Association of CD204⁺ macrophages with poor outcomes of malignant lymphomas not in remission treated by allogeneic HCT

Objective: CD204⁺ tumor-associated macrophages are associated with adverse outcomes of various malignancies. We performed a study to elucidate the role of CD204⁺ macrophages in allogeneic hematopoietic cell transplantation (allogeneic HCT). Methods: In a total of 81 patients who received allogeneic HCT for non-remission malignant lymphoma, immunohistochemical staining of CD204 using specimens preserved before allogeneic HCT was performed. According to the average number of CD204⁺ macrophages in a high-power field, patients were categorized into three groups: low (<25th percentile), intermediate (≥25th percentile and <50th percentile), and high (≥50th percentile). Results: The B-cell lymphoma proportion was higher in the low group, while T-cell lymphoma and adult T-cell leukemia proportions were higher in the high group. The 3-year overall survival (OS) was poorest in the high group; low vs intermediate vs high = 83.3% vs 43.7% vs 20.2% (P <.01). The 3-year cumulative incidences of relapse were significantly higher in the high group than the intermediate and low groups: 67.0% vs 38.1% vs 18.2% (P <.01). In multivariate analyses, the numbers of CD204⁺ macrophages were independent risk factors of poorer OS and cumulative incidences of relapse. Conclusions: CD204⁺ macrophages might be associated with poorer prognosis in allogeneic HCT for malignant lymphomas.