ABSTRACT
Objective To investigate the injury effects and mechanisms of circulating histones on the hepatocytes in patients with hepatitis B virus (HBV )-related liver failure (HBV-LF) .Methods Serum samples from patients with HBV-LF were collected . The levels of serum histone H3 , histone H4 , prothrombin activity (PTA ) ,total bilirubin (TBil) ,creatinine (Cr) and international normalized ratio (INR) of the patients were measured .Model for end-stage liver disease (MELD) score was calculated in the patients .The serum levels of histones were compared between patients and the healthy volunteers . The correlation of histones with the MELD score and PTA was analyzed .The human liver cell line L-02 cells were cultured and treated with the serum of patients or L-02 cellular lysate supernatant preincubated with or without anti-histone H3 and H4 antibodies .The cellular morphology and rate of apoptosis were observed .Intracellular calcium ion concentration and Caspase-3 activity were detected in the cultured L-02 cells treated with histones .Mean of two independent samples was compared using t tests .Relationship between histones and the MELD score or PTA was conducted using Spearman correlation analysis .Results The levels of serum histones in the patients with HBV-LF were much higher than those in the healthy volunteers (H3 :[5 390 .3 ± 1 032 .0] μg/mL vs [42 .7 ± 12 .8] μg/mL , t = 32 .76 , P < 0 .01 ; H4 :[4 205 .1 ± 662 .3] μg/mL vs [40 .3 ± 14 .6] μg/mL ,t = 39 .74 , P< 0 .01) .In addition ,serum histones (H3/H4) levels in patients were negatively correlated with serum PTA (r= - 0 .325 ,P= 0 .038 and r =- 0 .572 ,P= 0 .028 ,respectively) ,but positively correlated with the MELD score (r= 0 .359 ,P= 0 .021 and r = 0 .568 , P = 0 .007 , respectively ) . Both serum of patients with HBV-LF and L-02 lysate supernatant were toxic to cultured L-02 cells .The injury effect was inhibited by anti-histone antibodies ([9 .3 ± 1 .5]% vs [14 .3 ± 0 .6]% , t = 4 .259 , P= 0 .02) .L-02 cells treated with calf thymus histone were cultured for 4 h . Cellular toxicity of histones resulted in Caspase-3 activation . The effect was inhibited by anti-histone antibodies ([3 .5 ± 0 .5]% vs [5 .2 ± 0 .6]% ,t= 4 .243 ,P= 0 .02) .Conclusion The elevated circulating histones in the patients with HBV-LF may aggravate the liver damage .
ABSTRACT
Background: Detection of anti-nucleosome antibodies (anti-nuc) in patients with systemic lupus erythematosus (SLE) has been well established and it is claimed that their presence is associated with disease activity. Aims: The aim of this study is to evaluate the incidence of anti-nuc antibodies and to correlate them with disease activity and its association with other autoantibodies like anti-nuclear antibodies (ANA), anti-double stranded DNA (anti-dsDNA), anti-histone antibodies (AHA), as well as autoantibodies to histone subfractions like H1, (H2A-H4) complex, H2B, and H3. Methods: This cross-sectional study included 100 SLE patients referred from the Rheumatology, Dermatology, and Nephrology Departments. SLE disease activity was evaluated by using SLE-Disease Activity Index (SLEDAI) score. A patient was defined as having active SLE when the SLEDAI score was more than 5.0. Fifty normal controls were also tested as a healthy control group. Anti-nuc antibodies, anti-dsDNA, and AHA were tested by Enzyme-Linked Immunosorbent Assay (ELISA) and ANA was detected by an indirect immunofluorescence test. Results: All patients studied were in an active stage of disease and were untreated, of which 44 patients had renal biopsy-proven kidney involvement, which was categorized as lupus nephritis (LN) and 56 patients did not show any renal manifestations (SLE without LN). Anti-nuc antibodies were positive in 88%, anti-dsDNA in 80%, and AHA in 38% of the cases. ANA was positive in all SLE patients studied. None of the normal controls was found to be positive for these antibodies. Although a slightly higher incidence of autoantibodies were noted in LN, there was no statistical difference noted between LN and SLE without LN groups for anti-nuc and anti-dsDNA antibodies (p > 0.05). A higher incidence of autoantibodies to ANA specificities were noted in anti-nuc positive cases, but there was no statistical difference between anti-nuc positive and anti-nuc negative cases for ANA specificities among LN and SLE without nephritis groups (p > 0.05). Conclusions: Anti-nuc antibody detection could be a better tool for the diagnosis of SLE. Although there was no significant difference in LN and SLE without LN groups, this study suggests that anti-nuc detection can be useful as an additional disease activity marker to other laboratory tests.