Hepatitis C and the leptin system: bound leptin levels are elevated in patients with hepatitis C and decrease during antiviral therapy.
BACKGROUND
Serum leptin levels are elevated in alcoholic liver cirrhosis and thus might be involved in the anorexia and hypermetabolism often seen in those patients. We hypothesized that the leptin system is modulated in patients with hepatitis C and might be affected by antiviral therapy. The aim of this study was to investigate the different leptin components in serum of patients with hepatitis C before, during and after interferon alpha and ribavirin therapy and in controls.


METHODS
25 patients (11 female, 14 male) with chronic hepatitis C were compared with body mass index, gender and age-matched controls (n = 25). Patients were treated with interferon alpha alone (3 MU tiw) or in combination with ribavirin for 6-12 months. Free leptin and bound leptin levels were measured using specific radioimmunoassays before interferon therapy, at 12 weeks of therapy and after 3 months of follow-up.


RESULTS
Free leptin levels were higher in female than in male subjects, both for patients (P < 0.01) and controls (P < 0.05). Bound leptin levels were elevated in both female (P < 0.05) and male (P < 0.001) patients compared to controls. No alteration of free leptin levels was found during therapy, whereas bound leptin levels decreased after 3 months of therapy (P < 0.005) and re-increased to the baseline levels 3 months after therapy was stopped. Responder but not non-responder had decreased bound leptin levels (P < 0.01) comparing pre- and posttreatment levels. However, no significant correlations were determined between any of the leptin components to virus load, ALT, TNF alpha receptor levels (sTNFR-75, sTNFR-55) and histopathology at any time point.


CONCLUSIONS
Since no correlation was found between the different leptin components and any of the inflammatory markers, the decrease in bound leptin levels during antiviral therapy suggests either a direct interferon-dependent effect on the leptin system or an alteration of other leptin secretagogues.
Widjaja
A
A
Dept. of Gastroenterology and Hepatology, Hannover Medical School, Germany.
Wedemeyer
H
H
Tillmann
H L
HL
Horn
R
R
Ockenga
J
J
Jaeckel
E
E
von zur Mühlen
A
A
Manns
M P
MP
Brabant
G
G
D000328:Adult; D017677:Age Distribution; D000998:Antiviral Agents / Q000008:administration & dosage*; D015415:Biomarkers / Q000032:analysis; D004359:Drug Therapy, Combination; D005260:Female; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy*; D006801:Humans; D007372:Interferons / Q000008:administration & dosage*; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D011379:Prognosis; D011863:Radioimmunoassay; D012016:Reference Values; D012044:Regression Analysis; D012254:Ribavirin / Q000008:administration & dosage*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution
D000998:Antiviral Agents; D015415:Biomarkers; D020738:Leptin; D012254:Ribavirin; D007372:Interferons