GNs and AKI Flashcards
List the different ways HIV can cause kidney disease
- Glomerular disease
- HIV-associated nephropathy (collapsing FSGS)
- HIV immune complex kidney disease
- HIV-associated TMA
- Rare:
- MPGN+/- cryoblogulin-associated vasculitis
- Membranous
- Fibrillary, imunotactoid
- Amyloid
- Minimal change
- Tubular (med-related)
- AKI (aminoglycosides, cidofovir)
- Proximal tubule (Fanconi) - tenofovir, etc.
- DI - tenofovir, amphotericin, etc.
- Chronic tubular injury
- Crystal nephropathy - indinavir
- Interstitial - meds
Pathology for membranous nephropathy
- LM: GBM spikes, GBM thickening
- IF: Diffuse granular IgG and C3 along GBM
- EM: Foot process effacement, subepithelial electron-dense deposits
- Ehrenreich-Churg EM Classification (no clinical or prognostic significance):
- Stage I: deposits without basement membrane reaction
- Stage II: basement membrane spikes between deposits
- Stage III: basement membrane material between and surrounding deposits
- Stage IV: electron lucent areas consistent with resportion of subepithelial immune complexes
- Ehrenreich-Churg EM Classification (no clinical or prognostic significance):
Causes of secondary membranous nephropathy?
- Autoimmune: SLE, (RA, IgG-4, autoimmune thyroid dz, anti-GBM and ANCA GN)
- Infection: HepB, (HCV, HIV, syphilis, schistosomiasis)
- Malignancy: Solid tumors e.g colon, stomach, lung, prostate, (NHL, CLL, melanoma)
- Drugs/toxins: NSAIDs and COX-2 inhibitors, (gold, penicillamine, mercury)
- Miscellaneous: Sarcoidosis, anticationic bovine serum albumin
Drug causes of membranous nephropathy
penicillamine, gold, NSAIDs, mercury, captopril (high dose), TNF-inhibitors (infliximab, adalimumab, etanercept)
Indications to treat membranous nephropathy?
- At the time of diagnosis, high risk for progression if >=2 of:
- Cr >=133
- Progressive decline in GFR >=25% from baseline over last 2 years
- Severe nephrotic syndrome, defined as any of:
- Albumin <25- (bromocresol green) or <20 (bromocresol purple)
- Refractory edema
- VTE
- Persistent/worsening nephrotic proteinuria/GFR/anti-PLA2R levels despite 3-6 months supportive tx and observation
Management of primary membranous nephropathy?
- Conservative
- Edema: low Na diet, diuretic
- Proteinuria: ACE/ARB
- Hyperlipidemia: statin (LDL <2)
- Anticoagulation: consider if albumin <20-25, heavy proteinuria esp >10g/d
- Immunosuppressive therapy
- Ponticelli - Steroids (months 1, 3, 5) + CYC (months 2, 4, 6)
- Rituximab
- Calcineurin inhibitors
- ACTH
Cholesterol emboli: 3 risk factors, 3 procedures, and 3-4 clinical/non-renal manifestations?
- Risk factors for cholesterol emboli
- In the setting of vascular manipulation of the aorta
- 1)Male
- 2)Age >50
- 3)Risk factors for atherosclerosis: smoking, hypercholesterolemia, obesity, diabetes
- Procedures that may increase risk of cholesterol emboli
- 1)Angiography
- 2)AAA repair
- 3)CABG
- 4)Valve replacement (especially TAVI)
- 5)Intra-aortic balloon pump
- Manifestations of cholesterol emboli
- Renal
- 1)Subacute renal impairment within 1-2 weeks of inciting event (progressing over weeks to months)
- 2)Stuttering course
- 3)Little or no recovery of renal function
- 4)Bland urinalysis
- Non-renal
- 1)Timing 1-2 weeks after vascular manipulation
- 2)Eosinophilia
- 3)Hypocomplementemia
- 4)Signs of extrarenal atheroemboli (cyanosis, discrete gangrenous lesions, livedo reticularis, TIA/amarosis fugax/hollenhorst plaques, mesenteric ischemia)
- Renal
Patient-related risk factors and procedure-related risk factors for AKI after cardiac surgery?
