Background: Renal AA amyloidosis is a rare but severe complication of crohn's disease (CD), with high prognostic impact, even more important than the underlying disease itself.
Methods: We described the cases of 3 patients with renal AA amyloidosis associated with CD.
Results: Case 1: A 29-year-old patient had a paucisymptomatic stricturing ileal CD with ankylosing spondylitis, followed for 9 years and treated by salazopyrin. A severe hypoalbuminemia was discovered, with a limited ileal disease and without exsudative enteropathy, a nephrotic syndrome (NS) was diagnosed. Labial and rectal biopsies were performed but negative, the diagnosis of amyloidosis was confirmed on a percutaneous renal biopsy. The patient was put on colchicine and anticoagulants seeing the sever hypoalbuminemia. He is now stable on both digestive and renal plans.
Case 2: A 48-year-old patient has been followed for 12 years for an ileal penetrating CD, inaugurated by an appendicular plastron, operated, then put on azathioprine. During follow-up, we noticed ascites and renal feet oedema, a NS was diagnosed. A renal amyloidosis was confirmed on labial biopsy. Creatinine clearance was 14ml/min. The patient was put on Colchicine and anticoagulants seeing the major hypoalbuminemia. The evolution was marked by the occurrence of an intra-abdominal abcess in the right iliac fossa, treated by antibiotics and exclusive parenteral nutrition during 21 days. On the renal plan, there was a worsening of the renal function with a creatinine clearance of 11ml/min, despite the treatment by azathioprine. The patient underwent hemodialysis but was deceased after 15 days.
Case 3: A 41-year-old patient has been followed for 22 years for an ileal penetrating CD, inaugurated by an enterocutaneous fistula and a right psoas abscess, operated twice; then put on azathioprine, but the patient did not take the treatment. After 12 years, a NS was diagnosed, it was associated with renal failure. A renal AA amyloidosis was confirmed by a labial biopsy. On the digestive plan, the patient had a stricture of the ileo-colonic anastomosis, with an extensive inflammatory stenosis of the terminal ileon. According to nephrologists, the treatment of amyloidosis is based on treating the underlying disease. The patient has been put on Infliximab therapy seeing the multiplicity of post-operative recurrence risk factors. A further follow-up is needed to evaluate the renal response to anti-TNF therapy.
Conclusions: In CD, amyloidosis is a rare complication, predominant in men with ileal and penetrating disease. It usually manifests in a nephrotic syndrome with renal failure. Its treatment is based on colchicine and the underlying disease must be controlled, so the progression of both diseases could be prevented. New therapies are still in study and under evaluation.