Renal: Pathology Flashcards
- Kidneys connected at the Lower Pole
- Most common congenital Renal anomaly
- Abnormally located in the Lower abdomen
- Gets caught on the Inferior Mesenteric Artery root during Ascent from the Pelvis → Abdomen
Horseshoe Kidney
- Absent Kidney formation → Unilateral or Bilateral
- Unilateral agenesis – hypertrophy of the existing Kidney and Hyperfiltration leads to increase risk of Renal failure later in life
- Bilateral agenesis – Oligohydramnios w/ Lung Hypoplasia, Flat Face, and Low ears and developmental defects of extremities (Potter Sequence) = incompatible w/ Life
Renal Agenesis
- A condition in pregnancy characterized by a deficiency of amniotic fluid. It is the opposite of polyhydramnios
- The breathing of the amniotic fluid helps stretches the babies lungs and helps to promote lung development – w/out the lungs fail to develop correctly
Oligohydramnios
- Noninherited, Congenital malformation of the Renal Parenchyma characterized by Cysts, and Abnormal tissue (e.g. cartilage)
- Usually unilateral
- Bilateral – MUST be distinguished from Inherited Polycystic Kidney disease
Dysplastic Kidney
- Inherited defect – Bilateral enlarged Kidneys
- Cysts in the Renal Cortex and Medulla
-
Autosomal Recessive - PKHD1 (6q21-p23)– form presents in infants as worsening Renal failure and Hypertension
- Newborns present w/ Potter Sequence
- Congenital Hepatic Fibrosis (Portal Hypertension)
- Hepatic cysts – in the Liver and Kidney
- Newborns present w/ Potter Sequence
-
Autosomal Dominant – Young Adults as Hypertension due to increased Renin, Hematuria, and Worsening Renal Failure
- Mutations APKD1 (16p13.3) or APKD2 (4q21) genes – cysts develop over time
- A/w Berry aneurysm, Hepatic cysts, Mitral valve prolapse
Polycystic Kidney Disease (PKD)
- Inherited disease causing Tubulointerstitial fibrosis and Progressive Renal Insufficiency w/ inability to concentrate urine
- Autosomal dominant defect leading to Cysts in the Medullary collecting ducts
- Parenchymal Fibrosis results in Shrunken Kidneys and woresening Renal Failure
- Poor prognosis
Medullary Cystic Kidney Disease
- Acute, Severe decrease in Renal Function (develops w/in Days) as measured by GFR (Normal 115 - 125 mL/min
- Hallmark is Azotemia (↑ BUN and ↑ Creatinine [Cr], often w/ Oliguria (Urine < 500 mL/day) or Anuria (Urine < 100mL/day)), Polyuria (> 3 L/day)
- Increase in nitrogenous waste production
- Divided into PreRenal, PostRenal, and IntraRenal based on etiology
Acute Renal Failure (ARF)
- Decreased Blood flow to Kidneys (e.g. cardiac failure) → common cause ARF
- ↓ RBF → ↓ GFR – Azotemia and Oliguria - ↓ Urine production - Na+ / H2O and Urine retained
- Reasbsorption of Fluid and BUN ensues (serum BUN:Cr ratio > 15); Tubular function remains intact (Fractional excretion of Na [FENa] < 1% and Urine osmolality [osm] > 500 mOsm/kg – The Kidneys still have the ability to concentrate the Urine **Urine Na < 10 **(mEq/L) **
Prerenal Azotemia
- Due to Obstruction of Urinary Tract downstream from the Kidney (e.g. Ureters)
- ↓ GFR – Azotemia, and Oliguria
-
Early stage obstruction, increased Tubular pressure “forces” BUN into the blood - Urine Na+ < 20 mEq/L
- (serum BUN:Cr ratio > 20); Tubular function remains intact
- (FENa < 1% and Urine [osm] > 500 mOsm/kg – tubules still function
-
Long stage obstruction, Tubular damage ensues, resulting in decreased reabsorption of BUN
- (serum BUN:Cr ratio > 15)
