title: CD163 immunohistochemistry is superior to CD68 in predicting outcome in classical Hodgkin lymphoma.
abstract: OBJECTIVE
  In recent years, research has increasingly focused on the microenvironment of classical Hodgkin lymphoma (CHL) as a predictor of treatment outcome. The focus of this study was to assess the interobserver reproducibility in interpreting macrophage-associated immunohistochemistry (IHC) for CD68 and CD163 in a retrospective cohort of 88 patients with CHL.
  
  
  METHODS
  Staining results were correlated with clinical outcome in all patients and those with a high international prognostic score (IPS).
  
  
  RESULTS
  The intraclass correlation (ICC) for the five hematopathologists interpreting the IHC was stronger for CD163 (0.70) than for CD68 (0.50). Using a cutoff of 25% mean macrophage reactivity and including all patients, a statistically significant difference in overall survival (OS) was seen only for CD163 (P = .0006) and not for CD68 (P = .414). Patients with a mean CD163 reactivity of 25% or more had a median OS of 71 months vs 101 months for patients with less than 25% reactivity. CD163 retained statistical significance in multivariate analysis. In patients with advanced-stage CHL with high IPS, OS was also significantly worse for those with a mean CD163 reactivity of 25% or higher.
  
  
  CONCLUSIONS
  Our study confirms previous reports of a prognostic role of tumor-infiltrating macrophages in CHL, but only for CD163. Although most of the literature supports an increasing role of macrophage IHC as a predictor of clinical outcome, successful clinical translation will require a standardized method and reporting system.
authors: Dept of Pathology and Immunology, Washington University Medical Center, 660 S. Euclid Ave, Campus Box 8118, St Louis, MO 63110; e-mail: fkreisel@path.wustl.edu.
authors: Jonathan L
authors: JL
authors: Klein
authors: TuDung T
authors: TT
authors: Nguyen
authors: Gabriel A
authors: GA
authors: Bien-Willner
authors: Ling
authors: L
authors: Chen
authors: Kelley V
authors: KV
authors: Foyil
authors: Nancy L
authors: NL
authors: Bartlett
authors: Eric J
authors: EJ
authors: Duncavage
authors: Anjum
authors: A
authors: Hassan
authors: John L
authors: JL
authors: Frater
authors: Friederike
authors: F
authors: Kreisel
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006689:Hodgkin Disease / Q000175:diagnosis* / Q000378:metabolism / Q000401:mortality; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D000098902:CD163 Antigen; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D014408:Biomarkers, Tumor; D011956:Receptors, Cell Surface; D000098902:CD163 Antigen; C067980:CD68 antigen, human; D000097382:CD68 Molecule
keywords: CD163; CD68; Classical Hodgkin lymphoma; High IPS; Overall survival; Tumor-infiltrating macrophages