20 - Glomerular Disease 2

Question 1

minimal change disease etiology/pathogenesis

Answer 1

etiology unknown
thought to involve T cell derived circulating permeability factor that directly damages podocytes and permeability barrier

Question 2

who gets minimal change disease?

Answer 2

children (most common nephrotic syndrome in children)
adults in 5th-6th decade

males > females

Question 3

presentation of minimal change disease

Answer 3

nephrotic syndrome
sudden onset proteinuria and edema
otherwise nl renal function
HTN and hematuria UNcommon

Question 4

minimal change disease lab findings

Answer 4

hypoalbuminemia, nl complement

Question 5

minimal change disease biopsy findings

Answer 5

LM - nl glomeruli
EM - podocyte foot process effacement/fusion
IF - negative

Question 6

focal segmental glomerulosclerosis etiology/pathogenesis

Answer 6

primary idiopathic cases due to circulating factor (SuPAR) that directly injures podocytes

Question 7

who gets focal segmental glomerulosclerosis?

Answer 7

young adults
also can be seen in kids w/ minimal change disease that relapses

more common in african americans

people w/ HIV, obesity, heroin use

Question 8

presentation of focal segmental glomerulosclerosis

Answer 8

nephrotic syndrome

may have HTN, renal failure or microhematuria

Question 9

focal segmental glomerulosclerosis lab findings

Answer 9

hypoalbuminemia

nl complement levels

Question 10

focal segmental glomerulosclerosis biopsy findings

Answer 10

LM - focal sclerosis (duh), only part of glomerulus affected (segmental)
EM - podocyte foot process effacement/fusion
IF - negative

Question 11

membranous nephropathy etiology/pathogenesis

Answer 11

autoimmune - ab directed against phospholipase A2 receptor on podocytes
immune complex deposition and complement activation

Question 12

who gets membranous nephropathy?

Answer 12

MCC idiopathic nephrotic syndrome in adults (5th-6th decades peak)
males > females
most idiopathic, but some assoc w/ cancer (lung, breast, GI), hep B, SLE

Question 13

clinical presentation of membranous nephropathy

Answer 13

nephrotic syndrome

HTN and renal failure UNcommon

Question 14

membranous nephropathy lab findings

Answer 14

hypoalbuminemia
nl complement
check for assoc conditions (hep, ANA, cancer)

Question 15

membranous nephropathy biopsy findings

Answer 15

LM - thickening of glomerular BM
EM - subepithelial immune deposits
IF - granular deposits of Ig and complement along BM

Question 16

membranoproliferative GN etiology/pathogenesis

Answer 16

immune mediated glomerular injury
trapping circulating immune complexes > complement activation
circulating “nephritic factor” spontaneously activates complement on capillary wall

Question 17

who gets membranoproliferative GN?

Answer 17

any age
female > male
often assoc w/ hep C**, other infections, SLE, cryoglobulinemia

Question 18

presentation of membranoproliferative GN

Answer 18

nephrotic syndrome
many also have nephritic syndrome
HTN (often early)

Question 19

membranoproliferative GN lab findings

Answer 19

low complement

if assoc w/ HCV - cryoglobulins, rheumatoid factor

Question 20

membranoproliferative GN biopsy findings

Answer 20

LM - thickening of glomerular BM, glomerular cell prolif (usually mesangial)
EM - subendothelial immune deposits
IF - subendothelial pattern of C3 and IgG

Question 21

postinfectious GN etiology/pathogenesis

Answer 21

usually after group A strep infxn

circulating immune complexes from response to infxn lodge in glomeruli > activate complement

Question 22

how long does it take to get postinfectious GN?

Answer 22

14-21 d after infxn (sooner for throat than skin)

Question 23

presentation of postinfectious GN

Answer 23

nephritic syndrome
edema, sudden weight gain in children
HTN - often severe
renal failure common

Question 24

postinfectious GN lab findings

Answer 24

pos ASO titer, pos streptozyme

low complement levels

Question 25

postinfectious GN biopsy findings

Answer 25

LM - diffuse prolif and inflam EM - subepitheial "humps" IF - lumpy-bumpy IgG and C3 deposits

Question 26

IgA nephropathy etiology/pathogenesis

Answer 26

immune mediated - IgA containing complexes | deposit in mesangium

Question 27

who gets IgA nephropathy?

Answer 27

``` MCC primary glomeulonephritis young adults asians and caucasians > blacks male > female may have simultaneous pharyngitic or GI viral infxn ```

Question 28

presentation of IgA nephropathy

Answer 28

asymptomatic hematuria, nonnephrotic proteinuria, nl or mildly reduced renal fn rarely, will be much more severe

Question 29

IgA nephropathy lab findings

Answer 29

inc serum IgA in 50% | nl complement

Question 30

IgA nephropathy biopsy findings

Answer 30

LM - mesangial cell prolif and matrix expansion EM - mesangial deposits IF - globular mesagial IgA deposits

Question 31

Anti-GBM nephritis etiology/pathogenesis

Answer 31

ab against type 4 collagen in glomerular BM | may be accompanied by pulm hemorrhage (Goodpasture's syndrome)

Question 32

who gets Anti-GBM nephritis?

Answer 32

young adults male > female assoc w/ autoimmune disorders (goodpasture, ANCA assoc vasculitis)

Question 33

presentation of Anti-GBM nephritis

Answer 33

rapidly progressive glomerulonephritis w/ crescent formation

Question 34

Anti-GBM nephritis lab findings

Answer 34

pos anti-GBM ab | nl complements

Question 35

Anti-GBM nephritis biopsy findings

Answer 35

LM - crescent formation EM - breaks in glomerular BM, no deposits IF - linear IgG deposits along BM