The effect of alpha-interferon on bone marrow megakaryocytes and platelet production rate in essential thrombocythemia.
In 10 patients with previously untreated essential thrombocythemia (ET), by using 111In-labeled platelets and megakaryocyte morphometry, the relation between platelet production rate and bone marrow megakaryocytes was evaluated before and during alpha-2b-interferon (IFN) therapy. A highly significant decrease in platelet count occurred during IFN therapy; the platelet counts, at baseline and after 2 and 6 months of IFN therapy, were 1,102 +/- 345 x 10(9)/L, 524 +/- 169 x 10(9)/L (P less than .0001), and 476 +/- 139 x 10(9)/L (P less than .0001), respectively. The decrement in platelet count was mainly a result of diminished platelet production rate, which at baseline and after 2 and 6 months of IFN therapy was 89 +/- 30 x 10(10) platelets/d, 53 +/- 18 x 10(10) platelets/d (P = .0033), and 45 +/- 20 x 10(10) platelets/d (P less than .0001), respectively. Also, a slight shortening of platelet mean life-span (MLS) was observed in response to IFN treatment; platelet MLS was 7.96 +/- 0.69 days at baseline and 6.68 +/- 1.30 days (P = .012) after 6 months of IFN therapy. IFN induced a significant decrease in bone marrow megakaryocyte volume; both megakaryocyte nuclear and cytoplasmatic volumes were affected. The mean megakaryocyte volume was 372 +/- 126 x 10(2) pL/microL at baseline and 278 +/- 147 x 10(2) pL/microL (P = .049) after 6 months of IFN therapy. However, the number of megakaryocytes did not show any significant change in response to IFN. It is concluded that alpha-IFN reduces platelet production rate and the peripheral platelet count in ET mainly through an anti-proliferative action on the megakaryocytes and to a considerably lesser degree by a shortening of platelet MLS.
Wadenvik
H
H
Department of Medicine, Ostra Hospital, Gothenburg, Sweden.
Kutti
J
J
Ridell
B
B
Revesz
P
P
Jacobsson
S
S
Magnusson
B
B
Westin
J
J
Vilén
L
L
D000328:Adult; D000368:Aged; D001706:Biopsy; D001772:Blood Cell Count; D001792:Blood Platelets / Q000502:physiology*; D001854:Bone Marrow Cells; D002455:Cell Division; D002467:Cell Nucleus; D003593:Cytoplasm; D005260:Female; D006410:Hematopoiesis; D006801:Humans; D007205:Indium Radioisotopes; D007370:Interferon Type I / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008533:Megakaryocytes / Q000502:physiology*; D008875:Middle Aged; D013920:Thrombocythemia, Essential / Q000097:blood* / Q000503:physiopathology / Q000628:therapy
D007205:Indium Radioisotopes; D007370:Interferon Type I