Histone H4 acetylation by immunohistochemistry and prognosis in relapsed acute lymphocytic leukaemia (ALL)

P>Histone H4 acetylation was examined by immunohistochemistry in patients with acute lymphocytic leukaemia (ALL) in first relapse. Univariate and multivariate models identified correlates of complete remission (CR) and overall survival (OS). No variables were associated with achievement of CR. In multivariate analysis, weak histone H4 acetylation [Hazard Ratio (HR) 2 center dot 20, 95% confidence interval (CI) 0 center dot 93-5 center dot 23, P = 0 center dot 07], shorter interval from diagnosis to relapse (< 9 vs. 9-24 vs. > 24 months) (HR 1 center dot 82, 95% CI 1 center dot 20-2 center dot 75, P = 0 center dot 005), and central nervous system involvement (HR 3 center dot 43, 95% CI 1 center dot 31-8 center dot 99, P = 0 center dot 01) were independent poor prognostic factors for OS. These data provide a rationale for the use of histone deacetylase inhibitors in the treatment of relapsed ALL.