Renal Flashcards
Where is the site of action of loop diuretics?
Na/K/Cl cotransporter in the ascending loop of henle
Part of the nephron that is impermeable to water?
Ascending limb of the loop of henle
Pt with End stage renal disease can cause which metabolic dearangement?
Osteodystrophy due to decreased VitD3 ynthesis, decreases Ca absorption (and hyperphosphatemia), increased PTH, high resorption of bone aka osteitis fibrosa cystica
Pt is admnistered Enapril, where does It work and how does it affect GFR?
Acts by reducing angiotensin II which constricts efferent arteriole. Decreases GFR
Pt with hypotension, hyperventilates. Lab findings, metabolic acidosis, increased anion gap and high plasma lactate level. Which enzyme has low activity?
Pyruvate Dehydrogenase: hypoxia-induced lactic acidosis
Kidney transplant surgery, graft becomes cyanoric and molted soon after connection of vessels. Blood flow stops and no urine is produced. What kind of hypersensitivity?
Antibody mediated hypersensitivity Type II. Preformed antibodies within the recipient that are directed against donor antigens.
Kidney transplant surgery, graft becomes cyanoric and molted soon after connection of vessels. Blood flow stops due to fibrinoid necrosis, and extensive thrombosis within transplanted organ.
Hyperacute Rejection: Type II hypersensitivity
Type II hypersensitivity mismatches?
Hyperacite rejection, ABO blood grou antibodies, and anti-HLA antibodies.
Vasopressin injection causes the Urinary output to decrease. Renal clearance of which substance is reduced?
Urea. Vasopressin produces a V2 increase in permeability to water and urea in the luminal membrane of the inner medullary collecting duct. Therefore resoprtion of urea increase and clearance of urea decreases.
Where does ADH act?
luminal membrane of the inner medullary collecting duct via V2 receptor-mediated increase in permeability to water and urea.
Kid with colockiy abdominal pain, bloody stool, red urine, palpable skin lesions on his buttocks, other finding would be?
Joint pain (Henoch-Scholein Purpura)
Findings on Henoch-Schonlein Purpura
Abdominal pain, join pain, hematuria, lower extremity palpable purpura.
Pathophysiology of Henoch-schonlein purpura
young children preceded by an upper respiratory infection. Production of IgA antibodies causing an IgA hypersensitivity vasculitis.
What is the most important prognosis factor of poststreptococcal glomerulonephritis?
AGE
pt with cola-colored utine and facial dema after an outbreal of streptococcal skin infection.
post-strep glomerulonephritis
Pt with urine discoloration. She was treated for impetigo weks before. Hematuria, mild proteinuria, red blood cell casts. Renal biopsy reveals?
Discrete subepithelial humps on electron microscopy. (poststrep glomeruloneprhitis)
Findings on poststreptococcal glomerulonephritis
Hypercellular leukocyte infiltration, proliferation of mesangium. Electron dense deposits on epithelial side of basement membrane (hump). IF reveals granular depostis due to immune complex deposition causing a lump-bumpy appearance.
older female with knee pain and long term use of analgesics and has 1+ urianalysis. After knee replacement surgery, she no longer needs analgesics and urianalysis is normal. What is the pt experiencing?
Chronic interstitial nephritis
Staghorn calculi caused by which organisms
Ureaseposotove bugs: proteus mirabilis, klebsiella, staphylococcus
Causes of transitional cell carcinoma
Phenacetin, smoking, aniline dyes, cyclophosphamide
Biopsy of Chronic pyelonephritis
corticomedullary scarring, blunted calyx, tubules with eosinophilic casts aka thyroidization
Male with skin lesions on his lower abdomen, sample of fibroblast fail to metabolize ceramide trihexoside. Patient is at greatest risk of developing?
Renal failure
Inherited deficiency of alpha-galactosidase A
Fabry disease
What accumulates in Fabry disease?
globoside ceramide trihexosidase in tissues.
Hypohidrosis, acroparesthesis(burning neuropathic pain in extremities) and angiokeratomas(punctuate, dark, red, macules and papules between umbillicus and knees) leading to eventual renal failure present in?
Fabry disease
34 year old man, alcoholic, upper gastrointestinal bleeding. Upper endoscopy shows linear mucosal tear at the gastroesophageal junction. The etiology of the bleeding is associated with which acid-base disturbance?
