Glomerular diseases Flashcards
What does “segmental” vs “global” mean
segmental is only a portion of the glomerulus is involved
global is the entire glomerulus is involved
What does “focal” vs “diffuse” mean
Focal is some of the glomeruli are involved
Diffuse is all (or most) of the glomeruli are involved
What are the 3 parts of the filtration membrane
- Capillary endothelium
- Basement membrane
- Podocytes of glomerular capsule
What are the functions of the kidney
control water balance in the body control RBC production control blood actidity filter blood and pass waste into bladder control blood pressure
What are adult protein levels
average normal physiologic: 80 mg/day
pathologic proteinuria: >150 mg/day
What is the smallest plasma protein
albumin; makes up 20-40% of physiologic proteinuria
It is filtered more than other plasma proteins, so you’re more likely to get “microalbuminuria” before you reach “proteinuria”
What is Microalbuminuria
excretion of 30-300mg albumin/day
Macroalbuminuria is >300mg/day
What is nephrotic range proteinuria
daily excretion >3.5g protein per day
What is the MCC of pathologic proteinuria
Glomerular disease: altered permeability= injury of all 3 levels of filtration membrane
first to leak out is albumin, then other proteins
Other pathologic causes of proteinuria include
Overflow proteinuria: overproduction of small proteins overwhelms reabsorption in the proximal tubule
Tubular proteinuria: tubulointerstitial dz causes decreased ability of proximal tubule to reabsorb proteins
How are glomerular diseases categorized
Nephrotic vs Nephritic
Primary vs Secondary
All glomerular diseases cause
glomerular damage
hypoalbuminemia (low if blood because excess excreted)
What is the gold standard definitive dx for glomerular diseases
Biopsy!
What is Nephritic syndrome
There is an immune response in the capillaries leading to glomerular damage= blood cells pass through
What are possible findings in nephritic syndrome
Edema (LE>UE) Hematuria (coca cola) Granular casts WBC in urine Proteinuria (<3.5g=subnephrotic) HTN (2/2 NA retention and no filtration) Azotemia High creatinine Oliguria (low urine output, glomerulus cant filter as much) Periorbital edema pale puffy face swollen lips
What is rapidly progressive glomerulonephritis
severe injury to capillary wall, basement membrane, and bowmans capsule
*very severe, occurs at the end of the “Nephritic syndrome” spectrum and causes renal failure in weeks-months
What are the primary causes of Nephritic Syndromes
post infectious GMN IgA nephropathy Henoch-Schonlein purpura Pauci-immune glomerulonephritis Good Pasteur's
What is post-infectious GMN
immune mediated glomerular injury due to GABHS (pyogenes)
-immune complexes w/ strep antigens deposited 1-3 weeks after a strep infection
What are findings in P.I. GMN
oliguria
edema (protein cant stay in the capillary so fluid leaks out)
HTN
**coca cola urine
Lab findings in P.I. GMN are
UA- RBC, red cell casts, and proteinuria
-ASO titers high (unless they took abx)
What is the prognosis of P.I. GMN
in kids, good
in adults, not so great- can lead to RPGN or CKD
How do you treat P.I. GMN
Supportive! anti-HTN, salt restriction, diuretics prn
Steroids do NOT improve outcome
What is the MC glomerular disease world-wide
IgA nephropathy/ Berger’s disease
What occurs in IgA nephropathy
IgA deposits in the glomerular mesangium cause an inflammatory response
MC: kids/young adult, M>W
What are is your classic symptom of IgA nephropathy
coca cola urine 1-3 days after a URI or GI infection
What will IgA nephropathy labs show
hematuria
proteinuria
high IgA but normal complement levels
What is the prognosis of IgA nephropathy
1/3 remit spontaneously
20-40% develop CKD
rest have chronic microscopic hematuria and stable SrCr for life
What is the most favorable prognostic indicator in IgA nephropathy
Proteinuria <1g/day
How can you treat IgA nephropathy
If proteinuria 1-3.5g: STEROIDS
If higher: ACE/ARB
What is target BP in IgA nephropathy
<130/80
What is Henoch-Schonlein purpura
IgA deposits in vessel walls causing systemic small vessel vasculitis (similar to IgA nephropathy)
