[1456] CD163 Is a More Useful Immunohistochemical Stain than CD68 in Predicting Outcome of Patients with Classical Hodgkin Lymphoma

Jonathan L Klein, Gabriel A Bien-Willner, Kelley V Foyil, Nancy L Bartlett, Ling Chen, John L Frater, Eric Duncavage, Anjum Hassan, TuDung T Nguyen, Friederike Kreisel. Washington University School of Medicine, Saint Louis, MO

Background: Recent published studies have proposed an association of tumor-associated macrophages with clinical outcome in patients with classical Hodgkin lymphoma (cHL). Applying routine immunohistochemistry for CD68 and CD163 has offered a hopeful ancillary tool for clinicians and pathologists to better capture patients with lymphoma progression or relapse, where failures could not be predicted by clinical or biological markers alone. However, only a handful of these studies exist, with inconsistent results, and more studies are needed for validation.
Design: Immunohistochemistry for CD68 and CD163 was performed on diagnostic tissue of 89 patients with classical Hodgkin lymphoma. 94% represented lymph node samples. All patients were treated with either ABVD or an ABVD-like regimen with or without radiotherapy. Percentage of positively staining histiocytes was individually analyzed by several academic hematopathologists (JLF, ED, AH, TTN, and FK). Intraclass correlation (ICC) was performed to evaluate for inter-observer variability. Clinical data on 81 patients was available for correlation with CD68 and CD163 staining results.
Results: Inter-observer variability was shown to be poorer for CD68 (ICC = 0.45, fair agreement) compared to CD163 (ICC = 0.70, good agreement), within the group of hematopathologists. Additionally, cases of cHL with >25% mean CD163 reactivity were found to have significantly worse outcomes compared to <25% mean CD163 reactivity (mean 71 vs. 101 months overall survival, p = .002) in populations with a similar mean age at diagnosis. No significant correlation was found for CD68 and patient outcome. Furthermore, in patients who were considered clinically high risk (International Prognostic Scores >3), <25% mean CD163 positive macrophage staining showed better overall survival (mean 90 vs. 52 months overall survival, p = .008).
Conclusions: Enumeration of macrophages in diagnostic samples of cHL yielded correlation with clinical outcome only with CD163, which also showed a stronger ICC among the analyzing hematopathologists compared to CD68. Furthermore, CD163 may be a useful ancillary tool to more accurately predict response to treatment in high risk patients.
Category: Hematopathology

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 227, Monday Morning


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