[Autoimmune phenomena during interferon-alpha therapy for hematopoietic disorders].

The development of various kinds of autoimmune disease as a result of interferon-alpha (IFN-alpha) therapy has been reported among chronic myeloproliferative disorders(CMPD) including chronic myeloid leukemia(CML). Therefore, we investigated the frequency of autoimmune disorders in 33 patients with hematopoietic diseases treated with IFN-alpha in our department. Thirty-three patients (12 females, 21 males) included cases of CML (n = 23), essential thrombocythemia (ET) (n = 1), multiple myeloma (n = 8), and hypereosinophilic syndrome (HES) (n = 1). Autoantibodies (ANA, dsDNA, and RAPA), thyroid grand functions, and coagulant functions were examined. Twenty-five out of 33 patients were treated with natural IFN-alpha, and 8 patients were treated with recombinant IFN-alpha 2b (rIFN alpha-2b). Three patients were treated with IFN and anticancer agents. Antinuclear antibodies were detected in 2 of 33 patients. RAPA and anti-thyroglobulin antibody became positive in 3 and 4 patients, respectively. Ten patients showed low serum levels of either free T3 and/or free T4. However, none of them showed any clinical symptoms for developing autoimmune diseases. In addition, circulating anticoagulant antibodies were detected in 3 of 23 patients with CML treated with rIFN alpha-2b, but in no cases treated with natural IFN-alpha. Although none of the patients developed autoimmune diseases, we concluded that patients receiving IFN therapy should be carefully monitored for clinical signs and symptoms of autoimmune disorders.

Pulmonary alveolar proteinosis as a terminal complication in myelodysplastic syndromes: a report of four cases detected on autopsy.

Secondary pulmonary alveolar proteinosis (PAP) is one of the complications of hematologic malignancy and immunosuppressive diseases. We encountered four cases of myelodysplastic syndrome (MDS) associated with PAP detected on autopsy. They consisted of two refractory anemia (RA) and two patients with refractory anemia with excess blasts in transformation (RAEBt) at the time of MDS diagnosis, but all of them developed leukemic phase and were resistant to chemotherapy at the time of pulmonary episodes. Of the four MDS patients, two also had pulmonary aspergillosis. Previously, 69 patients with PAP associated with hematologic disorders have been reported, but there have been only seven cases with MDS, including our four patients. Of the 69 reported cases of PAP in hematologic malignancies, 24/63 (38%) informative patients with infection had fungal infections of the lung; 2/7 (29%) MDS cases had fungal infection. We should, therefore, pay careful attention to this possibility in cases of MDS with lung complications, including PAP, especially in patients in the leukemic phase of MDS.

Megakaryocytic Maturation is Regulated by Maintaining a Balance Against Cytokine Induced-cell Proliferation: Steel Factor Retards Thrombopoietin-induced Megakaryocytic Differentiation While Synergistically Stimulating Mitogenesis; Hematopoiesis.

Using a factor-dependent cell line MO7ER, which contains a stably transduced human erythropoietin (EPO) receptor gene in human megakaryoblastic cell line MO7e and which resulted in concomitant expression of EPO receptor, c-Mpl and c-Kit, we investigated the biological effects of these cytokines in terms of cell growth and differentiation. Thrombopoietin (TPO), EPO and Steel factor (SLF) all stimulated MO7ER cell proliferation in a dose-dependent manner. Combined stimulation of cells with SLF plus either TPO or EPO resulted in striking synergistic enhancement of MO7ER cell growth as compared with each cytokine alone, whereas combination of TPO plus EPO showed only an additive effect on cell proliferation. With regards to cell differentiation, either TPO or EPO treatment induced enhancement of platelet glycoprotein (GP) IIb/IIIa and GPIb expression. SLF induced GPIIb/IIIa and GPIb expression, but the effect was much weaker than that of EPO or TPO. However, addition of SLF to either TPO- or EPO- containing cultures (which induced potent mitogenesis in MO7ER cells) resulted in suppression of these megakaryocyte specific antigens. Addition of low-dose cytosine arabinoside (Ara-C)(1 to 10 ng/ml) enhanced TPO- or EPO- induced megakaryocytic differentiation in MO7ER cells while mildly suppressing cell growth. Treatment the cells with low-dose Ara-C plus TPO plus SLF overrode the proliferative enhancing effects of SLF and induced GPIIb/IIIa and GPIb expression as efficient as TPO alone. Retardation of TPO-induced megakaryocytic maturation was also observed in normal murine bone marrow cells by combined stimulation with TPO and SLF as assessed by the numbers of acetylcholinesterase staining-positive cells and megakaryocyte nuclear polyploidy. These results suggest that megakaryocytic maturation is, at least in part, regulated by countering cytokine-induced cell proliferation.