Identification of a tryptophan-like epitope borne by the variable surface glycoprotein (VSG) of African trypanosomes

Antibodies (Ab) directed against a tryptophan-like epitope (WE) were previously detected in patients with human African trypanosomiasis (HAT). We investigated whether or not these Ab resulted from immunization against trypanosome antigen(s) expressing a WE. By Western blotting, we identified an antigen having an apparent molecular weight ranging from 60 to 65 kDa, recognized by purified rabbit anti-WE Ab. This antigen, present in trypomastigote forms, was absent in procyclic forms and Trypanosoma cruzi trypomastigotes. Using purified variable surface glycoproteins (VSG) from various trypanosomes, we showed that VSG was the parasite antigen recognized by these rabbit Ab. Anti-WE and anti-VSG Ab were purified from HAT sera by affinity chromatography. Immunoreactivity of purified antibodies eluted from affinity columns and of depleted fractions showed that WE was one of the epitopes borne by VSG. These data underline the existence of an invariant WE in the structure of VSG from several species of African trypanosomes

Paritaprevir, ritonavir, ombitasvir, and dasabuvir with and without ribavirin in people with HCV genotype 1 and recent injecting drug use or receiving opioid substitution therapy

Background: Direct-acting antiviral therapy for hepatitis C virus (HCV) infection is safe and effective, but there are little data among people who have recently injected drugs. This study evaluated the efficacy, and safety of paritaprevir/ritonavir, ombitasvir, dasabuvir with or without ribavirin for chronic HCV genotype (G) 1 among people with recent injecting drug use and/or receiving OST. Methods: D3FEAT is an international open-label study that recruited treatment-naïve participants with recent injecting drug use (previous 6 months) and/or receiving OST with chronic HCV G1 infection between June 2016 and February 2017 in seven countries. Participants received paritaprevir/ritonavir, ombitasvir, dasabuvir with (G1a) or without ribavirin (G1b) administered twice daily in a one-week electronic blister pack (records timing of each dose) for 12 weeks. The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (SVR12). Results: Among 87 participants (median age 48 years), 23% were female, 8% had cirrhosis, and 90% had G1a. Overall, 71% were receiving OST, 61% injected in the previous six months, 45% injected in the previous month, and 15% injected > daily. Treatment completion was 97% (84 of 87). There were no virological breakthroughs, but three discontinuations (loss to follow-up, n = 1; non-adherence, n = 1; incarceration, n = 1). SVR was 91% (79 of 87, 95% CI, 83%–96%). Five participants who completed treatment did not have SVR (loss to follow-up, n = 1; death, n = 1; virologic relapse, n = 3). Drug use prior to and during treatment did not impact SVR12. Treatment-related adverse events were observed in 46 (53%) patients (six grade 3, no grade 4). Five (6%) patients had at least one serious adverse event (two possibly/probably related to therapy; nausea and myoclonus). Two cases of reinfection were observed. Conclusion: Paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without ribavirin for 12 weeks is effective among people with HCV genotype 1 with recent injecting drug use and/or receiving OST.Jason Grebelya, Brian Conwayb, Evan B. Cunninghama, Chris Fraserc, Alberto Moriggiad, Ed Ganee, Catherine Stedmanf, Curtis Cooperg, Erika Castroh, Patrick Schmidi, Kathy Petoumenosa, Behzad Hajarizadeha, Phillipa Marksa, Amanda Erratta, Olav Dalgardj, Karine Lacombek, Jordan J. Feldl, Julie Bruneaum, Jean-Pierre Dauloueden, Jeff Powiso, Philip Bruggmannp, Gail V. Matthewsa, Ian Kronborgq, David Shawr, Adrian Dunlops, Margaret Hellardt, Tanya L. Applegatea, Sione Crawfordu, Gregory J Dorea, on behalf of the D3FEAT Study Grou

Paritaprevir, ritonavir, ombitasvir, and dasabuvir with and without ribavirin in people with HCV genotype 1 and recent injecting drug use or receiving opioid substitution therapy.

Direct-acting antiviral therapy for hepatitis C virus (HCV) infection is safe and effective, but there are little data among people who have recently injected drugs. This study evaluated the efficacy, and safety of paritaprevir/ritonavir, ombitasvir, dasabuvir with or without ribavirin for chronic HCV genotype (G) 1 among people with recent injecting drug use and/or receiving OST. D3FEAT is an international open-label study that recruited treatment-naïve participants with recent injecting drug use (previous 6 months) and/or receiving OST with chronic HCV G1 infection between June 2016 and February 2017 in seven countries. Participants received paritaprevir/ritonavir, ombitasvir, dasabuvir with (G1a) or without ribavirin (G1b) administered twice daily in a one-week electronic blister pack (records timing of each dose) for 12 weeks. The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (SVR12). Among 87 participants (median age 48 years), 23% were female, 8% had cirrhosis, and 90% had G1a. Overall, 71% were receiving OST, 61% injected in the previous six months, 45% injected in the previous month, and 15% injected > daily. Treatment completion was 97% (84 of 87). There were no virological breakthroughs, but three discontinuations (loss to follow-up, n = 1; non-adherence, n = 1; incarceration, n = 1). SVR was 91% (79 of 87, 95% CI, 83%-96%). Five participants who completed treatment did not have SVR (loss to follow-up, n = 1; death, n = 1; virologic relapse, n = 3). Drug use prior to and during treatment did not impact SVR12. Treatment-related adverse events were observed in 46 (53%) patients (six grade 3, no grade 4). Five (6%) patients had at least one serious adverse event (two possibly/probably related to therapy; nausea and myoclonus). Two cases of reinfection were observed. Paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without ribavirin for 12 weeks is effective among people with HCV genotype 1 with recent injecting drug use and/or receiving OST