Influence of alpha-1 antitrypsin heterozygosity on treatment efficacy of HCV combination therapy.
BACKGROUND
The role of heterozygosity for alpha-1 antitrypsin (A1AT) alleles in patients with chronic hepatitis C virus (HCV) is unclear. There is limited evidence to suggest that there is an increased prevalence of heterozygous A1AT carriers in HCV, but it is unclear how this affects treatment success.


OBJECTIVE
To investigate the (i) prevalence of A1AT heterozygosity among two HCV cohorts and (ii) its effect on treatment outcome.


METHODS
We performed a retrospective cohort study using two different cohorts. Cohort 1 consisted of 678 German HCV patients, 507 of them were treated for HCV with standard therapy. Cohort 2 consisted of 370 Dutch HCV patients of which 252 were part of a clinical trial (treatment with amantadine or placebo, in combination with pegylated interferon alpha-2b and ribavirin) whereas 37 HCV patients received standard therapy. We analyzed A1AT status using direct sequencing of the A1AT gene (cohort 1) or isoelectric focusing of serum (cohort 2). In addition, we measured A1AT serum levels (cohort 2).


RESULTS
In total, we included 1048 HCV patients; 986 (94%) were wildtype [protease inhibitor (Pi) MM], whereas 61 (6%) were heterozygous for a mutant A1AT allele (41 Pi MS, 20 Pi MZ). Mean A1AT serum levels (370 patients) were lower in A1AT heterozygous patients (1.68 vs. 1.36 g/l), (P<0.05) compared with wildtypes. Sustained viral response (SVR) after treatment was equal between the wildtypes and heterozygotes (54 vs. 56%).


CONCLUSIONS
We found a heterozygosity rate of 0.06, in line with healthy controls in other studies. Serum A1AT levels from A1AT heterozygous HCV patients are significantly lower compared with wildtype patients, although they do not discriminate on an individual level. Finally, SVR in A1AT wildtypes was not different from SVR in A1AT heterozygotes.
Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. K.Kok@MDL.umcn.nl
Karin F
KF
Kok
Hanneke
H
van Soest
Antonius E
AE
van Herwaarden
Martijn G H
MG
van Oijen
Greet J
GJ
Boland
Juliane
J
Halangk
Thomas
T
Berg
Richard A
RA
de Vries
Joost P H
JP
Drenth
D000328:Adult; D000547:Amantadine / Q000627:therapeutic use*; D000998:Antiviral Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005858:Germany; D019698:Hepatitis C, Chronic / Q000188:drug therapy*; D006579:Heterozygote; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009426:Netherlands; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D011994:Recombinant Proteins; D012189:Retrospective Studies; D012254:Ribavirin / Q000627:therapeutic use*; D016896:Treatment Outcome; D000515:alpha 1-Antitrypsin / Q000097:blood / Q000235:genetics*
D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D000515:alpha 1-Antitrypsin; D011092:Polyethylene Glycols; D012254:Ribavirin; D000547:Amantadine; C417083:peginterferon alfa-2b