8-20 Chronic Kidney Disease - Nephritic Pathology Flashcards
What are the essentials of Dx for nephritic syndrome?
Glomerular hematuria (dysmorphic red blood cells), modest proteinuria (usually 0.3–3 g/d).
Red blood cell casts may be present if glomerular bleeding is heavy.
Nephritic syndrome in more severe/inflammatory cases:
–Glomerular hematuria and proteinuria.
–Hypertension.
–Edema.
–Rising creatinine over days to months.
What are the essentials of Dx for RPGN?
Rapidly progressive glomerulonephritis in most severe cases:
- Glomerular hematuria and proteinuria.
- Hypertension and edema uncommon.
- Rising creatinine over days to months
What are the symptoms and signs of nephritic disease?
edema is seen in regions of low tissue pressure
- periorbital and scrotal areas
Hypertension
- sodium retention resulting from acute decrease in GFR.
Heavy glomerular bleeding from inflammation
- gross hematuria (smoky or cola-colored urine).
What are some helpful serologic studies to order when Dx’ing a nephritic problem?
complement levels
antinuclear antibodies
cryoglobulins
hepatitis serologies
ANCAs
anti-GBM antibodies
antistreptolysin O (ASO) titers
- order based on Hx and exam
What urinalysis and dipstick results would you expect from nephritic pathology?
The urine dipstick is positive for protein and blood.
Urinary microscopy reveals red blood cells that are misshapen or dysmorphic from traversing a damaged glomerular filtration barrier.
Red blood cell casts are seen with heavy glomerular bleeding and tubular stasis. When quantified, proteinuria is usually subnephrotic (< 3 g/d)
What are the essentials of Dx for postinfectious glomerulonephritis?
Proteinuria.
Glomerular hematuria.
Symptoms 1–3 weeks after infection (often pharyngitis or impetigo).
What is the typical presentation of postinfectious glomerulonephritis?
Children: abrupt onset of nephritic syndrome and acute kidney injury but can present anywhere in nephritic spectrum
What associations should you make with postinfectious glomerulonephritis?
Streptococci, inc. pharyngitis and/or impetigo
other bacterial infections (eg, staphylococci, endocarditis, shunt infections)
What are the expected laboratory findings for postinfectious glomerulonephritis?
Serum complement levels are low;
anti-streptolysin O (ASO) titers can be high
Glomerular hematuria and subnephrotic proteinuria are present;
severe cases may demonstrate elevated serum creatinine and urinary red blood cell casts.
What morphological findings would you expect if you did a kidney biopsy on a case of postinfectious glomerulonephritis? List changes seen with light, EM, and IF microscopy.
Kidney biopsy shows a diffuse proliferative pattern of injury on light microscopy
Immunofluorescence demonstrates granular deposition of IgG and C3 in the mesangium and along the capillary basement membrane.
Electron microscopy shows large, dense subepithelial deposits or “humps.”
How do you treat postinfectious glomerulonephritis?
underlying infection should be identified and treated appropriately
Supportive:
Antihypertensives, salt restriction, and diuretics
Corticosteroids have not been shown to improve outcome.
What is the prognosis for post-infectious glomerulonephritis?
depends on the severity of the glomerular injury and age of the patient.
Children are more likely to fully recover
adults are more prone to the development of severe disease (RPGN with crescent formation) and CKD.
What are the essentials to Dx’ing IgA nephropathy?
Proteinuria: minimal to nephrotic range.
Glomerular hematuria: microscopic is common; macroscopic (gross) after infection.
Positive IgA staining on kidney biopsy.
What causes Berger disease? Is it primary or secondary?
IgA nephropathy
primary renal disease of IgA deposition in the glomerular mesangium
due to deficient O-linked glycosylation of IgA subclass 1 molecules.
IgA nephropathy can be a primary (renal-limited) disease, or it can be secondary to hepatic cirrhosis, celiac disease, and infections such as HIV and cytomegalovirus. Susceptibility to IgA nephropathy seems to be inheritable.
What is the most commonly seen glomerular disease worldwide? What populations do you see it in?
IgA nephropathy
More common in Asia.
seen in children and young adults,
males affected two to three times more commonly than female
What is the typical clinical presentation of IgA nephropathy?
episode of gross hematuria
- associated with a mucosal viral infection, URI
red or smokey-colored urine 1–2 days after illness onset
—a so-called “synpharyngitic” presentation in contradistinction to the latent period seen in postinfectious glomerulonephritis.
IgA nephropathy can present anywhere along the nephritic spectrum from asymptomatic microscopic hematuria to RPGN. Rarely, nephrotic syndrome can be present as well.
What are some serologic tests that aid in Dx of IgA nephropathy?
There are no serologic tests that aid in this diagnosis
Serum complements are normal
What microscope findings would you expect for IgA nephropathy? (light and IF)
focal glomerulonephritis with mesangial proliferation
immunofluorescence demonstrates diffuse mesangial IgA and C3 deposits
How would you treat IgA nephropathy?
disease course varies widely - tailor to progression risk
Patients with low risk for progression can be monitored annually
Patients at higher risk (proteinuria > 1.0 g/d, decreased GFR, or hypertension or any combination of these three conditions)
- ACE inhibitor or ARB
- methylprednisolone
IgA neuropathy & a rapidly progressive course with crescent formation on biopsy
- cyclophosphamide and corticosteroid therapy should be considered
- Kidney transplantation - recurrent disease in 30% of patients 5–10 years posttransplant, graft failure rare
What is the presentation of Henloch-Schonlein purpura?
systemic small-vessel leukocytoclastic vasculitis
- associated with IgA subclass 1 deposition in vessel walls.
most common in children, male predominance
- often associated with an inciting infection, such as group A streptococcus or other exposure.
It classically presents with palpable purpura in the lower extremities and buttock area; arthralgias; and abdominal symptoms, such as nausea, colic, and melena.
What problems does Henoch-Schonlein purpura cause in the kidney?
decrease in GFR
nephritic presentation
.
The renal lesionsidentical to those in IgA nephropathy
- underlying pathophysiology appears to be similar
microscopic hematuria and minimal proteinuria will recover fully
Progressive CKD and possibly ESRD are more likely to develop in those with the nephrotic syndrome
presence of both nephritic and nephrotic syndrome poses the worst renal prognosis.
What connection does Henoch-Schonlein purpura have to ANCAs?
Rapidly progressive disease with crescent formation on biopsy may be treated as in ANCA-associated vasculitis
