Renal Pathology 2 (HTN, UTI)

Terms in this set (22)

Drugs that increase Renin

Contraceptives
Glucocorticoids
Diuretics
Anti-hypertensives

Renal HTN + LOW Renin

Primary Aldosteronism
Licorice ingestion

Essential Hypertension

sustained > 140/90mmHg
impaired pressure-naturiesis mechanism
improved with diuretics
increased TPR usually a consequence, not a cause of HT
rightward shift of PN curve
etiology unknown

Renal Artery Stenosis

aka Renalvascular HTN
most common cause of 2nd Secondary HTN
MALES = atherosclerosis (elderly)
YOUNG FEMALES = fibromuscular dysplasia

140/90, clinically silent = benign neprhosclerosis

microscopically: hyaline arteriolosclerosis (proteins leak into arteriole wall), hylanization of glomeruli, interstitial fibrosis, tubular atrophy

>180/120, schistocytes, hematuria, acute end-organ damage, papilledema, medical emergency, leads to malignant nephrosclerosis

malignant HTN

malignant nephrosclerosis:
1. focal small hemorrhages flea bite apperance
2. fibrinoid necrosis of arterioles = hematuria
3. hyperplastic arteriolitis
4. necrotizing glomerulitis = hematuria

Hyperplastic arteriosclerosis

part of malignant nephrosclerosis

hyperplasia of smooth muscle = onion skin appearance

nonpregnant woman, E Coli, Proteus Mirabilis, vesico-uretral reflux a possibility, usually related to sexual activity

Uncomplicated UTI
95% are Cystitis

Labs:
WBCs, RBCs, Nitrates, Leukocyte Esterase, no WBC CASTS

pregnancy, upper UTI, structural abnormalities, catherization, children, recurrent (>3yr), men, elderly

Complicated UTI

elderly man with UTI

may be prostatic hypertrophy

can lead to 1. urine accumulation 2. distention 3. compromised blood flow to bladder

community-acquired UTIs
binds blood group P antigens
fimbriae allow better adherence to uroepithelial cells

Tx: Amox, Bactrim, Cipro

Proteus Mirabilis

Urease = Staghorn Stone formation
Hyperflaggelated
Urease splits Urea into ammonia & raises pH of urine, precipitating MgNH3 and CaPO4

usually E. Coli, may have predisposing factors of vesico-urethral reflux, indwelling catheter, UT obstruction, diabetes or pregnancy, chills, high fever, flank pain radiating to groin, urinalysis: WBC casts, bacteria, RBCs, nitrates, leukocyte esterase

Acute Pyelonephritis
can lead to Renal Papillary Necrosis or Staghorn Stone

Renal Papillary Necrosis

Nephropathy of papilla supplied by vasa rectae, gross hematuria, flank pain

Neutrophilia, no bacteria, in urine

caused by anything that can cause ischemia: SAAD papa

Sickle Cell
Acute Pyelonephritis
Analgesia (NSAIDs) abuse
Diabetes Mellitus

recurrent episodes of acute pyelonephritis can lead to chronic pyelonephritis with gross and micro findings:

gross: asymmetric corticomedullary scarring (U-shaped/geographic scarring), blunted calyx

micro: tubules with eosinophilic casts resembling thyroid tissue + hyaline casts in tubules

mercury, ethylene glycol, ABX (sulfa, neomycin, polymixin)

TOXIC ACUTE TUBULAR NECROSIS
tubular cells sough into PCT
3 phases:
1. oliguria: hyperkalemia, muddy brown casts, possible metabolic acidosis
2. polyuria: loss of H2O, NaCl, K
3. recovery (17th day): regeneration of tubules, can conx urine, risk of hypokalemia but BUN/Creatinine normalize

oxalate crystals in urine

etylene glycol
can cause Tubular Necrosis

Tx: Fomepizole

hypovolemia, hypotension, shock, sepsis gram negative, hemorrhage, HF, mismatched blood transfusions, burns,

ISCHEMIC ACUTE TUBULAR NECROSIS

exact same as Toxic Acute Tubular Necrosis except in PCT AND DCT

pyuria w/ eosinophils, azotemia, nephritis 1-2 weeks after administering of drugs (methicillin), can occur one month after starting NSAIDs, fever, rash, hematruira, flank tenderness but can be asymptomatic

Drug-Induced Interstitial Nephritis

Methicillin-Induced Acute Interstitial Nephritis

1-2 weeks post administration
HS rxn (T-cell mediated)?
eosoniphilia in kidney and urine, IgE in urine

NSAID-induced Chronic Interstitial Nephritis

aspirin inhibits PGE
phenacetin direct toxic effect

papillary necrosis, interstitial lymphocyte infiltrates

Multiple Myeloma Renal Failure

Myeloma Cells produce monoclonal IgG and free light chains =

1. obstructive uropathy
2. destruction of tubules
3. Amyloidosis
4. interstitial disease
5. light chain glomerulonephritis nodular lesions (like Diabetes)
6. Calcinosis, increased bone reabsorption

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