- Decreased reabsorptoin of sodium (FENa > 4%) and Urine [osm] < 350 mOsm/kg, Urine Na > 40 mEq/L
Postrenal Azotemia
- Injury and Necrosis of Tubular Epithelial cells
- Most common cause of Acute Renal Failure (ARF) (intrarenal azotemia) may have Oliguria and Azotemia
- A/w Rhabdomyolysis and Crush injury
- Necrosis cells plug Tubules; Obstruction decreases GFR
- Muddy-brown, Granular, Casts are seen in the Urine
- Dysfunctional Tubular Epithelium results in Decreased Reabsorption of BUN (serum BUN:Cr ratio < 15)
- Decreased reabsorption of sodium (FENA > 2%)
- Inability to concentrate Urine (Urine [osm] < 500 mOsm/kg)
Acute Tubular Necrosis
- Decreased blood supply results in Necrosis of Tubules (decreased ATP leads to ischemia)
- A/w rupture of the Basement membrane (Tubulorrhexis)
- 1st: Often Preceded by Prerenal Azotemia
- Proximal Tubule and Medullary segment of the Thick Ascending Limb are particularly Susceptible to Ischemic Damage
Ischemic Acute Tubular Necrosis
- Toxic agents result in Necrosis of Tubules
- Proximal tubule is particularly susceptible
- 2nd: Causes include Aminoglycosides (most common), Heavy metals, Myoglobinuria (crush inj.), Ethylene glycol (a/w oxalate crystals in urine), Radiocontrast dye, Urate, Tumor lysis syndrome
- Hydration and Allopurinol are used prior to initiation of Chemotherapy to Decrease risk of Urate-induced ATN
- Dx: Oliguria (2-3 weeks before recovery, regen.) w/ ‘Muddy’ Brown Granular casts
- Elevated BUN and Creatinine
- Hyperkalemia w/ Metabolic acidosis – decreases excreating of organic acids – Anion gap
- Tx: Reversible but requires Supportive Dialysis since Electrolyte imbalance – Fatal (Oliguric phase)
Nephrotoxic Acute Tubular Necrosis
- Drug-induced Hypersensitivity involving the Interstitium and Tubules - acting as Haptens
- Results in Acute Renal Failure (intrarenal azotemia)
- Caused by NSAIDS, Penicillin, and Diuretics
- Presents w/ Oliguria, Fever, and Rash days to weeks after starting a drug; Eosinophils and Azotemia may be seen in Urine
- WBC casts
- Resolves w/ cessation of drug
- May progress to Renal papillary necrosis
Acute Interstitial Nephritis
- Necrosis of Renal papillae ‘sloughing’
- Presents w/ Gross Hematuria and Flank Pain
- Polyuria, Rust-colored urine, ARF, Sediment, Casts
- CXR - Ring of calcification (neprocalcinosis)
- Causes include:
- Chronic Analgesic abuse (long term Phenacetin or Aspirin use) (Acetaminophen is a derivative)
- Diabetes mellitus
- Sickle cell traits or Disease
- Severe Acute Pyelonephritis
Renal Papillary Necrosis
-
Glomerular disorders characterized by Proteinuria (> 3.5 g/day) resulting in:
- Hypoalbuminemia – pitting edema
- Hypogammaglobulinemia – increased risk of infection – protein in blood
- Hypercoagulable state – due to loss of Antithrombin III – loss of anti-coagulant protein – breaking up of thrombi and prevention of thrombi anti-coagulet
- Hyperlipidemia and Hypercholesterolemia – may result in Fatty Casts in urine – thin blood – Liver adds Fat to Thicken the blood
Basics of Nephrotic Syndrome
- Most common cause of Nephrotic syndrome in Children (idopathic) (80%)
- Usually Idiopathic; may be a/w Hodkin lymphoma (cytokine-mediated damage)
- Normal glomeruli on H&E stain; Lipid may be seen in Proximal tubule cells - “Lipoid nephrosis” - ‘Foamy’
- Effacement of Foot processes on electron microscopy
- No immune complex deposits; negative immunofluorescence – not deposit mediated
- Selective Proteinuria (Loss of Albumin, but not immunoglobulin)
-
