Nephrotic syndrome
Nephrotic syndrome is a constellation of clinical findings seen in a number of medical kidney diseases. This article deals with them. An introduction to the medical kidney is in the medical kidney diseases article.
In children nephrotic syndrome is assumed to be minimal change disease. Biopsies are done only there is no response to steriods.
Clinical definition
Features:
- Anasarca (whole body - edema).
- Proteinuria (>3.5 g/24h).
- Hypercholesterolemia.
- Hypoalbuminemia.
Overview
Immune complex negative:
Immune complex positive:
Specific entities
Minimal change disease
- Abbreviated MCD.
General
- Responds to steroids.
- Most common cause of nephrotic syndrome in children.
- Onset rapid when compared to FSGS.
- Proteinuria usually higher in FSGS.
Microscopic
Features:
- No changes on light microscopy.
EM
Features:
- Diffuse loss of foot processes.
Note:
- Foot processes on urinary space side.
Image:
Focal segmental glomerulosclerosis
- Abbreviated FSGS.
General
- Presents as nephrotic syndrome.
- Does not respond to steroids (unlike MCD).
Etiology
| Feature | Primary | Secondary |
| Proteinuria (onset) | sudden | progressive |
| Albumnin | low | normal |
| Glomerulus size | normal | increased |
| Foot process effacement | diffuse | mild |
Notes:
- Primary FSGS needs ~70-80% foot process effacement.[3]
Microscopic
Features:
- Partial sclerosis of less than 50% of glomeruli.
- +/-Adhesions between the glomerular tuft and Bowman's capsule.
Image:
Histologic classification
FSGS can be subdivided into the following subgroups:[5]
| Subtype | Comment |
|---|---|
| Cellular | abrupt severe onset |
| Collapsing | poor prognosis, viral/toxic etiology |
| Tip lesion | good prognosis |
| Perihilar | reduced renal mass |
| Not otherwise specified (NOS) | most common |
Stains
Features:[6]
- PAS +ve crescents.
IF
- No immune deposits.
- No IgG.
- No IgA.
Note:
- IgM, C3 - may be focally positive due to trapping.
EM
- Foot process loss.
- Secondary causes tend to have a thinner foot process width.
Membranous nephropathy
- AKA membranous glomerulonephritis.
- Abbreviated MN.
General
- Presents as nephrotic syndrome.
- Variable course.
Clinical DDx:[7]
- Hepatitis B.
- Hepatitis C.
- Carcinoma.
- NSAID toxicity.
- SLE.
- Idiopathic.
Microscopic
Features:
- Subepithelial immune complex depositions:
- Spikes or pinholes - seen on silver stain.
- +/-Tram-tracking.
- Advanced lesions.
Image:
IF
- Diffuse granular capillary loop - IgG, C3, kappa, lambda.
EM
- Diffuse subepithelial deposits - spike forming.
See also
References
- ↑ Sánchez de la Nieta MD, Arias LF, Alcázar R, et al. (2003). "[Familial focal and segmentary hyalinosis]" (in Spanish; Castilian). Nefrologia 23 (2): 172–6. PMID 12778884.
- ↑ URL: http://www.kidneypathology.com/English_version/Focal_segmental_GS.html. Accessed on: 11 February 2011.
- ↑ 3.0 3.1 D'Agati, V. (Mar 2003). "Pathologic classification of focal segmental glomerulosclerosis.". Semin Nephrol 23 (2): 117-34. doi:10.1053/snep.2003.50012. PMID 12704572.
Cite error: Invalid
<ref>tag; name "pmid12704572" defined multiple times with different content - ↑ Noël, LH. (1999). "Morphological features of primary focal and segmental glomerulosclerosis.". Nephrol Dial Transplant 14 Suppl 3: 53-7. PMID 10382983.
- ↑ Thomas, DB.; Franceschini, N.; Hogan, SL.; Ten Holder, S.; Jennette, CE.; Falk, RJ.; Jennette, JC. (Mar 2006). "Clinical and pathologic characteristics of focal segmental glomerulosclerosis pathologic variants.". Kidney Int 69 (5): 920-6. doi:10.1038/sj.ki.5000160. PMID 16518352.
- ↑ URL: http://www.kidneypathology.com/English_version/Focal_segmental_GS.html. Accessed on: 11 February 2011.
- ↑ Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 241. ISBN 978-1416002741.