Abstract: Provided are Adenosine Deaminase (ADA), or a polypeptides or peptides having an ADA activity, or an ADA conjugate, pharmaceutical compositions and formulations, products of manufacture and kits, and methods containing them for the prevention and treatment of a scleroderma-associated vasculopathy, in particular proliferative obliterative vasculopathy, progressive obliterative vasculopathy or an idiopathic obliterative vasculopathy and/or preventing or decreasing the progression of scleroderma, wherein optionally the scleroderma comprises a local scleroderma or a diffuse, or a systemic scleroderma.