Nephrogenic systemic fibrosis is associated with transforming growth factor β and Smad without evidence of renin-angiotensin system involvement

• DOI: 10.1016/j.jaad.2008.02.038
• Publication Date: 2008-05-16T17:05:34Z
• Authors: Brent Kelly; Matthew Petitt; Ramon Sanchez
• Keywords: Nephrogenic Systemic Fibrosis

The mechanisms of fibrosis associated with nephrogenic systemic fibrosis (NSF) are largely unknown. Transforming growth factor beta (TGF-beta), a known profibrotic cytokine, is theorized to play a central role. The renin-angiotensin system has been linked with both TGF-beta expression and fibrosis in other organ systems.We sought to investigate whether these mechanisms were involved with NSF.Eleven biopsy specimens from 8 patients with NSF were evaluated by immunohistochemistry for the expression of TGF-beta, Smad 2/3, angiotensin-converting enzyme (ACE), and angiotensin II receptor 1 (AT1).TGF-beta was detected in 8 of 11 samples of NSF. Smad 2/3 nuclear staining was seen in 8 of 11 samples. Conversely, only faint staining for ACE was seen in 2 of the 11 specimens. No AT1 staining was seen.We did not perform our studies on a cohort of comparable patients with renal dysfunction without NSF. Our technique may not have been sufficiently sensitive to detect renin-angiotensin system involvement.TGF-beta, as well as its second messengers, Smad 2/3, appears to be associated with the fibrosis seen in NSF. No definitive evidence of renin-angiotensin system involvement could be determined.