Excellent response to Corticosteroids (knock out cytokine production) (damage is mediated by cytokines from T cells)
- Hodgekins Lymphoma – overproduction of cytokines by Reed-Sternberg cells – Fever, Chills, Night sweats
Minimal Change Disease (MCD)
- Most common cause of Nephrotic Syndrome in Hispanics and African Americans
- Usually Idiopathic; may be a/w HIV, Heroin use, and Sickle cell disease, Massive obesity, INF treatment
- **Focal accumulation of Hyaline material (<50%) **(some glomeruli) and Segmental Sclerosis (involving only part of the glomerulus) – sclerosis on H&E stain
- Effacement of Foot processes on EM
- No immune complex deposists; Negative IF
- Poor response to steroids -> Cyclophosphamide and Cyclosporine -> Progresses to Chronic Renal Failure
Focal Segmental Glomerulosclerosis (FSGS)
- Most common cause of Nephrotic syndrome in Caucasian Adults
- Usually idiopathic; may be a/w Hepatitis B and C, Solid tumors, SLE, Rheumatoid arthritis, Syphilis, Schistosomiasis, Malaria, Leprosy, **Phospholipase A2 receptor, **Drugs (NSAIDs and Penicillamine)
- GBM Thickening on H&E w/ ‘Spike and dome’
- Due to Immune Complex Deposition (granular IF; subepithelial deposits), and Nephrotic SLE
- Poor response to Steroids progresses to Chronic Renal Failure
Diffuse Membranous Glomerulopathy
- Thick Glomerular basement membrane on H&E, often w/ ‘TRAM-Track’ appearance - Hypercellular glomeruli
- Immune Complex Deposition (granular IF)
- Dividied into (2) Types based on Location of Deposits
- Type I – Subendothelial (**HBV, **HCV, Cryoglobulinemia) (Type III Hypersensitivity)
- Type II – “dense deposit disease” – Intramembranous; a/w C3 Nephritic Factor (auto-Ab that Stabalizes C3 Convertase, leading to Overactivation of Complement, inflammation, and Low Levels of circulating C3), No IgG present
- Poor response to Steroids; progresses to Chronic Renal Failure
Membranoproliferative Glomerulonephritis
- High Serum glucose leads to Nonenzymatic glycosylation of the Vascular basement membrane resulting in Hyaline arteriolosclerosis (basement membrane becomes Leaky – leaking protein – Hyaline prolif.) -> mesangial expansion
- Glomerular Efferent >> Glomerular Afferent in the Arteriole – leading to High Glomerular Filtration process
- Hyperfiltration injury leads to Microalbuminuria
- Eventually progresses to Nephrotic Syndrome
- Characterized by Sclerosis of the Mesangium w/ formation of Kimmelstiel-Wilson nodules
- ACE inhibitors slow progression of Hyperfiltration-induced damage
Diabetic Nephropathy
- Kidney is the most commonly involved organ in Systemic Amyloidosis
- Amyloid deposists in the Mesangium, resulting in Nephrotic Syndrome
- Characterized by Apple-green Birefringence under Polarized light after straining w/ Congo red
Systemic Amyloidosis
- Glomerular Inflammation and Bleeding -> Hematuria
- Mild Proteinuria (< 3.5 g/day)
- Oliguria (< 400 mL/day) and Azotemia (↑ BUN and Creatinine) – decrease in urine and increase in nitrogenous waste products w/in the blood
- RAAS w/ Periorbital / Pitting Edema and Hypertension
- RBC casts and Dysmorphic RBCs in urine
- Biopsy reveals Hypercellular, Inflamed glomeruli
- Immune-complex deposition activates complement; C5a attracts Neutrophils – which Mediate damage – Hypercellularity
- **C3 levels, anti-GBM titer, **and ANCA titer
Nephritic Syndrome
- Nephritic syndrome w/ Group A β-hemolytic Streptococcal Infection of the skin (impetigo) or pharynx - ‘**Starry-sky’ **appearance - Type III Hyper.
