Althy controls (5-hmCyt mean index 0.22 ?0.005 versus 0.24 ?0.01, NS), while significant differences were

Althy controls (5-hmCyt mean index 0.22 ?0.005 versus 0.24 ?0.01, NS), while significant differences were observed for the intermediate-risk group (index 0.18 ?0.04; p = 0.002) and the high-risk group (index 0.19 ?0.03; p = 0.03).Bagacean et al. Clinical Epigenetics (2017) 9:Page 3 ofFig. 1 a, b Progression (PFS)- and treatment-free survival (TFS) according to cytogenetic risk groups. Kaplan eier survival curves from the date of diagnosis depicted for 127 chronic lymphocytic leukemia patients. Statistical differences between the curves were calculated using the log-rank testBivariate analysis of cytogenetic and epigenetic characteristicsIn order to further test the interplay between cytogenetic risk groups and epigenetic factors, a Cox regression analysis was performed on TFS for 5-mCyt and 5-hmCyt levels to segregate the 60 CLL patients tested by ELISA into subgroups with low and high levels. Next, two groups of patients were considered: first, the low-risk group with isolated del(13q) (n = 30) and, buy ARA290 second, the cytogenetic intermediate/high-risk groups (n = 30). Concerning the latter, results were combined for statistical purposes, as the number of patients belonging to these two cytogenetic risk groups and classified as high for 5-mCyt or 5-hmCyt levels, was reduced (n = 5 and 7, respectively). As depicted in Fig. 3a and presented in Table 2, the Kaplan eier survival curves reveal that the 5-mCytlow subgroup had markedly reduced PFS and TFS when considering the CLL patients presenting an isolated del(13q) (PFS 44.5 versus > 120 months, p = 0.01, and TFS 45 versus > 120 months, p = 0.0008). For 5-hmCyt (Fig. 3c and Table 2), differences were also significant when considering patients with del(13q) as a sole cytogenetic abnormality (PFS 56 versus > 120 months, p = 0.02; TFS 63 versus > 120 months, p = 0.04). Regarding the cytogenetic intermediate/high-risk group (Fig. 3b, d and Table 3), the same trend was observed for both 5mCyt PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/29072704 and 5-hmCyt but did not reach significance. We conclude from these experiments that combining cytogenetic and epigenetic parameters improves CLL patient outcome prediction and that 5-mCyt levels have a higher impact predominantly on those patients with isolated del(13q).Table 1 Patients’ characteristics according to cytogenetic risk groupsCytogenetic risk groups Age at diagnosis, mean ( D) Age at study entry, mean ( D) Binet stage, No. of patients ( ) A B C Lymphocytosis (Giga/L), mean ( D) IGHV mutational status, No. of patients ( ) Unmutated ( 98 homology) Mutated (< 98 homology) CD38 > 30 , No. of patients ( ) LDT from diagnosis, median (months) PFS, median (months)a TFS, median (months)a aLow (n = 64) 64.4 (?9.4) 68.7 (?9.3)Intermediate (n = 19) 67.8 (?8.2) 72.2 (?8.4)High (n = 30) 64.9 (?10.7) 69.7 (?9.8)Statistics (p) NS NS 0.50/64 (78.1 ) 8/64 (12.5 ) 6/64 (9.4 ) 30.7 (?29.3)11/19 (57.9 ) 5/19 (26.3 ) 3/19 (15.8 ) 74.7 (?71.1)16/30 (51.7 ) 11/30 (37.9 ) 3/30 (10.3 ) 49.6 (?40.60) 0.006 NS1/22 (4.5 ) 21/22 (95.5 ) 12/58 (20.7 ) 48 > 120 >2/12 (16.7 ) 10/12 (83.3 ) 9/19 (47.4 ) 24 723/10 (30 ) 7/10 (70 ) 6/25 (24 ) 17 40 72 NS 0.0004 0.003 0.Abbreviations: NS not significant, No. number, SD standard deviation, IGHV immunoglobulin heavy-chain variable region, LDT lymphocyte doubling time, PFS progression-free survival, TFS treatment-free survival a Kaplan eier survival analysisBagacean et al. Clinical Epigenetics (2017) 9:Page 4 ofFig. 2 Global DNA methylation and hydroxymethylation according to cytogenet.