Diseases of nephron Flashcards
What is normal pH?
7.4
What is the systemic approach to determining acid base issues?
Look at pH Determine primary disorder Calculate expected compensation calculate anion gap review change in HCO3- and change in AGAP (delta/delta)
What is the equation for determining compensated pCO2 for metabolic acidosis?
pCO2=1.5*[HCO3-]+8
What is the equation for determining compensation for pCO2 in metabolic alkalosis?
pCO2=0.9*[HCO3-]+9
What is pCO2 and [HCO3-] at normal pH?
40mmHg pCO2
24 mmol/L HCO3-
Urine flow is equal to what?
Urine volume/time of collection
What equation is for renal clearance?
(Ux*UF)/Px
How do you measure renal excretion
X=Ux*UF
What is the presentation of Apparent Mineralcorticoid Excess?
low birth weight failure to thrive severe HTN organ damage Renal failure
w/ HTN hypokalemia metabolic alkalosis low plasma renin low plasma aldosterone
similar to primary aldosteronism
How do you diagnose AME?
measure urine cortisol to cortisone ratio
gene sequencing of 11Beta-HDS2
AR inheritence
What is the pathogenesis of AME?
11-BetaHSD mutation leading to lack of conversionof cortisol to cortisone
What is Liddle syndrome and clinical picture of it?
pseudoaldosteronism
Clinical picture: HTN hypokalemia metabolic alkalosis low plasma renin activity low plasma aldosterone and urinary aldosterone
What is the diagnosis of liddle syndrome?
gene sequencing of SCNN1g and SCNN1B along with clinical picture
What is the pathogenesis?
mutation in the renal epithelial sodium channel leading to constituitive expression
gain of function mutation
What is the cellular ultrastructure and tranport characteristics of principal cells of late distal tubule and cortical collecting duct?
reabsorbs Na and secretes K
regulated by aldosterone
water permeability regulated by ADH
reabsorption of sodium and secretion of potassium blocked by K sparing diuretics
How do you treat apparent mineralcorticoid excess?
therapy to reduce endogenous cortisol production -amiloride -triamterene block mineral corticoid receptor -spironolactone -eplerenone potassium repletion dexamethasone for ACTH suppression poor prognosis
How do you treat LIddle syndrome?
agents that decrease sodium channel activity
-amiloride
-triamterene
with treatment prognosis is good
What is Bartter syndrome presentation?
early childhood growth and mental retardation
polyuria and polydipsia
hypercalciuria
What is Gitelman syndrome presentation?
adolescence/adulthood cramping of arms and legs fatigue hypomagnesemia polyuria and nocturia
What is the clinical picture?
hypokalemia
hyperreninemia
hyperaldosteronism
metabolic alkalosis
What is bartter syndrome?
mutations in genes that encode proteins in ascending part of henle’s loop
tubular defect mimic chronic loop diuretic ingestion
poor prognosis
What is Gitelman syndrome?
mutation in SLC12A3 gene
tubular defect mimic chronic thiazide ingestions
prognosis is good with tx
What is nephrotic syndrome?
proteinuria>3.5 g/day hypoalbuminemia edema -loss of plasma oncotic pressure vs. Na/H2O retention hyperlipidemia -increased hepatic protien production
lipiduria
hypercoagulability
-loss of proteins C and S
What is nephritis?
mild proteinuria hematuria -RBCs and RBC casts HTN Edema
What causes acute glomerulonephritis?
IgA nephropathy Post-infectious GN Anti-GBM disease/Goodpasture's Small vessel vasculitis Lupus nephritis membranoproliferative GN
What is the most common glomerulonephritis worldwide?
IgA Nephropathy
What are the clinical features of IgA nephropathy?