- W/ Nephritogenic strains – Carry **M protein Virulence Factor - Serum chemistry -> Antitreptolysin-O **and anti-DNAase B are elevated, ANCA and anti-GBM neg.
- After Infection w/ Nonstreptococcal organisms as well
- Presents 2 -3 weeks after infection as Hematuria (cola-colored urine), Oliguria, Hypertension, and Periorbital edema -> “Smokey-brown” or “Cola-colored” urine
- Usually seen in Children but may occur in Adults
- Hypercellular, inflamed Glomeruli on H&E
- Mediated by immune complex deposition (Granular IF); Subepithelial ‘humps or lumpy-bumpy’ on EM
- Tx: Children rearely (1%) profress to Renal Failure
- Some Adults develop Rapidly Progressive Glomerulnephritis (RPGN) (wks – mths)
Poststreptococcal Glomerulonephritis (PSGN)
Acute Proliferative Glomerulonephritis
- Malignant form of Nephritic syndrome that progresses to Renal Failure in Weeks to Months
- Characterized by Crescents in Bowman space (of Glomeruli) on H&E stain
- Crescents are comprised of Fibrin and Macrophages
- Clinical picture and IF help resolve etiology
- (3) Distinct Types:
- Goodpasture syndrome - Type II, ANCA-negative
- Poststrep GN, SLE, IgA neph. Henoch-Schonlein purpura - ANCA-negative - Type III
- Wegener granulo. or ideopathic - PR3-ANCA / c-ANCA - positive
Rapidly Progressive Glomerulonephritis
- IgA immune complex deposition in Mesangium of Glomeruli
- Most common nephropathy worldwide
- Presents during Childhood as Episodic Gross or Microscopic Hematuria w/ RBC casts
- Usually following Mucosal Infection – IgA production in increased during Infection, a/w Hnoch-Schonlein purp.
- IgA immune complex deposition in the Mesangium is seen on IF – glomerular bleeding
- Every episodic infection you get bleeding from the Kidney a/w Celiac disease
- Slow progress to Renal failure
IgA Nephropathy (Berger Disease)
- Hereditary Glomerular injury, defect in Type IV collagen
- Most commonly X-linked –> Mostly males
- Results in Thinning and Splitting of the Glomerular basement membrane ‘**Foamy’ **changes
- Presents as Gross Hematuria (males) and **Sensory Hearing Loss and Ocular distribution – damage to basement membrane (nerve deafness, lens dislocation, cataracts**) -> Females are carriers (mild symptoms)
- Presented w/in Family History
- ANCA and anti-GGM both negative, C3 lvls normal
Alport Syndrome (Hereditary Nephritis)
- Infection of Urethra, Bladder, or Kidney
- Most commonly arises due to Ascending Infection, Increased Incidence in Females
- Risk factors include Sexual Intercourse, Urinary stasis, and Catheters
Basics of Urinary Tract Infection
- Infection / Inflammation of the Bladder
- Presents as Dysuria, Urinary frequency, Urgency, and Suprapubic pain, Systemic signs (Fever) are usually absent - “Honeymoon cystitis”, indwelling catheters
- Lab:
- Urinalysis – cloudy urine w/ > 10 WBC/high power field
- Neg. Culture – Urethritis – Chlamydia trachomatis and Neisseria gonorrhoeare
- Dipstick – Positive leukocyte esterase (due to Pyuria) and Nitrites (bacteria convert Nitates to Nitrites)
- Culture – greater than 100,000 colony forming units (GOLD-Standard)
- Etiology: E. coli (80%), Stapjylococcus saprophyticus (young sexually active women), Klebsiella pneumoniae,** **Proteus mirabilis – Alkaline urine w/ Ammonia scent, Enteroccus faecalis, Adenovirus
