Renal Flashcards
Where is horseshoe kidney normally found? Why?
- Lower abdomen
- Gets stuck on IMA as it ascends from pelvis
What is dysplastic kidney?
- Non inherited, congenital malformation of renal parenchyma
- With cysts and abnormal tissue eg: cartilage
Ddx with bilateral dysplastic kidney?
Inherited PKD “Polycystic kidney disease”
What is PKD?
“Polycystic kidney disease”
- Inherited defect of bilaterally enlarged kidneys
- Cysts in renal cortex and medulla
Associations with recessive PKD?
- Hepatic fibrosis and cysts: portal HTN
Presentation of ARPKD?
- Infantile presentation with HTN and worsening renal failure
- Potter’s sequence
- Hepatic fibrosis and cysts
ADPKD associations?
- Berry aneurysm
- Hepatic cysts
- Mitral valve prolapse
Presentation ADPKD?
Adults with HTN, hematuria, and renal failure
- Cysts in brain, heart, and liver
What is medullary cystic kidney disease?
- Inherited AD defect
- Cysts in medullary collecting ducts
- Parenchymal fibrosis = shrunken kidneys with renal failure
What is hallmark of acute renal failure?
- Azotemia: increased nitrogenous waste products
2. Oliguria
What are the renal parameters indicative of prerenal failure?
- BUN:CR > 15
2. FeNa 500 (tubular function still in tact)
What is normal BUN:Cr?
15
Why does BUN:Cr increase in prerenal failure?
- Low blood flow increases renin / aldosterone
- Aldosterone increase Na / H2O absorption
- Bun follows water and Na out of tubules
What is normal FENa and urine osmolality?
FENa: 500
Difference between ST / LT post renal azotemia?
ST: tubular function preserved to FENa and OSM normal and BUN:CR increases as bun pushed back
LT = tubular damage: FENA > 2%, osm
What is most common cause of ARF?
- ATN
What happens in ATN?
- Injury and necrosis of tubular epithelial cells
- Necrotic cells plug tubules decreasing GFR
- Brown casts will be seen in urine
What are brown casts in urine indicative of?
ATN
Urine parameters in ATN?
- BUN:CR 2%
3. Urine OSM
2 etiologies of ATN?
- Ischemic: preceded by prerenal azotemia
2. Nephrotoxic
Which part of kidney most susceptible to ischemic ATN?
- Proximal tubule
2. Medullary segment thick ascending limb
Part of kidney most affected in toxic ATN?
Proximal tubule
Causes of toxic ATN?
- Aminoglycosides
- Heave metals
- Myoglobinuria: crush injury
- Ethylene glycol: antifreeze
- Radiocontrast dye
- Urate: tumor lysis syndrome
How to prevent tumor lysis syndrome?
- Hydrate patient
- Allopurinol to prevent formation of uric acid
Prognosis of ATN?
- Damage is reversible but often requires dialysis due to deadly electrolyte imbalances that can ensue
- Oliguria persists for 2 - 3 weeks
What is acute interstitial nephritis?
- Drug induced HSR of interstitium and tubules
- Causes ARF
What can cause AIN?
- NSAIDs
- PCN
- Diuretics
Presentation of AIN?
- Rash
- Fever
- Oliguria
- EOSs in urine
* **Days to weeks after drug
What are eosinophils in urine indicative of?
AIN
What can AIN progress to?
Renal papillary necrosis
Presentation of renal papillary necrosis?
- Flank pain
2. Gross hematuria
Causes of AIN?
- Chronic analgesic use
- TIIDM
- Sickle cell
- Severe pyelonephritis
Presentation of nephrotic syndrome? and why are they occurring?
- Proteinuria > 3.5 g / day
- HYPOalbuminemia = edema
- HYPOgammaglobulinemia = increased risk infx
- Hypercoagulable state = loss of ATIII
- Hyper lipids and cholesterol = liver drops fat to counteract thin blood
Most common cause of nephrotic syndrome in kids? Cause?
- MCD
- Usually idiopathic but can be associated with hodgkin lymphoma
What do the podocytes sit on?
Epithelial layer
What is happening in MCD?
