If everything went according to plan, this post was automatically sent shortly after Mom and I arrived in the Chicago area to attend the familial amyloidosis meeting. If I have time I will post one or more updates this weekend. Otherwise I will certainly post my synopsis of the meeting next week.
Today's article under review is not actually an article, but it was in the correspondence section of a medical journal.
Title: Hereditary fibrinogen A alpha-chain amyloidosis (1)
Authors: Stephen W. Lane, Hugh J. Goodman, Leo Francis, Andrew Bofinger, Peter N. Mollee (Princess Alexandra Hospital, University of Queensland; Royal Brisbane and Women's Hospital Brisbane, Queensland, Australia; National Amyloidosis Centre, London, UK)
Journal: Pathology - The Journal of the Royal College of Pathologists of Australasia (2006)
Here is a link to the article (not free) if you would like to follow along: http://journals.lww.com/pathologyrcpa/Citation/2006/38040/Hereditary_fibrinogen_A_alpha_chain_amyloidosis.24.aspx
This article describes what the authors believe is the first case of a patient being diagnosed with fibrinogen amyloidosis in Australia. A 62-year-old man presented in 2004 with sacral oedema, hypertension and proteinuria. Eventually a kidney biopsy was done which showed deposits in the glomeruli that stained positive with Congo red. Various tests were done to determine if he had primary amyloidosis, but when those all came back negative his doctors asked for assistance from the National Amyloidosis Centre in the United Kingdom. They confirmed the amyloid deposits in the glomeruli, and some additional analysis of the biopsy material showed slightly stronger staining for fibrinogen. Genetic testing showed the Glu526Val mutation in this patient.
The article then gives a short description of the various types of amyloidosis, followed by a paragraph about fibrinogen amyloidosis and how it compares to some of the other hereditary types. Fibrinogen amyloidosis is somewhat unique due to the fact the kidneys are typically the only organ affected, especially in the early stages of the disease. For instance, amyloidosis caused by transthyretin mutations (ATTR) typically does not involve the kidneys, and amyloidosis caused by apolipoprotein A-I or lysozyme mutations may involve the kidneys but usually something else is clinically significant.
The article then discusses some of the challenges involved in determining the amyloid type from tissue biopsies, and includes this statement about fibrinogen in particular: "In AFib amyloidosis, the staining of deposits with antifibrinogen antibody is usually positive but with varying intensity and is dependent on specimen preparation and the specific mutation involved."
After providing some general guidelines on how to diagnose AL amyloidosis vs. a familial type, there is a paragraph about treatment for fibrinogen amyloidosis. They mention kidney transplants, with the caveat that renal failure often occurs within 5 to 7 years as a result of amyloid deposition in the transplanted kidney. The article mentions combined liver-kidney transplants but considers that an experimental therapy at this point, since there is no direct evidence of a survival advantage over just a kidney transplant.
In this article we have another patient who presents with the typical symptoms of fibrinogen amyloidosis, and then a kidney biopsy shows amyloid deposits in the glomeruli. Compared to some patients in previous articles, this patient was very fortunate to be properly diagnosed due to some good work by his doctors. First, it was good work to diagnose him with any type of amyloidosis in the first place. Then they did the right thing by not treating him with chemotherapy for AL amyloidosis, since that does more harm than good. Unfortunately he would not have been the first patient with a familial type of amyloidosis to receive chemotherapy because the doctors thought he had AL amyloidosis.
One topic the article mentions that I don't think I have discussed before is whether or not fibrinogen amyloidosis can be determined from a kidney biopsy. As the article mentions, there are specific stains which will illuminate fibrinogen, but the intensity varies and it is dependent on preparation of the specimen. There are some future articles that discuss this in much greater detail, including the newer techniques that go beyond simply staining.
Next up will hopefully be a report from the Windy City.
(1) Lane SW, Goodman HJ, Francis L, Bofinger A, Mollee PN. Hereditary fibrinogen A alpha‐chain amyloidosis. Pathology - Journal of the RCPA. 2006;38(4):380-382 310.1080/00313020600820823.