title: Serum Soluble CD163 and its association with various disease parameters in patients with systemic sclerosis.
abstract: OBJECTIVE
  Cluster of differentiation 163 (CD163) is a receptor that binds haptoglobin-hemoglobin complexes and is mainly expressed on macrophages and monocytes. As a result of shedding, the extracellular portion of CD163 circulates in the blood as a soluble CD163 (sCD163). This study aimed to measure serum sCD163 levels in patients with systemic sclerosis (SSc) and to assess its association with the clinical, laboratory, and radiological features of the disease.
  
  
  METHODS
  We measured serum sCD163 levels in 24 patients with SSc and in 30 healthy controls. Complete history of the patients was recorded and thorough clinical, rheumatological, and dermatological examinations were performed. For SSc, the skin thickness score was scored according to the modified Rodnan skin score method and pulmonary involvement was assessed in all patients using high-resolution computed tomography and by performing pulmonary function tests.
  
  
  RESULTS
  The mean serum sCD163 levels in patients with diffuse and limited SSc (61.64±19.57 and 60.8±21.43 ng/mL, respectively) demonstrated a highly statistically significant increase compared with the mean serum levels in healthy controls (36.97±16.37 ng/mL) (p<0.001). Patients with SSc having elevated serum sCD163 levels had significantly higher pulmonary artery systolic pressure (PASP) than those with normal serum sCD163 levels (p<0.05). Furthermore, the serum sCD163 levels were significantly correlated with PASP (r=0.53, p<0.05) in patients with SSc. The mean serum sCD163 level in patients with SSc having digital ulceration (DU) (70.82±18.3 ng/mL) demonstrated a statistically significant increase (p<0.05) compared with that in SSC patients without DU (53.23±18.09 ng/mL).
  
  
  CONCLUSIONS
  The elevated serum sCD163 levels in patients with SSc and its association with pulmonary hypertension suggest a possible role of macrophages in the pathogenesis and vascular involvement of SSc.
authors.affiliation: Department of Rheumatology and Rehabilitation, Benha University School of Medicine, Qalubiya, Egypt.
authors.forename: Waleed Ahmed Salah Eldeen
authors.initials: WA
authors.lastname: Hassan
authors.affiliation: Department of Rheumatology and Rehabilitation, Benha University School of Medicine, Qalubiya, Egypt.
authors.forename: Eman Abd Elaleem
authors.initials: EA
authors.lastname: Baraka
authors.affiliation: Department of Rheumatology and Rehabilitation, Benha University School of Medicine, Qalubiya, Egypt.
authors.forename: Basant Mohammed
authors.initials: BM
authors.lastname: Elnady
authors.affiliation: Department of Chest, Benha University School of Medicine, Qalubiya, Egypt.
authors.forename: Tahany Mahmoud
authors.initials: TM
authors.lastname: Gouda
authors.affiliation: Department of Microbiology and Immunology, Benha University School of Medicine, Qalubiya, Egypt.
authors.forename: Nehad
authors.initials: N
authors.lastname: Fouad
keywords: Systemic sclerosis; macrophages; modified Rodnan skin score; soluble CD 163