A Prospective Study of Cyclophosphamide Treatment for Idiopathic Retroperitoneal Fibrosis (IRPF)

A Prospective Study to Evaluate the Efficacy and Safety of Cyclophosphamide in the Treatment of Idiopathic Retroperitoneal Fibrosis

This prospective, interventional, controlled study is aimed to evaluate the efficacy and safety of cyclophosphamide in the treatment of idiopathic retroperitoneal fibrosis, which refers to the chronic nonspecific inflammation of retroperitoneal fascia and adipose tissue that gradually evolves into fibroproliferative disease.

Idiopathic retroperitoneal fibrosis is a chronic disease that requires treatment for a few years. Patients with this disease respond well to glucocorticoid therapy, so you need to take glucocorticoid medication once the diagnosis is established. In addition, most patients need to use immunosuppressants when taking glucocorticoids. At present, the most commonly used immunosuppressants in the world are cyclophosphamide, azathioprine, methotrexate and mycophoranate, etc. The function of the above drugs is to improve the disorder of the immune system function, in order to restore the normal immune state, so that the inflammation and swelling of the affected organs disappear, restore the normal function. It should be emphasized that if the use of hormones and immunosuppressant is not standard or stopped too early, it can lead to disease recurrence. Therefore, after the disease is under control, long-term adherence to medication is needed to maintain a stable state of the disease. At present, there is no clear treatment guideline for idiopathic retroperitoneal fibrosis in the world, and the addition of immunosuppressant is also out of debate. Therefore, a comprehensive evaluation of its pathogenesis, clinical characteristics and treatment response is needed.

Through the selective depletion of proliferating lymphocytes, cyclophosphamide has an inhibitory effect on both humoral and cellular immunity. Cyclophosphamide 50mg per day for 6 months and decrease to 50mg Qod for 6 months.

Prednisone/prednisolone: started at 0.6-0. 8mg/kg.d for 2 to 4 weeks, tapered at 5mg per 1-2 weeks before 15mg per day, and tapered at 2.5-5mg per 2 weeks to equal to or less than 5mg per day in 6 months.

Prednisone/prednisolone: started at 0.6-0. 8mg/kg.d for 2 to 4 weeks, tapered at 5mg per 1-2 weeks before 15mg per day, and tapered at 2.5-5mg per 2 weeks to equal to or less than 5mg per day in 6 months. Cyclophosphamide 50mg per day for 6 months and decrease to 50mg Qod for 6 months.

Steroids have fast onset of action and multiple anti-inflammatory effects. Prednisone/prednisolone: started at 0.6-0. 8mg/kg.d for 2 to 4 weeks, tapered at 5mg per 1-2 weeks before 15mg per day, and tapered at 2.5-5mg per 2 weeks to equal to or less than 5mg per day in 6 months.

Patients achieve remission in symptoms and laboratory tets or radiologic images and have a low diseae activity after treatment.

Patients have a recurrence of symptoms or laboratory abnormalities and have a considerable diseae activity after achieving remission.

Inclusion Criteria: age 18-75 diagnosed as IRPF. The diagnosis of idiopathic retroperitoneal fibrosis is based on the following aspects :(1) the swelling of retroperitoneal tissue , which seems neoplastic; (2) A large number of lymphocytes proliferated and infiltrated in the affected tissues and organs, and tissues showed inflammation, fibrosis and sclerosis, in which IgG4-positive cells accounted for less than 50% of plasma cells; (3) Increased inflammatory markers, such as ESR and CRP; (4) Good response to glucocorticoid therapy. Exclusion Criteria: malignancy retroperitoneal fibrosis secondary to other diseases or drugs or abdominal surgeries.

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