Sustained virologic response following interferon-based antiviral therapy in patients with hepatitis C reduced the risk for extrahepatic manifestations, according to results of a recently published study. The researchers suggested this means greater impact from direct-acting antiviral treatments.
“In this large cohort study of HCV-infected U.S. veterans, we found that SVR reduces the risk of some HCV-associated [extrahepatic manifestations (EHM)], such as mixed cryoglobulinemia, glomerulonephritis, [porphyria cutanea tarda], [non-Hodgkin’s lymphoma], diabetes and stroke,” Parag Mahale, MBBS, PhD, MPH, from the National Cancer Institute, Maryland, and colleagues wrote. “These findings further strengthen the epidemiological evidence for their association with HCV infection. Furthermore, HCV-related EHMs carry a significant economic burden due to direct medical costs and indirect costs due to loss of productivity.”
The researchers accessed the Department of Veterans Affairs HCV Clinical Case Registry and obtained data on 160,875 patients from Oct. 1, 1995, to Jan. 1, 2010. Most patients (52.1%) were aged between 50 to 59 years and 97.1% were men. Overall, 31,143 patients received antiviral therapy and 10,575 achieved SVR.
Patients who received antiviral therapy — compared with those who did not — were more often younger (50.8 vs. 52.3 years; P < .0001), white (54.8% vs. 42.5%; P < .0001), had higher BMI (27.9 vs. 26.7 kg/m2; P < .0001), had aspartate aminotransferase to platelet ratio index of 2 or higher (26.4% vs. 24.5%; P < .0001); were less likely to have hepatitis B (1% vs. 1.3%; P < .0001), HIV (2.4% vs. 3.4%; P < .0001) or hypertension (46.2% vs. 52.7% P < .0001); and less likely to smoke (54.5% vs. 60.3%; P < .0001) or abuse alcohol (48.5% vs. 60.6%; P < .0001).
Those who received antiviral therapy and achieved SVR had lower risk for mixed cryoglobulinemia (adjusted HR = 0.61; 95% CI, 0.39-0.94), glomerulonephritis (aHR = 0.62; 95% CI, 0.48-0.79), porphyria cutanea tarda (aHR = 0.41; 95% CI, 0.2-0.83), non-Hodgkin’s lymphoma (aHR = 0.64; 95% CI, 0.43-0.95), diabetes (aHR = 0.82; 95% CI, 0.76-0.88) and stroke (aHR = 0.84; 95% CI, 0.74-0.94), compared with untreated patients.
Patients who received antiviral therapy but did not achieve SVR still had a lower risk for glomerulonephritis (aHR = 0.82; 95% CI, 0.69-0.96) and stroke (aHR = 0.82; 95% CI, 0.75-0.9). However, these patients had an increased risk for lichen planus (aHR = 1.56; 95% CI, 1.22-1.99) and diabetes (aHR = 1.14; 95% CI, 1.08-1.2).
Additionally, the researchers found significant reductions in risk for extrahepatic manifestations with earlier initiation of antiviral therapy, specifically in cases of glomerulonephritis, non-Hodgkin’s lymphoma and stroke.
“Our findings also have important clinical implications. With the advents of DAAs, substantial improvements in SVR rates have been achieved with a short duration of [antiviral therapy] and fewer side effects than interferon-based [antiviral therapy],” the researchers concluded. “As more patients are treated with DAAs, we expect greater benefits of SVR including reduced risk of EHMs of chronic HCV infection, assuming that the clinical benefits of SVR remain similar with interferon-based compared with interferon-free treatment regimens.” – by Talitha Bennett
Disclosure: Mahale reports no relevant financial disclosures. Please see the full study for the other researchers’ relevant financial disclosures.