We agree with Drs. Vaglio, Greco, and Buzio that standardized classification criteria for RPF are lacking. However, our own experience and interpretation of the literature led us to believe that, in a subset of patients with presumed idiopathic disease, the condition is actually a local complication of advanced atherosclerosis (1). The higher incidence of symptomatic atherosclerotic disease in men may also explain the increased incidence of RPF in men. Some researchers even suggest that the future of this disorder lies in the prevention and treatment of atherosclerosis (2). Consequently, the proposed term chronic periaortitis (encompassing patients with and without aortic aneurysm) (3) seems more appropriate in these particular patients, who have what we consider to be a secondary form of RPF. However, in pediatric patients or adult patients without mild atherosclerotic disease in whom no other etiologic factor can be identified, true idiopathic disease may be present. We deliberately included all patients with RPF except those who needed immunosuppressive treatment or had concurrent malignancy. This was done to assess the efficacy of tamoxifen therapy in patients with RPF regardless of the possible underlying cause. Our failure to observe an improvement of renal function over time may reflect the relatively low frequency of severe renal failure at presentation, but it also reflects the presence of preexisting chronic renal failure caused by nephrosclerosis or diabetic nephropathy in several patients. In addition, long-standing obstructive nephropathy may result in irreversible renal damage.

Of note, short-term improvement of renal function may simply reflect renal drainage (for example, after ureteral stenting). We agree that RPF has a chronic relapsing course and that we do not yet have data on the long-term efficacy of tamoxifen therapy. However, our encouraging results with tamoxifen therapy may be particularly relevant for patients with chronic periaortitis. Corticosteroid therapy may be hazardous in these patients with established vascular disease because it accelerates the atherosclerotic process and increases the risk of cardiovascular morbidity and death (4). Conversely, more data now suggest that tamoxifen therapy may have significant cardioprotective effects (5). In our study, we also observed a decrease in serum cholesterol levels following initiation of tamoxifen therapy. Therefore, we suggest serious consideration of tamoxifen as first-line treatment in patients with chronic periaortitis and in other patients with RPF for whom long-term corticosteroid therapy is (relatively) contraindicated.