CD34 stromal expression is inversely proportional to the extent of morphea

Abstract

Background: Fibrosis is thought to be the main pathophysiology of scleroderma, and myofibroblasts play a main role in abnormal fibrotic pathologies. Altered distribution of dermal dendrocytes, particularly loss of CD34+ fibrocytes, has been reported in scleroderma. Objective: To investigate the relative expression and distribution of myofibroblast and CD34+ fibrocytes in morphea, we performed immunohistochemical stains using several relevant antibodies. Methods: Skin lesions of 50 patients with morphea and age-, sex- and site-matched normal skin of 50 subjects were evaluated for the following antibodies: SMA, CD34, CD31, and VCAM-1. Results: The patient group showed significantly higher expression of SMA and VCAM-1 stain than the control group (p=0.000 and p=0.027, respectively), while CD34 stromal stain was significantly decreased in the patient group (p=0.000). Within the patient group, CD34 stromal stain had an inverse correlation with SMA and VCAM-1 stains (r=-0.286, p=0.044, and r=-0.296, p=0.037, respectively). In subtype analysis, CD34 stromal expression was lost more in generalized morphea than non-generalized morphea. Limitations: Retrospective nature of the study. Conclusion: Mutually exclusive staining patterns of CD34 stromal and SMA stains suggest a phenotypic change of CD34+ fibrocytes into myofibroblasts with progression of disease in morphea. CD34 may be a useful marker in predicting the extent of morphea.