الفهرس 
HCVOnly 14 pages are availabe for public view
 |  | from | 210 |  |  |
| | | from | 210 | | |
Abstract
Tumors are generally classified as either liquid or solid. The former includes
leukemia and lymphoma comprising neoplastic cells whose precursors are usually
motile. Solid tumors comprise either epithelial or mesenchymal cells that are usually
immobile. Lymphoma, which originates in the cells of the immune system include HL
and NHL (Pelengaris and Khan, 2006).
NHL is the sixth most common cause of cancer death; representing 4% of all
cancer cases (Horikawa et al., 2011; McNally, 2011). Approximately 287,000 new
cases of NHL were annually reported (Oluwasola et al., 2011). In Egypt, lymphoma
is the most common cancer in children and NHL is the second most common cancer
in adults (Soliman and Boffetta, 2006).
Cytokines are secreted proteins that play a critical role in regulating the
immune system; they control lymphoid cell development and differentiation, and
regulate the balance between the Th1 and Th2, immune responses. Given these
biologic properties, there is reason to postulate that cytokine activity might influence
the pathogenesis of NHL (Purdue et al., 2007).
Many cytokines are known to be involved in the pathogenesis of NHLs
including IL-10 and IL-6 which act as a growth factor for normal activated human B
and T lymphocyte stimulation and proliferation (El-Far et al., 2004; Skibola et al.,
2007). Some studies focused on the role of both cytokines in NHL following CD38
expression. A secretion of IL-6 and IL-10 upon CD38 ligation has been demonstrated
in the study of Malavasi et al. (2008). Furthermore, Xu et al. (2004) found that IL-10
augmented the expression of CD38 on plasma cells.
A number of studies have examined the role of genetic polymorphisms in the
development of malignant lymphomas. Various genes have been evaluated, including
144
genes that: influence DNA integrity and methylation; involved in xenobiotic
metabolism; involved in innate immunity, oxidative stress, energy regulation and
hormone production; and, that alter B-cell survival and growth, such as those of proinflammatory
and regulatory cytokines (Hennessy et al., 2004).