodontology and Radiology, Faculty of Dental Medicine, Al Azhar University (Girls Branch), Cairo, Egypt.|Oral Medicine, Diagnosis, Periodontology and Radiology, Faculty of Dentistry, Nahda University, Beni Swaif, Egypt.
authors.forename: Hala H A
authors.initials: HH
authors.lastname: Hazzaa
authors.affiliation: Oral Medicine, Diagnosis, Periodontology and Radiology, Faculty of Dental Medicine, Al Azhar University (Girls Branch), Cairo, Egypt.
authors.forename: Naglaa M
authors.initials: NM
authors.lastname: El-Wakeel
authors.affiliation: Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: Enas A S
authors.initials: EA
authors.lastname: Attia
authors.affiliation: Oral and Dental patholology, Faculty of Dental Medicine, Al Azhar University (Girls Branch), Cairo, Egypt.
authors.forename: Eman A
authors.initials: EA
authors.lastname: Abo Hager
mesh_terms: D030301:Activin Receptors, Type II / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000368:Aged; D043925:Angiogenesis Inducing Agents / Q000378:metabolism; D018952:Antigens, CD34 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D003238:Connective Tissue / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017676:Lichen Planus, Oral / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D055806:Microvessels / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged
chemical_list: D043925:Angiogenesis Inducing Agents; D018952:Antigens, CD34; D015415:Biomarkers; C425364:ACVRL1 protein, human; D030301:Activin Receptors, Type II
keywords: ALK1; CD34; microvessel density; oral lichen planus