- Flattening of podocyte foot processes from production of cytokines
MCD on imaging?
HE: normal
EM: podocyte foot effacement
IF: negative as no IC involved
Proteinuria characteristics in MCD?
- Selective with loss of albumin but no loss of immunoglobulin
Rx for MCD?
- Great response to steroids
- Makes sense as caused by cytokines
3 layers of filtration barrier?
- Endothelial layer: next to vessels
- Basement membrane
- Epithelial layers: podocytes
Who is FSGS common in?
- Hispanics
2. Blacks
What can cause FSGS?
- Idiopathic
- HIV
- Heroin
- Sickle cell disease
Imagine of FSGS?
HE: Focal / segmental pink sclerosis
EM: effacement of foot processes
IF: negative
What does MCD progress to?
FSGS if they do not respond to steroids
Prognosis of FSGS?
- Poor response to steroids with progression to chronic renal failure
What are the nephrotic syndromes?
- MCD
- FSGS
- Membranous nephropathy
- Membranoproliferative glomerulonephritis
- TIIDM
- Amyloidosis
Most common cause of nephrotic syndrome in white people?
Membranous nephropathy
Causes of membranous nephropathy?
- Idiopathic
- HBV / HCV
- SLE
- Solid tumors
- Drugs
Most common cause of death in SLE?
- Renal failure
- Membranous nephropathy in nephrotic
- Diffuse proliferative glomerulonephritis if nephritic
Imaging in membranous nephropathy?
HE: Thick basement membrane
EM: spike and dome
IF: granular, this is what is thickening membrane
What is spike and dome appearance on EM indicative of?
Membranous nephropathy
WHat is happening in all renal diseases with membranous in name?
Thickening of GBM from IC deposition
WHat is causing membranous nephropathy?
- IC deposition under the podocytes
- Leads to granular / spike and dome appearance
- Podocyte does not like having IC under it so secretes more basement membrane on top of it leading to spike and dome
When is tram track appearance seen?
Membranoproliferative Glomerulonephritis
2 locations of IC deposit in membranoproliferative glomerulonephritis? How does it lead to imaging?
“Proliferative” mesangial cell is proliferating through IC
- Basement membrane: mesangial cell splits it in half with its cytoplasm
- Endothelium
Location in type 1 / 2 membranoproliferative? Associations?
Type 1: Subendothelial
- HBV / HCV
Type 2: Intramembranous
- C3 nephritic factor
What is C3 nephritic factor associated with?
- Type II membranoproliferative glomerularnephritis
What is going on in type II membranoproliferative?
- C3 convertase normally converts C3 -> C3a/b
- Normally has short 1/2 life: in disease is stabilized by Ig
- Leads to drop in C3 and overactive complement
- Leads to inflammation in kidneys
Where are subepithelial deposits seen?
Membranous nephropathy
Pathogenesis of TIIDM nephrotic syndrome?
- High glucose = non enzymatic glycosylation of vascular basement membrane = hyaline arteriolosclerosis
Does diabetic nephrotic system like afferent or efferent arterioles?
- Efferent - this is why GFR increases
How to slow progression of diabetic nephrotic syndrome?
ACEIs
- Angiotensin II is squeezing down on efferent as well
- So if we stop this we decrease the already increased hyperfiltration that is occurring from the hyaline arteriolar sclerosis of efferent
Classic histology in diabetic nephropathy?
- Sclerosis of mesangium
- Formation of kimmelstiel wilson nodules
What are kimmelstiel wilson nodules indicative of?
Diabetic nephropathy
Most common site of systemic amyloidosis?
- Kidney where amyloid deposits in mesangium
Imaging of renal amyloidosis?
Apple green birefringence under polarized light
Presentation of nephrotic syndrome?
“Glomerular inflammation and bleeding”
- RBC casts and RBCs in urine
- Oliguria / azotemia
- Salt retention: periorbital edema
- HTN
- Proteinuria
What is periorbital edema associated with?
Nephritic syndrome
What is causing nephritic syndrome?
- IC deposition activates complement
- C5a attracts neuts who mediate damage
Biopsy in nephritic syndrome?
