Pure Red Cell Aplasia Associated with Imatinib-Treated FIP1L1-PDGFRA Positive Chronic Eosinophilic Leukemia

• Published in: Internal Medicine Vol. 49; no. 12; pp. 1195 - 1200
• Main Authors: Tanaka, Hideo, Iwato, Koji, Asou, Hiroya, Kimura, Akiro
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Internal Medicine 01.01.2010
• Subjects: Adult; Benzamides; CEL; Chronic Disease; FIP1L1; Humans; Hypereosinophilic Syndrome - complications; Hypereosinophilic Syndrome - drug therapy; Hypereosinophilic Syndrome - genetics; imatinib; Imatinib Mesylate; Male; mRNA Cleavage and Polyadenylation Factors - biosynthesis; mRNA Cleavage and Polyadenylation Factors - genetics; Oncogene Proteins, Fusion - biosynthesis; Oncogene Proteins, Fusion - genetics; PDGFRA; Piperazines - therapeutic use; PRCA; Pyrimidines - therapeutic use; Receptor, Platelet-Derived Growth Factor alpha - biosynthesis; Receptor, Platelet-Derived Growth Factor alpha - genetics; Red-Cell Aplasia, Pure - drug therapy; Red-Cell Aplasia, Pure - etiology; Red-Cell Aplasia, Pure - genetics
• ISSN: 0918-2918; 1349-7235; 1349-7235
• DOI: 10.2169/internalmedicine.49.3178

A 28-year-old man with marked eosinophilia is described. FIP1L1/PDGFRA mRNA showed multiple alternatively-spliced fusion transcripts. Sequencing analysis showed that the deduced DNA breakpoints were intron 10 in the FIP1L1 gene and exon 12 in the PDGFRA gene. Then, a diagnosis of chronic eosinophilic leukemia (CEL) was made. Whereas the response to the treatments with prednisolone and hydroxyurea were unsatisfactory, treatment with imatinib showed a rapid decrease of eosinophils. The hemoglobin level also dropped and bone marrow examination showed pure red cell aplasia. Continued administration of very low dose imatinib (100 mg every 5 days) led to and maintained complete molecular remission, with good tolerability.