MC in kids with inciting infection, like group A strep
How does Henoch-Schonlein present symptomatically
palpable purpura in LE and buttocks
Arthralgias
abdominal Sx (nausea, colic, melena)
low GFR
How do you treat Henoch-Schonlein purpura
plasma exchange
DMARDS (anti-rheumatic drug)
What is Pauci-immune GMN
Associated with small vessel vasculitides (Wegener’s granulomatosis, Churg-Strauss, microscopic polyangiitis)
What are symptoms of Pauci-immune GMN
fever malaise weight loss purpura -If w/ Wegener's, nodular lesions and respiratory tract Sx
What do Pauci-immune GMN labs show
ANCA antibodies
hematuria
proteinuria
How do you treat Pauci-immune GMN
high dose steroids
DMARDS (rheum)
What is the prognosis of Pauci-immune GMN
with Tx: 75% complee remission
w/o Tx: poor prognosis
What is Good Pasteur’s syndrome
Basement membrane injury 2/2 anti-GBM antibodies (usually s/p URI) leading to Glomerulonephritis + pulmonary hemorrhage
-peak 2-3 or 6-7 decade
What are Sx of Good Pasteur’s syndrome
hemoptysis
dyspnea
RPGN
What will Good Pasteur’s diagnostics show
labs: anti-GBM antibodies- hemosiderin macrophages in sputum
CXR: pulmonary infiltrate
How do you treat Good Pasteur’s
- Plasma exchange (remove abs)
- Immunosuppressive drugs (steroids, DMARDS) s new abs dont form, and decrease inflammaiton
What is Nephrotic syndrome
Increased basement membrane permeability causing protein to leak out
What components are essential in diagnosing Nephrotic syndrome
Proteinuria >3.5g/d Hypoalbuminemia (<3g) bland urinary sediment (+/- oval fat bodies) Peripheral edema HLD
What are Sx of Nephrotic syndrome
**Peripheral edema
dyspnea (pulm. edema, pleural effusion, diaphragm compromise form ascites)
When does peripheral edema develop
when serum albumin <2g
Na retention 2/2 renal disease
What will Nephrotic Syndrome look like on UA
Proteinuria (few cellular elements or casts microscopically)
Oval fat bodies 2/2 HLD
What will Nephrotic syndrome blood panel show
Hypoalbuminemia (<3g)
Hypoproteinemia (<6g)
HLD (liver compensates for low albumin by making lipids)
low Vit. D, zinc, and copper
When can protein malnutrition occur
when urinary protein loss >10 g/d
How do you treat Nephrotic syndrome
- increase diet protein
- salt restrict/thiazides/loops (edema)
- diet and exercise, aggressive statins (HLD)
- Anticoags if with renal vein thrombosis, PE, or recurrent thromboemboli
Why are patients with Nephrotic syndrome hypercoagulable
Because one of the things that leaks out is AT-III (anti-thrombin III), as well as protein C and S
without these, you are more prone to clot
What are secondary causes of Nephrotic syndrome
Minimal change disease
membranous nephropathy
focal segmental glomerulosclerosis
What is Minimal change disease
increased glomerular permeability due to foot processes thinning out
Who is minimal change disease mostly seen in
kids! 80% of proteinuria in kids
in kids, M>F
in adults, M=W
How do you treat Minimal change disease
oral steroids w/ prolonged taper (adults up to 16 wks)
-likely relapse after stopping steroids, but rarely progress to ESRD
Most complications from minimal change disease arise from
long term steroid therapy!
What is the MCC of primary nephrotic syndrome in adults
Membranous nephropathy- an idiopathic immune mediated glomerulonephropathy causing immune complexes to deposit into capillary walls= increased permeability
How does membranous nephropathy present
edema frothy urine (from protein) venous thromboemboli (low AT-III, pro C&S)
How do you treat membranous nephropathy
ACE/ARB to decrease urine protein (if BP >125/75)
What is the prognosis of membranous glomerulonephropathy
if subnephrotic, good
if nephrotic, 30% recover spontaneously- the rest need steroids + 6 months of conservative care if w/ renal failure
What is focal segmental glomerulosclerosis
podocyte injury leads to increased permeability
Sx is proteinuria (and nephrotic syndrome Sx)
What causes FSGS
primary renal dz: idiopathic, or genetic alterations in africans
secondary: obesity, HTN, HIV, analgesic/biphosphate exposure, or chronic urinary reflux
How do you treat FSGS
Diuretics
Statins
ACE/ARB
If it’s a primary cause: steroids w/ 16 week taper
