SM_205a: Renal Syndromes Flashcards
Describe the classification of renal syndromes
Dysmorphic RBCs indicate ______
Dysmorphic RBCs indicate glomerular bleeding
In a urine workup, _____, _____, and _____ are abnormal
In a urine workup, hematuria, proteinuria, and casts are abnormal
RBC cell casts indicate _______
RBC cell casts indicate glomerular hematuria (nephritic syndrome)
Lipid casts / oval body indicate ______
Lipid casts / oval body indicate nephrotic syndrome
If asymptomatic hematuria without proteinuria or other renal abnormalities, patient needs _____
If asymptomatic hematuria without proteinuria or other renal abnormalities, patient needs urological workup
If proteinuria is alone, first ______. If there is no obvious cause and significant proteinuria, patient needs ______
If proteinuria is alone, first quanitfy. If there is no obvious cause and significant proteinuria, patient needs renal workup
If hematuria + proteinuria, casts, or elevated serum creatinine, patient needs ______
If hematuria + proteinuria, casts, or elevated serum creatinine, patient needs renal workup
Purpose of a kidney biopsy is to ______ and ______
Purpose of a kidney biopsy is to confirm diagnosis and dictate management
Patients with _____, _____, _____, and _____ for which the cause is not obvious require a kidney biopsy
Patients with nephrotic syndrome, nephritic syndrome, AKI and kidney transplant for which the cause is not obvious require a kidney biopsy
- Nephrotic syndrome: lot of proteinuria
- Nephritic syndrome: results from glomerular inflammation and presents with hematuria
Describe the different ways of analyzing kidney biopsies
Analyzing kidney biopsies
- Light microscopy: cell proliferation, GBM abnormalities
- Immunofluorescence microscopy: immunocomplement / Ig staining
- Electron microscopy: immune complex deposits, thickness of GBM, foot process effacement of podocytes
This is a _____ glomerulus
This is a normal glomerulus
- No proliferation, crescent, or segmental lesions
Describe nephrotic syndrome
Nephrotic syndrome
- Constellation of findings: proteinuria >3g/day, hypoalbuminemia, HLD, lipiduria, edema
- Primary causes: minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy
- Secondary causes: diabetes, amyloidosis
Describe minimal change disease
Minimal change disease
- Most common cause of nephrotic syndrome in children
- Due to secondary cause in adults (hematologic malignancy, medications)
- Presents with sudden onset edema + other features of nephrotic syndrome sometimes following infection
Most common cause of nephrotic syndrome in kids is ______
Most common cause of nephrotic syndrome in kids is minimal change disease
Kidney biopsy of minimal change disease reveals _____, _____, and _____
Kidney biopsy of minimal change disease reveals normal-appearing glomeruli on LM, negative IF, and diffuse podocyte foot process effacement on EM
Minimal change disease is often responsive to treatment with _____
Minimal change disease is often responsive to treatment with steroids
Describe focal segmental glomerulosclerosis
Focal segmental glomerulosclerosis
- Most common cause of primary nephrotic syndrome in African Americans
- Recently linked to APOL1 mutation
- Often primary or idiopathic but can be secondary to other conditions
- HTN, edema
- Proteinuria ± hematuria
- Serum creatinine normal or elevated
_____ is most common cause of primary nephrotic syndrome in African Americans
Focal segmental glomerulosclerosis is most common cause of primary nephrotic syndrome in African Americans
Describe kidney biopsy findings of focal segmental glomerulosclerosis
Kidney biopsy findings of focal segmental glomerulosclerosis
- Focal: not all glomeruli involved
- Segmental: only a portion of glomerulus involved
- Need ≥ 1 lesions of segmental sclerosis on LM
- Scant or non-specific staining of IgM, C3, or C1q on IF
- Podocyte foot process effacement (focal or diffuse) on EM
Describe treatment of focal segmental glomerulosclerosis
Treatment of focal segmental glomerulosclerosis (FSGS)
- Challenging
- Treat secondary cause (HIV, obesity, etc) if possible
- If primary/idiopathic FSGS, start with steroids -> most do not respond -> try Calcineurin inhibitor or Cellcept
Describe membranous nephropathy
Membranous nephropathy
- Most common cause of primary nephrotic syndrome in Caucasian adults
- Can be associated with solid tumor cancers, medication exposures (NSAIDs, Gold), infections (Hepatitis B or C), or autoimmune disease (SLE)
- If no secondary cause, called primary
- Onset occurs over days to weeks
Describe kidney biopsy findings of membranous nephropathy
Kidney biopsy findings of membranous nephropathy
- Thickened GBM on LM
- “Spikes and holes” on silver stain
- Granular IgG on IF
- Subepithelial immune deposits on EM
- PLA2R in primary disease
Describe treatment of membranous nephropathy
Treatment of membranous nephropathy
- Prompt treatment needed to avoid complications of the disease
- Treatment of an existing secondary cause may cause resolution of membranous nephropathy
- If primary depends on degree of proteinuria: low level treated with RAAS blockade, salt restriction, and diuresis; high level treated with immune modulation (cyclophosphamide, calcineurin inhibitor)
Describe nephritic syndrome