- Patient
- 1.Age
- 2.CHF
- 3.Preoperative IABP/Cardiogenic Shock
- 4.Diabetes
- 5.Pre-operative CKD
- 6.Chronic Lung Disease
- B) Procedure
- 1.Length of cardiopulmonary bypass
- 2.Duration of aortic cross-clamping
- 3.Off-pump vs on-pump CABG
- 4.CABG only vs. Valve only vs. CABG + Valve
- 5.Reoperation
- (Based on Clevland and Mehta scores)
What is an MPGN histologic pattern?
- Pathologic pattern of subendothelial and mesangial deposition of immune complexes and/or complement factors with proliferative changes in the glomeruli
Categories and causes of MPGN?
- Immune-complex mediated
- Infection:
- Viral: HCV and HBV (cryoglobulinemic GN), HIV
- Bacterial: endocarditis, infected ventriculoatrial shunt, visceral abscesses, leprosy, meningococcal meningitis
- Protozoa/other: malaria, schistosomiasis, mycoplasma, leishmaniasis
- Autoimmune: SLE, RA, Sjogren’s, undifferentiated CTD, PSC, Grave’s
- Malignancy: MM, lymphoma, Waldenstrom macroglobulinemia, MGRS
- Fibrillary GN
- Infection:
- Complement-mediated
- DDD
- C3GN
- GN with dominant C3
- MPGN without immune-complex or complement
- “Idiopathic”
Difference between the C3 glomerulopathies?
- Dense deposit disease: a form of C3G with characteristic EM appearance of intensely osmiophilic transformation of GBM
- C3 glomerulonephritis: C3 glomerulopathy without the characteristic appearances of DDD
- Glomerulonephritis with dominant C3: morphologic term for cases of GN with dominant staining for C3c (>=2 orders of magnitude than other immune reactant). Many will represent C3G.
Pathophysiology of C3 glomerulopathy?
- Problem with the alternative complement pathway/excess activation
- Normally, the alternative complement pathway is always activated but at a very low rate -> constant generation of small accounts of activated C3
- When there’s a pathogen, there is rapid amplification of C3b (positive C3b amplification loop) -> millions of C3b molecules within minutes.
- Therefore, systems are in place to prevent inappropriate activation of the pathway:
- C factor H (CFH): inhibits C3b amplification (by binding to C3b
- Factor H-related proteins (CHFR): promotes C3b amplification, by inhibiting CFH
Caues of C3 glomerulopathy?
-
Genetic
- Complement-regulating proteins: CFH, CFI, CFHR5
- Antibodies to complement regulating proteins: C3Nef, Ab against CFH, CFI, or CFB
- Complement factors: C3, CFB
- Infection
- Paraproteinemia
Pathology findings (LM, IF, EM) for C3GN
- LM: variable.
- MPGN pattern (glomerular lobulation, increased mesangial matrix/cells, capillary wall thickening with double contouring)
- PIGN pattern (diffuse endocapillary proliferative GN)
- IF: Granular C3 staining in capillary walls and mesangium. C3 at least 2 orders of magnitude compared with others.
- EM:
- DDD: Osmiophilic dense transformation of GBM, large densities in the mesangium
- C3GN: electron-dense material expands the GBM but without marked density as in DDD
- Both: subepithelial humps/deposits (like PIGN)
What is ocular drusen and which GN can you see this?
Lipoprotein deposits of complement-containing debris in retinal epithelium
Seen in DDD
Patient and procedure-related risk factors for choelsterol emboli syndrome?