Inflamed, hypercellular glomeruli
What causes PSGN?
Group A, beta hemolytic strep infx of skin or pharynx
What makes strep capable of causing PSGN?
M protein
PSGN presentation?
- 2 - 3 weeks post infx
- Cola colored urine
- Oliguria
- HTN
- Periorbital edema
- Subepithelial humps on imaging
When are subepithelial humps seen? What is happening?
- PSGN
- IC is deposited endothelial then moves epithelial creating hump
PSGN prognosis?
Kids: rarely progress to failure
Adults: RPGN
What is characteristics of RPGN?
Crescents in bowman’s space
What are crescents indicative of?
RPGN
What are crescents composed of?
Fibrin and macrophages
When is linear IF seen? What is causing it?
- Goodpasture’s
- Anti GBM Ig is binds membrane in linear fashion
Presentation and pathogenesis of goodpasture’s?
- Ig against collagen in GBM and alveolar basement membrane
- Presents as hematuria and hemoptysis
- Classic in young males and adults
Causes of granular IF?
- PSGN
- Diffuse, proliferative glomerulonephritis
* ***Caused by IC deposition in both cases
What is occurring in diffuse proliferative glomerulonephritis?
- Most often seen in SLE
- Subendothelial IC deposition
Possible causes of pauci immune crescents?
- Wegener’s granulomatosis: c-ANCA
- Microscopic polyangiitis: p-ANCA
- Churg Strauss: p-ANCA
Presentation of wegener’s?
- Hemoptysis
- Hematuria
- Nasopharynx involvement
How do differentiate wegener’s from goodpasture’s?
Both: renal and pulm symptoms
Wegener’s also involves nasopharynx
How to tell churg strauss from microscopic polyangiitis?
Churg strauss has:
- Asthma
- Eosinophils
- Granulomatis inflammation
What happens in IgA nephropathy?
- IgA, IC deposition in mesangium
- Most common worldwide nephropathy
Presentation of IgA nephropathy?
- Episodic hematuria
- Usually in kids following mucosal infx
- Can slowly progress to renal failure
- IgA IC deposition in mesangium
Imaging of IgA nephropathy?
- Granular IF
Cause / presentation of Alports?
X linked defect in collagen Type IV:
- Thinning and splitting of GBM
- Sensory hearing loss
- Hematuria
- Ocular disturbances
What is cystitis?
Bladder infx
Presentation of cystitis?
- Dysuria
- Frequency / urgency
- Suprapubic pain
- No systemic signs
Labs in cystitis?
Urinalysis: cloudy, > 10 WPCs / hPF
Dipstick: Leukocyte esterase and nitrate +
Culture: > 100k colony forming units
What is sterile pyuria and what does it suggest?
- Pyuria but culture does not meet 100k colony forming units
Suggests URETHRITIS due to:
1. Chlamydia
2. Gonorrhea
Pyelonephritis symptoms?
- Cystitis symptoms
- Fever
- Flank pain
- WBC casts
- Leukocytosis
Most common causes of pyelonephritis?
- E Coli
- Klebsiella
- Enterococcus
What is chronic pyelonephritis?
- Interstitial fibrosis and tubules atrophy from recurrent acute infx
- Causes cortical scarring and blunted calyces
What is cortical scarring and blunted calyces characteristic of?
Chronic pyelonephritis
What is scarring at upper poles of kidneys indicative of?
Vesicoureteral reflux
What is the following indicative of:
- Atrophic tubules w/ eosinophilic proteinaceous material
- Reminiscent of thyroid follicles
- Waxy casts in urine
“Thyroidization of kidney”
- Chronic pyelonephritis
What is the following indicative of:
- Collicky pain
- Hematuria
- Flank tenderness
Nephrolithiasis
Rx for Ca stones?
- Hydrochlorothiazide and other Ca sparring diuretics
2. Citrate
What disease are Ca stones seen in?
Chrohns
What orgs cause AMP stones?
Urease positive orgs:
- Proteus vulgaris
- Klebsiella
* **The alkaline urine is leading to formation of stone
Which stones cause staghorn calculi?
