Dear Gayle and any other interested readers,

I find it interesting that labs are still using immunofluorescence for the
evaluation of renal biopsies considering the alternatives that have been
available for some time. Immunocytochemical methods are routinely applied to
renal biopsy tissue to determine the presence/or absence of immune complexes
(IgG, IgA, IgM etc), complement components (usually C3c and/C1q) and
fibrinogen (I feel that immuno methods applied to transplant biopsies rather
useless unless there is an occurrence (based on clinical features such as
proteinuria etc) of the patient's original disease. In acute medical
situations (apart from transplants) the diagnosis and subsequent treatment
is determined largely by the immuno results ie linear glomerular basement
membrane staining with IgG would indicate a very serious disease process
whereas a negative result should instigate a series of other tests to find a
working diagnosis. Only in very acute cases involving macroscopic haematuria
and haemoptysis is frozen section immunofluorescence indicated only because
frozen section immunofluorescence is quick to perform.

Puncturing someone's kidney to remove biopsy tissue is serious business and
optimal utilization of the tissue obtained should be the priority in any
laboratory. From my point of view, to obtain a meaningful diagnosis, far
more useful information from the tissue may be aquired from serial sections
of paraffin embedded tissue. These sections may be stained with H+E,
trichromes, silver nitrate, and elastin stains which demonstrate the degree
of inflammation, scarring, acute necrotizing lesions, vascular legions etc
and for transplant biopsies demonstrate the features of interstitial or
vascular rejection -- not to mention cyclosporin toxicity changes.

Further sections (or intermitent sections) may be used for immuno staining
(in my case I would use a direct, peroxidase conjugated antibody method for
IgA, IgG, IgM, fibrinogen and complement) taking just over 90 min to
perform. This results in a permanent record with no need for time consuming
photography. This method of dealing with renal tissue does not require
freezing of specimens or expensive and time consuming fluorescence
microscopy setups. I feel that immunofluorecence for diagnostic renal
pathology is past its use by date and alternative, permanent
immunocytochemical methods should be applied to this valuable tissue.

Ian Birchall
Melbourne, Australia.


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