- Patient:
- Male
- Age >50
- Risk factors for atherosclerosis: smoking, hypercholesterolemia, obesity, diabetes
- Procedure:
- Angiography
- AAA repair
- CABG
- Valve replacement (especially TAVI)
- Intra-aortic balloon pump
Renal manifestations of cholesterol emboli syndrome
-
Renal
- Subacute renal impairment within 1-2 weeks of inciting event (progressing over weeks to months)
- Stuttering course
- Little or no recovery of renal function
- Bland urinalysis
Non-renal manifestations of cholesterol emboli syndrome
- Timing 1-2 weeks after vascular manipulation
- Eosinophilia
- Hypocomplementemia
- Signs of extrarenal atheroemboli (cyanosis, discrete gangrenous lesions, livedo reticularis, TIA/amarosis fugax/hollenhorst plaques, mesenteric ischemia)
Overall management of ligh chain cast nephropathy?
- Anti-myeloma therapy (CyBorD)
- Stop all nephrotoxins
- Correct hypercalcemia
- Fluids, target urine output 3L/day
- Urinary alkalinization
- Avoid loop diuretocs
- Dialysis
- +/- High-cutoff dialysis, plasmapheresis
Reasons for diuretic resistance?
- Poor GFR with inappropriately low dose
- Fluid and salt dietary non-compliance
- Low albumin
- Anasarca with poor gut absorption
- Rebound Na uptake after volume loss
- RAS activation
- Hypertrophy of distal nephron
5 types of cardiorenal syndrome
- Type 1 (acute) – Acute HF results in acute kidney injury
- Type 2 – Chronic cardiac dysfunction (eg, chronic HF) causes progressive chronic kidney disease
- Type 3 – Abrupt and primary worsening of kidney function due, for example, to renal ischemia or glomerulonephritis causes acute cardiac dysfunction, which may be manifested by HF.
- Type 4 – Primary CKD contributes to cardiac dysfunction, which may be manifested by coronary disease, HF, or arrhythmia.
- Type 5 (secondary) – Acute or chronic systemic disorders (eg, sepsis or diabetes mellitus) that cause both cardiac and renal dysfunction.
Causes of renal failure in Crohn’s disease
- IgAN
- Kidney stones/obstruction
- AIN secondary to meds (5-ASA, NSAIDs)
- MCD secondary to 5-ASA, NSAIDs
- Drug-induced SLE (anti-TNF)
- Membranous, secondary (anti-TNF)
- Secondary amyloidosis (AA)
- Prerenal from diarrhea
- ATN from intra-abdo sepsis
Renal manifestations of sickle cell disease
- Sickle cell nephropathy
- Renal infarction, papillary necrosis
- UTI, pyelonephritis
- Renal medullary carcinoma
- BP abnormalities (hypo or hypertension)
- Hyperuricemia, gout
- Hyperkalemia
- Enuresis
Worst renal disease from sickle cell trait?
How to diagnose?
Renal medullary carcinoma - rare, aggressive cancer
CT or MRI (US not sensitive enough) +/- scans to look for metastatic disease
Prognosis poor
HIVAN clinical presentation?
- African American ethnicity
- Advanced HIV disease – high viral load, low CD4 count
- Heavy proteinuria
- Rapid decline in kidney function
- Other – hematuria, HTN, edema
Treatment of HRS
- Albumin 1mg/kg (to max 100g divided twice per day), Midodrine 7.5-15mg PO TID, Octreotide 100-200mg TID
- Liver transplant
- NE or Terlipressin
Diagnosis of HRS
- Cirrhosis + ascites
- AKI
- NO response after diuretic withdrawal for 2 days and volume expansion with albumin (1g/kg body wt)
- Absence of shock
- No concurrent nephrotoxic drugs
- No structural kidney disease (normal US, no proteinuria or hematuria)
Differentiation of type 1 and 2 HRS
- Type 1: double of creatnine in 2 weeks or less
- Type 1: higher mortality
- Type 2: major feature is diuretic resistant ascites
Absolute and Relative contraindications to kidney biopsy
- Uncontrolled BP
- Bleeding diathesis
- Uncooperative patient/no consent
- Infection over biopsy site
- Small, hyperechoic kidneys (less than 9cm)
- Solitary native kidney
- Hydronephrosis
- Renal or peri-renal infection
- Multiple, bilateral cysts
- Pregnancy?
- Uncooperative patient
How to diagnose orthostatic proteinuria?