- AMP: adult
2. Cysteine: kid
Which stone is radiolucent?
Uric acid = not visible on xray
Risk factors for uric acid stones?
- Hot / arid climate
- Low urine volume
- Low PH
- Gout
Rx for uric acid stone?
- Hydration
- Alkalization of urine: K/bicarb
- Allopurinol: if gout
Types of Ca stones and environment they prefer?
- Oxalate: acidic
2. Phosphate: basic
Which stones are envelope or dumbbell shaped?
Ca
Some causes of Ca stones?
- Antifreeze
- Hypocitraturia
- Chrons
- Vitamin C abuse
Which stone looks like coffin lid?
AMP
Which stones are rhomboids or rosettes?
Uric acid
Which stones are hexagonal?
Homocystinuria: ‘cyxteine’ six sides
Most common causes of renal failure?
- TIIDM
- HTN
- Glomerular disease
What is uremia?
Increased nitrogenous products in blood causing:
- Nausea
- Anorexia
- Pericarditis
- Platelet dysfunction
- Encephalopathy + asterixis
- Urea deposition in skin
* *Cause by end stage renal failure
Where is EPO made?
Renal peritubular interstitial cells
Signs of end stage renal failure?
- Uremia
- HTN from salt and water retention
- Hyper K with metabolic acidosis
- Anemia - decrease EPO
- HYPOcalcemia: decreased 1-a-hydroxylation of vit. D
- Also cannot excrete P - increased P - Renal osteodystrophy
3 components of renal osteodystrophy?
- Osteitis fibrosis cystica
- Osteomalacia
- Osteoporosis
What is osteitis fibrosis cystica?
- Low Ca = increased PTH pulling more Ca out
- Leads to fibrosis and cysts in bone
What is osteomalacia?
- Cannot mineralize osteoid being make by osteoblasts
What do osteoblasts do?
Lay down osteoid that needs to be mineralized by Ca and P
What leads to osteoporosis?
Metabolic acidosis seen in renal failure being buffered b lead of Ca from bone
Negative impact of dialysis on kidneys?
- Renal cell carcinoma
- Cysts
- Shrunken kidneys
Renal tumor at increased risk in tuberous sclerosis?
Angiomyolipoma
What is renal cell carcinoma?
- Malignant epithelial tissue arising from kidney tubules
Presentation of renal cell carcinoma?
- Hematuria
- Palpable mass
3 Flank pain - Fever / weight loss
- Many paraneoplastic syndromes
Appearance of RCC?
Gross: yellow mass
Micro: clear cytoplasm if clear cell type
Pathogenesis of RCC?
- Loss of VHL tumor suppressor gene causing:
- ***IN both sporadic and herediatary
1. Increase IGF 1
2. Increased HIF: TF increasing VEGF and PDGF
Who is sporadic RCC most commonly seen in?
- Adult spoker
- Single tumor in upper pole
What is VHL disease?
Increased risk of:
- RCC
- Hemangioblastoma of cerebellum
* Autosomal dominant inactivation of VHL suppressor
What nodes does RCC spread to?
Retroperitoneal
Presentation of wilms tumor?
- Unilateral flank mass in kid
Composition of wilms tumor?
- Blastema
- Stromal cells
- Primitive glomeruli and tubules
Mutation in wilms tumor?
WT1 mutation
What is WAGR syndrome?
- Wilms tumor
- Aniridia
- Genital abnormalities
- Mental / motor retardation
What is beckwith wiedeman syndrome?
- Wilms tumor
- Neonatal HYPOglycemia
- Muscular hemihypoertrophy
- Organomegaly - tongue
What makes up lower renal tract?
Everything past kidney:
- Bladder
- Renal pelvis
- Ureter
- Urethra
Where does urothelial cancer usually arise and from what does it?
- Usually in bladder
- Arises from urothelial lining
What lines the lower urinary tract?
Urothelium
Risk factors for urothelial carcinomas?
- Cigarettes
- Naphthylamine
- Azo dyes
- Cyclophosphamide
- Phenacetin
What is painless hematuria indicative of?
Urothelial carcinoma
2 pathways of urothelial carcinoma? How do they progress? Mutations?
