CONTEXT: Complement activation, evidenced by deposition of C4d, is important in the diagnosis of antibody-mediated 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 from 70 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 from 2 patients, both of whom had concordant (IF and IP) 3+ results on prior biopsies. The weighted κ 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 κ 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.
CONTEXT: Complement activation, evidenced by deposition of C4d, is important in the diagnosis of antibody-mediated 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 from 70 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 from 2 patients, both of whom had concordant (IF and IP) 3+ results on prior biopsies. The weighted κ 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 κ 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.
Authors: Jon Kobashigawa; Maria G Crespo-Leiro; Stephan M Ensminger; Hermann Reichenspurner; Annalisa Angelini; Gerald Berry; Margaret Burke; Lawrence Czer; Nicola Hiemann; Abdallah G Kfoury; Donna Mancini; Paul Mohacsi; Jignesh Patel; Naveen Pereira; Jeffrey L Platt; Elaine F Reed; Nancy Reinsmoen; E Rene Rodriguez; Marlene L Rose; Stuart D Russell; Randy Starling; Nicole Suciu-Foca; Jose Tallaj; David O Taylor; Adrian Van Bakel; Lori West; Adriana Zeevi; Andreas Zuckermann Journal: J Heart Lung Transplant Date: 2011-03 Impact factor: 10.247