Alpha interferon as initial treatment of essential thrombocythemia. Analysis after two years of follow-up.
OBJECTIVE
Recombinant alpha-interferon has been shown to be effective in essential thrombocythemia and in thrombocytosis associated with other myeloproliferative disorders.


METHODS
Twenty-five untreated patients were enrolled in our study from May 1989 to April 1992. Recombinant alpha interferon-2b was administered at an initial dose of 2 megaunits (MU)/m2 three times a week at escalating doses to 5 MU/m2 or the maximum tolerated dose. The mean follow-up for patients still in treatment at the time of this report was 35.9 months (range, 24-63).


RESULTS
Fourteen patients (56%) had achieved a complete remission by a mean time of 152 days; 6 patients (24%) had achieved a good partial remission by a mean of 180 days. In addition to the favorable effect on platelet count, a marked improvement in clinical symptoms was observed. Treatment had to be discontinued in 9 patients (36%), 5 for toxicity (3 neurologic, 1 anemia and 1 severe hypertriglyceridemia) at a median of 155 days from the beginning of therapy (range, 30-400). Four patients refused to continue therapy because of low tolerance (flu-like syndrome) at mean of 160 days from the beginning of therapy (range, 34-301).


CONCLUSIONS
In our study, lower doses were administered compared with previous short-time trials. The present data show that interferon is an effective alternative to cytostatic agents in long-term treatment of patients with essential thrombocythemia, even when used at lower dosages.
Hematology Unit, Monza Hospital, Italy.
E M
EM
Pogliani
F
F
Rossini
I
I
Miccolis
A
A
Ferrario
D
D
Perego
I
I
Casaroli
S
S
Bolis
D
D
Fagnani
M
M
Brambilla
G
G
Corneo
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins; D013922:Thrombocytosis / Q000188:drug therapy*; D016896:Treatment Outcome
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins