Dr. Howell’s clinical interests include management of chronic liver diseases, particularly hepatitis B and C, primary biliary cirrhosis and autoimmune hepatitis. He has 3 main research interests: 1) understanding the pathogenesis of liver injury due to chronic hepatitis C, 2) studying host genes and cellular pathways that mediate HCV clearance spontaneously and during interferon and ribavirin therapy; and 3) racial disparities in hepatitis C and primary hepatocellular carcinoma.

Dr. Howell was chair of the Steering Committee and principal investigator for the Baltimore site of the NIDDK Study of Viral Resistance to Antiviral Therapy for Chronic Hepatitis C (VIRAHEP-C)  (2001-2006). In addition, he is a recipient of a RO1 award  (2004-2007) titled “Predicting the Outcomes of Hepatitis C Treatments”. Using gene microarray technology, this project is testing the hypothesis that differential expression of host immune and inflammatory genes in the livers of African American and Caucasian HCV patients prior to treatment might be responsible for the racial disparity in treatment outcomes. If so, measuring the global patterns of gene expression in liver biopsies obtained prior to treatment might be predict the efficacy of antiviral therapy for chronic HCV in genotype 1. The results should provide new insights into the basis for the racial differences in the sensitivity and resistance to antiviral therapy, and facilitate development of more effective treatments for HCV genotype 1.

In 2005, Dr. Howell received a NIH mid-career investigator inpatient-oriented research (K24) award. The longterm objective of the award is to decrease racial disparities in liver diseases in the United States by conducting well-designed patient-oriented research and by increasing the number of highly trained research scientist engaged in patient-oriented research in digestive diseases. A better understanding of the causes for health disparities based on race is necessary to develop comprehensive strategies to improve the health of racial minorities in the US. The award provides protected time for Dr. Howell to engage in clinical research; to mentor trainees interested in patient-oriented liver research at the University of Maryland; and to strengthen his background for future patient-oriented research projects and mentoring by completing didactic coursework in clinical investigation; and to conduct preliminary studies on racial disparities in primary hepatocellular carcinoma (HCC) in the US.