Examination of IL-13 and IL-5 expression by Northern blot analysis and enzyme-linked immunosorbent assay confirmed these results and revealed the expression of IL-13 in a third HD-derived cell line, HDLM2.
T-cell clones were also raised from purified CD4+ lymphocytes of one HD lymph node and one reactive lymph node and tested for IL2, IL4, IL5 and IFN-gamma secretion in culture supernatants by immunoassays.
Using this procedure, we detected a 293-base pair, IL-5-specific amplification product in the three cases of T-cell lymphoma with eosinophilia and in 11 of 12 positive validation controls, including 10 cases of Hodgkin's disease with eosinophilia.
Because eosinophils as well as Reed-Sternberg (RS) cells express membrane receptors (CD23) for IgE, this study was performed to determine if IgE is present in tissue sections of HD and to correlate the results, when possible, with serum IgE levels and the presence of interleukin-5 (IL-5) messenger RNA (mRNA) in RS cells.
To determine if interleukin-5 (IL-5) is implicated in producing the eosinophilia, we performed in situ hybridization studies on cytopreparations of 16 cases of Hodgkin's disease with eosinophilia as well as cells from various controls.