Nephritic syndrome

Question 1

What is nephritic syndrome ?

Answer 1

It is caused by damage to glomerular basement membrane causing hematuria and RBC cast in urine.

Question 2

What is the presentation of nephritic syndrome induced renal failure ?

Answer 2

• Oliguria
• Arterial HTN due to Na+ retention.
• peripheral and periorbital oedema due to increased hydrostatic pressure.

Question 3

What are the laboratory findings in nephritic syndrome ?

Answer 3

• increased BUN and Creatinine.
• Hematuria
• Proteine urea
• RBC cast in urine.

Question 4

What is the protein urea threshold in nephritic syndrome ?

Answer 4

< 3.5 g/ day. In severe cases it may exceed > 3.5 gm.

Question 5

What are the steps to identify the cause of nephritic syndrome ?

Answer 5

• A careful Hx and kidney biopsy.

Question 6

What are the type III HSRs that can cause nephritic syndrome ?

Answer 6

• PSGN
• IgA nephropathy
• Diffuse proliferative glomerulonephritis

Question 7

What are the multiple potential ethologies of nephritic syndrome ?

Answer 7

• Membranoproliferative glomerulonephritis
• Rapidly progressive glomerulonephritis.

Question 8

What is the genetic cause of nephritic syndrome ?

Answer 8

Alport syndrome caused by defect in collagen synthesis.

Question 9

what is the pathophysiology of PSGN ?

Answer 9

It is typically occurs in children after 3 to 4 weeks of streptococcal infection. Strep M-protein mediated IgG-IgM immune complex deposition within the glomerular basement membrane. This will trigger C3 mediated inflammation leading to the release of cytokines, oxidants and proteases causing podocyte destruction.

Question 10

What are the lab findings in PSGN?

Answer 10

• positive strep titers.
• reduced serum C3.

Question 11

What is the PSGN immunohistochemistry appearance ?

Answer 11

Stary sky appearance due to the deposition of IgG, IgM and C3 along the GBM and Mesangium.

Question 12

What is the electron microscopic finding in PSGN ?

Answer 12

Humps of subepithelial deposits.

Question 13

What are the light microscopic findings in PSGN ?

Answer 13

Glomerular hypertrophy and hypercellularity.

Question 14

What is the prognosis of PSGN ?

Answer 14

• It spontaneously resolves in children.
• In adults it can sometimes progress to renal failure.

Question 15

What is IgA nephropathy or Berger’s disease ?

Answer 15

The immune system incorrectly detects IgA released by the GI pear patches or respiratory IgA
releasing cells during local infections as pathogenic antigen and releases IgG leading to IgA -IgG immune complex deposition in the glomerular mesangium. This causes complement mediated glomerular injury.

Question 16

What are the microscopic findings in IgA nephropathy ?

Answer 16

Mesangial proliferation.

Question 17

What is the difference b/w Berger’s disease and Henoch-Schonlein- purpura ( IgA vasculatis) ?

Answer 17

IgA nephritis is localised to the kidney. Whereas in HSP there is coliky abdominal pain, desentery, arthritis and vasculitic nodular palpable skin lesions.

Question 18

What is DPGN ?

Answer 18

It is an immune complex mediated called lupus nephritis class IV in which > 50% of glomeruli bilaterally affected . The immune complexes consist of Anti-ds-DNA and C3 deposits in the subendothelial space.

Question 19

What is the light microscopy appearance of DPGN ?

Answer 19

Wire loop appearance due to overall thickening of the capillary wall.

Question 20

What is membrano-proliferative glomerulo-nephritis ?

Answer 20

There are three types of MPGN they all cause proliferation of glomerular mesangial and endothelial cells.

Question 21

What is type 01 MPGN ?

Answer 21

It is the most common form of MPGN. It can be idiopathic or secondary to HBV or HCV infection.

Question 22

What is the pathophysiology of type 01 MPGN ?

Answer 22

It is a type III HSR caused by immune complex deposition formed by the HBV or HCV antigen and immune antibodies. These immune complexes also cause the activation of classical complement pathway leading to complement deposition in the subendothelium. In addition there is also inappropriate activation of alternate pathway by the nephritic factor which converts C3 to C3a and C3b. This process is maintained by the IgG antibodies stabilizing C3 convertes. This will lead to low serum C3.

Question 23

What is the cause of tram track appearance of GBM in MPGN type 01 ?

Answer 23

It is due to the mesangial cell interpositioning

Question 24

What is type 02 MPGN also known as dense deposit disease ?

Answer 24

It is caused by nephritic factor, but no immune complex formation involved in it. In type II MPGN the nephritic factor stabilizes C3 convertase enzyme which leads to persistent conversion of C3 to C3a and C3b. However, in contrast to type I MPGN in Type II MPGN the complement deposition happens within the GBM instead of subendothelium.

Question 25

What are lab and microscopic findings in MPGN 1 and II?

Answer 25

Low C3 and Tram-track pattern of GBM.

Question 26

What is RPGN ?

Answer 26

This can be triggered by Type II or III HSR with or without immune complex deposition. It can be ideopathic or secondary such as progression of PSGN or DPGN to RPGN, Good pasture disease, and Pauci vasculaitis. In RPGN the glomerular inflammation causes breakdown of the GBM leading to rapidly progressive renal failure.

Question 27

What is Good-pasture disease associated RPGN ?

Answer 27

It is a type II HSR caused by anti-GBM antibodies inducing complement mediated destruction of the alpha 3 chain of type 04 collagen in the GBM and glomerular capillary endothelium. A similar anti-GBM mediated endothelial destruction also happens in the lung which presents as hemoptysis.

Question 28

What is Pauci immune vasculitis ?

Answer 28

It is a type III HSR and is called pauci immune vasculitis because there is little or no Anti-GBM anti-bodies or immune complexes and the vasculitic syndromes are Wegner’s disease and microscopic polyangitis.

Question 29

What is granulomatosis with polyangitis ( Wegner’s granulomatosis ?

Answer 29

It is an C-ANCA associated vasculitis presents with noncaciating granulmoas, URT symptoms such as chronic sinusitis, mastoiditis, ottitis media and perforation of the nasal septum. LRT symptoms is hemoptysis and the renal symptom is glomerulonephritis.

Question 30

What is the symptomatological difference b/w Wegner and good pasture ?

Answer 30

In good pasture there is no URT symptoms.

Question 31

What is the difference between Wegner and microscopic polyangitis ?

Answer 31

Absence of URT symptoms and granulomas in microscopic polyangitis. But presence of p-ANCA. It is precipitated by medications such as abx penicilin.

Question 32

What is the cause of crescent moon shaped epithelial layer of bowmann’s capsule in RPGN?

Answer 32

The desiccation of GBM causes large plasma content to move to the bowman’s space this causes monocyte mediated inflammation leading to the hypertrophy of bowman’s space eptihilium which has a crescent moon configuration.

Question 33

What is the Tx of good pasture disease ?

Answer 33

Plasmapharesis

Question 34

What is Alport syndrome

Answer 34

It is caused by genetic mutation of the gene responsible for making type IV collagen leading to thinning of GBM. In addition to glomerulonephritis, the patients also develops hearing lose and lense dislocation during late childhood.

Question 35

What is the electron microscopic finding in Alport syndrome ?

Answer 35

It will show a basket weave appearance of GBM due to the concurrent presence of thinning and thickenning of the GBM.