Lower Treatment Response Rates in Hispanic Patients

While considerable research has evaluated treatment response in African American patients with hepatitis C, fewer studies have assessed the response of Hispanic/Latino patients -- although some prior data suggests this population may have higher rates of treatment discontinuation and somewhat lower response rates.

A study presented at the recent Digestive Disease Week conference in Los Angeles looked at sustained virological response (SVR) rates in Hispanic patients with genotype 2 or 3 HCV compared with non-Hispanic whites.

This retrospective review assessed data from 116 treatment-naïve Hispanic and 148 white patients with chronic hepatitis C at the University of New Mexico Hospital and the Albuquerque Veterans Administration Hospital who were treated with pegylated interferon plus ribavirin between October 2001 and November 2005.

Hispanic and white patients were similar in terms of age (mean 48 years), proportion of women (42% vs 32%), body mass index (mean 28), pretreatment HCV viral load, baseline laboratory values, and HCV genotype distribution (65% vs 58% genotype 1 or 4; 35% vs 42% genotype 2 or 3).

Results

In an intent-to-treat analysis including all genotypes, SVR rates were similar in the Hispanic and white patients (36.5% vs 47.3%; P = 0.10). Among patients with genotype 1 or 4, the corresponding SVR rates were 33% vs 30%, a non-significant difference. Among patients with genotype 2 or 3, however, Hispanics had a significantly much lower SVR rate compared with whites (42.5% vs 71%; P = 0.007). Overall treatment discontinuation rates were similar in the two groups (33% vs 24%; P = 0.10). In a multivariate analysis, treatment discontinuation was the largest predictor of treatment failure (P < 0.001). After excluding patients who discontinued treatment prematurely, however, Hispanic ethnicity remained an independent predictor of SVR among genotype 2 or 3 patients (59% vs 86%; P = 0.01).

Conclusion

The researchers concluded that patients with genotype 2 or 3 chronic hepatitis C infection have lower rates of sustained response to treatment with pegylated interferon plus ribavirin, and that this difference was not fully explained by early treatment discontinuation.

Further study is needed to explain what factors might be contributing to this poor rate of response, for example, a higher prevalence of steatosis or insulin resistance in the Hispanic population.

6/13/06

Reference
Douglass J, Qualls C, Wiggins C, and others. Hispanic patients with genotype 2 or 3 chronic hepatitis C have lower rates of sustained virologic response to treatment with pegylated interferon and ribavirin. Abstract 653. Digestive Disease Week 2006. May 20-25, 2006. Los Angeles, CA.