Monday, January 19, 2009

Differential Diagnosis of Fibrillary Glomerulopathies

The finding of fibrils on electron microscopy of a renal biopsy specimen may be an extremely important clue in establishing the diagnosis.  In fact, for many of the conditions listed below, the diagnosis may be based PURELY on a detailed ultrastructural characterization of the fibril, as in fibrillary or immunotactoid glomerulopathy.  

The first step in the differential diagnosis of fibrillary glomerulopathies is to divide the condition into an IMMUNOGLOBULIN-MEDIATED versus a NON-IMMUNOGLOBULIN MEDIATED process, which is typically done by immunofluorescent staining against different heavy and light chain classes.

IMMUNOGLOBULIN-MEDIATED fibrillary glomerulopathies include:
-AL amyloidosis.
-MIDD (monoclonal immunoglobulin deposition disease).
-type 2 cryoglobulinemia.
-immunotactoid glomerulopathy (see picture)
-fibrillary glomerulopathy.

NON-IMMUNOGLOBULIN-MEDIATED fibrillary glomerulopathies include:
-AA amyloidosis.
-fibronectin glomerulopathy.
-diabetic fibrillary glomerulopathy.
(note:  the latter two on this list are pretty rare).

Another crucial distinction here is whether the biopsy specimen stains negative or positive for CONGO RED (indicating the beta-pleating sheet structure of precipitated amyloid protein).  


Barb0355 said...

I am 59 years old and have been just diagnosed with fibillary kidney disease. My doctor told me it is very rare and not much is known about it. He told me in 6 months to a year, he will put me on the list for a transplant. He told me it may be genetic and that I have had it for a long time, but no one picked up on it. I have many medical problems which may be related to it. Is there anyone else out there who has the same thing and can give me some information on it?

Anonymous said...

I came across this article while trying to find out if fibrillary glomerulopathy is associated with septic shock. I developed proteinuria about three months after septic shock from a perforated colon.It has continued at about the same level for about 18 months. However, I also have CLL, which has never required treatment. My recent renal biopsy showed fibrillary gomerulopathy. My nephrologist says that is associated with CLL. However, she did not say if it is also associated with septic shock. I am a 66-year-old male living out in the middle of the ocean on Maui and I am concerned that the doctors here may never have seen a case like this. Would someone please tell me if fibrillary glomerulopathy is associated with septic shock? Please reply to Thank you.

LeslieO. said...

I too have been diagnosed with fibrillary glomerulopathy. I was wondering what type of treatments you have undergone for this condition. I am now on predisone & have shown no improvement. Is a transplant the only option?

LeslieO. said...

I would appreciate any information anyone with this condition. I forgot to leave my e-mail address. It is

Anonymous said...

In m a 57 year old male who has been diagnosed with FG through a kidney biopsy. My doctor had be do a bone marrow and it was determined that I have CLL. It has been established that the CLL (Chronic Lymphocytic Leukemia) is causing the "deposits" called B cell light chains in my kidney. I am on a chemo program combining Retuxmab and Bendamustine (Treanda) to eliminate the leukemia and subsequently "arrest" further damage to the kidneys. This path was recommended by the Cleveland Clinic. Questions??