- Flat: starts as high grade
- Early p53 - Papillary: low grade, to high grade, to invasion
Prognosis of urothelial carcinoma?
- Many tumors with frequent recurrence
“Field effect:” urothelium has been hit by so many toxins for so long that it is grossly mutated
Risk factors for Squamous cell carcinoma of lower tract?1
- Chronic cystitis
- S. haematobium: middle eastern males
- Long standing kidney stones
* usually seen in bladder
Risks of lower tract adenocarcinoma?
- Urachal remnant - dome of bladder
- Cystitis glandularis
- Exstrophy
What does PS innervation cause relative to urination?
- Detrusor contraction
- Sphincter relaxation
* **Sympathetic does opposite
What does ADH cause to be resorbed other than water?
Urea
Blood supply to proximal ureter?
Renal artery
Distal: vesicular
Presentation of henoch Schonlein purpura?
- Abdominal pain
- Arthralgia
- Palpable purpura
- Hematuria
Pathogenesis of Henoch?
- IgA IC vasculitis following URI
What does PAH clearance estimate?
RPF
Handling of PAH?
Some is freely filtered but most is secreted in PCT
Where is PAH lowest in kidney?
Bowman’s Space
Another name for goodpasture’s?
Anti GBM disease
What is attacking in anti GBM disease?
IgG and C3 complex
Impact of angiotensin II?
- Efferent arteriole constriction
2. Systemic constriction
Where is angiotensinogen produced?
Liver
What does RCC originate from?
Epithelium of PCT
Which diuretic can cause hearing deficits?
Loops
What causes uric acid to precipitate?
Low PH
Lowest PH in kidney?
Distal tubules
Collecting duct
What is the most potent diuretic?
IV loops
What are antiphospholipid Igs and what do they cause?
- From SLE
- Falsely elevate PTT when actually hypercoag
- False RPR for syphillis
What layer are kidneys derived from?
Mesoderm
- Muscle, bone, connective tissue as well
When is pronephros around?
Until 4 weeks: degenerates to become mesonephros
What is the first functional unit of fetal kidney?
- Mesonephros which is functional during the first trimester
What becomes permanent kidney and when does it develop?
Metanephros developing in 5th week
- Metanephric mesenchyme, ureteric bud
What is WT1 mutation involved in?
Wilms tumor
What does the mesonephros turn into?
- Collecting duct
- Calyces
- Pelvis
- Ureters
- Vas def
Vertebral level of kidneys?
“1,2,3 is where you find kidneys”
T12 - L3
Which anterior branch of aorta are kidneys next to?
SMA
Where do horseshoe kidneys get stuck?
IMA
- Commonly seen in turner’s syndrom
Is multicystic kidney disease hereditary?
No
How to ureteric bud progress?
Grows laterally from mesonephric duct connecting to mesonephric mesenchyme forming metanephros
How would one kidney have 2 ureters?
“Duplex collecting system”
Ureteric bud bifurcates before reaching mesonephros in embryogenesis
*High risk for vesicoureteral reflux and infx
What results in unilateral renal agenesis
Aberrant interaction between ureteric bud and metanephric mesenchyme
What are the retroperitoneal structures?
“SAD PUCKER”
Suprarenal glands
Aorta + IVC
Duodenum 2 - 4th
Pancreas (except tail) Ureters Colon (ascending / descending) Kidneys Esophagus (lower 2/3) Rectum
Where do Renal arteries branch?
L1
Where do renal veins run?
Anterior to renal arteries and aorta
Which renal vein is longer?
Left: because IVC is right of aorta so left vein has further to go
Where do right and left gonadal veins drain?
Right: directly into IVC
Left: Renal vein - > IVC
Relation to ureter and gonadal vessels?
- Runs under them “water under the bridge”
- Also is running under vas def
Are autonomic and somatic voluntary or involuntary and how does this related to the two urethral sphincters?
Somatic: voluntary, external sphincter
Autonomic: involuntary, internal sphincter
Where does the vasa recta come off?
“peritubular capillaries”
Efferent arteriols
Functions of angiotensin II?
