The clinical utility of using Catrimox-14-treated whole blood in detecting hepatitis C virus RNA.
BACKGROUND
Measuring hepatitis C virus (HCV) RNA in serum or plasma may underestimate the true HCV burden. Extracting viral RNA from whole blood (WB) with a cationic surfactant (Catrimox-14) has resulted in HCV RNA concentrations up to 1000-fold higher than from serum or plasma in some studies, but not others. We compared the Catrimox-14 WB assay with a standard serum assay.


METHODS
Seventy-two chronic HCV patients received 48 weeks of standard or pegylated interferon alpha-2b and ribavirin therapy. Catrimox-14-treated WB and corresponding serum samples were obtained at baseline and weeks 12, 24, 48 and 72. HCV RNA concentrations from WB and serum were quantified by a previously validated RT-PCR assay.


RESULTS
Overall mean (+/- SD) baseline serum log10 HCV RNA concentration was 6.5 ((+/- 0.58) copies/ml. Out of 72 patients, 33 had no detectable virus at 72 weeks. Neither assay detected virus in these patients at 12 weeks and neither WB nor serum assays detected virus at end-of-treatment in the 10 patients who subsequently relapsed at 72 weeks. HCV RNA concentrations from WB and serum assays were linearly correlated (R2 = 0.73; P < 0.001), although mean serum HCV RNA concentrations were 0.5 log10, copies/ml higher in serum than in WB [6.0 (+/- 0.82) vs 5.5 ((+/- 0.84), respectively, P = 0.12].


CONCLUSIONS
Catrimox-14-treated WB assays detect changes in HCV RNA, but do not offer clinical advantage over a conventional serum RT-PCR based assay.
Patel
Keyur
K
Duke Clinical Research Institute and Division of Gastroenterology, Duke University Medical Center, Durham, NC, USA. keyur.patel@duke.edu
Albrecht
Jeff
J
Owens
Erin
E
Dev
Anouk
A
Heaton
Shanon
S
Pianko
Stephen
S
Pockros
Paul J
PJ
Conrad
Andrew
A
Blatt
Lawrence M
LM
McHutchison
John G
JG
D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D015331:Cohort Studies; D005260:Female; D016174:Hepacivirus / Q000302:isolation & purification*; D019698:Hepatitis C, Chronic / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012367:RNA, Viral / Q000097:blood*; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use; D013501:Surface-Active Agents / Q000737:chemistry*; D050337:Trimethyl Ammonium Compounds
D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D000644:Quaternary Ammonium Compounds; D012367:RNA, Viral; D011994:Recombinant Proteins; D013501:Surface-Active Agents; D050337:Trimethyl Ammonium Compounds; D012254:Ribavirin; C009410:tetradecyltrimethylammonium