Glomerular Disease 1 (Regner) Flashcards Preview

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Flashcards in Glomerular Disease 1 (Regner) Deck (35):
1

What are the most common etiologies of glomerular diseases?

By far, idiopathic or immune. This may be deposition of immune complexes, direct antibody action against GBM/glomerular antigens, or chronic inflammation.

2

What is meant by a "subepithelial" deposition?

Which glomerular disease is this associated with?

In the context of "subepithelial" glomerular deposition, the podocytes act as the "epithelium", deposition is just beneath them.

Subepithelial deposition is typical of membranous nephropathy ("Spike & Dome")

3

Distinguish between the descriptors of diffuse, focal, global and segmental in the context of glomerular disease.

Diffuse/focal refer to the ennumerative glomerular involvement (all or some).

Global/segmental refer to how much of a glomerulus is involved (all or some).

4

Describe the major and minor signs of nephrotic syndrome.

Major: Proteinuria (>3.5g/day), hypoalbuminemia, edema, hyperlipidemia.

Minor: Lipiduria, hypercoagulability.

5

Why are edema, hyperlipidemia, and hypercoagulability seen in nephrotic syndromes?

Edema: Loss of albumin & other proteins that contribute to plasma π.

Hyperlipidemia: Response by the liver to the "thinning" of blood.

Hypercoagulability: Loss of proteins C, S; anti-thrombin 3.

6

Describe the features seen in nephritic syndromes.

Mild proteinuria (<3.5g/day)

Hematuria (often with RBC casts and/or dysmorphic RBCs)

Hypertension

Edema

7

Which glomerular diseases tend to blur the lines between nephrotic and nephritic pathophysiologies?

Membranoproliferative GN, IgA nephropathy.

8

IgA Nephropathy

Describe its epidemiology.

What are its clinical features?

What is revealed on histology?

IgA Nephropathy

Most common GN worldwide, usually younger patients.

Prominent hematuria, with dysuria and loin pain, often synpharyngitic. Sometimes subclinical. HTN in severe cases.

Mesangial hypercellularity, granular mesangial IgA deposits.

9

IgA Nephropathy

How is it treated?

Describe its prognosis.

IgA Nephropathy

Fish oil to slow progression, ACE-I for HTN, steroids/immunosuppressants.

Prognosis is mixed, may slowly develop kidney disease/failure.

10

What is the pathophysiology of Henoch-Schonlein Purpura?

Describe its clinical presentation.

IgA deposition in multiple organs.

Skin: Non-blanching purpura in lower body.

Joint arthralgias.

GI tract: Pain, vomiting, melena/hematochezia

IgA nephropathy.

11

Post-Strep Glomerulonephritis

Describe its epidemiology.

What are its clinical features?

What is revealed on histology?

Post-Strep Glomerulonephritis

Typically affects young patients following pharyngeal or skin GAS infection.

Sudden onset hematuria, HTN, oliguria, azotemia and periorbital edema. Labs reveal low C3 and high ASO titers.

Mesangial/endocapillary proliferation with neutrophils. Granular IF deposits in mesangium & subepithelial ("hump-like")

12

Post-Strep Glomerulonephritis

How is it treated?

Describe its prognosis.

Post-Strep Glomerulonephritis

Supportive treatment only.

95% of children recover; adults don't do as well. Small progression to renal failure or RPGN.

13

What are the classic signs of a Rapidly Progressive Glomerulonephritis?

Renal failure occurring within weeks. Biopsy shows crescents comprised of fibrin and macrophages.

14

Goodpasture's Syndrome

Describe its epidemiology.

What are its clinical features?

What is revealed on histology?

Goodpasture's Syndrome

Mostly affects younger adult men.

Rapidly Progressive GNitis with pulmonary involvement (hemoptysis, pulmonary infiltrates)

Linear IgG/C3 on kidney biopsy IF.

15

Goodpasture's Syndrome

Describe its etiology.

Is there always pulmonary involvement?

How is it treated?

Goodpasture's Syndrome

Antibodies directed against GBM, probably achain of Type IV collagen.

Goodpasture's implies pulmonary involvement. If not present, this is termed "Anti-GBM disease"

Plasmapheresis, prednisone/cytoxan.

16

How does a pauci-immune GN present on histology?

What are its causes?

Pauci-immune GNs feature the crescenteric deposits that all RPGNs do, but with no deposition of immun reactants.

Sometimes idiopathic, but may be caused by ANCA vasculites.

17

How can the ANCA vasculites be distinguished from one another in the context of diagnosing a pauci-immune GNitis?

Wegener's: cANKA. Granulomas and nasopharyngeal involvement.

Churg-Strauss: pANKA. Granulomas, asthma, eosinophilia.

Microscopic Polyangiitis: pANKA. No granulomas/asthma/eosinophilia.

18

What are some other signs and symptoms of ANKA vasculites?

Which are specific to Wegener's granulomatosis?

Alveolar hemorrhage, purpura, mononeuritis multiplex.

