Platelet and white blood cell counts during therapy with different types of alpha interferon in patients with chronic viral hepatitis. Investigators of the Alpha Interferon Study Group of Piemonte, Italy.

BACKGROUND: Platelet and white blood cell counts decrease in chronic viral hepatitis patients treated with alpha interferon. AIM: To analyse whether delta negative variations in platelets and white blood cells are influenced by type, dose and duration of alpha interferon treatment, we studied 340 consecutive patients (mean treatment 8 months, range 4-18 months). PATIENTS AND METHODS: A total of 204 (60%) patients were treated with recombinant alpha interferons (30% alpha-2a and 30% alpha-2b), 64 (19%) with N3.leukocytic and 72 (21%) N1.lymphoblastoid natural interferons. Median age and male/female ratios were comparable in the 3 groups (41, 41 and 43 years and 2.3, 2.6 and 2.5, respectively). The lowest platelets and white blood cells counts were observed between the 2nd and the 4th month of therapy in all patients. Age, sex, aetiology and duration of interferon therapy did nor influence the platelets and white blood cells reduction rates. The decrease was lower for patients treated with N3.leukocytic interferon than for the other interferons. A significant difference was observed between interferon doses when the groups treated with 3 or 9-10 MIU were compared. However, dose or cirrhosis-related bias are ruled out by similar proportions of cirrhosis and patients treated with 3 MIU in the 3 groups of patients treated with different types of interferon. CONCLUSIONS: The type of interferon appears to represent a major cause of the different haemopoietic toxicity. The lowest toxicity of N3.leukocytic interferon may have clinical implications for the choice of interferon in patients with low baseline platelets and white blood cells counts. These findings prompt prospective studies on larger series of patients.