Nephritic syndrome
- Clinical sequelae of glomerular inflammation
- Hematuria
- Dysmorphic RBCs and/or RBC casts
- Proteinuria (usually < 3g/day)
- Varying degrees of renal insufficiency, HTN, and edema
- Rapidly progressive glomerulonephritis (RPGN): glomerular inflammation that causes renal failure in weeks to months, crescentic glomerulonephritis on biopsy
Rapidly progressive glomerulonephritis manifests as _____ on biopsy
Rapidly progressive glomerulonephritis manifests as crescentic glomerulonephritis on biopsy
Three broad classifications of nephritic syndrome are _____, _____, and _____
Three broad classifications of nephritic syndrome are immune-complex mediated, pauci-immune, and anti-glomerular basement membrane disease
- Immune-complex mediated: post-infectious GN, IgA nephropathy, lupus nephritis, membranoproliferative GN
- Pauci-immune (ANCA positive): granulomatosis with polyangiitis, microscopic polyangiitis
- Ant-glomerular basement membrane disease
Describe anti-GBM disease
Anti-GBM disease
- Pulmonary-renal syndrome
- Auto-antibodies that bind to type IV collagen in the GBM
- Goodpasture’s when lung involvement
- Symptoms: malaise, weight loss, hemoptysis
- Labs: hematuria, proteinuria, often rising Cr, + anti-GBM anitbody
- Biopsy: diffuse crescentic glomerulonephritis on LM, classic linear IgG staining on IF
- Treatment: steroids + cyclophosphamide + plasmapheresis (aggressive)
Anti-GBM characteristic lab finding is ______ and characteristic biopsy finding is ______
Anti-GBM characteristic lab finding is + anti-GBM antibody and characteristic biopsy finding is linear IgG staining on IF
Describe post-infectious glomerulonephritis
Post-infectious glomerulonephritis
- Onset of nephritic syndrome 10-14 days after Strep pharyngitis or skin infection
- Symptoms: gross hematuria, fever, malaise, HTN
- Labs: elevated Cr, hematuria, proteinuria, low C3/C4, possibly +ASO titer
- Biopsy: hypercellularity on LM, “starry sky” on IF, subepithelial humps on EM
- Treatment: supportive (antibiotics for infection), steroids if severe to reduce inflammation
Post-infectious glomerulonephritis manifests as _____ on IF and ______ on EM
Post-infectious glomerulonephritis manifests as starry sky on IF and epithelial humps on EM
Describe lupus nephritis
Lupus nephritis
- Prototypical immune-complex GN
- Usually younger woman with known lupus
- Symptoms: malaise, joint pain, rash, oral ulcers, serositis, edema
- Labs: + ANA, + anti-dsDNA, low C3/C4, anemia
- Urine: hematuria and/or proteinuria
- Kidney biopsy required for diagnosis
- Treatment: supportive for minimal inflammation, high dose steroids + immune-modulating drugs (cyclophosphamide + Cellcept) for active inflammation
____ is required for diagnosis of lupus nephritis
Kidney biopsy is required for diagnosis of lupus nephritis
(6 classes)
Describe IgA nephropathy
IgA nephropathy
- Most common GN worldwide
- Can be secondary to inflammatory bowel disease or cirrhosis
- Symptoms: hematuria at the same time or 1-2 days after upper respiratory infection (or diarrheal illness)
- Labs: Cr normal or elevated, C3/C4 normal, variable proteinuria
- Biopsy: mesangial proliferation on LM and + IgA on IF
- Treatment: ACE-i/ARB if mild, steroids or immunosuppressive therapy if high risk
Kidney biopsy in IgA nephropathy shows _____ on LM and _____ on IF
Kidney biopsy in IgA nephropathy shows mesangial proliferation on LM and +IgA on IF
Describe membranoproliferative glomerulonephritis
Membranoproliferative glomerulonephritis
- Often associated with underlying infection (Hepatitis C)
- Can also be related to genetic mutation (C3 nephritic factor) or be idiopathic
- Presentation: nephritic or nephrotic features
- Labs: Cr usually elevated, C3 may be low
- Biopsy: lobular glomeruli on LM, tram-track appearance on Jones/silver stain, IF often shows C3 and IgG staining, various types of immune complex deposits on EM
- Treatment: for infection of Hep-C associated, otherwise difficult
Membranoproliferative glomerulonephritis manifests as _____ on LM and has a _____ appearance on Jones/silver stain
Membranoproliferative glomerulonephritis manifests as lobular glomeruli on LM and has a tram-track appearance on Jones/silver stain
(IF often shows C3 and IgG staining, various types of immune complex deposits on EM)
Describe granulomatosis with polyangiitis (Wegener’s granulomatosis)
Granulomatosis with polyangiitis (Wegener’s granulomatosis)
- Pulmonary-renal syndrome
- Middle age or older individuals
- Symptoms: constitutional, nasal or sinus (saddle nose deformity), palpable purpura
- Labs: hematuria, proteinuria, elevated Cr, + c-ANCA, PR-3
- Biopsy: necrotizing crescentic GN
- Treatment depends on level of organ involvement/damage, often high-dose steroids + cyclophosphamide
Describe microscopic polyangiitis
Microscopic polyangiitis
- Pulmonary-renal syndrome
- Middle-aged individuals
- Symptoms: constitutional, lower respiratory tract (hemoptysis), palpable purpura
- Labs: hematuria, proteinuria, elevated CR, + p-ANCA, MPO
- Biopsy: necrotizing crescentic GN
- Treatment: depends on level of organ involvement/damage, often high-dose steroids + cyclophosphamide
Nephritic syndrome is the result of ______
Nephritic syndrome is the result of glomerular inflammation