- Enhances aldosterone release
- Vasoconstriction
- Constricts efferent arteriole
- Increased Na absorption in PCT
Where is renin secreted
JG cells: Modified smooth muscles cells in afferent tunica media
3 things increasing renin?
- Decreased flow
- Decrease Na
- Increased sympathetic tone
Where does collecting duct drain?
Minor calyx at the renal papillae
Arterial suppel of ureters?
Upper 1/3: Renal artery
Middle: gonadal / common iliac
Lower: Internal iliac
What is the break out of water in the body?
60 - 40 - 20 60% total body weight is water - 2/3 of this is ICF (40%) - 1/3 of this is ECF (20%) 40% of body weight is non water mass
How is volume of ECF measured?
Inulin
- Moves out of vasculature but cells do not take up
Break out of ECF?
Plasma: 1/4 (volume of fluid inside vascular system)
- Measured by albumin
Interstitial fluid: 3/4
How are plasma levels measured?
Radio labeled albumin: moves into vasculature but too large to move into ECF as inulin does
Major cations in ICF and ECF?
“The cell is like a banana in the open sea”
ICF: K
ECF: Na
What is the charge barrier of the GFR?
- Heparan sulfate in the basement membrane blocks negative molecules
- Lost in nephrotic syndrome which is why albumin is now able to cross barrier as it is a negatively charged molecule
Layers of glomerulus from in to out?
Endothelium: size barrier
Basement membrane: heparan charge barrier
Epithelium: podocytes
3 things that are freely filtered?
- AAs
- Glucose
- Electrolytes
* Majority resorbed in PCT
What is clearance?
Volume of plasma in ml cleared of substance in minutes
C = UV/P
U: urine[x]
V: urine flow rate
P: plasma [x]
How is GFR measured?
Inulin clearance: freely filtered neither reabsorbed, nor secreted
- **Creatinine is used clinically and it overestimates since a small amount is secreted in tubules
- Inulin is also measure of ECF fluid volume)
What does inulin measure?
GFR - freely filtered and neither secreted nor reabsorbed
- Cr is actually used in practice
What is EPRF, how is it measure?
“Effective renal plasma flow”
- Measured by PAH
- PAH is both filtered and secreted
What does PAH measured?
RPF
Equation for RBF?
RPF / (1 - hematocrit)
***This includes both plasma and cell mass
What part of CO do the kidneys receive?
- 2 L / Min
- This is 25% of resting CO
Filtration fraction equation?
FF = GFR / RPF
- Normally 20%
Effects of angiotensin II and prostaglandins on GFR?
Angiotensin: constricts efferent so increase GFR
Prostaglandins: Dilate afferent increasing BOTH GFR and RPF
Effects of dehydration on kidney dynamics?
Decreased in GFR and even greater decrease in RPF
**Leads to increase in filtration fraction
Equation for filtered load?
= GFR x [plasma]
Equation for excretion rate?
= V x [U]
Urine flow x urine [ ]
What what plasma glucose is it seen in urine?
- 200
- PCT transporters are fully saturated at 375
What type of drug is acetazolamide? Major indication?
- Carbonic anhydrase inhibitor
- High altitude pulmonary and cerebral edema “acute mountain sickness”
What is permeability of thin ascending limb?
- Impermeable to Na
- Water is passively absorbed
- Urine is being concentrated
- **Being caused by hypertonicity of medulla
What is permeability of thick ascending limb?
- Impermeable to water
- Allows for solute resorption
- **Urine is being diluted
Transporter found in thick ascending limb?
NaK2Cl
- Mg/Cl also reabsorbed paracellularly
Which diuretics increase renal excretion of Ca?
Loops: Eg, furosemide
Contraindication of loops?
- Ca kidney stones as loops are increasing excration / tubular [Ca] which will lead to more stones
What diuretics lead to decreased Ca excretion?
- Thiazides
Transporter in distal tubule?
NaCl
- No water being absorbed so filtrate is being diluted
Where is PTH functioning?
DCT increasing Ca absorption via Na/Ca apical transporter
Where does ADH function?
- V2 receptor on principal cell of collecting tubule leading to aquaporin insertion in lumen
K sparing diuretics?
