RENAL Flashcards
What are 3 reasons the parathyroid would secrete PTH?
low calcium, high phosphate, or low active vitamin D
How is medullary cystic kidney disease inherited? Discuss the appearance of the kidneys
AD; there are cysts in the COLLECTING DUCTS. The parenchyma is fibrosed, the kidneys are shrunken. There is progressive renal disease
What may interstitial nephritis progress to?
papillary necrosis (SODA)
What functions as the kidney for the first trimester?
mesonephros (eventually becomes part of male reproductive system)
Major cause of death in Potter’s
pulmonary hypoplasia
How do you treat uric acid stones and cystine stones?
alkalinize the urine (NaHCO3)
What syndrome is associated with renal cell CA?
Von Hippel Lindau
What are the 4 aspects of Beckwith-Weidmann syndrome (gene and chromosome?)
Wilm’s tumor, Aniridia, Genitourinary malformation, MR; WT1 gene on chromosome 11
What are the 3 stages of acute tubular necrosis?
Inciting phase; Maintenance phase (oliguria for 1-3 weeks with hyperkalemia risk) and then Recovery phase (polyuria with decrease in BUN creatinine and the risk of hypokalemia)
Explain how the hyperphosphatemia of renal osteodystrophy leads to further decrease of Ca
It binds it up and causes metastatic tissue calcifications
What effect does constriction of the ureter have on 1) RPF 2) GFR 3) FF
1) no change 2) decrease 3) decrease
How do you measure the anion gap? What is normal?
Na - (Cl +HCO3)
Why does BUN increase in pre-renal azotemia?
The low flow leads to a decrease in GFR with increased water reabsorption, thus, increased BUN since urea follows water
What is the most commonly involved organ in systemic amyloidosis
kidney
What do fatty casts in urine indicate?
Nephrotic syndrome (oval fat bodies)
Ballooning degeration in kidney
Toxic cause (acute interstitial nephritis or acute tubular necrosis from toxin)
What is the deal with medullary cystic kidney?
inherited disease causing tubulointerstitial fibrosis and progressive renal insufficiency with inability to concentrate urine
What is the response of most nephrotic syndromes to steroids?
Poor with progression to CKD; except minimal change dz
Which PKD is associated with liver cysts? Congenital hepatic fibrosis?
ADPKD; ARPKD (can lead to portal HTN)
What is the hallmark of nephritic syndrome?
glomerular bleeding
Which nephrotic syndrome responds well to steroids?
Minimal change disease
8 causes of wide anion gap metabolic acidosis (MUD PILES)
Methanol, Uremia, DKA, Propylene glycol, Iron tablets and Isoniazid, Lactic acidosis, Ethylene glycol, and Salycylates late
What is absorbed via paracellular route in the TALH? Why?
Mg and Ca because the NKCC channel creates a positive lumen due to K backleak, this shoves Ca and Mg through
What are 2 causes for aldosterone synthesis?
AT II in result to blood loss or hyperkalemia
What is the hallmark of acute renal failure?
azotemia (increased BUN AND creatinine) also oliguria
Why do you give DM the “benefit” of the ACE I?
DM nephropathy involves hyalinization preferentially of the efferent arteriole (prob bc the sugar has more time to chill there). ACE-I prevent constriction of the efferent arteriole; this decreases hyperfiltration injury
Which casts are seen in bladder cancer and kidney stones?
no casts, just hematuria
Which nephritic syndrome follows gastroenteritis?
Berger’s IgA nephropathy (mesangial deposits)
Give a basic explanation for the dry cough of ACE I
ACE degrades bradykinin, lose of ACE involves buildup of bradykinin
3 syndromes with Wilms tumor
Beckwith-Weidmann syndrome; Denys-Drash syndrome; WAGR syndrome
Thyroidization of the kidney
Eosinophilic casts in chronic pyelonephritis give it the look of thyroid follicles
What is the value for Tm of glucose?
350
Which is reabsorbed, BUN or creatinine?
BUN for countercurrent exchange. So if both BUN and creatinine go up that is renal failure
What is type 4 renal tubular acidosis?
Hypoaldosteronism (Addison’s) or lack of response to aldosterone at CD? The hyperkalemia impairs ammoniagenesis in the PCT leading to decreased buffering capacity and a low urine pH? However, this still causes a metabolic acidosis
Which nephritic syndrome splits the basement membrane? (2)
Acquired = MPGN I due to mesangial proliferation that splits GBM, this can present nephritic or nephrotic; INHERITED = Alport Syndrome, an XR collagen 4 defect that leads to splitting
Name 3 urease positive bugs that can cause struvite stones
PROTEUS!!!! And Staphylococcus and Klebsiella
Why is there hyperkalemia and metabolic acidosis in CKD?
Because there is a decreased ability to secrete organic acids and because you don’t secrete as much K, the cells exchange K for H
What is cystitis glandularis? Risk?
Columnar (glandular) metaplasia of transitional urothelium; increase risk of adenocarcinoma
Which embryological structure is responsible for most of the kidney as distal as the DCT?
intermediate mesoderm? i.e. metanephric mesenchyme? The ureteric bud makes up the calyces
What causes hexagonal stones?
Cystine (secondary to cystinuria, a defective PCT transporter for cysteine, ornithine, lysine, and arginine
Why does Crohn’s Dz increase the risk of kidney stones?
mucosal damage increases oxalate absorption from the gut leading to calcium oxalate stones
In essence how should you interpret a TF/P curve?
This is tubular fluid/plasma; Basically, if the concentration is higher in TF than P, water was reabsorbed faster than the solute. In other words, it is excreted.
What is multicystic dysplastic kidney?
