慢性肾脏病：你需要了解的知识

Overview

Retroperitoneal fibrosis (RPF) is a rare chronic condition where excess fibrous (scar-like) tissue builds up in the retroperitoneum—the space behind your abdominal organs, including your kidneys, intestines, and major blood vessels. In many cases, RPF is linked to autoimmune activity, most commonly a condition called IgG4-related disease, where the immune system mistakenly attacks healthy tissue and triggers inflammation and scarring. Less often, RPF is idiopathic (no known cause) or linked to certain medications, infections, or abdominal cancers. If left untreated, the fibrous tissue can compress vital structures like the ureters (tubes that carry urine from the kidneys to the bladder), blood vessels, or nerves, leading to serious complications.

Signs & Symptoms

• New, persistent lower back, side, or abdominal pain (often the first symptom)
• Unexplained weight loss, fatigue, or low-grade fever
• Painful urination, blood in urine, or reduced urine output (from compressed ureters)
• Swelling in one or both legs (from compressed blood vessels)
• High blood pressure that is hard to control
• Abdominal fullness, nausea, or early satiety (feeling full after eating only a small amount)
• Numbness, tingling, or weakness in the legs (from compressed nerves)

Causes & Risk Factors

The exact cause of RPF is not fully understood, but it is strongly linked to autoimmune dysfunction. The most common identifiable cause is IgG4-related disease, an autoimmune condition where immune cells called IgG4 plasma cells accumulate in tissues and trigger inflammation and scarring. Other risk factors and potential causes include:

• Autoimmune conditions: Besides IgG4-related disease, RPF has been linked to other autoimmune disorders like systemic lupus erythematosus (SLE) and rheumatoid arthritis
• Medications: Long-term use of certain drugs, including methysergide (used for migraines) and some pain medications, has been associated with RPF
• Infections: Rarely, bacterial or fungal infections in the abdomen may trigger RPF
• Cancer: In very rare cases, RPF is a paraneoplastic syndrome, meaning it is triggered by an underlying abdominal cancer
• Age and sex: RPF most commonly affects people between 40 and 60 years old, and is 2-3 times more common in men than women

Diagnosis

Diagnosing RPF often requires a combination of tests, because early symptoms are non-specific. Your healthcare provider will start with a physical exam and medical history, then may order:

Treatment & Management

There is no cure for RPF, but treatment can effectively reduce inflammation, stop fibrosis from progressing, and prevent complications. The main goals of treatment are to relieve symptoms, preserve organ function, and avoid long-term damage. Treatment is tailored to the underlying cause of your RPF:

• Corticosteroids: These are the first-line treatment for autoimmune-related RPF (especially IgG4-related disease) to reduce inflammation and shrink fibrous tissue. You will usually start with a high dose, then gradually taper over months to years.
• Immunosuppressive medications: If steroids are not effective or cause side effects, medications like azathioprine, mycophenolate mofetil, or rituximab may be used to suppress abnormal immune activity.
• Ureteral stents or surgery: If the fibrous tissue is blocking your ureters, a thin tube (stent) may be placed to keep the ureter open, or surgery may be needed to reroute the ureter around the blocked area.
• Pain management: Over-the-counter or prescription pain medications may be recommended to manage chronic pain.
• Regular monitoring: You will need regular imaging scans and blood tests to check for disease progression and complications like kidney damage.

Living With It

RPF is a chronic condition, but most people can manage it effectively with consistent care and lifestyle adjustments. Working closely with a rheumatologist (a doctor who specializes in autoimmune conditions) and a nephrologist (a kidney specialist) if your ureters or kidneys are affected is key to long-term management.