Diffuse Proliferative GN vs Membranous Nephropathy

[Photonic]

Quick question,

I just did a qbank question where I had to differentiate diffuse proliferative GN from membranous GN. The patient had SLE, granular immunofluorescence, and 4.2g urine protein. I thought it would be membranous GN since it was nephrotic but the answer was diffuse proliferative GN. The explanation said it was because you can see wire looping in the immunofluorescence image.

If I'm right, wire looping is just a thickening and inflammation of the capillaries and should be seen in light microscopy of both conditions right?

Also, membranous nephropathy should additionally have basement membrane thickening. Basement membrane thickening can't be distinguished from capillary thickening on a typical light micrograph right?

Thanks in advanced for any answers. Figuring this out would really help me get a better understanding of this topic.

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[Foot Fetish]

Quick question,

I just did a qbank question where I had to differentiate diffuse proliferative GN from membranous GN. The patient had SLE, granular immunofluorescence, and 4.2g urine protein. I thought it would be membranous GN since it was nephrotic but the answer was diffuse proliferative GN. The explanation said it was because you can see wire looping in the immunofluorescence image.

If I'm right, wire looping is just a thickening and inflammation of the capillaries and should be seen in light microscopy of both conditions right?

Also, membranous nephropathy should additionally have basement membrane thickening. Basement membrane thickening can't be distinguished from capillary thickening on a typical light micrograph right?

Thanks in advanced for any answers. Figuring this out would really help me get a better understanding of this topic.

Personally, I would have just answered that question via "buzzword association." I just know that DPGN is associated w/ SLE. I don't know why, but it just is. I know that's not a helpful response...hopefully someone else can weigh in.

 

[iBS1972]

As Foot Fetish has said, this is pretty much a "buzzword association" question. Wire-looping=SLE. Period.
SLE is not a distinguinishing factor in this case because membranous GN is the most common nephrotic syndrome due to SLE, while DPGN is the most common nephritic syndrome due to SLE. Also, granular IF suggests DPGN over membranous GN (which would be "spikes and dome").

 

[Photonic]

Thanks for the responses. You guys are right I probably should have just thought SLE+granular IF = DPGN. What threw me off was that the patient was nephrotic + SLE + granular IF. I usually think SLE+nephrotic = MGN and SLE+nephritic = DPGN. Also, the explanation said the differentiating factor was that there was wiring looping in the IF image (they did not say "wire looping" in the question only gave me an image). When I look at micrographs of MGN and DPGN they both look like they have wire looping.

 

[iBS1972]

I thought the exact same as you. Looking at FA, DPGN is a nephritic-nephrotic syndrome, along with membranoproliferative GN. Just something to keep in mind.

 

[Ven0m]

Sorry for necro, but does anyone know how to differentiate "wire-looping of DPGN
from "diffuse capillary wall thickening of MN" by only looking at a light microscopy? Wondering because they look the same and are both common renal manifestations of SLE.

 

[Anon_]

Sorry for necro, but does anyone know how to differentiate "wire-looping of DPGN
from "diffuse capillary wall thickening of MN" by only looking at a light microscopy? Wondering because they look the same and are both common renal manifestations of SLE.

I had the same question as you did, and Figure 1 in this article may help: Th Subset Balance in Lupus Nephritis

It suggests looking for hypercellularity, which is in Diffuse Proliferative GN but not Membranous GN.

 

[Ven0m]

It suggests looking for hypercellularity, which is in Diffuse Proliferative GN but not Membranous GN.

that's actually a good point thanks