Cystitis
- Infection of the Kidney - Cortex
- Usually due to Ascending infection – increased Risk w/ Vesicoureteral reflux
- Fever, Flank pain, WBC casts, and Leukocytosis, in addition to symptoms of Cystitis - ‘striated parenchymal enhancement’
- Most commonly: Tx: ABX
- E. coli (90%)
- Enterococcus faecalis (species)
- Klebsiella species
Acute Pyelonephritis
- Interstitial fibrosis / **scarring **and Atrophy of Tubules due to Multiple bouts of Acute Pyelonephritis
- Vesicourecteral reflux (VUR) (Children) or Obstruction (Benign prostati hypertrophy BPH or Cervical carcinoma) - due to predisposition to infections
- Leads to Cortical scarring w/ Blunted calyces
- Low-grade Fever, Flank pain, Nausea / Vomiting, Failure to thrive, HTN, Renal insufficiency, Protenuria
- Atrophic tubules containing Eosinophilic proteinaceous material resemble Thyroid follicles (‘Thyroidization’ of the Kidney, waxy casts may be seen in Urine)
Chronic Pyelonephritis
- Precipitation of a Urinary solute as a Stone
- Risk factors include High concentration of Solute in the Urinary filtrate and Low Urine Volume
- Presents as a Colicky Pain w/ Hematuria and Unilateral Flank Tenderness
- Stone is usually passed w/in Hours; if not, Surgical Intervention may be required
Nephrolithiasis
- Radiopaque Stone type, Adults, Colorless Octahedron
- Calcium Absorption of the gut > Excretion in the Urine or Primary Renal defect of Calcium re-absorption
- Most common cause is Idiopathic Hypercalciuria, 2nd Hyperparathyroidism, Vit. D intoxication, Sarcoidosis; Hypercalcemia and its related causes must be excluded
- Can also form from Ethylene glycol (antifreeze)
- a/w Crohn disease – small bowel damage – increased abs. Oxolate – binds Ca2+ - stone
- Tx: Hydrochlorothiazide (calcium-sparing diuretic)
Calcium Oxalate stones (↓ pH)
Calcium Phosphate stones (↑ pH)
- 2nd most common Stone type
- Radioopaque, Rectangular prism, like ‘Coffin-lids’
- Most common cause is Infection w/ Urea-positive organisms (Proteus vulgaris, Staphylococci, Klebsiella, and Psuedomonas, but NOT E. coli); Alkaline urine leads to formation of stone + ABX
- Results in Staghorn calculi cast (kidney stone) in Renal Calyces – act as a Nidus for Urinary tract infections
- Tx: Surgical removal of stone (size) and Eradication of Pathogen, Carbonic anhydrase inhibitors (Acetazolamide)
Ammonium Magnesium Phosphate (AMP stone) (↑ pH)
‘Stuvite’
- Third most common stone (5%)
- Radiolucent on CXR
- Yellow or Red-brown, Diamond or Rhombus
- Hot, Arid climates, Low urine volume, Acidic Urine pH
- Most common stone seen in pts. w/ Gout
- Hyperuricemia (in Leukemia or Myeloproliferative disorders) increases risk
- Tx: Hydration and Alkalinization of Urine (potassium bicarbonate); Allopurinol is also administered in pts. w/ Gout
Uric acid (↓ pH)
- Rare cause of Nephrolithiasis; most commonly see in Children
- A/w Cystinuria (a genetic defect of tubules that results in decreased reabsorption of Cysteine, Ornithine, Lysine, Arginine), more likely in Acidic Urine pH
- Fairly opaque w/ Ground-glass appearance CXR
- Sodium nitroprusside test
- Flat, Yellow, Hexagonal
