Increased macrophage density of cardiac allograft biopsies is associated with antibody‐mediated rejection and alloantibodies to HLA antigens. (11th April 2014)

• Record Type: Journal Article
• Authors: Xu, Lauren; Collins, Jennifer; Drachenberg, Cinthia; KuKuruga, Debra; Burke, Allen
• Is Part Of: Clinical transplantation. Volume 28:Number 5(2014:Sep./Oct.)
• Page Start: 554
• Page End: 560
• Publication Date: 2014-04-11
• Subjects: Transplantation of organs, tissues, etc -- Periodicals; 617.95
• DOI: 10.1111/ctr.12348
• Languages: English
• ISSNs: 0902-0063

Abstract

<abstract abstract-type="main" id="ctr12348-abs-0001"> <title>Abstract</title> <sec id="ctr12348-sec-0001" sec-type="section"> <title>Background</title> <p>Antibody‐mediated rejection (AMR) is characterized histologically by intracapillary macrophages. Macrophage density may be an alternative method of determining inflammatory changes in AMR.</p> </sec> <sec id="ctr12348-sec-0002" sec-type="section"> <title>Methods</title> <p>We identified 118 heart transplant patients with serologic testing for HLA alloantibodies. Macrophage density was graded as 1+ (<45/mm<sup>2</sup>), 2+ (46–90/mm<sup>2</sup>), and 3+ (>90/mm<sup>2</sup>). Maximal macrophage density and complement staining over multiple biopsies were correlated with peak panel reactive antibodies (PRA), donor‐specific antibodies (DSA), and the clinical diagnosis of AMR.</p> </sec> <sec id="ctr12348-sec-0003" sec-type="section"> <title>Results</title> <p>The presence of PRA correlated with macrophage score (p = 0.001). Macrophage density correlated with any DSA (p < 0.0001), class I DSA (p < 0.0001), class II DSA (p < 0.0001), and class II DQ (p < 0.0001). Nine patients had clinical AMR. Among patients with AMR, 89% had a biopsy over the period of AMR with ≥3+ macrophage density (89% sensitivity); among patients without AMR, 93% of patients had no biopsy at any time with ≥3+ macrophage density (specificity). There was perfect concordance between the scores of C4d positivity and macrophage density in 61% and only partial concordance in 20%, with complete discordance in 19% in biopsies taken during clinical episodes of AMR.</p> </sec> <sec id="ctr12348-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Macrophage density in allograft endomyocardial biopsies is frequently elevated during clinical episodes of AMR and correlates well with alloantibodies.</p> </sec> </abstract>