According to the World Health Organization (WHO), there are over 130 million people living with chronic hepatitis C virus (HCV
) infection. Many patients with HCV remain asymptomatic and those with an acute infection can be free of the virus within 6 months. However, it is becoming increasingly clear that HCV can wreak havoc on a patient’s psychological well-being, even in the absence of a continued viral presence.
To this end, Karin Weissenborn, MD, Professor in the Hanover Medical School, and colleagues analyzed the link between fatigue and neurological impairment in patients suffering from an HCV infection. Their research
was recently published in the Journal of Viral Hepatitis
The authors recruited one hundred and fifty-nine patients from Hanover Medical School. In order to avoid confounding variables, the authors excluded any patients with other diseases that could distort the results of the study, such as HIV co-infection. The remaining patients were given various psychological assessments, measuring alertness, learning, and memory. In addition, patients were asked to fill out questionnaires regarding fatigue and depression.
The researchers on the study divided the patients into four groups, those who received successful or unsuccessful interferon/ribavirin (IFN) therapy, those who spontaneously cleared the viral infection, and those who had HCV but were never treated. All patients in the study had normal liver function and none of the patients were diagnosed with liver cirrhosis.
The authors concluded that the most common neurological symptom in patients with mild liver disease was chronic fatigue, with around 77% of patients displaying this symptom. In addition, the authors demonstrated a negative correlation between fatigue and health-related quality of life (HRQOL
), which is a score that reflects a patients’ physical and mental status. In addition, the results of the study showed that approximately 30% of the patients exhibited attention deficits and 45% failed to accurately identify figures or words.
Most importantly, Prof. Dr. Weissenborn and colleagues showed that no fundamental differences exist in neuropsychiatric symptoms when comparing PCR-positive and PCR-negative patients, meaning that neurological symptoms in these patients are not related to the replication status of the virus in the blood. This indicates that patients that clear the virus from their system may not be free from the neurological impact of an HCV infection. Although more work is needed to explain why neurological symptoms persist long after clearance, the authors posed a potential explanation that perhaps some form of the virus remains or that the infection elicits a persistent inflammatory response. According to the authors, recent studies have shown that viral RNA was detected in patients that have achieved a sustained viral response (SVR) following IFN therapy, even after 4 to 5 years.
The work by Prof. Dr. Weissenborn and colleagues represents the largest study to date that examined neurological symptoms in both PCR-positive and PCR-negative HCV patients without advanced liver disease. It is also the only study to assess multiple parameters, including mood, learning, quality of life, and cognition.
Future work is needed to examine if the new direct-acting antiviral agents (DAAs), many of which are still in clinical trials, will lead to the same neurological symptoms seen in patients treated with the traditional IFN approach.
Samar Mahmoud graduated from Drew University in 2011 with a BA in Biochemistry and Molecular Biology. After two years of working in industry as a Quality Control Technician for a blood bank, she went back to school and graduated from Montclair State University in 2016 with an MS in Pharmaceutical Biochemistry. She is currently pursuing her PhD in Molecular and Cellular Biology at the University of Massachusetts at Amherst.
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