- May form Staghorn calculi
- Tx: Hydration and Alkalinization of Urine
Cystine Stones (↓ pH)
- End-stage Kidney Failure – may result from Glomerular, Tubular, Inflammatory, or Vascular insults
- Most common causes are Diabetes mellitus, HTN, and Glomerular disease (GFR < 60 mL/min)
- Uremia, Azotemia, Nausea, Anorexia, Pericarditis, Platelet dysfunction, Encephalopathy w/ Asterixis, Deposition of Urea crystals in skin
- Salt and Water retention w/ resultant Hypertension
- Hyperkalemia w/ Metabolic acidosis – cannot get rid of organic acids
- Anemia due to decreased Erythropoietin production by Renal Peritubular Interstitial cells
- Hypocalcemia due to decreased 1-alpha-hydroxylation of Vit. D by Proximal Renal tubule cells and Hyperphosphatemia – cannot excrete PO4 bind to Ca2+ - low [Ca2+]
- Renal Osteodystrophy – due to secondary Hyperparathyroidism osteomalacia and osteoporosis
- Tx: Dialysis or Renal Transplant w/ cysts in shrunken end-stage Kidneys on dialysis
Chronic Renal Failure
- Hamartoma comprised of (3) components
- Blood vessels
- Smooth muscle
- Adipose tissue
- Increased frequency in Tuberous sclerosis
Angiomyolipoma
- Malignant epithelial tumor from Proximal tubules
- Classic Triad (3) Hematuria (most common), Palpable mass, and **Flank pain, **Polygonal clear cells
- Fever, Weight loss, or Paraneoplastic syndrome (EPO – reactive polycythemic??, Renin – HTN, PTHrP – Hyper Ca2+, ACTH – Coshney’s symptom??)
- A/w Left-sided Variocele – left spermatic vein involvement, Men - 50 - 70 years-old
- Yellow-Mass w/ clear cytoplasm
- Loss of VHL (3p) tumor supressor gene – increased IGF-1 (promotes growth) – increase HIF transcription factor – increases VEGF and PDGF
- Sporadic – adult makes (60 y.o.) single tumor in Upper pole of Kidney
- Hereditary tumors – young adults, Bilateral tumor, Von Hippel-Lindau disease (VHL gene)
Renal cell Carcinoma
- Malignant Kidney tumor comprised of Blastemal (immature kidney mesenchyme), Primitive **Embryonic **Glomeruli and Tubules, and Stromal cells
- Common in Children, avg. 2 - 4 y.o.
- Large, Unilateral Flank mass w/ Hematuria and Hypertension (Renin secretion)
- (3) Sporadic (90%) tumors w/ syndromic tumors
- WAGR syndrome – Wilms tumor, Aniridia, Genital abnormalities, and Mental and Motor Retardation a/w deletion of WT1 tumor suppressor gene (11p13)
- Denys-Drash syndrome – Wilms tumor, progressive Renal (glomerular) disease, and male Pseudohermaphroditism, a/w mutation of WT1
- Beckwith-Wiedemann syndrome – Wilms tumor, neonatal hypoglycemia, muscular hemihypertrophy, and organomegaly (including tongue); a/w WT2 gene cluster (11p15.5 ) particularly IFG-2
Wilms Tumor
- Maliginant tumor; Urothelial lining of Renal pelvis, Ureter, Bladder, or Urethra
- Most common type of Lower Urinary tract cancer (Bladder) (No casts)
- Pee SAAC-N - Phenacetin, Smoking, Aniline/Azo dyes**, ** Long - term Cyclophosphamide and Naphthylamine
- Older adults; w/ Painless Hematuria
- (2) Pathways
- Flat – High-grade tumor then Invades, a/w early P53 mutation
- Papillary – low-grade papillary tumor then High-grade then Invades, NOT a/w P53 mut.
- Multifocal and Recur (‘Field defect’ = entire endothelium has been exposed to carcinogen exp.)
