Complement activation, evidenced by deposition of C4d, is important in the diagnosis of antibodymediated rejection of cardiac allografts. C4d deposition can be assessed by either immunofluorescence (IF)- or immunoperoxidase (IP)-based methods. The use of methods varies considerably among institutions, but there are few data addressing their diagnostic equivalence. Objective.-To compare IF and IP C4d staining on paired endomyocardial biopsy samples from a large number of heart transplant patients. Design.-Retrospectively selected paired frozen and paraffin-embedded samples from the same biopsy were stained for C4d by IF and IP methods. Capillary staining was scored by using a 0, 1 , 2 , 3 scale. Results.-A total of 296 biopsy pairs from70 patients were studied. There were two hundred forty-three cases that were scored 0, twenty-four scored 1 , sixteen scored 2 , and thirteen scored 3 by IF. Two hundred thirty-one cases scored 0, forty scored 1 , ten scored 2 , and fifteen scored 3 by IP. Complete agreement was seen in 81%of cases.Among discrepant cases, 89%(n = 51) were minor (± 1) and 11% (n = 6) were major (± 2). Five of the 6 major discrepancy biopsies came from2 patients, both ofwhomhad concordant (IF and IP) 3 results on prior biopsies. The weighted k value for the entire sample set was 0.78 and for the first biopsy only set (to correct for bias introduced by multiple biopsies from the same patient) the weighted k value was 0.88. Conclusions.-Immunofluorescence and IP C4d staining methods are highly comparable and are both viable options for antibody-mediated rejection surveillance in transplant heart biopsies. (Arch Pathol Lab Med.
|Original language||English (US)|
|Number of pages||6|
|Journal||Archives of Pathology and Laboratory Medicine|
|State||Published - Nov 1 2010|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Medical Laboratory Technology