RESPONSE TO ALPHA-INTERFERON (IFN) THERAPY IN GENOTYPE 1a,b PATIENTS CAN BE PREDICTED WITHIN 48 HOURS.

Author: TE Wiley, NP Lam, L Breidi, DR GretchØ{*}, TJ Layden. Depts of Medicine and Pharmacy Practice, University of Illinois at Chicago Medical Center and Hepatitis LaboratoryØ{*}, University of Washington, Seattle.

Only 20 to 30 % of patients (pts) clear serum HCV RNA with standard doses of IFN (3mu tiw) and response is even less in patients infected with genotype 1a,b. It has been suggested that successful response to therapy can be predicted based on one month HCV RNA levels (J Med Vir 1995;46:109-115). In the present study we examined whether HCV RNA values measured at 24 and 48 hours after 3 mu of IFN would predict RNA values at 1 and 3 mo in pt infected with genotype 1a,b. Pt (n=12) who had not received IFN were asked to participate. Pt were genotype 1a or 1b as assessed by the modified nested PCR method. HCV RNA levels (eq/ml) were measured by bDNA method at baseline, 24 and 48 hr, 1 week, and 1 and 3 mo during IFN therapy (3 mu tiw).

  0 hr    24 hr    48 hr    1 wk     1 mo     3 mo
  HCV RNA   8.4±2.5  3.7±1.1  5.2±1.5  5.9±1.8  4.5±1.6  5.2±1.8
  ALT IU/ml  98±15    99±15    97±14    82±11     69±9    74±12
  mean±SEM
A significant 55±6% (p<.02) fall in HCV RNA levels was noted by 24 hr after 3 mu IFN. However, by 48 hr RNA values significantly increased by 40±6%; and HCV RNA levels increased in 12 of 13 pt. At 1 and 3 mo there was no significant difference in mean HCV RNA values compared to results at 48 hr (paired t-test). ALT values were not significantly reduced during 3 mo of therapy. SUMMARY. In pt with genotype 1a or 1b HCV the initial 24 hr response to IFN is short lived with RNA values returning towards baseline by 48 hr. RNA levels at 48 hr are predictive of values at 1 and 3 mo. These results indicate that higher doses of IFN are required to reduce HCV RNA production in genotype 1a,b infected individuals and that failure to significantly reduce values by 48 hr predicts an unfavorable response.
Supported by a grant from Schering Corp.

Source: American Association for the Study of Liver Diseases - 1996 Annual Meeting


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