Circulating Epstein-Barr virus DNA and cell-free DNA in pediatric lymphomas.

BACKGROUND AND OBJECTIVES: Quantification of serum Epstein-Barr virus (EBV) DNA and/or cell-free total DNA (cf-DNA) may become valuable sources for prognosis evaluation and monitoring treatment response in lymphomas. We aimed to investigate their roles as potential markers in pediatric Hodgkin (HL) and non- Hodgkin lymphomas (NHL). METHOD: Between the years 2005-2008, 34 patients with HL and 45 with NHL were prospectively included. Serum samples were collected upon diagnosis, after 1-3 and 4-6 months and at the end of treatment, or at disease recurrence. RT-PCR determination of cf-DNA and EBV DNA were performed using amplification of BAMH1W region of EBV genome and of human ß-globin gene. Results were analyzed for correlation with clinical and pathological characteristics. RESULTS: Median ages were 8.9 years for HL and 8.8 years for NHL cases. Twenty-three healthy children cured from various childhood cancers served as the control group. In the controls, median serum EBV DNA copy number was `0` and median serum cf-DNA level was 50 ng/ml. At initial diagnosis, serum EBV DNA copy numbers were elevated in 20/34 HL and 8/45 NHL cases (p < 0.001). Median serum EBV DNA copy numbers were 15987/mL (125-6032075) and 25162 (1475-1214550) for HL and NHL cases, respectively (p= 0.9). Median serum cf-DNA levels were 435 ng/ml (2.3-17306) in HL and 700 ng/ml (4.9-14009) in NHLs (p= 0.12). Serum EBV DNA copy numbers and cf-DNA levels decreased significantly after induction treatment and in the follow-up. In 10/13 NHL cases with a relapse, marked elevations were detected in serum cf-DNA levels at recurrences. No significant differences were detected between median cf-DNA levels according to disease stages, response status to treatment or presence of recurrent disease. CONCLUSION: Serum EBV DNA copy numbers and cf-DNA levels were elevated at initial diagnosis in both HLs and NHLs and decreased parallel to treatment response. In NHL cases, remarkable elevation of cf-DNA levels at recurrences indicated that cf-DNA levels might be useful in the follow-up of pediatric NHLs.

TP53 Staining in Tissue Samples of Chronic Lymphocytic Lymphoma Cases: An Immunohistochemical Survey of 51 Cases.

OBJECTIVE: Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disease in adults. The aim of this study is to find out if the extent of proliferation centers or the immunohistochemical expression of p53 is related to disease prognosis. MATERIALS AND METHODS: In the scope of this study, 54 biopsy specimens from 51 patients (50 of lymph nodes; the others of spleen, tonsil, orbit, and liver) diagnosed with CLL at the Hacettepe University Department of Pathology in 2000-2013 were reevaluated. The clinical and demographic data of the patients were obtained from our patient database. Biopsy samples were assessed semi-quantitatively for the percentage of proliferation center/total biopsy area (PC/TBA) and an immunohistochemical study was performed on representative blocks of tissues for p53 expression. RESULTS: When the patients were divided into two categories according to Rai stage as high and low (stages 0, 1, and 2 vs. stages 3 and 4), it was seen that patients with low Rai stage had a better prognosis than those with high stages (p=0.030). However, there was no statistically significant correlation between overall survival and PC/TBA ratio or p53 expression levels. CONCLUSION: In our cohort, PC/TBA ratio and immunopositivity of p53 did not show correlations with overall survival.