Non-human immunodeficiency virus Kaposi's sarcoma can be effectively treated with low-dose interferon-α despite the persistence of herpesvirus-8

Three patients, negative for human immunodeficiency virus (HIV), with histologically and polymerase chain reaction-proven non-HIV Kaposi's sarcoma who received low-dose interferon (IFN) as first-line treatment because of disseminated symptomatic disease are reported. Applying 3–18 million IU of IFN-α2a per day, 3 days a week, subcutaneously for 8–20 months, major responses were achieved in all three cases. Tumour regression was observed within 4 months and has continued for 57 and 18 months to date (cases 1 and 2, respectively). Influenza-like symptoms, including fever, headaches and fatigue, were mild side-effects. However, in the third patient interferon injections had to be stopped because of hepatic enzyme elevation. Including this case report, 27 non-HIV Kaposi's sarcoma patients subcutaneously treated with IFN-α have been reported in literature. Most therapy regimens included 3–18 million IU IFN-α per day for 3 days a week. Twenty of 27 patients, or 74%, responded to therapy, whereas seven patients or 26% had stable or progressive disease. Relapse after IFN withdrawal can occur but is frequently delayed and limited, as in case 1. Following the response to IFN treatment, human herpesvirus-8 DNA was detected in the blood mononuclear cells of all three patients, possibly contributing to future relapses.