Detection of interleukin-5 messenger RNA in Reed-Sternberg cells of Hodgkin's disease with eosinophilia

Abstract

Hodgkin's disease of nodular sclerosis and mixed cellularity subtypes is frequently associated with eosinophilia. 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. A single-stranded, anti-sense complementary DNA (cDNA) probe coding for a portion of the human IL-5 molecule was tail-labeled with digoxigenin - 11-dUTP using terminal transferase, and then hybridized to messenger RNA (mRNA) within cells. An alkaline-phosphatase-conjugated antibody directed to digoxigenin was used with a chromogenic substrate to detect hybridized probe within cells. In all seven cases of nodular sclerosis subtype and nine cases of mixed cellularity subtype with eosinophilia, there was strong hybridization signal localizable to the cytoplasm of morphologically identifiable Reed-Sternberg cells and variants. Similar activity was detected only in rare cells from three normal spleens, and was undetectable in two cell lines used as a negative control and in one case of Hodgkin's disease without eosinophilia. Pretreatment of the cytopreparations with the RNase inhibitor diethylpyrocarbonate greatly increased the hybridization signal. Based on this controlled study, we conclude that mRNA coding for IL-5 is expressed in Reed-Sternberg cells and variants. This observation may explain the eosinophilia associated with Hodgkin's disease and provide insight into the origin of the Reed- Sternberg cell.

Type 1 and type 2 cytokine dysregulation in human infectious, neoplastic, and inflammatory diseases.

“…Furthermore, Clerici et al have recently observed that the in vitro Th-cell response patterns of patients with HD are very similar to those reported for HIV-infected patients, in terms of a spectrum of impaired IL-2 responses to recall antigens, alloantigens, and mitogens (66). The RS cell is known to express IL-5 mRNA, and this cytokine has been implicated in the eosinophilia associated with HD (331). Eosinophils are reported to be the primary source of the transforming growth factor ␤ in the nodular sclerosis form of HD.…”

The molecular pathogenesis of Hodgkin lymphoma

“…Proteomic analysis of cell lines and primary tissue has also revealed elevated levels of TARC, IL‐1R2, migration inhibitory factor (MIF), CD26, CD44 and cathepsin S 93 . A summary of these, and other, molecules implicated in the cross‐talk between HRS cells and their micro‐environment is given in Table 1 24,32,34,56,79,84,85,88,89,91,94–114 …”

Follicular lymphoma with marked infiltration of eosinophils

“…IL‐5, IL‐3, or GM‐CSF mRNA have been detected on RT‐PCR in the peripheral blood leukemic cells of a few patients with eosinophilia, 7,19 and most of the analyzed cells were composed of tumor cells in those cases. IL‐5 mRNA has also been detected in Hodgkin lymphoma Reed–Sternberg cells on in situ hybridization, 20 and in Hodgkin‐lymphoma‐derived cell lines on real‐time RT‐PCR, 21 but IL‐5 mRNA has not been detected in several cases of Hodgkin lymphoma or Hodgkin lymphoma cell lines 21 . Gruss et al .…”