Urothelial (Transitional cell) Carcinoma
- Maliginant tumor, Squamous cells, usually w/in Bladder
- In background of Squamous metaplasia (normal bladder does not have squamous epithelium)
- ‘Warty’ or Ulcerated lesions
- Chronic cystitis (older woman), Schistosoma hematobium infection (Middle Eastern and Egyptian males), and Long-standing Nephrolithiasis (chronic infection / Cystitis in young males)
Squamous Cell Carcinoma
- Maliginant proliferation of Glands, usually involving the Bladder
- Arises from a Urachal Remnant (@ the Dome of the Bladder)
- Urachus is a duct that connect the Bladder into the Yolk sac – remnant becomes Adenocarcinoma
- Cystitis glandularis (columnar metaplasia)
- Exstrophy (congenital failure to form the Caudal portion of the Anterior abdominal wall and Bladder walls)
Adenocarcinoma
Diseases associated w/ Red Blood Cell casts?
- Glomerulonephritis
- IgA nephropathy
- Poststreptococcal glomerulonephritis
- Goodpasture syndrome (rapidly progressive glomneph.)
- Malignant HTN
- Vasculitis
- Renal ischemia
What diseases are a/w White Blood Cell casts?
- Acute Pyelonephritis
- Interstitial nephritis
- Tubulointerstitial inflammation
- Lupus Nephritis
- Transplant rejection
- WBCs in Urine indicate UTI
What diseases are a/w
Granular ‘Muddy-brown’ casts?
- Acute Tubular Necrosis (ATN)
- Chronic Renal failure
- Nephrotic Syndrome
- Fatty casts are also seen in Nephrotic syndrome
What diseases are a/w Epithelial cell casts?
- Acute tubular necrosis (ATN)
- Ethylene glycol toxicity
- Heavy-metal poisoning
- Acute rejection of Transplant graft
What diseases are a/w Hyaline casts?
- Often seen in Normal Urine
- Concentrated urine samples
- Pyelonephritis
- Deposition of Fibrous, Insoluble proteins in β-pleated configuration deposits in the Kidney
- ‘Light-chain deposition disease’
- Proteinuria, Severe-Edema, Renal insufficiency, also a/w secondary diseases (Multiple Myeloma, TB, RA, etc.)
- Congo red stain -> Apple-green birefringence = amyloidosis
- Tx: Melphalan and Prednisone
Renal Amyloidosis
- A/w both Nephrotic and/or Nephritic syndromes
- Weight gain, High BP, Darker ‘foamy’ urine, Swelling around the eyes, legs, ankles, or fingers
- A/w 5 classes of involvement
Lupus Nephritis
- Class I - No evidence of disease
- Class II - Mesangial involvement
- Class III - Focal proliferative nephritis
- Class IV - Diffuse proliferative nephritis (most common type in SLE)
- Class V - Membranous nephritis, characterized by extreme edema and protein loss
- antibodies against proteins in Globular Basement Membrane (anti-GBM)
- Can be seen in Lung and Kidnes due to cross-reactivity of antigens (eg. α3 chain of collagen type IV) common to both alveolar and GBM
- Type II Hypersensitivity
- Hematuia, Proteinuria, and Rapidly Progressive Glomerulonephritis (RPGN), Hymoptysis, Dyspnea
- Serum anti-GBM Ab, ANCA typically neg. C3 is normal
- RBC casts and mile proteinuria, Linear ribbon-like IgG
Goodpasture syndrome
- Focal / Segmental Necrotizing vasculitis and Necrotizing granulomas in Upper and Lower respiratory tract (Lungs) w/ occasional Crescent Formation
- Nonspecific symptoms, Fever, Arthralgias, Lethargy, Malaise, Chronic sinusitis, Hemoptysis, and Hematuria
- Nephritic symptoms and mild Proteinuria
- Cytoplasmic staining ANCA (c-ANCA) - positive
- NO IgG or anti-GBM, and Complement are normal
- Tx: Corticosteroids and Cyclophosphamide w/ Dialysis and Renal Transplantation
Wegener Granulomatosis
- Develops as a result of ‘patchy’ Infarction of the Cortices of the Kidney secondary to Ischemia -> can progress to Acute Renal Failure (ARF) - Bilateral
- A/w Abruptio placentae, Eclampsisa / Preeclampsia, Septic shock, Hemolytic-uremic syndrome (in children)
- Sepsis, Disseminated Intravacular Coagulation (DIC), Obstetric complications, Anuria, evidence of ARF, Flank pain, and FEVER
Diffuse Cortical Necrosis
Nephritic Syndrome Diseases?