Metabolic alkalosis, mallory-weiss tear due to vomit
The principal site of uric acid precipitation in the nephron is?
Collecting ducts and distal tubules due to low pH.
Prevention of tumor tysis syndrome:
Urine alkalinization and hydration
Calcineurin
essential protein in the activation of IL-2 which promotes the growth and differentiation of T cells.
immunosupressant that inhibit calcineurin activation
cyclosporine and tacrolimus
low grade fever and decreased urine output one week after kideny transplant. Bipsy has dense nsterstitial infiltration by mononuclear cell. What is the cause?
Acute rejection: Host T cell sensitization against graft MHC antigens.
How do you prevent acute rejection
Calcineurin inhibitors, cyclosporine n tacrolimus
kid with cola-colored urine after a flu-like illness with mesangial deposits
IgA nephropathy
IgA nephropathy associated with extra-renal symptoms such as purpuric lesions on skin of buttocks, legs n arms and GI abd pain and intussuception.
Henoch-schonlein disease.
Right sided flank pain that radiates to the groin shortly after surgery for cervical carcinoma. On exam there’s a palpable mass deeo in the right upper abd. Quadrant.
Hydronephrosis. The ureter cuurse posterior to the uterine artery in cervix area which makes it vulnerable to injury. Thereforeurine cant drain and pressure builds up in the ureter and calyceal system causing distention of renal pelvis.
why are ureter at risk of injury during pelvic surgery
they run posterior to the uterine artery and can be ligated.
pt with heart failure in multidrug treatment. An agent is added to benefit overall survival. Which on?
Spironolactone: aldosterone antagonist that reduces morbidity and mortality in heart failure by decreasing ventricular remodeling and cardiac fibrosis.
Drug to prevent hypercalciuria in neprholithiasis
Thiazides: decrease calcium extretion by inhibiting Na/Cl cotransporter in the distal convoluted tubule, increse intraluminal Na and creates a separation of charge, opens Ca channels forcing Ca out of the urine.
MOA f thiazides
inhibit Na/Cl cotransporter in the distal convoluted tubule, increase Na intraluminal and creates electrical gradient, open voltage-gated Ca chanenel forcing Ca out of the urine.
a nurse overdoses on aspirin, which metabolic abnormalities will you find
Initial respiratory alkalosis followed by an anion gap metabolic acidosis.
describe K through the nephron
100% is filtered , 2/3 is reabsorbed in the proximal convoluted tubules, 20% is filtered in the loop of henle by the action of the Na/K/Cl cotransporter, regulated resorbtion/secretion in the collecting duct.
Collecting duct regulation of K: hypokalemic state
alpha-intercalated cells resorb extra K via H/K-ATPase
collecting duct Regulation of K: increase K secretion by
aldosterone leading to loss of K and Na retention; thiazide and loop diuretics which increase K loss due to high flow through collecting ducts hence dilute fluid, shift of K into tubule.
Filtration fraciton formula
GFR/RPF
Clearance formula
(Urine concentration times urine flow rate) divided by plasma concentration
MOA of furosemide
inhibits NaK2Cl symporter in the ascending limb of loop of henle and stimulate protaglanding release , vasodilation, increased renal blood flow and enhance drug delivery
adverse effects of Amphotericin B
Nephrotoxicity. Decrease in glomerular filtration rate and direct toxic effect on tubular epithelium. Hypokalemia and hypomagnesemia due to increased membrane permeability in distal tubule.
structure in nephron most likely to demonstrate signs of ischemic injury?
Proximal convolted tubule and thick ascending limb the loop of henle cuz they are located in the outer medulla.
Linear deposits of IgG and C3 along the glomerular basement membrane on IF and crescent formation on LM
antiglomerular basement membrane disease aka goodpastures syndrome
what is acute renal graft rejection
antibody-mediated or cell-mediated process (lymphocytic infiltration)
mononuclear cell expressing IL-2 receptors and receptors that bind MHC class II will have which other receptor?
CD3 recceptor, CD3 antigen is required for proper funtion of T-cell receptors.
Anti-CD3 antibodies
muromonab-CD3 inhibits T-lymphocytes so it is useful in treatment of acute rejection
What increases the risck for transitional cell carcinoma of bladder
Phenacetin, smoking, Aniline dyes, Cyclophosphamide. Exposure to rubber, plastics, textiles and leather
patient with excessive thirst and frequent urination. Treatment of bipolar disorder with lithium.
