Tissue eosinophilia in relation to immunopathological and clinical characteristics in Hodgkin's disease

Eosinophils frequently infiltrate tissues involved by Hodgkin's disease (HD), and blood eosinophilia is frequently observed. However, the clinical significance and the mechanisms underlying eosinophilia need further elucidation. In this study the grade of eosinophilic infiltration (EoI) was evaluated in biopsies from 259 HD-patients. In a selected group (n=32), the numbers of Hodgkin-Reed-Sternberg (HRS) -cells were counted, and the phenotype of small lymphocytes, the expression of cytotoxic lymphocyte-associated proteins, CD3-zeta -chain, HLA-DR, proliferation markers, latent membrane protein 1 (LMP-1) and blood lymphocyte function were evaluated. Samples from 88 HD patients (34%) showed high EoI Significantly higher EoI was seen in nodular sclerosis 2 (NS2; p <0.001), bulky disease (p <0.05) and in patients < 50 years (p <0.05). Patients with high EoI did not differ from the remainder with regard to distribution of sex, stage, B-symptoms, blood lymphocyte function and outcome. HRS-cells were significantly more frequent in NS HID as compared to mixed cellularity (MC) (p <0.001) irrespective of EoI. LMP-1-expression, proliferative fraction and phenotypes of small lymphocytes did not differ between the cases with low and high EoI, respectively. MC HD samples had significantly higher numbers of small cells positive for CD8 (p <0.01), T-cell intracellular antigen-1 (p <0.01) and Granzyme B (p <0.05) than NS. LMP-1-positive cases had significantly higher frequency of CD8-positive cells than LMP-1-negative. In conclusion, high EoI remains a feature of certain clinical subgroups of HD. However, there was no association between the degree of EoI and numbers of HRS-cells, phenotypes of small lymphocytes, EBV status and clinical outcome. Determination of EoI is of limited diagnostic and prognostic clinical value in HD. However, the differences in small cell distribution of CD8, TIA-1, GrB and CD57 between the histopathological groups and between LMP-1-expressing/non-expressing cases may contribute to our understanding of the biology of the disease.