Nephritic syndromes Flashcards
IgA nephropathy (Maladie de Berger): pathology and causes
- abnormal IgA forms, -> IgA-antibody complex formation -> deposits in kidneys → kidney damage
Associated with gastrointestinal (GI)/respiratory tract infections
IgA nephropathy (Maladie de Berger): RF
- Most common nephropathy worldwide
- usually presents in childhood
- Highest prevalence in people of East Asian/European ancestry
- Family history of chronic nephritis, alcohol consumption, recurrent infections
IgA nephropathy (Maladie de Berger): Signs and symptoms
- Episodic hematuria
Sometimes accompanying upper respiratory tract infections - Asymptomatic microscopic hematuria, with subnephrotic proteinuria
- Classic nephrotic syndrome/kidney injury (minority)
IgA nephropathy (Maladie de Berger): Diagnosis
Perform urinalysis and a renal biopsy
Urinalysis -> hematuria
- RBCs, RBC casts
Renal biopsy:
- Light microscopy: Mesangial proliferation, immune complexes deposited in mesangium
- Electron microscopy: Immune complexes deposited in mesangium
- Immunofluorescence: Mesangial IgA deposits, +/- IgA, +/- IgM
IgA nephropathy (Maladie de Berger): treatment
- Prednisone (Oral/parenteral glucocorticoid intermediate actions)
Rapidly Progressive Glomerulonephritis: pathology and causes
- Inflammation of kidney’s glomeruli → crescent-shaped proliferation of cells in Bowman’s capsule → renal failure within weeks/months
RPG: Primary type
- Idiopathic
RPG: Secondary type
Type I: anti-GBM antibodies
- Goodpasture syndrome
Type II: immune complexes
- Poststreptococcal glomerulonephritis
- systemic lupus erythematosus
- IgA nephropathy
- Henoch-Schonlein purpura
Type III: anti-neutrophilic cytoplasmic antibodies (ANCA)
- Cytoplasmic ANCA (C-ANCA): Wegener’s granulomatosis
- Perinuclear ANCA (P-ANCA): microscopic polyangiitis, Churg-Strauss syndrome
RPG: Signs and symptoms
Nephritic syndrome:
- Hematuria,
- oliguria,
- edema,
- hypertension
RPG: Complications
-> rapid progressive to acute renal failure if untreated
RPG: Diagnosis
Perform a kidney biopsy + immunofluorescence
Urinalysis: -> hematuria
Kidney biopsy
- Light microscopy: crescent-shaped glomeruli
Immunofluorescence
- Type I: linear, antibodies bind to collagen of glomerular basement membrane
- Type II: granular, immune complex deposition in subendothelium
- Type III: negative (pauci-immune), associated with ANCAs in blood
RPG: treatment
Pulse methylprednisolone, then:
- prednisone
- cyclophosphamide
- rituximab
- plasmapheresis
In case of renal failure -> dialysis + kidney transplant
Goodpasture syndrome: pathology and cause
- anti-GBM antibody disease -> damage to the basement membrane in lungs + kidneys
Mostly composed of Type IV collagen
Goodpasture syndrome: RF
- Bimodal distribution: male between 20-30, female between 60-70
- genetic: predisposition for genes that code for HLA-DR15
- Environmental: infection, smoking, oxidative stress, hydrocarbon-based solvents
Goodpasture syndrome: Signs and symptoms
Pulmonary manifestations usually occur before renal ones. Minority (20–40%) with only renal manifestations
- Damaged lung alveoli → cough, hemoptysis, dyspnea
- Kidney filtration problems -> hematuria, proteinuria), nephritic syndrome
Goodpasture syndrome: complications
- Chronic renal failure
will require dialysis/kidney transplant
Goodpasture syndrome: Diagnosis
Perform a renal biopsy
- Light microscopy: Crescentic glomerulonephritis
- Electron microscopy: Diffuse thickening of glomerular basement membrane
- Immunofl uorescence: Linear deposition along basement membrane
Goodpasture syndrome: treatment
- Prednisone
- cyclophosphamide,
- plasmapheresis to filter plasma/fluid of blood (reduces risk of chronic renal failure
Post-streptococcal glomerulonephritis (PSGN): pathology and causes
Also called Acute proliferative Glomerulonephritis
- Inflammation of glomeruli, complication of bacterial infection
- Commonly arises several weeks after group A beta-hemolytic streptococcus infection
- IgG/IgM antibodies bind to bacterial antigens, form immune complexes →complexes travel through bloodstream to glomerulus, deposit in glomerular basement membrane
PSGN: causes
- Group A beta-hemolytic streptococcus infection
PSGN: RF
- Most commonly in children, male
Six weeks after impetigo, 1–2 weeks after throat infection
PSGN: symptoms
- Nephritic syndrome: hematuria, oliguria, edema, hypertension
- Fever, headache, malaise, anorexia, nausea
PSGN: complications
Rapidly progressive glomerulonephritis -> renal failure
PSGN: Diagnosis
Lab results
- proteinuria + hematuria
- Antibodies against group A streptococcus (e.g. anti-DNase B antibodies, anti-Streptolysin O antibody)
- decreased complement levels
Renal biopsy
- Light microscopy: Mesangial proliferation → hypercellular glomerulus
- Electron microscopy: Subepithelial deposits of immune complexes, “humps”
- Immuno fluorescence“Starry sky -> granular deposition of IgG, complement in basement membrane, mesangium
PSGN: treatment
- usually supportive
Lupus nephritis: pathology and causes
- Inflammation of kidney due to systemic lupus erythematosus
- Focal (nephrons in one area)/diffuse (all nephrons in both kidneys)
- Caused by antinuclear antibodies ( anti-dsDNA): bind to nuclear antigens, form antigen-antibody complexes -> deposits in capillary walls, basement membrane, Bowman’s space -> type III hypersensitivity reaction
Lupus nephritis: types
Class I: Minimal mesangial glomerulonephritis
Class II: Mesangial proliferative glomerulonephritis
Class III: Focal glomerulonephritis
Class IV: Diffuse proliferative nephritis
Class V: Membranous glomerulonephritis
Class VI: Advanced sclerosing lupus nephritis
Lupus nephritis: signs and symptoms
- Nephrotic, nephritic syndrome
- hyperlipidemia (less protein more fat)
- Nephritic syndrome:
hematuria, hypertension, proteinuria -> hypoalbuminemia -> decreased oncotic pressure -> edema, oliguria
Lupus nephritis: complications
- Renal vein thrombosis
- pulmonary embolism
- rapidly progressive glomerulonephritis
Lupus nephritis: diagnosis
Perform a kidney biopsy - Microscopic presentation depends on class of lupus nephritis
Lupus nephritis: T
- Prednisone
- mycophenolate
- cyclophosphamide