Lithium-induced nephrogenic Diabetes insipidus. Lithium reduces the ability of the kidneys to concentrate urine by inhibiting ADH from binding to its receptors in collecting tubules.
Proteinuria in minimal change disease
Selective proteinuria of low molecular weight proteins such as albumin and tranferrin.
painless hematuria and cystic dilatation of the medullary collecting ducts in otherwise normal kidenys.
Medullary sponge kidney
most common complication of medullary sponge kidney
Kidney stones. Ot dont develop chronic renal failure cuz it is benign.
Laboratory findings of post-streptococcal glomerulonephritis
elevated titers of antistreptolysin O and anti-DNAase B and low serum complement levels
Immune-complex mediated condition where antibodies to the streptococcal antigen form, bind streptococcal antigen circulating in the blood and fix complement in the glomeruli causing inflammation and kidney manifestations.
Poststreptococcal glomerulonephritis pathophys.
Poststreptococcal glomerulonephritis findings on EM and IF
EM: electron-dense deposits on the epithelial side of BM (humps) IF: granular depostis of IgG and C3 (lumpy-bumpy)
woman with peripheral edema. Serum contains IgG4 antibodies to phospholipase A2 receptor, a transmembrane protein abundant on podocytes.
Membranous nephropathy
Hematuria, proteinuria, RBC casts, hypercellular glomeruli
Poststreptcoccal glomerulonephritis findings
65 year old male with painless hematuria
Urothelial cancer until proven otherwise
Clear cell carcinoma on a histologic preparation
High glycogen or lipid content
Cellular proliferation, focal necrosis and crescent formation of most glomeruli. On IM no immunoglobulin or complement deposits. What additional findings?
Serum anti-neutrophil cytoplasmic antibodies
newborm with normal kidneys. If diagnosed later in life with renal disease, what would it be?
Autosomal dominant polycystic renal disease
Hemoptysis, HTN and hematuria with positive ANCA
Wegener’s
Wedeners triad
- pulmonary: hemoptysis due to necrotixing granuloma formation. 2.upper respiratory tract: chronic sinusitis 3.Renal: crescents
Persistent back pain, constipation, easy fatigability. Renal atrophic tubules with large obstructing eosinophilic casts.
Multiple Myeloma
Multiple Myelopma renal failure pathogenesis
Due to excess excretion of the free light chains (bence jones proteins) which precipitate with tamm horsfall protein and form eosinophilic casts. Bence jones porteins are also directly toxic to tubular epithelial cell and cause atrophy.
What are the 3 phases of acute tubular necrosis?
initiation: injury; maintenance: oliguric, granular casts; Recovery: re-epithelization of tubules.
What is the most important complication during the recovery phase of acute tubular necrosis?
Hypokalemia
what is hartnups disease
deficiency of tryptophan. Causes pellagra
Diarrhea, dermatitis, dementia, death
Pellagra: no tryptophan
MOA of aldosterone
increases the number of NA/K-ATPase proteins and Na channels in the cell membrane of the collecting tubules.
Aldosterone consequences
K ion secretion from principal cells and H ion secretion from intercalated cells of the renal collecting tubules. Na and water resorption.
pt with vomit, prolonged oliguria. Biopsy reveals ballooning and vacuolar degeneration of proximal tubules. Multiple oxalate crystals in tubular lumen. What is the condition?
Toxic Rena injury: ethylene glycol
Ethylene glycol ingestion findings
Acute renal failure due to precipitation of oxalate crystal in renal tubules, ballooning and vacuolar degeneration of proximal tubules. Anion gap metabolic acidosis.
Where In the nephron is urine most concentrated in the absence of ADH
Descending loop of henle: permeable to water and no reabsorption of electrolytes takes place, fluid in lumen becomes hypertonic
what part of the nephron is most concentrated in the presence of ADH
End of the collecting duct
Where does ADH act?
On the MEDULLARY portion of the collecting duct
Where does aldosterone act?
CORTICAL segment of the collecting duct
antibodies detected in male are found to react with the alpha-3-chain of collagen type IV. What is the clinical finding?
Hemoptysis and oliguria (good pastures)
good pastures syndrome etiology
anti-glomerular basement membrane antibodies that target the alpha-3 chain collagen type IV. Causes acute renail failure and hemoptysis.
pt with mebranous glomerulopathy. On exam, theres a left sided varicocele. Urine with increased proteinuria. What caused this condition?