Arises from weird interaction between the ureteric bud and the metanephric mesenchyme. It causes a nonfunctional kidney. If unilateral it will result in contralateral hypertrophy
What is the difference between a primary glomerular disease and a secondary glomerular disease?
A primary glomerular disease only affects the kidney (e.g. minimal change disease)? A secondary glomerular disease affects other organs as well (SLE, diabetic nephropathy)
What do muddy brown casts indicate?
Acute tubular necrosis (granular casts)
What is type 2 renal tubular acidosis?
“proximal”? this is a defect in HCO3 reabsorption and may be seen in Fanconi’s. This is associated with hypokalemia and may increase the risk of hypophosphatemic rickett’s
Which type of urothelial CA is associated with p53 mutations?
Flat; papillary is not? So flat urothelial CA is much more serious and harder to Dx
What makes up the crescents in rapidly progressive glomerulonephritis?
Fibrin and macrophages
What do you see in the following for membranous nephropathy: LM; EM; and IF?
LM = diffuse capillary and GBM thickening; EM = subepithelial deposits with spike and dome; IF = granular
What are the kidney delayed compensations in respiratory alkaloses and acidoses?
Alkalosis = decreased reabsorption of HCO3 (reason for giving acetazolamide in altitude sickness); Acidosis = increased HCO3 reabsorption
T/F: polycystic kidney disease can cause Potter’s
True but only ARPKD
What EKG findings are present in hypokalemia? Hyperkalemia?
Hypo = flat T waves and U waves, arrhythmias; Hyper = peaked T-waves, wide QRS, arrhythmias
What are the 2 most common causes of nephrotic syndrome in adults?
Focal segmental glomerulosclerosis and membranous nephropathy
What causes the hypertension in nephritic syndrome?
Salt retention since there is oliguria? Same reason there is azotemia!
What is diffuse cortical necrosis of the kidneys? Cause?
acute generalized necrosis of the cortices of both kidneys? usually from vasospasm and DIC (obstetric complications, abruptio placentae)
What effect does PTH have on the PCT? DCT?
At PCT, PTH inhibits phosphate reabsorption; at DCT, PTH increases calcium reabsorption via a Ca/Na exchanger
Which MPGN is associated with C3 nephritic factor?
Type II dense deposits
What is type 1 renal tubular acidosis
“distal”? This is a defect in the ability to secrete H? This increases the risk for Calcium phosphate stones as a result of both increased urine pH and bone resorption (acidic environment)
Subendothelial deposits with nephrotic syndrome are associated with what 2 infections?
HBV and HCV (this is MPGN I)
What is the main concern during the recovery phase of acute tubular necrosis?
hypokalemia; this is when they start peeing again
Where are juxtaglomerular cells located? Where are macula densa cells located?
JG = afferent arteriole; MD = DCT
What if you have cystitis that smells like ammonia?
Proteus since converts NH3 to CO2 and ammonia
What is the most important (trump card) reason for ADH secretion?
Low blood volume, but more commonly it is to regulate osmolarity
What is the prognosis for crescentic glomerulonephritis?
Poor if Rapidly Progressive Glomerulonephritis, can lead to deteriorating renal fxn in days to weeks
genetics of ADPKD
Autosomal Dominant, PKD1 gene chromosome 16
What is the filtration fraction?
GFR/RPF (the only way to change it is to change one but not the other)
What are 3 causes of rapidly progressive (crescentic) glomerulonephritis?
Goodpasture’s disease (type II hypersens)? Pauci-immune glomerulopathies = Wegner’s (c-ANCA) and Microscopic Polyangiitis (p-ANCA)
What is the diagnosis of renal Bx with LM = diffuse capillary and GBM thickening; EM = spike and dome appearance with subepithelial deposits; and IF = granular?
Membranous nephropathy (nephrotic)? Presentation of SLE and some solid tumors
What is seen on LM, EM and IF for diffuse proliferative glomerulonephritis?
LM = wire looping of capillaries; EM = subendothelial deposits, IF = granular
What other major organ is cystic in ADPKD?
liver
What are 3 ways NSAIDs can cause acute renal failure?
by inhibiting prostacyclin synthesis in the afferent arteriole leading to decrease in GFR; by causing interstitial nephritis which is a hypersensitivity; also renal papillary necrosis (SODA)
What 2 diseases present as Diffuse Proliferative Glomerulonephritis?
SLE (main cause of death in this Dz) and MPGN when presenting as nephritic syndrome
Why are nephrotic syndromes associated with thromboemboli?
There is a loss of antithrombin III (heparin may not be effective since it is losing its substrate!!!)
How does PTH cause calcium reabsorption and phosphate excretion?
Decrease phosphate reabsorption in PCT; increases Ca reabsorption in DCT
Why are there eosinophils in the urine of interstitial nephritis?
It is a hypersensitivity rxn to drugs that act as haptens, so it is a type I hypersensitivity which involves eosinophil chemotactic factor and IL-5
What is uremic frost?
deposition of urea crystals in the skin
What would the histology of Goodpasture’s, Wegener’s and Microscopic polyangiitis be on renal Bx?
Rapidly progressive (Crescentic) glomerulonephritis; fibrin and plasma proteins make up the crescents, pretty serious!
What does aldosterone do exactly?
Aldosterone puts a sodium channel on the luminal side of intercalated cells in the collecting tubules which eventually causes the loss of K. Therfore, K sparing diuretics can either inhibit spironolactone or they may inhibit the Na channel
Which syndrome does membranoproliferative glomerulonephritis present with? Differentiate the appearance of type I and type II
Either or both nephritic and nephrotic; Type I = tram-tracking from GBM splitting due to mesangial growth with subendothelial deposits; Type II = intramembranous deposits with “dense deposits” in lamina densa