Dear Hiroyuki Wakiguchi,

SLN probably present an early stage in the natural history of LN with lowered CIC and increased CH50 and C3 serum levels when compared with OLN. This is a possible reason why in these patients immune deposits can be detected only by IF (not with light microscopy). Most SLN patients show changes compatible with Class I or II of WHO LN histopathological classification with small renal histological lesions and without clinical abnormalities.. Only about 40% of unselected patients with SLE have abnormalities in the urine or in renal function early in their course.

Hope that helps!

Dear Nemanja Zdravkovic,

Thank you for your valuable comments.

What about the Class III or IV in SLN?

Do they also present the early stage in the natural history of LN?

I appreciate all your help.

Dear Hiroyuki Wakiguchi,,

Please read this articale to be able to notice that some cases of SLN involve proliferative GN such as ISN/ RPS class III or IV, with renal dysfunction progressing over the long term in some cases.

It can be helpful!

Dear Nemanja Zdravkovic,

I appreciate the 2 papers you suggested.

However, these papers showed biomarkers, but not precise pathophysiology of SLN.

As you know, the frequency of Class III/IV in SLN, is unexpectedly high in SLE patients.

Why do some patients with Class III/IV LN have normal urine?

What is the differences of pathophysiology between SLN and OLN, especially, in Class III/IV?

Thank you for your assistance.

Article Treatable renal disease in children with silent lupus nephri...

Dear Hiroyuki Wakiguchi,

We know that LN is not a static entity and it has a high capacity of transformation from one histological Class to another. ISN/RPS classification is not perfect classification and we can supposed that will be modify throw the time. It shows histological stage in SLE kidney involvement in this moment of our knowledge. I tried to explain that some cases of SLN class III or IV with renal dysfunction progressing over the long term in some cases. One study showed that in the long-term observations of SLN, abnormal urinalysis results were observed in 22 of the 211 (10.4%) patients during a mean observation period of 51 months, with 5 patients eventually developing end-stage renal failure. Another study reported abnormal urinalysis results and/or renal impairment in 25.8% of SLN patients at a mean duration of 58 months after renal biopsy. SLN probably present an early stage in the natural history of LN. Biomarkers represent pathophysiology on disease. The serum levels of CIC and C3 can reflect these effects on kidney if we are know they functions. 

There are different subsets of lupus nephritis, well described in any medical textbook. Some are mild, e.g., mesangial and then more severe subtypes, e.g., DPGN; there is also tubulo-interstitial disease, etc. The milder forms of LN often have negative urine findings, 

Dear Nemanja Zdravkovic,

Thank you for your valuable comments.

On the other hand, what is the differences of histopathology between SLN and OLN in Class III/IV nephritis?

I appreciate all your help.

Dear Prof. Gonzalez,

I understand what you mean.

In addition, Class III/IV nephritis in silent LN are severe forms but these have negative urine findings.

I believe that the presence or absence of urinary findings does not show severity of LN.

Thank you for your assistance.

Dear Hiroyuki Wakiguchi,

According to ISN/RPS classification we can observe Class III/IV in SLN on the other hand Class II in OLN. Obviously, ISN/RPS classification dominantly presents histological stage which does not precisely define urinary findings.

Dear Nemanja Zdravkovic,

Right.

What about the differences of glomerular filtration barrier impairment: size or charge selectivity between SLN and OLN in Class III/IV nephritis?

Thank you for your kind cooperation.

Usually, severe forms of lupus nephritis, e.g., DPGN would present with an active urine sediment, with the presence of red cell casts, and proteinuria; often, these patients are also hypertensive, and may have an increased serum creatinine. Pure membranous lupus nephritis would present with significant proteinuria and nephrotic syndrome, however, with a normal serum creatinine. Mixed forms like membrano-proliferative lupus nephritis would have nephrotic and nephritic components, and the urine findings would likely be abnormal in most if not all cases. For the precise histopathologic findings, including the latest WHO classification, including electron microscopy, you may want to consult a pathology book, 

Dear Prof. Gonzalez,

Sure.

I know the membranous LN is associated with abnormal urine.

The point I would like to know the reason why some patients with DPGN have normal urine.

Do you know the pathology book described the histopathologic findings of silent LN with DPGN?

I appreciate all your help.

Dear Dr. Hiroyuki Wakiguchi, I am not a pathologist; however, would recommend any traditional pathology textbook such as Robbins, for example. Also, if you can, I would contact a renal pathologist and discuss with him/her your interest in learning more about the specific findings in lupus nephritis, 

Dear Prof. Gonzalez,

Thank you for your reply.

I'll consult the book of Robbins and Cotran Pathologic Basis of Disease.

Also, I hope to discuss the pathological findings of silent LN with renal pathologists.

Thank you for your kindness.

My best wishes,

Best wishes, too

Very interesting question too and discussion which I will gladly continue to follow!

Thank you for your good wishes.

Nice question. Following.