Pathogenesis
Lupus nephritis is primarily driven by this type of hypersensitivity reaction.
What is Type III hypersensitivity?
In this class of lupus nephritis, the glomeruli appear normal on light microscopy, but immunofluorescence reveals mesangial immune complex deposits.
What is Class I, minimal mesangial lupus nephritis?
A patient with SLE has persistent proteinuria and an active urinary sediment. Which diagnostic procedure provides the most definitive information about the histologic class and the activity versus chronicity of the renal disease?
What is a renal biopsy?
This medication is generally recommended for all patients with lupus nephritis at baseline unless contraindicated and requires ophthalmologic monitoring.
What is hydroxychloroquine?
A patient has active lupus nephritis with low complement levels. Although lupus nephritis involves complement activation through all three pathways, this complement component has a stronger correlation with renal involvement than the other commonly measured component.
What is C3?
A patient has severe nephrotic-range proteinuria. Biopsy reveals thickened capillary loops caused by subepithelial immune-complex deposits. Which class is most likely?
What is Class V membranous lupus nephritis?
This classic immunofluorescence pattern in active lupus nephritis contains IgG, IgA, IgM, C3, and C1q.
What is the “full house” pattern?
What is belimumab classified as, and what does it inhibit?
Monoclonal antibody directed against the cytokine BLyS, also known as B-cell activating factor (BAFF).
How long after SLE onset does lupus nephritis typically develop?
3–5 years
A biopsy shows immune-complex deposition involving the mesangium, subendothelial region, and subepithelial region. Hypercellularity is present in 60% of glomeruli.
What is Class IV lupus nephritis?
Proteinuria above this amount per day is considered nephrotic-range.
What is 3.5 g/day?
Mycophenolate mofetil (MMF) inhibits this, which leads to?
This drug inhibits inosine monophosphate dehydrogenase, decreasing GMP synthesis and consequently reducing B- and T-cell proliferation
Immune complexes in lupus nephritis can deposit in the mesangium and these two locations near the glomerular basement membrane.
What are the subendothelial and subepithelial spaces?
Identify this finding: Extracapillary hypercellularity involving 10% or more of the circumference of the Bowman capsule. Name the subtypes.
Crescent
Cellular crescent: More than 75% cells and fibrin, with less than 25% fibrous matrix.
Fibrous crescent: More than 75% fibrous matrix, with less than 25% cells and fibrin.
Fibrocellular crescent: Between 25% and 75% cells and fibrin, with the remainder consisting of a fibrous matrix.
What are the normal ranges for creatinine clearance in adults?
Males: 107-139 mL/min or 1.78-2.32 mL/s (SI units)
Females: 87-107 mL/min or 1.45-1.78 mL/s (SI units)
What is the indication for triple therapy, and what are its components?
Glucocorticoids plus a mycophenolic acid analog (MPAA) plus a third targeted agent (a calcineurin inhibitor, belimumab, or obinutuzumab) — is now conditionally recommended as first-line induction for active class III/IV (± class V) lupus nephritis
A patient initially develops immune-complex deposits limited to the mesangium. Over time, additional autoantibodies develop and deposits appear in the subendothelial and subepithelial spaces. This progression illustrates what immunologic phenomenon?
What is epitope spreading?
Identify 2 findings in chronic lesional activity in lupus nephritis
Global and segmental sclerosis, fibrous crescents, tubular atrophy, interstitial fibrosis
This glomerular cell is particularly important because injury to it disrupts the filtration barrier and produces clinically detectable proteinuria.
What is the podocyte?