Virological and Clinical Response to Interferon-Free Regimens in Patients with HCV-Related Mixed Cryoglobulinemia: Preliminary Results of a Prospective Pilot Study.

Mixed Cryoglobulinemia (MC) is the most frequent extrahepatic manifestation of Hepatitis C virus (HCV) infection. MC is an autoimmune /B-cell lymphoproliferative disorder characterized by circulating immune-complexes, named cryoglobulins. MC patients exhibit symptoms due to a systemic vasculitis of small/medium size vessels (mixed cryoglobulinemia syndrome, MCS) in a percentage going from 5 to 30%. The first-line therapeutic option in MCS patients is the etiologic treatment and, in the past fifteen years, antiviral therapy with Pegylated-Interferon (Peg-IFN) plus Ribavirin (RBV) represented the standard of care. Lately, the arrival of direct acting antivirals (DAAs) significantly modified the cure of HCV infection, consenting the use of IFN-free regimens. Here we report a review of the literature about the role of antiviral treatment, following its evolution, in treating HCVrelated MC. Furthermore, we report the results, after 8 weeks of treatment, of a preliminary pilot prospective study, counting 17 patients with HCV-related MC with or without MCS, treated with new generation DAAs in IFN-free regimens. After 8 weeks of DAA administration, all the subjects were HCV RNA negative. Moreover, in 6/17 (35%) patients cryoglobulins disappeared and, on the whole, in all patients a decrease of the cryocrit values was observed (p<0.05). Furthermore, three MCS-HCV patients (30%) resulted to be complete clinical responders and 5 subjects (50%) partial clinical responders. Therefore, IFN-free anti-HCV treatment appears to be safe and effective in MC patients from virological and clinical points of view, thus supporting the importance of HCV eradication in leading MC remission.

Identification of a human immunodominant T-cell epitope of mycobacterium tuberculosis antigen PPE44.

BACKGROUND: Recently our group has identified a novel antigen of Mycobacterium tuberculosis, protein PPE44, belonging to the "PPE protein" family. Although its role in infection is largely unknown, PPE44-specific immune responses were detected in mice infected with M. tuberculosis; moreover, immunization of mice with PPE44 subunit vaccines resulted in protective efficacy comparable to the one afforded by BCG against M. tuberculosis (Romano et al., Vaccine 26, 6053-6063, 2008). RESULTS: In the present paper, we investigated anti-PPE44 T-lymphocyte responses during human infection by evaluating the frequency of PPE44-specific interferon (IFN)-γ-secreting cells by ELISpot and flow cytometry in a small cohort of healthy subjects that had proven positive to PPD (PPD+) in vitro, in patients with active tuberculosis, in subjects vaccinated with BCG and in unvaccinated, PPD- healthy controls. We showed IFN-γ+ T cell immune responses to recombinant PPE44 in at least a very high proportion of PPD+ individuals tested and, to a lower extent, in subjects vaccinated with BCG. By the use of a panel of overlapping synthetic 20-mer peptides spanning the PPE44 primary amino acid sequence, we identified a strong CD4+ T-cell epitope, encompassed by peptide p1L (VDFGALPPEVNSARMYGGAG), in the NH2-terminus of the PPE44 molecule at the amino acid position 1-20. Conversely, our experiments did not provide evidence of a significant IFN-γ+ CD4+ T cell response to PPE44 or its immunodominant peptide p1L in most (7 out of 8) patients with active TB. CONCLUSIONS: Our data suggest an important immunological role of PPE44 and its immunodominant epitope p1L that could be useful in the design of anti-tuberculosis vaccines and in the immunological diagnosis of M. tuberculosis infection.