Systemic Lupus Erythematosis (SLE)

1. Class I – normal kidney
2. Class II –Minimal/Mesangial Lupus Nephritis
• Earliest and mildest form of renal involvement
• Characterized by mesangial deposits of Ig and C3
• Proteinuria and hematuria present
• Nephrotic syndrome and renal insufficiency are very uncommon
• EM – IC deposits in mesangium
• IF – appears similar to IgA
3. Class IIA – mesangial proliferative change
4. Class IIB – no proliferative change

5. Class III – Focal proliferative Lupus Nephritis

• Proliferative changes present in <50%>
• ALL glomeruli have immune deposits of IgG, IgA, C3, and often IgM and fibrin-related Ags – seen on IF
• Mainly mesangial deposits with occasional subendothelial deposits (seen on EM – most reliable predictor of progression)
• All patients show proteinuria, but nephrotic syndrome and renal insufficiency are rare
• Hypocomplementemia more severe
• Long-term prognosis is good, but there is a high incidence of transformation to class IV

6. Class IV – Diffuse Proliferative Lupus Nephritis

• Most common and most severe form
• Proliferation seen in >50% of glomeruli, with crescent formation and necrosis common
• Extensive mesangial and subendothelial deposits
• Nephrotic range proteinuria
• Renal function decreased in 75% of patients at presentation
• Hypocomplementemia, high levels of anti-DNA Ab, and circulating Igs present in most patients
• Long-term survival rate is ~75% past five years
• Best prognosis is with those who show remission of nephrotic syndrome and normalization of serologic parameters achieved w/in 1 year of starting therapy

7. Class V

• Occurs in ~15% of SLE patients – hard to distinguish from idiopathic MN on LM
• IF – all sorts of Ig – contrast to idiopathic MN
• EM – other deposit sites in addition to those normally associated w/ MN
• May have undetectable levels of anti-DNA Ab at presentation
• Long-term prognosis about the same as with II (good)

Category: Pathology Notes