Wegener's: Pulmonary involvement (sinusitis, nasopharyngeal lesions, hemoptysis).

19

You are suspicious of an RPGN. Histology of a kidney biopsy reveals granular fluorescence, mostly subendothelial, on IF.

What is being stained? What are some possible causes?

Granular fluorescence suggests immune complex deposition.

Causes: Post-strep GN, Lupus ("diffuse proliferative" GN).

20

Minimal Change Disease

Describe its epidemiology & associations.

What is revealed on histology?

Minimal Change Disease

Most common nephrotic syndrome of children. In adults, associated with NSAIDs, Hodgkin's lymphoma, and some other neoplasms & infections.

Normal light microscopy and IF (maybe some mesangial IgM). EM reveals podocyte foot effacement.

 

21

Minimal Change Disease

How is it treated?

Why might Hodgkin's lymphoma cause this disease?

Minimal Change Disease

Good response to steroids, though relapses may occur.

Hodgkin's lymphoma promotes cytokines which contribute to the podocyte effacement.

22

Membranous Nephropathy

Describe its epidemiology & associations.

What are its clinical features?

What is revealed on histology?

Membranous Nephropathy

Most common nephrotic syndrome of caucasians. Secondary causes include HBV/HCV, SLE, many neoplasms and drugs (eg NSAIDs, penicillamine)

Insidious onset with heavy proteinuria, sometimes HTN, azotemia, and renal vein thrombosis.

Diffuse GBM thickening. Subepithelial granular IgG deposits.

23

Membranous Nephropathy

Describe its prognosis.

How is it treated?

Membranous Nephropathy

Rule of thirds: 1/3 spontaneous recover, 1/3 are stable, 1/3 have progressive loss.

ACE-I/ARBs, maybe steroids or immunosuppressants.

24

Focal Segmental Glomerulosclerosis

Describe its epidemiology.

What are its clinical features?

What is revealed on histology?

Focal Segmental Glomerulosclerosis

Most common nephrotic syndrome in Af-Ams.

Aggressive progression; HTN, hematuria, renal failure.

Focal & Segmental Glomerular Sclerosis! Some podocyte effacement. Negative IF (no complex deposition).

25

Distinguish between primary, and secondary FSGS presentation.

What are some secondary causes of FSGS? Primary?

Primary is acute onset, secondary tends to manifest slowly.

Primary: Hereditary mutation in slit diaphragm protein.

Secondary: Drugs (eg Heroin), Infections (HIV), Sickle-cell, impaired renal function (prior injury, loss of mass)

26

Membranoproliferative Glomerulonephritis (MPGN)

What are its clinical features?

What are its secondary causes?

What is revealed on histology?

Membranoproliferative Glomerulonephritis (MPGN)

Proteinuria AND hematuria (presents as both nephrotic and nephritic). HTN, low C3 in Type II.

SLE, HBV/HCV, endocarditis, cancers, cryoglobulinemia.

LM shows proliferation of capillaries & glomeruli. Subendothelial granular C3 deposits ("Tram & Track")

27

Lupus Nephrites

What is the type of GN seen with lupus? How many classes are there?

How often to SLE patients develop glomerulonephritis?

How is it treated?

Lupus Nephrites

Diffuse Proliferative GN. 6 classes defined by nature of deposition.

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BP & lipid control. Class III, IV, V treated with steroids/cytoxan (higher risk of renal failure)

28

A kidney biopsy reveals granular deposition of immune complexes subepithelially. "Spike & Dome" comes to mind.

What race is this patient?

The microscopy is suggestive of membranous nephropathy, which is the #1 nephrotic syndrome of caucasians.

29

What glomerular disease is commonly seen in Hodgkin's lymphoma patients?

Minimal Change Disease

30

What are the secondary etiologies of the glomerular disease which most commonly affects african americans and hispanics?

The disease is Focal-Segmental Glomerulosclerosis. Secondary etiologies include HIV, Sickle-cell anemia, various tumors and drugs (NSAIDs, Heroin)

31

A patient presents with hematuria. He also is partially deaf and has a history of ocular surgeries.

Describe the etiology of the hematuria.

The disease is Alport syndrome, which results from a mutation in a Type IV collagen subunit. Usually X-linked recessive inheritance, sometimes autosomal recessive.

32

What do Wegener's Granulomatosis and Goodpasture's syndrome have in common?

How could you differentiate them (without examining the patient)?

Both can cause rapidly progressive GN.

Wegener's is pauci-immune; the biopsy will show no immunofluorescence against IgG/C3 as compared to a linear stain in Goodpasture's due to anti-GBM antibodies.

33

Which glomerular disease responds well to steroids?

Minimal change disease.

34

Why are ACE Inhibitors indicated in many nephrotic diseases?

Protein (& cellular) filtration can be reduced by relaxing the efferent arteriole, upon which AngII acts to constrict.

35

What glomerular disease is associated with cryoglobulins?

What is its most notable secondary etiology?

Membranoproliferative GN.

HCV, but also SLE, HBV, endocarditis...

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