- Triamterene
- Amiloride
* **Inhibit Na reabsorption making lumen more positive driving K into cells
Impact of aldosterone?
- Mineralocorticoid receptor in both Principal and A cells in collecting duct
- Causes Na channel insertion on lumen increasing its resorption
- Increases K / H loss
What is Cohns syndrome?
“Primary hyperaldosteronism”
- Hypertension from increase Na/H2O Resorption
- Hypokalemia
- Metabolic alkalosis
How to remember the renal tubular defects?
The kidneys make “FABulous Glittering LiquidS”
FAnconi syndrome
Bartter syndrome
Gitelman syndrome
Liddle syndrome
Syndrome of apparent mineralocorticoid excess
What happens in fanconi?
- Non functional cells in PCT leading to loss of:
1. Glucose
2. AAs
3. Bicarb
4. Phosphate
What is bartter’s syndrome?
Resorption defect in thick limb of NaK2Cl causing: 1. HYOP Ca 2. HYPO K 3. Metabolic alkalosis Increased: renin / aldosterone Normal BP
What is Gitelman syndrome?
- DCT issue, similar to bartter but less severe
HYPO: Mg/Ca
What is liddle syndrome? Treatment?
- Increased Na reabsorption in distal / convoluted tubules
- Increased activity of Na channel here
- Causes HTN and reflex decrease in aldosterone
Rx: Amiloride (K sparing)
What happens in syndrome of apparent mineralocorticoid excess?
- 11-B-Hydroxysteroid Dehydrogenase which normally converts cortisol into cortisone
- If enzyme absent, excess cortisol begins to activate mineralocorticoid receptors
What causes release of ANP?
- Stretching of cardiac atria from increased BV
- Can be caused by volume overload or aortic stenosis
How does ANP work?
- Relaxes vascular smooth muscle to lower BP
- Dilates afferent increasing GFR
- Decreases renin
What does the macula densa do? JG?
MD: Sense [Na] in distal tubule
- MD can stimulate JG to release renin
JG: Sense pressure in afferent
What is an endocrine hormone?
Something that acts at a distant site
What is a paracrine hormone?
Hormone that acts locally
What causes secondary polycythemia?
COPD
Processing of vitamin D?
- Liver 25-a-hydroxylase: vitamin d -> 25-H-vitamin D
2. Kidney 1-a-hydroxylase 25-H-vitamin D -> 1-25-OH-2-D
What enzyme activated vitamin D and where is it found?
1 alpha hydroxylase in PCT
- Stimulated by PTH
Functions of vitamin do?
- Increased GI absorption Ca/P
- Decrease renal absorption P
- Increased renal reabsorption Ca
Drug often associated with renal papillary necrosis?
Chronic NSAID use: stops creation of prostaglandins constricting efferent leading to ischemia
Effect of De on kidney?
Low dose: dilates afferent
High dose: vasoconstrictor via A1 action
4 things shifting K into cells?
- Insulin
- Adrenergic agonists
- Alkalosis - exchanging for H
- HYPOsmolality
What do flattened and peak T waves indicated?
Flattened: HYPO K
Peaked: HYPER K
Normal PH of blood?
7.4
Values in metabolic acidosis?
PH: decreased
CO2: Decreased
Bicarb: Decreased
Response: HYPERventilation
Values in metabolic alkalosis?
PH: Increased
CO2: Increased
Bicarb: Increased
Response: HYPOventilation
Values in respiratory acidosis?
PH: Decreased
CO2: Increased
Bicarb: Increased
Response: increased renal bicarb
Values in respiratory alkalosis?
PH:
CO2:
Bicarb:
Response: decreased renal bicarb
What does opiated OD cause relative to acid base?
Respiratory acidosis from respiratory depression
Difference in onset between compensatory metabolic / respiratory mechanisms?
Respiratory = immediate Metabolic = delayed
What is the normal PCO2?
40
How to calculate anion gap?
[Na] - ([Cl] + [bicarb])
**Normal is between 8 and 12
What is normal anion gap?
8 - 12
Causes of increased anion gap metabolic acidosis?
