Clinical Indices for Overlapping Syndrome (ANCA Associated Crescentic Glomerulonephritis [AACGN] and Immune Complex Medicated Glomerulopathy) are Similar to AACGN Only Cases

Document Type

Conference Proceeding

Publication Date

3-2020

Publication Title

Laboratory Investigation

Abstract

Background: Overlapping syndromes of ANCA-associated crescentic glomerulonephritis (AACGN) and other types of glomerulopathies characterized by immune complex deposition have been reported in the literature. Most of these are case series that concentrate on a single type of immune complex disease when AACGN is present, with a number comparing the immune complex mediated glomerulopathy (ICMGN) of interest versus that disease with co-existing AACGN. However, very few have compared AACGN alone versus AACGN with ICMGN. No series has done the comparison regardless of ICMGN etiology. The aim of this series was to make that comparison, following serum creatinine (sCr) to determine whether the two groups (AACGN-only group versus AACGN plus mixed ICMGN group) behave differently over time. Design: We evaluated our database of 4049 renal biopsies over the past 11 years (January 2008 to August, 2019) and identified 14 cases with dual diagnoses of AACGN and other ICMGN. Data was collected and compared with 15 randomly selected AACGN-only cases over the similar period of time, using unpaired student t tests (significant difference = p< 0.05). Results: The concurrent cases represented 0.35% of our overall biopsies (14/4049). Patients’ ages ranged from 48 to 79 years old. There were 8 female patients and 6 male patients. All 14 patients were ANCA positive and had crescentic glomerulonephritis. Percentage of crescents in the biopsies ranged from 10% to 78%. ICMGN included the following: 5 membranoproliferative glomerulonephritis (MPGN) type 1, 1 MPGN type 3, 2 post-infectious glomerulonephritis, 2 membranous glomerulopathies, 1 idiopathic mesangial proliferative glomerulonephritis, 1 class 3 lupus nephritis, 1 type 2 lupus nephritis, and 1 IgA nephropathy. With the exception of the class 3 lupus nephritis, most of the ICMGN appeared to be mild. When compared to the AACGN-only group, there were no significant differences in clinical and histologic indices including age, % crescents, sCr on biopsy days, and sCr during the follow-up periods in months (m) and years (y) as seen in Table 1 below. Conclusions: Although numbers of follow-up cases were limited over time, the two groups showed similar % of crescent formation but no differences in renal functional changes over up to 5 years of follow-up. The findings imply that AACGN is the dominant disease process in the majority of overlapping syndromes of AACGN with ICMGN, similar to the clinical processes of AACGN-only disease.

Volume

100

Issue

Suppl 1

First Page

1585

Comments

United States and Canadian Academy of Pathology (USCAP) 109th Annual Meeting, February 29 - March 5, 2020, Los Angeles, CA

Last Page

1585

DOI

10.1038/s41374-020-0394-7

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