Monday, May 30, 2016

Article Review (2013) - Fibrinogen A alpha-chain amyloidosis: Report of the first case in Latin America

Today's post will be a quick update on me, then the article review, and then the monthly blog stats.

Regarding my anemia, I had a small bowel follow through exam on May 11. That is a procedure in which the patient drinks a barium solution (after fasting at least 8 hours), and then a series of x-rays are taken to follow the solution through the stomach and small intestines, looking for any signs of leakage. The doctor's office contacted me two weeks later and said no abnormalities were found, so the next test they will schedule is a capsule endoscopy. You can expect a blog post about that in June or July.

On to the article review, in which fibrinogen amyloidosis makes an appearance on yet another continent.

Title: Fibrinogen A alpha-chain amyloidosis: Report of the first case in Latin America (1)

Authors: Juliana Reis Machado, Marcos Vinícius da Silva, Precil Diego Miranda de Menezes Neves, Flavia Aparecida de Oliveira, Rosana Rosa Miranda Corrêa, Willians Vinícius Dutra Rodrigues, Merril Benson, and Marlene Antônia dos Reis (Brazil and USA)

Journal: Amyloid (March 2013)

Here is a link to the PDF file (not public) if you would like to follow along:

Background: Hereditary fibrinogen A alpha-chain (AFib) amyloidosis affects different organs, especially the kidneys. No case of this disease has been reported in Latin America.
Case report: A 52-year-old previously healthy Brazilian woman presented with a seven-month history of proteinuria in the absence of hematuria. The patient had normal blood pressure and reported no other symptoms. A renal biopsy was obtained and light microscopy revealed the presence of Congo red positive deposits (apple-green birefringence under polarized light) only in the glomerular compartment. These deposits were strongly immunoreactive to fibrinogen in all glomeruli. Electron microscopy showed the presence of organized deposits compatible with AFib. The diagnosis was confirmed by DNA analysis of the AFib gene, which demonstrated a Glu526Val mutation in one allele.
Conclusion: This first description of hereditary AFib amyloidosis in Latin America highlights the need to include this type of amyloidosis in the differential diagnosis, especially in Brazil where the degree of miscegenation is high.

After a brief introductory paragraph providing some basic information on the different types of amyloidosis, this specific case is described. The patient was a 52-year-old previously healthy Brazilian woman who presented with proteinuria in 2006. There was no family history of kidney disease. In 2009 a 24-hour urine collection showed 2 grams of protein, which increased to 3.7 grams seven months later. There were no other urinary symptoms and her blood pressure was normal.

After ruling out some of the more common kidney diseases (glomerulopathies), a kidney biopsy was performed. The article gives a very detailed description of the biopsy results, some of which I will summarize here:

  • Various stains were used, with Congo Red indicating the presence of amyloid.
  • Most glomeruli had large amyloid deposits.
  • Immunofluorescence was positive for fibrinogen.

Based on the biopsy results they made the diagnosis of fibrinogen amyloidosis That diagnosis was confirmed by DNA analysis which showed the patient had the Glu526Val mutation.The last thing mentioned about the patient is that she still has proteinuria without edema, and her blood pressure and renal function are still normal.

The discussion section of the article goes into some more detail about the various types of hereditary amyloidosis, and states that ATTR and gelsolin types have been previously reported in Brazil. Some background on fibrinogen amyloidosis and where it has been reported is then provided, followed by a few sentences regarding organ transplant as a treatment option. The article concludes by stating that this type of amyloidosis needs to be included in the differential diagnosis, especially in Brazil where the degree of miscegenation (mixed-race sexual relations) is high.


There are a couple of interesting things about this case I want to mention. The initial presentation of proteinuria is very common among AFib patients, but what I find really unusual is that this patient still had normal kidney function at the time this article was written. Given the publication date of 2013, we can assume the article was written in 2012, perhaps 2011 at the earliest. So five years or more after the initial presentation with proteinuria, the patient still only had proteinuria with presumably normal creatinine and GFR levels. That is a very slow progression compared to other reported cases.

The other interesting thing about this case is that the biopsy results gave a rather clear indication of fibrinogen amyloidosis. We know that usually is not the case unless mass spectrometry is used, so this patient is very fortunate the pathologists did a thorough job analyzing the biopsy with immunofluorescence. We have to wonder how many cases of AFib have gone undiagnosed or misdiagnosed in Brazil.

There have now been published reports of fibrinogen amyloidosis cases in North and South America, several European countries, Asia, and Australia. I do not think there have been any published reports of an AFib patient in Africa, although I do know of one patient in Africa (with English heritage) as of the writing of this blog post. So it is safe to say that fibrinogen amyloidosis has now been diagnosed in at least one person living on each continent with permanent human inhabitants.

=====Monthly Blog Status Update=====

As of April 30, 2016:

Total posts: 166 (1 in April)

Total pageviews: 39,700 (~1200 in April)

Email subscribers: 14 (unchanged)

Total number of countries that have viewed the blog: 116

Three new countries viewed the blog in April:

Netherlands Antilles


(1) Machado JR, Silva MV, Neves PD, et al. Fibrinogen A alpha-chain amyloidosis: report of the first case in Latin America.Amyloid. 2013;20(1):52-55.

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