Interferons are naturally occurring substances. In fact,
interferons are intercellular signalling
proteins produced by cells in response to various
biological and synthetic stimuli. Three major classes of
interferons have been identified:
interferons alpha, beta and gamma.
Interferons originate from natural sources and are products of recombinant technology. Two forms of recombinant alpha-
interferons, 2a and 2b, are available. Alpha-
interferons are secreted and synthetised by leucocytes and lymphoblasts. The objective herein is to review the current therapeutic implications of alpha-
interferons.
Interferons alpha have
antiviral, anticancer and immunomodulatory activities. Clinical trials have proved
interferons alpha to be of special value as adjuvant
therapy (first line drugs) for
hairy cell leukemia, virus hepatitis B and C and
condylomata acuminata. The efficacy of
interferons alpha is now also being evaluated in other
malignancies and
virus diseases. For instance,
interferons alpha are an important advanced modality in the management of chronic
myelogenous leukemia and can be considered a first-line
therapy option in patients who cannot receive or relapse following allogenic bone marrow transplant. Of course, further research is also required to evaluate combination
therapies with
interferons alpha and other agents. Presently
malignancies have the broadest potential in application of
interferons alpha
therapy.
Hairy cell leukemia responds to
interferons alpha in up to 90% of patients,
Kaposi's sarcoma, which occurs primarily in association with
AIDS, benefit in up to 40% of patents,
lymphomas respond in about 65% of patients whereas chronic myelogeneous
leukemia in more than 80% of patients in early cases. The uses of
interferons alpha in
infectious diseases (condylomaty acuminata, rhinovirus
infection, protozoal, parasitic and fungal intracellular
infections) may also be significant. However, the cost of
interferons alpha is too high. This makes
interferons alpha a second line
therapy, but not in patients where it is more effective than alternative treatment.
Interferons alpha are
cytokines (intercellular signalling
proteins) which have
antiviral, anticancer and immunomodulatory activities.
Interferons alpha
therapy represents an important advanced modality in the management of patients with
hematological diseases,
malignancies,
lymphomas, solid malignant tumours and
viral infections. Clinical trials have proved
interferons alpha to be of special value as first line drugs for
hairy cell leukemia, virus hepatitis B and C and condylomata accuminata.
Interferons alpha are used as single primary
therapy, adjuvant
therapy and maintenance
therapy. The limiting factor for the application of
interferons alpha is the cost of treatment.