- 24-hr split urine collection
- Discard first AM void
- Collect all day until bed, lie down 2 hrs before bed -> orthostatic collection
- Collect all night and AM firstvoid -> recumbent collection
- Orthostatic proteinuria is diagnosed if the urinary protein excretion rate is normal for the nighttime collection (adults <50 mg over an eight-hour period) and the daytime collection exceeds the normal protein excretion rate.
Causes of CKD in oncology
- Use of nephrotoxic chemo
- Age at diagnosis
- Chronic pre-renal disease
- Pre-existing comorbid conditions, HTN, DM
- Pre-renal – diarrhea, poor oral intake
- ATN – chemotherapy, N/V/dehydration
- TLS – with therapy
- Obstruction – based on extent of malignancy
- Radiation nephritis
- GN from malignancy
- Hypercalcemia
Minimal change disease definitions: complete vs. partial remission, steroid-senitive, -resistant, -dependent, frequently relapsing
- Remission:
- Resolution of edema
- Normalization of albumin >=35
- Marked reduction in proteinuria
- “Complete” remission – Proteinuria <0.3 g/day
- “Partial” remission – Proteinuria <3.5 g/day AND decrease >50%
- Steroid-sensitive – response with pred 1mg/kg/d within 16wks
- Steroid-resistant – no response with pred 1mg/kg/d within 16 wks
- Steroid-dependent – relapse during therapy or within 15 days of stoping
- Infrequently-relapsing - <2 relapse/6 months (<4 relapse/12 months)
- Frequently-relapsing - >=2 relapse/6 months (>=4 relapse/12 months)
MCD secondary causes
- Drugs: NSAIDs, lithium (usually chronic interstitial nephritis), gold (usually membranous), interferon-alpha, tyrosine kinase inhibitors
- Allergy: Pollens, house dust, bee sting, immunizations, poison oak
- Autoimmune: SLE, celiac, myasthenia gravis, autoimmune pancreatitis, diabetes, allogenic stem cell transplant
- Infections: Mycoplasma pneumoniae, viral, parasitic
- Malignancy: Hodgkin disease, NHL, CLL (usually MPGN), MM, mycosis fungoides
Pathogenesis of MCD
Possibly impaired T cell regulation and circulating factors that permits permeability and foot process effacement
4 mechanisms for increased edema in nephrotic syndrome?
- Lack of oncotic pressure
- Sodium retention (w/ increased ENaC activity)
- Fluid retention
- AKI
- Increased capillary permeability in the peripheral capillary beds
- Dietary Na non-adherance
- Diuretic resistance
4 mechanisms for VTE in nephrotic syndrome
- Urinary losses of:
- anti-thrombin III
- plasminogen
- Protein C
- Protein S
- Increased platelet activation
- Hyperfibrinogenemia
- Venous stasis due to edema
- Hemoconcentration in renal vein – hemoconcentration post glomerular + diuretics
Pathology of MCD
- LM: Normal.
- IF: Negative. +/- mesangial IgA, C1q.
- EM: Diffuse FPE. Normal GBM. No deposits
Medical treatment options for MCD
- Prednisone 1mg/kg/d x 4-16 wks, taper over6 months
- Late relapse (>4 wks), do same
- Early relapse (<4 wks), longer taper
- Cyclophosphamide 2mg/kg/day x 12 weeks
- CNI (Cyclosporine or Tacrolimus)
- Rituximab
Side effects of non-steroid treatments for MCD?