50-60% episodic gross hematuria
30% presistent microhematuria
proteinuria, if present, is generally mild
Dysuria and loin pain
hematuria occurs in cojunction with URI
What are the histologies associated with IgA nephropathy
LM: variable mesangial hypercellularity
IF: mesangial IgA deposition
EM: mesangial electron dense deposits
How is IgA nephropathy treated?
progonosis based on creatinine and proteinuria
fish oil may slow progression
ACE-inhibitor controls BP
corticosteroids, other immunosuppressants also may be used in progressive disease
What is henoch-Schonlein purpura?
systemic disorder characterized by IgA deposition
- skin
- joints
- GI tract
- hematuria
What is post-strep GN?
sudden onset HTN, azotemia, oliguria, edema and tea colored urine
labs:
low C3 complement level
anti-streptolysin O can be elevated
urinalysis: red blood cell castts, mild proteinuria
What are the histology features of post-strep GN?
LM: enlarged, hypercellular glomeruli. DIffuse mesangial endocapillary proliferation with neutrophils
IF: granular capillary wall and mesangial
EM: mesangial and large subepitheila hump like depoists
What causes rapidly progressive GN?
anti-GBM/Goodpastures Immune complex GN -lupus nephritis -post-infectious -cryoglobulinemia ANCA associated GN (Pauci immune)
What is the syndrome associated with anti-GBM/GOodpastures?
hemoptysis pulmonary infiltrates glomerulonephritis -GN alone in anti-GBM disease due to circulating anti-GBM antibody
What is the diagnosis of anti-GBM/Goodpastures?
anti-GBM antibody in blood
linear IgG and C3 on kidney biopsy IF
What is the treatment of anti-GBM/Goodpasture?
plasmapheresis
prednisone
cytoxan
What is the syndrome associated with pauci GN?
crescenteric GN with little deposition of immune reactants
idiopathic or associated with antineutrophil cytoplasmic antibody vasculitis
What are the three small vessel vasculitis?
microscopic polyangiitis
wegners
churg-strauss
How do you diagnose wegneners granulomatosis in kidney problems?
renal biopsy, c-ANCA
What primary renal diseasses cause nephrotic syndrome?
membrane nephropathy
focal segmental glomerulosclerosis
minimal change disease
What is the primary cause of nephrotic syndrome in children?
80% will ahve minimal change disease
What are the secondary causes of nephrotic syndrome?
systemic diseases-DM, SLE, amyloidosis
infections-HIV, Hep B, Hep C, syphilis
drugs-NSAIDS, gold, penicillamine
What is the treatment for all causes of nephrotic syndrome?
Ace inhibitor or angiotensin-II blcoker
lipid lowering therapy
diuretics, slat restriciton to improve edema
What is minimal change disease associated with in adults?
drugs-NSAIDs
neoplasma esp Hodgkins lymphoma
infections-symphilis or HIV
What are the histology/morphology of minimal change disease?
all but EM normal, EM reveals podocyte foot pocess efacement and fusion
What is the treatment for minimal change disease?
corticosteroids
What is the most common cause of nephrotic syndrome in caucasion adults?
membranous nephropathy
What are secondary causes of membranous nephropathy?
HBV
SLE
neplasms, pretty much all of them
drugs
What is the presentation of membranous nephropathy?
onset insiduous
present with heavy proteinuria and nephrotic syndrome
What is the morphology/histology of membranous nephropathy?
diffuse thickening of GBM, GBM spikes on silver stain
What is the most common cause of idiopathic nephrotic syndrome in african-americans?
focal segmental glomerulosclerosis idiopathic
What are common causes of focal segmental glomerulosclerosis?
NSAIDs HIV** massive obesity healed previous glomerular injury loss of funciton renal mass
What is the focal segmental glomerulosclerosis morphology/histology?
focal and segmental glomerular sclerosis with capillary collaspe
podocyte foot process effacement
What is the clinical syndrome associated with membranoproliferative glomerulonephritis?
proteinuria and hematuria
HTN in 1/3
low C3
variable clinical presentation
What is the common cause of membranoproliferative glomerulonephritis secondarily?
SLE
HCV**
cyroglobulinemia
neoplasms
What is the morphology of membranoproliferative glomerulonephritis?
hypercellular glomeruli, endocapilary cell proliferation
granular C3 deposition
