Alpha Omega Alpha Honor Medical Society

2012 Research Abstract

Risk factors for Bacteremia in Hepatitis C Virus Infected Hemodialysis Patients

Investigator: Puja Chebrolu, Medical College of Georgia at Georgia Regents University

Mentor: N. Stanley Nahman, Jr., MD, Medical College of Georgia at Georgia Regents University

Background: Hepatitis C virus (HCV) is a major cause of liver disease in hemodialysis (HD) patients and a known immunomodulator. HCV establishes chronic infection by regulating the innate and adaptive immune systems through molecular mimicry. We have previously shown that HCV infection is associated with an increased risk of bacteremia. However, little is known about the factors that influence this risk. We hypothesized that previous infectious and/or immunosuppression-associated comorbidities may impact risk of bacteremia in HCV positive HD patients.

Methods: All HCV-positive incident HD cases from the years 2005-2008 from the United States Renal Data System were included in the analysis. Comorbidities were defined by ICD9 billing codes submitted to Medicare, and included infectious comorbidities, autoimmune conditions, immunosuppressive states, and other known risk factors for bacteremia.

Results: The analysis included 7596 HCV-positive HD patients from the 4 yr period of study. Bacteremia occurred in 39% of the group. Demographic characteristics showed a median age of dkdk years, 67% male, 53% African American, and 44% Caucasian. Catheter was the vascular access type at the time of first dialysis for 85%, arterio-venous fistula (AVF) for 10%, and arterio-venous graft (AVG) for 4%. Eight percent had a history of IV drug use, and 25% had cirrhosis.

Of the factors found to be significantly associated with increased risk of bacteremia on univariable analysis, prior or concurrent methicillin resistant Staphylococcus aureus (MRSA) colonization [adjusted relative risk (aRR) 1.89, 95% confidence interval (CI) 1.65-2.15], total parenteral nutrition (TPN) [aRR 1.72, 95% CI 1.39-2.12], candidemia [aRR 1.71, 95% CI 1.28-2.28], and catheter as initial vascular access type [aRR 1.59, 95% CI 1.36-1.85] were associated with the highest risk of bacteremia after adjusting for all other significant variables including cirrhosis. Evaluated autoimmune conditions, diabetes mellitus, intravenous drug use, age, race and gender were not significantly associated with risk of bacteremia. Having undergone a transplant was negatively associated with bacteremia on adjusted analysis.

Conclusions: Infectious comorbidities, such as prior or concurrent MRSA colonization and candidemia, represent major risk factors for bacteremia in HD patients with HCV. Starting dialysis with a catheter for vascular access and receipt of TPN are two other potentially modifiable risk factors for bacteremia. Measures focused on reducing the occurrence of these conditions may help prevent the development of bacteremia in HCV infected HD patients.

This abstract was submitted to the conference of the American Federation for Medical Research.

Updated on June 6, 2013.

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