Loss of antithrombin III (nephrotic syndrome)
which side if more susceptible to get a varicocele?
LEFT! because the left testicular vein dumps into the left renal vein and then enter the IVC. However, the right empties directly in the inferior vena cava. So a Renal vein thrombosis can cause it.
Digoxin toxicity
visual changes, GI disturbaces
Where is digoxin cleared
Renal
pt with long standing HTN has crackles on lung auscultation and edematous swelling in lower extremities. IV drug used causes diuresis and symptom relief. Which drug was used I this acute setting?
Loop diuretics, furosemide or ethacrynid acid in ordet o reduce volume overload
Side of action of loop diuretics
Na/K/2Cl ascending loop
Side effects of loop diuretics
Ototoxicity, hypokalemia,Hypocalcemia, dehydration, Allergy, Nephritis, Gout
difference between loop diuretics and thiazides
Loop diuretics cause hypocalcemia, act on the thick ascending loop of henle and thiazides cause hypercalcemia and act on the distal tubule Na/Cl
Pt with severe right-sided eye pain and ipsilateral headache. Nausea and halos around objects. Treated with medication that caused relief and increased diuresis and highly alkaline urine. Where does the drug act?
Proximal tubule: acetazolamide
Acyclovir side effects
Nephrotoxicity. It is excreted in the urine via glomerula filtration and tubular secretion. When its concentration increases, crystallization occurs causing damage. Prevent with Fluids.
Side ffects of amphoterecin B
Renal toxicity. Causes renal vasoconstriction and reduction in the glomerular filtration rate. Causes Hypokalemia and hypomagnesemia.
Mucormycosis treatment
Amphoterecin B
Elevated Blood pressure, low K, high renin and high aldosterone. What is the cause?
Juxtaglomerular cell tumor
Causes of secondary hyperaldosteronism?
Nerovascular hypertension, diuretic use, malignant hypertension and renin secreting tumors.
ototoxic agents
aminoglycosides, salicylates, cisplatin, loop diuretics
pt treated with drug, develops pulmonary edema. Which is the drug?
Mannitol, osmotic diuretic
Most severe toxicities of osmotic diurectics?
pulmonary edema
Contraindications for osmotic diuretics
congestive heart failure and pre-existing pulmonary edema
pt is given PAH. In which segment is the concentration the lowest?
Bowman’s space
kid stung by bee develops urticaria. Develops puffy face and foamy urine. 4.5 protein in his urine. What is the most likely abnormal n useful diagnosis in his condition?
Electron microscopy of the renal biopsy sample (minimal change disease)
Diagsnotic tool used in minimal change disease
electron microscopy of renal biopy showing foot effacement.
Drug that causes an increase in K and increase in Creatinine used for hypertension?
ACE inhibitor
pt with polycystic renal disease presents with complaint of persistent bone pain. Which abnormalities will you find?
Increased PTH and decreased calcitriol
painless hematuria with right sided mass. Malignant cells with chromosome 3p deletion. Which gene is involved?
VHL: von hippel-lindau disease is autosomal dominant chatacterized by cerebellar hemangioblastomas, clear cell carcinoma and pheochromocytoma.
Hyperacute rejection is mediated by?
antibodies preformed within the recipient that are directed against donor antigens. Type II hypersensitivity.
Side effects of foscarnet
renal wasting of magnesium leading to hypomagnesemia, a reduction of PTH and hypocalcemia.
MOA of foscarnet
pyrophosphate analog that chelates calcium
Lithium induced Diabeted insipidus
Inhibits the ability of vasopressin to bind to its receptors in the collecting ducts. Polyuria and polydipsia.
Organism incoorporates uracil into their DNA molecules during replication. Which enzyme mediates this?
Primase: synthesizes a short RNA primer.
Triad of Hemolytic uremic Syndrome
Microangiopathic hemolytic anmeia, thrombocytopenia and acute renal failure
Organisms that cause Hemolytic Uremic Syndrome
Shiga toxin producing organisms (verotoxin) E.coli or shigella dysenteriae
Woman with bilateral renal masses composed of fat, smooth muscle and blood vessels, what other finding would you have?
Brain hamartomas and Ash-leaf skin patches
What is Renal angiomyolipoma associated with?
tuberous sclerosis
Cardiac rhabdomyomas, facial angiofibromas, ash-leaf-shaped patches present in?
tuberous sclerosis: autosomal dominant