“MUD PILES” - think, you are piling the anions up
Methanol - formic acid
Uremia
Diabetic Ketoacidosis
Propylene glycol Iron / Isoniazid (INH) Lactic acidosis Ethylene Glycol Salicylates
Causes of Normal anion gap metabolic acidosis?
"HARD ASS" Hyperalimentation Addison's RTA Diarrhea - Losing both Na / bicarb in stool
Acetazolamide
Spironolactone
Saline infusion
Causes of hyperventilation?
- Hysteria
- Hypoxemia
- Salicylates
- Tumor
- Pulmonary Embolism
Causes of metabolic alkalosis?
- Dehydration
- Vomit
- Antacids
- Hyperaldosteronism
- Loops / thiazides
Other names for type 1, 2, and 4 RTA? What happens to urine PH?
1: Distal: PH > 5.5
2: Proximal: PH
Causes of Type I RTA?
- Amphotericin
- Analgesics
- Multiple myeloma
Cause of Type I RTA?
Inability of a-intercalated cells in distal to secret H:
- Leads to HYPO K: decreased lumen charge pulls K
- Increase lumen PH: Ca/P stones
What happens in type II RTA?
PCT can not resorb bicarb, distal secretes H to compensate = Decreased PH
1. K being secreted with H = HYPOkalemia
Causes of type II RTA?`
- Fanconi
- Lead
- Aminoclydosides
Cuase of Type IV RTA?
HYPOaldosteronism: normally causes Na resorp and K dumb
- without, K is being held in
DDx for RBC casts?
- Glomerulonephritis
- Ischemia
- Malignant Htn
Ddx for granular casts?
ATN
DDx for fatty casts?
Nephrotic syndrome
Ddx WBC casts?
- Interstitial inflammation
- Pyelonephritis
- Transplant rejection
What is being disrupted in nephritic/rotic syndromes?
Nephritic: GBM
Nephrotic: Podocytes
What type of hypersensitivity is PSGN?
III
What hypersensitivity is goodpasture’s?
II`
What is wire looping of capillaries indicative of?
DPGN: most common cause of death in SLE
LOOPus for LOOPing
Another name for IgA nephropathy?
Bergers
RBC casts in kidney stones?
No, problem is after tubules
When most likely to die during ATN?
Oliguric / maintenance phase
- Recovery phase is polyuric
Renal drug causing gynecomastia?
Spirinolaction
More water resorbed in collecting duct or PCT?
PCT
What is hyperacute rejection?
- Occurs immediately upon insertion of transplant
- Type II IgG mediated
First step in working up a metabolic alkalosis?
Volume status and urine chloride
What is a positive Na-cyanide-nitroprusside test indicative of?
Homocysteinuria
What does hypo K do to muscles?
- Cramps
- Weakness
- Rhabdo
* **Can be caused by thiazides
Where in nephron does lowest osmolality occur?
DCT
Which diuretic leads to increase in Cr upon administration?
Ace inhibitors as they are dilating the efferent decreasing GFR
Most serious complication during recovery phase of ATN?
HYPOk as diuresis but epithelial cells of tubules can not yet function
What are phospholipase A2 Receptor (PLAR2) Ig indicative of?
Membranous nephropathy
Secondary effect of loops?
Stimulation of Pg release
Side effect of aggressive osmotic diuretic therapy?
Pulmonary edema
What type of hypersensitivity is serum sickness?
Type II: Ig mediated complement activation
What leads to meckel’s diverticulum?
Persistence of the vitelline / omphalomesenteric duct
- Think VITTTTTY for SHITTTTY
What does the allantois become?
- The urachus, a duct between bladder and yolk sac
- Think UUUUUrine, for UUUUURACHUS
When is serum C3 decreased?
PSGN
What is starry sky appearance indicative of?
PSGN
Which vessels cross under and over the ureter?
Over: Gonadal artery and vein
Under: interior iliac artery
How do EOSs kill parasites?
Ig dependent, cell mediated toxicity
IF in PSGN?
Granular deposits in lumpy bumpy formation
Prevalence of posterior urethral valves?
Only seen in males