- Acute poststreptococcal glomerulonephritis
- Rapidly progressive glomerulonephritis
- IgA glomerulonephropathy (Berger disease)
- Alport Syndrome
Diseases that are both Nephritic and Nephrotic?
- Diffuse proliferative glomerulonephritis
- Membranoproliferative glomerunephrtis
Disease of Nephrotic Syndrome?
- Focal segmental glomerulsclerosis
- Membranous nephropathy
- Minimal Change Disease
- Amyloidosis
- Diabetic glomerulonephropathy
Consequences of Renal Failure?
- MAD HUNGER
- Metabolic Acidosis
- Dyslipidemia (esp. ↑ Triglycerides)
- Hyperkalemia
- Uremia - marked by Azotemia
- Na+/H2O retention
- Growth retardation and developmental delay
- Erythropoietin Failure (anemia)
- Renal osteodystrophy
- Defect in ability of α intercalated cells to secrete H+
- New HCO3- is not generated -> Metabolic Acidosis
- A/w Hypokalemia -> ↑ Risk for Ca-PO4 Kidney Stones due to ↑ Urine pH and ↑ Bone turnover
- Causes: Amphotericin B toxicity, Analgesis nephropathy, Multiple myeloma (light chains), and Congential anomalies (Obstruction) of the Urinary tract
Type I - Renal Tubular Acidosis
(Distal Tubule, pH > 5.5)
- Defect in Proximal Tublue HCO3- reabsorption
- Results in ↑ excretion of HCO3- in Urine and subsequent Metabolic Acidosis
- Urine is acidificed by α intercalated cells in Collecting Tubule
- A/w Hypokalemia, ↑ Risk of Hypophosphatemic Rickets -> Fixed acid lost in Urine
- Causes: Fanconi Syndrome (Wilson disease), Chemicals toxic to Proximal tubule (Lead, Aminoglycosides), and Carbonic Anhydrase Inhibitors
Type II - Renal Tubular Acidosis
(Proximal, pH < 5.5)
- Hypoaldosteronism
- Aldosterone resistance or K+ - sparing diuretics
- Results in HyperKalemia -> impairs Ammoniagenesis in the Proximal Tublue
- > ↓ Buffering capacity
- > ↓ H+ excretion into Urine
Type IV - Renal Tubular Acidosis
(HyperKalemic, pH < 5.5)
- Reabsorptive defect in PCT
- A/w ↑ Excretion of nearly all Amino acids, Glucose, HCO3-, and PO43-
- May result in Metaboic Acidosis (Proximal Renal Tubular Acidosis) -> HyperKalemia
- Causes: Hereditary defects (Wilson disease), Ischemia, and Nephrotoxins / drugs
- The Kidneys put out FABulous Glittering Liquid
Fanconi Syndrome
- FABulous Glittering Liquid
- FAnconi syndrome in the 1st defect of PCT
- Bartter syndrome is next (Thick ascending loop of Henle)
- Gitelman syndrome is after Bartter (DCT)
- Liddle syndrome is last (Collecting tubule)
- Reabsorptive defect in Thick Ascending Loop of Henle
- Autosomal recessive
- Affects Na+ / K+ / 2Cl- Cotransporter
- Results in HypoKalemia and Metabolic Alkalosis w/ HyperCalciuria
Bartter Syndrome
- Reabsorptive defect of NaCl in DCT
- Autosomal recessive
- Less severe than Bartter syndrome
- Leads to HypoKalemia and Metabolic alkalosis, but w/out HyperCalcuria
Gitelman Syndrome
-
↑ Na+ reabsorption in Distal and Colecting tubules
(↑ activity of Epithelial Na+ channel) - Autosomal dominant
- Results in HTN, HypoKalemia, Metabolic alkalosis,
↓ Aldosterone - Tx: Amiloride
Liddle Syndrome