- Cyclophosphamide – infertility, hemorrhagic cystitis, increased malignancy, cytopenias, teratogenicity, alopecia
- CNI – Hypertension, Diabetes, AKI, CKD, TMA, Gingival hyperplasia
- Rituximab – hypogammaglobulinemia, infusion reactions
- MMF – leukopenia, GI upset
AIN DDx
- Drugs
- NSAIDs, PPIs, penicillins and cephalosporins, fluoroquinolones/ciprofloxacin, rifampin, TMP-SMX, diuretics, allopurinol, indinavir, 5-ASA, cimetidine)
- Eosinophils on bx
- Infections
- Legionella, Leptospira, cytomegalovirus (CMV), Streptococcus, Mycobacterium tuberculosis, Corynebacterium diphtheriae, Epstein-Barr virus (EBV), Yersinia, polyomavirus, Enterococcus, Escherichia coli, adenovirus, Candida, and others
- Neutrophils on Bx
- Autoimmune
- SLE, Sarcoidosis, Sjögren’s syndrome, IgG4RD, hypocomplementemic tubulointerstitial nephritis, anti-tubular basement membrane (TBM) antibodies
- Lymphocytes on Bx
- TINU
- Patients present with interstitial nephritis and uveitis and occasionally with systemic findings including fever, weight loss, fatigue, malaise, anorexia, asthenia, abdominal and flank pain, arthralgias, myalgias, headache, polyuria, and/or nocturia
- Lymphocytic on Bx
Complications of nephrotic syndrome
- Edema
- VTE
- Dyslipidemia
- Infection / hypogammaglobulinemia
- Protein malnutrition
Ways to prevent tumor lysis syndrome?
- IV fluids (increase urinary flow rate)
- Allopurinol (xanthine oxidase inhibitor, decrease uric acid pdn)
- Rasburicase (do not use in G6PD deficiency; increase urate metabolism)
- Hold ACE, nephrotoxins
- No role for urinary alkalinization
What is PTU and renal side effects
Propylthiouracil
ANCA vasculitis, AIN
Cardiorenal syndrome types
- Type 1 (acute) – Acute HF results in acute kidney injury
- Type 2 – Chronic cardiac dysfunction (eg, chronic HF) causes progressive chronic kidney disease
- Type 3 – Abrupt and primary worsening of kidney function due, for example, to renal ischemia or glomerulonephritis causes acute cardiac dysfunction, which may be manifested by HF.
- Type 4 – Primary CKD contributes to cardiac dysfunction, which may be manifested by coronary disease, HF, or arrhythmia.
- Type 5 (secondary) – Acute or chronic systemic disorders (eg, sepsis or diabetes mellitus) that cause both cardiac and renal dysfunction.
Causes of AKI after hematopoeitic stem cell tx
- Prerenal, post-HCT capilary leak syndrome
- ATN secondary to ABx while pancytopenic
- CNIs (used to prevent GVHD)
- Hepatic sinusoidal obstruction syndrome (venoocclusive disease - chemoradiation-induced hepatic sinusoidal endothelial cell injury, which results in sinusoidal thrombosis and obstruction and portal hypertension)
- TMA
- Engraftment syndrome (presents like cytokine storm)
Classic features of HSP/IgAV
- Clinical feature - classic tetrad:
- Palpable purpura without thrombocytopenia and coagulopathy - leukocytoclastic vasculitis, predominant IgA
- Arthritis/arthralgia - oligo, migratory
- Abdominal pain
- Renal disease - IgA
Pathologic findings of IgA that worsen prognosis
MEST-C
Glomerulosclerosis, IFTA, fibrous crescents
Poor clinical markers of IgA nephropathy
HTN >140/90
Proteinuria >1g/d
High Cr at presentation
Smoking, obesity
Causes of secondary IgA nephropathy
IBD
Celiac disease
Cirrhosis
RA
Sarcoidosis
HIV
Causes of urate nephropathy
- TLS
- Gout (more chronic urate nephropathy)
- Tissue catabolism (seizures, treatment of solid tumor)
- Fanconi syndrome (uricosuria)
- Lesch-Nyhan syndrome (primary overproduction of uric acid due to hypoxanthine-guanine phosphoribosyltransferase deficiency
- IBD
Chemotherapy drugs and mechanism of AKI
- Cisplatin (and carboplatin though less) - ATN, TMA, Fanconi
- Cyclophosphamide - hemorrhagic cystits
- Ifosfamide - hemorrhagic cystitis, prox RTA, distal RTA
- Gemcitabine - TMA
- Methotrexate - ATN, prerenal
- 5-Fluorouracil - prerenal AKI