Therapeutic efficacy and safety of chaperonin 10 in patients with rheumatoid arthritis: a double-blind randomised trial.

BACKGROUND: Chaperonin 10 (heat shock protein 10, XToll) has anti-inflammatory properties related to the inhibition of Toll-like receptor signalling pathways. Our aim was to establish whether chaperonin 10 is safe and effective in the treatment of rheumatoid arthritis. METHODS: In this randomised, double-blind, multicentre study, 23 patients with moderate to severe active rheumatoid arthritis receiving disease-modifying antirheumatic drugs were randomly allocated to three treatment groups receiving intravenous chaperonin 10 twice weekly for 12 weeks at doses of 5 mg (n=8), 7.5 mg (8), or 10 mg (7). The primary outcomes were change in disease activity score (DAS28) and improvement of core disease measures (American College of Rheumatology response score) from baseline to week 12. All analyses were done by intention to treat. This study is registered with the Australian Clinical Trials Registry, number ACTRNO12606000041550. FINDINGS: Primary endpoint measures improved from day 14 in all groups and continued to improve to day 84. By end of study, a 20% improvement of core disease measures was seen in six (86%, 95% CI 43-100), a 50% improvement in four (57%, 14-86), and a 70% improvement in two (29%, 0-57) patients given the highest dose of chaperonin 10. Clinical remission (as defined by a DAS28 <2.6) was achieved in three (13%) of 23 patients. Three individuals dropped out during the study: one in the 5 mg group (rheumatoid arthritis not controlled), one in the 7.5 mg group (adverse event), and one in the 10 mg group (lost to follow-up). The most common adverse events were exacerbation of rheumatoid arthritis (both during and after the study) and upper respiratory tract infection. Only one adverse event was judged to be of severe intensity. INTERPRETATION: Chaperonin 10 seems to be well tolerated and efficacious in treatment of the symptoms of rheumatoid arthritis, at least in the short term.

Heat shock protein 10 inhibits lipopolysaccharide-induced inflammatory mediator production.

Heat shock protein 10 (Hsp10) and heat shock protein 60 (Hsp60) were originally described as essential mitochondrial proteins involved in protein folding. However, both proteins have also been shown to have a number of extracellular immunomodulatory activities. Here we show that purified recombinant human Hsp10 incubated with cells in vitro reduced lipopolysaccharide (LPS)-induced nuclear factor-kappaB activation and secretion of several inflammatory mediators from RAW264.7 cells, murine macrophages, and human peripheral blood mononuclear cells. Induction of tolerance by contaminating LPS was formally excluded as being responsible for Hsp10 activity. Treatment of mice with Hsp10 before endotoxin challenge resulted in the reduction of serum tumor necrosis factor-alpha and RANTES (regulated upon activation, normal T cell expressed and secreted) levels and an elevation of serum interleukin-10 levels. Hsp10 treatment also delayed mortality in a murine graft-versus-host disease model, where gut-derived LPS contributes to pathology. We were unable to confirm previous reports that Hsp10 has tumor growth factor properties and suggest that Hsp10 exerts anti-inflammatory activity by inhibiting Toll-like receptor signaling possibly by interacting with extracellular Hsp60.

Steatosis and liver cell apoptosis in chronic hepatitis C: a mechanism for increased liver injury.

Steatosis is increasingly recognized as a cofactor influencing the progression of fibrosis in chronic hepatitis C; however, the mechanisms by which it contributes to liver injury remain uncertain. We studied 125 patients with chronic hepatitis C to assess the effect of steatosis on liver cell apoptosis and the expression of Bcl-2, Bcl-x(L), Bax, and tumor necrosis factor alpha (TNF-alpha) and the relationship between liver cell apoptosis and disease severity. A significant increase in liver cell apoptosis was seen in liver sections with increasing grade of steatosis (r = 0.42; P <.0001). Hepatic steatosis and previous heavy alcohol consumption were the only two variables independently associated with the apoptotic index. Increasing steatosis was associated with decreased Bcl-2 mRNA levels and an increase in the proapoptotic Bax/Bcl-2 ratio (r = -0.32, P =.007; and r = 0.27, P =.02, respectively). In the absence of steatosis, increased liver cell apoptosis was not associated with stellate cell activation or fibrosis (r = 0.26, P =.11; r = 0.06, P =.71, respectively). In contrast, in the presence of steatosis, increasing apoptosis was associated with activation of stellate cells and increased stage of fibrosis (r = 0.35, P =.047; r = 0.33, P =.03, respectively), supporting the premise that the steatotic liver is more vulnerable to liver injury. In patients with hepatitis C virus genotype 3, there was a significant correlation between TNF-alpha mRNA levels and active caspase-3 (r = 0.54, P =.007). In conclusion, these observations suggest a mechanism whereby steatosis contributes to the progression of liver injury in chronic hepatitis C. Further investigation will be required to determine the molecular pathways responsible for the proapoptotic effect of steatosis and whether this increase in apoptosis contributes directly to fibrogenesis.

Increased mononuclear cell activation and apoptosis early after human liver transplantation is associated with a reduced frequency of acute rejection.

Experimental models of orthotopic liver transplantation (OLT) have shown that the very early events post-OLT are critical in distinguishing immunogenic and tolerogenic reactions. In rodents, increased leukocyte apoptosis and cytokine expression have been demonstrated in tolerogenic strain combinations. Information from human OLT recipients is less abundant. The aim of this study was to determine the amount of early leukocyte activation and apoptosis following human OLT, and to correlate this with subsequent rejection status. Peripheral blood mononuclear cells (PBMC) were isolated from 76 patients undergoing OLT - on the day prior, 5 hrs after reperfusion (day 0), and 18-24 hrs post-OLT (day 1). The mean level of apoptotic PBMCs on post OLT day 1 was higher than healthy recipients (0.9% +/- 0.2 vs. 0.2% +/- 0.1, p=0.013). Apoptosis was greater in nonrejecting (NR) (1.1% +/- 0.3) compared with acutely-rejecting (R) (0.3% +/- 0.1, p=0.021) patients. On day 1, PBMC from NR patients had increased expression of IFN-gamma (p=0.006), IL-10 (p=0.016), and CD40 ligand (p=0.02) compared with R. Donor cell chimerism on day 1 did not differ between the groups indicating that this was unlikely to account for increased PBMC apoptosis in the NR group. Interestingly, the level of chimerism on day 0 was significantly higher in NR (3.8% +/- 0.6) compared with R (1.2% +/- 0.4, p=0.004) patients and there was a close correlation between chimerism on day 0 and cytokine expression on day 1. These results imply that similar mechanisms are occurring in the human liver to promote graft acceptance as in the experimental models of liver transplantation and suggest that strategies that promote liver transplant acceptance in rodents might be applicable to humans.