title: Correlates of elevated interleukin-6 and C-reactive protein in persons with or at high risk for HCV and HIV infections.
abstract: BACKGROUND
  HIV and hepatitis C virus (HCV) infections may increase interleukin-6 (IL-6) and C-reactive protein (CRP). However, relationships between inflammatory biomarkers, chronic viral infections, clinical factors, and behavioral factors remain poorly understood.
  
  
  METHODS
  Using linear regression, we modeled cross-sectional associations between loge IL-6 or loge CRP levels and HCV, HIV, injection drug use, and comorbidity among 1191 injection drug users.
  
  
  RESULTS
  Mean age was 47 years, 46.0% reported currently injecting drugs, 59.0% were HCV monoinfected, and 27% were HCV/HIV coinfected. In multivariable models, higher loge IL-6 was associated with HCV monoinfection [β = 0.191, 95% confidence interval (CI): 0.043 to 0.339] and HCV/HIV coinfection (β = 0.394, 95% CI: 0.214 to 0.574). In contrast, HCV monoinfection (β = -0.523, 95% CI: -0.275 to -0.789) and HCV/HIV coinfection (β = -0.554 95% CI: -0.260 to -0.847) were associated with lower CRP. Lower CRP with HCV infection was independent of liver fibrosis severity, synthetic function, or liver injury markers; CRP decreased with higher HCV RNA. Increased injection intensity was associated with higher IL-6 (P = 0.003) and CRP (P < 0.001); increasing comorbidity (P < 0.001) and older age (P = 0.028) were associated with higher IL-6; older age was associated with higher CRP among HCV-uninfected participants (P = 0.021).
  
  
  CONCLUSIONS
  HIV and HCV infections contribute to chronic inflammation; however, reduced CRP possibly occurs through HCV-mediated mechanisms. Findings highlight potentially modifiable contributors to inflammation.
authors: *Department of Epidemiology, Johns Hopkins University School of Public Health, Baltimore, MD; †Johns Hopkins University Center on Aging and Health, Baltimore, MD; Divisions of ‡Geriatric Medicine; and §Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD.
authors: Megan L
authors: ML
authors: Salter
authors: Bryan
authors: B
authors: Lau
authors: Shruti H
authors: SH
authors: Mehta
authors: Vivian F
authors: VF
authors: Go
authors: Sean
authors: S
authors: Leng
authors: Gregory D
authors: GD
authors: Kirk
mesh_terms: D000328:Adult; D002097:C-Reactive Protein / Q000032:analysis*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D019698:Hepatitis C, Chronic / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015819:Substance Abuse, Intravenous
chemical_list: D015850:Interleukin-6; D002097:C-Reactive Protein
references: Annu Rev Med. 2000;51:245-70
references: 10774463
references: Antivir Ther. 2012;17(5):813-21
references: 22418880
references: Adv Clin Chem. 2009;48:111-36
references: 19803417
references: Ann N Y Acad Sci. 1982;389:406-18
references: 6953917
references: Braz J Med Biol Res. 2005 May;38(5):783-8
references: 15917961
references: Am J Cardiol. 2002 May 1;89(9):1133-5
references: 11988210
references: Clin Infect Dis. 2011 Dec;53(12):1256-64
references: 21976463
references: J Acquir Immune Defic Syndr. 2008 Jun 1;48(2):142-8
references: 18344877
references: Presse Med. 1994 Dec 17;23(40):1854-8
references: 7899316
references: J Infect Dis. 2011 Jun 1;203(11):1637-46
references: 21592994
references: Nat Med. 2006 Dec;12(12):1365-71
references: 17115046
references: Am J Cardiol. 2003 Sep 1;92(5):522-8
references: 12943870
references: J Gerontol A Biol Sci Med Sci. 2006 Apr;61(4):380-7
references: 16611705
references: PLoS Med. 2008 Oct 21;5(10):e203
references: 18942885
references: Am J Physiol Heart Circ Physiol. 2007 Jan;292(1):H130-9
references: 17213480
references: Neurobiol Aging. 1994 Nov-Dec;15(6):771-2
references: 7534383
references: Exp Gerontol. 2004 May;39(5):687-99
references: 15130663
references: Am J Clin Pathol. 1994 Dec;102(6):802-5
references: 7801895
references: Dig Liver Dis. 2005 Sep;37(9):674-80
references: 15951255
references: Ann Intern Med. 2002 Jul 2;137(1):1-10
references: 12093239
references: Clin Chem. 1997 Jan;43(1):52-8
references: 8990222
references: Arch Intern Med. 2007 Jan 22;167(2):166-73
references: 17242318
references: Gastroenterology. 2008 Jul;135(1):226-33
references: 18457674
references: Am J Drug Alcohol Abuse. 2010 Mar;36(2):92-7
references: 20337504
references: J Acquir Immune Defic Syndr. 2011 Jan 1;56(1):36-43
references: 20930640
references: Int J Cardiol. 2012 Nov 15;161(2):83-7
references: 21600668
references: Am J Med. 1999 May;106(5):506-12
references: 10335721
references: Arch Intern Med. 2006 Jan 9;166(1):64-70
references: 16401812
references: Curr Opin HIV AIDS. 2010 Nov;5(6):498-503
references: 20978393
references: Psychosom Med. 2008 Jul;70(6):646-52
references: 18606725
references: AIDS. 2011 Jan 28;25(3):303-14
references: 21192231
references: Clin Immunol. 2010 Mar;134(3):237-50
references: 19910258
references: Annu Rev Med. 2011;62:141-55
references: 21090961
references: Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2413-8
references: 16214925
references: J Neuroimmune Pharmacol. 2009 Sep;4(3):350-8
references: 19347588
references: J Infect Dis. 2010 Jun 15;201(12):1788-95
references: 20446848
references: Am Fam Physician. 1999 Apr 15;59(8):2223-30
references: 10221307
references: Stem Cells. 1995 Jan;13(1):32-7
references: 7719246
references: J Infect Dis. 2009 Sep 15;200(6):973-83
references: 19678756
references: J Acquir Immune Defic Syndr. 2005 May 1;39(1):44-54
references: 15851913
references: JAMA. 2001 Jul 18;286(3):327-34
references: 11466099
references: BMC Public Health. 2008 Dec 09;8:405
references: 19068133
references: NIDA Res Monogr. 1991;109:75-100
references: 1661376