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An Immunohistopathologic Study to Profile the Folate Receptor Beta Macrophage and Vascular Immune Microenvironment in Giant Cell Arteritis
Published on: February 8, 2019
[Clinicopathologic analysis of 34 patients with microscopic polyangitis]
Xian-fa Xuan1, Hui-juan Wu, Ye Liu
1Department of Pathology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Objective:
To study the clinicopathologic features of microscopic polyangitis (MPA), and to compare the differences in anti-neutrophil cytoplasmic autoantibody (ANCA)-positive and ANCA-negative patients, as well as in ANCA-positive cases with or without glomerular immunoglobulin deposition.
Methods:
Thirty-four biopsy-proven cases of MPA were retrieved from the archival files of the Department during the past 7 years. The clinicopathologic characteristics between ANCA-positive and negative patients, as well as between ANCA-positive cases with and without glomerular immunoglobulin deposition, were compared.
Results:
Amongst the 34 MPA patients studied, about one-fifth to one-half were accompanied by various extrarenal symptoms. Serum ANCA was positive in 26 patients (76.5%). A slight to moderate increase in urinary protein was demonstrated in 31 patients, while 3 patients had nephrotic syndrome. Elevated serum creatinine was detected in 32 cases. Renal biopsy revealed crescentic glomerulonephritis in 24 cases, focal segmental glomerulonephritis in 8 cases, vascular fibrinoid necrosis with inflammation in 7 cases, intimal thickening of arterioles in 24 cases, interstitial inflammatory cells, including neutrophil infiltration (21 cases), in 29 cases. Crescentic formation was more common in the ANCA-positive group than in the ANCA-negative group (P < 0.05). Amongst the 26 ANCA-positive cases, 10 had glomerular immunoglobulin deposits (including 1 case with IgA nephropathy). In general, these cases had a greater degree of proteinuria than those without glomerular immunoglobulin deposits (P < 0.05).
Conclusions:
The diagnosis of MPA relies on histologic examination of renal biopsy and clinicopathologic correlation. Serum ANCA seems important for glomerular crescent formation. Glomerular immunoglobulin deposition may also play a significant role in the exacerbation of proteinuria.
Insights
Microscopic polyangitis (MPA) diagnosis requires renal biopsy and clinicopathologic correlation. Anti-neutrophil cytoplasmic autoantibody (ANCA) positivity is linked to glomerular crescent formation, while immunoglobulin deposition may worsen proteinuria.
Area of Science:
- Nephrology
- Immunology
- Pathology
Context:
- Microscopic polyangitis (MPA) is a systemic vasculitis affecting small vessels.
- Distinguishing MPA subtypes is crucial for prognosis and treatment.
- The role of anti-neutrophil cytoplasmic autoantibodies (ANCA) and immunoglobulin deposition in MPA pathogenesis requires further elucidation.
Purpose:
- To investigate the clinicopathologic features of MPA.
- To compare MPA patients based on ANCA status (positive vs. negative).
- To analyze differences in ANCA-positive MPA with and without glomerular immunoglobulin deposition.
Summary:
- Thirty-four biopsy-proven MPA cases were analyzed.
- ANCA was positive in 76.5% of patients.
- ANCA positivity correlated with increased crescentic glomerulonephritis (P < 0.05).
- Glomerular immunoglobulin deposition in ANCA-positive cases was associated with greater proteinuria (P < 0.05).
Impact:
- This study highlights the diagnostic importance of renal biopsy and clinicopathologic correlation in MPA.
- Serum ANCA positivity is a significant indicator for glomerular crescent formation.
- Glomerular immunoglobulin deposition may contribute to increased proteinuria in MPA.