Retroperitoneal fibrosis (RPF) patients at a large hospital in Japan
A recent Japanese study looked at 49 patients with RPF (Ando, 2023). This is what they found.
Why is this important?
Retroperitoneal fibrosis (RPF) is a rare condition in which there is fibrous tissue (scarring) in the retroperitoneal space, which is located behind the abdomen (tummy), in front of the spine. The scar tissue in the retroperitoneum can compress the ureters (tubes that carry urine from the kidneys to the bladder) causing AKI, CKD or AKI on CKD. In other words it is an (albeit rare) cause of obstructive nephropathy.
CT scan showing RPF (arrowed) around the aorta and vena cava. There is hydronephrosis (blockage) of the ureters blocking the flow of urine from the kidneys.
What did the study show?
The researchers analysed 49 patients with RPF at their hospital. 78% were male. 76% had ‘idiopathic’ RPF (unknown cause) and 24% had secondary RPF (cause is known). Among the idiopathic patients, 54% had an autoimmune condition called ‘IgG4-RD’.
Patients presented with abdominal and low back pain, and/or constitutional symptoms including generalised fatigue and fever. The idiopathic patients were more likely to have higher levels of antibodies called IgG4 and IgG in the blood, and lower complement (C3; another component of the immune system) levels, compared to secondary RPF.
The IgG4-RPF patients were likely to have higher blood IgG4 levels, and lower serum C-reactive protein and ferritin (both markers of whole body inflammation), and lower C3 levels – compared to the idiopathic RPF patients without IgG4-RD.
How does this affect you?
Unless you have RPF it does not. But if you do, the study shows there is underlying whole-body inflammation and over-activity of the immune system in the disease. And regular blood tests are required to monitor inflammation and the immune system.
Other resources
The treatment of RPF has been reviewed in this paper: Tanaka, 2020.
Also, CKDEx has more information on retroperitoneal fibrosis.
Last Reviewed on 10 November 2023