Hepatitis C Virus Relapse Uncommon After Sustained Virological Response

By Will Boggs MD

February 16, 2016

NEW YORK (Reuters Health) - Late relapse of hepatitis C virus (HCV) infection is very uncommon after achieving a sustained virological response (SVR), according to a systematic review and meta-analysis including more than 9,000 patients.

SVR at 12 or 24 weeks after completion of antiviral therapy is associated with an improved prognosis, compared with no treatment or failed therapy.

Bryony Simmons from Imperial College London, U.K., and colleagues used data from 59 studies of post-SVR recurrence to provide recurrence rates for three risk groups of HCV-infected patients: low-risk patients (with monoinfection and no recognized risk factors for reinfection); high-risk patients (with monoinfection and at least one identified risk factor for reinfection, such as injecting drug users and prisoners); and coinfection with HCV and HIV.

For the low-risk group, the pooled estimate was 0.82/1,000 person-years of follow-up (PYFU) for late relapse and 0.00/1,000 PYFU for reinfection, which yielded five-year rates of 0.40% for late relapse and 0.00% for reinfection.

The high-risk group had an even lower rate of late relapse (0.00/1,000 PYFU), but the pooled estimate for reinfection was far higher (19.06/1,000 PYFU). The risk of reinfection was highest for prisoners (45.48/1,000 PYFU), the researchers report in Clinical Infectious Diseases, online January 19.

Late relapse rates were also low for those with HCV/HIV coinfection (0.00/1,000 PYFU), and reinfection rates were high (32.02/1,000 PYFU).

Combining these outcomes, five-year recurrence rates remained very low for low-risk patients (0.95%), but were higher for high-risk patients (10.67%) and HCV/HIV coinfected patients (15.02%).

"Thus, despite higher recurrence rates in those with identified ongoing risk behaviors and/or HIV infection, SVR is durable, and the great majority of patients have SVR at 5 years post-treatment," the researchers note.

"The current analysis suggests that the greater recurrence risk in the high-risk and HIV coinfected populations is driven by an increased likelihood of reinfection, highlighting the need for prevention campaigns targeted at individuals who continue to place themselves at high-risk of HCV re-exposure," they write.

It's important to note that most studies included in the analysis evaluated recurrence after treatment with interferon-based therapies, which are being supplanted by interferon-free regimens.

Dr. Havard Midgard from Akershus University Hospital in Lørenskog, Norway, who was not involved in the new work, told Reuters Health by email that the "results are consistent with a very recent study published by our group, which was not included in this review. We performed a 7-year follow-up of 138 Norwegian patients who had obtained SVR in a treatment study in 2004-06. Of 94 individuals with a history of injection drug use (IDU) prior to treatment, 37 had relapsed to IDU after treatment. We identified 10 cases of persistent reinfection, all of which occurred in the subgroup who had relapsed to IDU post SVR."

"Scaling up HCV treatment among people who inject drugs (PWID) is essential to control the HCV epidemic, and I think it is 'the nature of the game' that some individuals will get reinfected," Dr. Midgard said. "However, the issue should be addressed systematically when providing HCV care for high-risk groups. To prevent infection, HCV treatment in PWID should be linked to harm reduction (opioid substitution therapy and needle and syringe program), and individuals should be educated about the risk of reinfection associated with sharing of needles and all kinds of injections paraphernalia."

"Although reinfection might compromise treatment outcomes at the individual level, treating HCV in high-risk individuals may actually prove great prevention benefits at the population level," Dr. Midgard concluded. "As high-risk transmitters are 'kept out of the pool,' onwards transmission will be prevented for a shorter or longer period. In a public health perspective, high-risk individuals should thus be targeted and prioritized for treatment. This approach is now highlighted in international guidelines for HCV treatment."

Simmons did not respond to a request for comments.

SOURCE: bit.ly/1TgbsET

Clin Infect Dis 2016.