TY - JOUR

T1 - Undetectable hepatitis C virus RNA during syphilis infection in two HIV/HCV-co-infected patients

AU - Salado-Rasmussen, Kirsten

AU - Knudsen, Andreas

AU - Krarup, Henrik Bygum

AU - Katzenstein, Terese Lea

AU - Gerstoft, Jan

PY - 2014/9

Y1 - 2014/9

N2 - BACKGROUND: Treponema pallidum, the causative agent of syphilis, elicits a vigorous immune response in the infected host. This study sought to describe the impact of syphilis infection on hepatitis C virus (HCV) RNA levels in patients with HIV and chronic HCV infection.METHODS: Patients with chronic HIV/HCV and syphilis co-infection were identified by their treating physicians from 1 October 2010 to 31 December 2013. Stored plasma samples obtained before, during, and after syphilis infection were analysed for interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and IFN-γ-inducible protein 10 kDa (IP-10).RESULTS: Undetectable HCV RNA at the time of early latent syphilis infection was observed in 2 patients with HIV and chronic HCV infection. After treatment of the syphilis infection, HCV RNA levels increased again in patient 1, whereas patient 2 initiated HCV therapy and remained HCV RNA-negative. Available plasma samples obtained before and after the episode with undetectable HCV RNA were phylogenetically identical, making the possibility of spontaneous clearance and HCV reinfection less likely. The IL-10, TNF-α, and IP-10 levels increased at the time of syphilis diagnosis in patient 1 and decreased again after treatment of the syphilis infection.CONCLUSIONS: We propose that T. pallidum-induced cytokine secretion resulted in an immune response hindering HCV replication during syphilis infection. We suggest that HIV/HCV-co-infected patients with unexpected undetectable HCV RNA are tested for syphilis infection and that the serological tests include both non-treponemal and treponemal tests to avoid false-positive results caused by HCV.

AB - BACKGROUND: Treponema pallidum, the causative agent of syphilis, elicits a vigorous immune response in the infected host. This study sought to describe the impact of syphilis infection on hepatitis C virus (HCV) RNA levels in patients with HIV and chronic HCV infection.METHODS: Patients with chronic HIV/HCV and syphilis co-infection were identified by their treating physicians from 1 October 2010 to 31 December 2013. Stored plasma samples obtained before, during, and after syphilis infection were analysed for interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and IFN-γ-inducible protein 10 kDa (IP-10).RESULTS: Undetectable HCV RNA at the time of early latent syphilis infection was observed in 2 patients with HIV and chronic HCV infection. After treatment of the syphilis infection, HCV RNA levels increased again in patient 1, whereas patient 2 initiated HCV therapy and remained HCV RNA-negative. Available plasma samples obtained before and after the episode with undetectable HCV RNA were phylogenetically identical, making the possibility of spontaneous clearance and HCV reinfection less likely. The IL-10, TNF-α, and IP-10 levels increased at the time of syphilis diagnosis in patient 1 and decreased again after treatment of the syphilis infection.CONCLUSIONS: We propose that T. pallidum-induced cytokine secretion resulted in an immune response hindering HCV replication during syphilis infection. We suggest that HIV/HCV-co-infected patients with unexpected undetectable HCV RNA are tested for syphilis infection and that the serological tests include both non-treponemal and treponemal tests to avoid false-positive results caused by HCV.

KW - Adult

KW - Cytokines

KW - HIV Infections

KW - Hepacivirus

KW - Hepatitis C, Chronic

KW - Humans

KW - Male

KW - RNA, Viral

KW - Syphilis

KW - Treponema pallidum

U2 - 10.3109/00365548.2014.920102

DO - 10.3109/00365548.2014.920102

M3 - Journal article

C2 - 24934985

VL - 46

SP - 617

EP - 623

JO - Infectious Diseases

JF - Infectious Diseases

SN - 2374-4235

IS - 9

ER -