Clinical significance of platelet derived growth factor in hodgkin's disease and non hodgkin lymphoma

ABSTRACT

Platelet-derived growth factor [PDGF] is one of the numerous proteins that regulate cell growth and division. It is a major mitogenforfibroblasts, smooth muscle cells and other cells. Many tumors have been shown to express PDGF and its cognate receptors, and in these, an autocrine stimulation of tumor cell growth may prevail. The aim of this work was to study PDGF levels in patients with Hodgkin's disease [HD] and non Hodgkin lymphoma [NHL], both before and after 3 cycles of chemotherapy and their relation to disease progression and response to treatment. This study was conducted on 20 lymphoma patients [gpl] including 7 patients with Hodgkin s disease and 13 patients with non-Hodgkin lymphoma. 10 age and sex-matched normal healthy controls were also included in our study [gpII]. All patients were subjected to thorough history taking, clinical examination, routine laboratory investigations, lymph node biopsies to diagnose the lymphoma and staging of the lymphoma was done by radiological studies and bone marrow aspiration and trephine biopsies when needed, PDGF was measured in the serum of controls and patients before starting chemotherapy. This measurement was repeated after completion of 3 cycles of chemotherapy, together with assessment of response to chemotherapy, both clinically and radiologically. Serum PDGF levels in our lymphoma patients, both before and after 3 cycles of chemotherapy were significantly higher than the control group. No significant differences were noted between our ND and NHL patients as regards serum PDGF levels. There was a sigmfi cant positive correlation between serum PDGF levels and serum LDH levels in our patients. Patients with advanced disease [stage III, IV] at presentation had significantly higher serum PDGF levels than patients with earlier stages [stage I, II]. Also, patients who showed a response to therapy had significantly lower pretreatment values of serum PDGF than patients with no response or with progressive disease. In conclusion, serum PDGF levels were significantly higher in lymphoma patients, compared to normal controls. Significant reduction in serum PDGF levels occurred in patients who responded to 3 cycles of chemotherapy. There was no signfi cant dUiference between our HD and NHL patients as regards PDGF levels and there was a significant positive correlation between serum PDGF and serum LDH levels, both before and after treatment