BACKGROUND: Based on the site of breakpoint in t(9;22) (q34;q11), bcr-abl fusion in leukemia patients is associated with different types of transcript proteins. In this study we have seen the association of HLA genes with different types of bcr-abl transcripts. The association could predict the bcr-abl peptide presentation by particular HLA molecules. METHODS: The study included a total of 189 patients of mixed ethnicity with chronic myelogenous leukemia and acute lymphocytic leukemia who were being considered for bone marrow transplantation. Typing of bcr-abl transcripts was done by reverse transcriptase PCR method. HLA typing was performed by molecular methods. The bcr-abl and HLA association was studied by calculating the relative risks and chi-square test. RESULTS: Significant negative associations (p < 0.05) were observed with HLA-A*02 (b2a2, e1a2), -A*68 (b2a2, b3a2, e1a2), -B*14 (b2a2, b3a2, e1a2), -B*15 (b2a2, b3a2), -B*40 (b2a2), -DQB1*0303 (b2a2, b3a2), -DQB1*0603 (b2a2), -DRB1*0401 (e1a2), -DRB1*0701 (b3a2), and -DRB1*1101 (b2a2). CONCLUSIONS: The negative associations of a particular bcr-abl transcript with specific HLA alleles suggests that these alleles play a critical role in presenting peptides derived from the chimeric proteins and eliciting a successful T-cell cytotoxic response. Knowledge of differential associations between HLA phenotypes and bcr-abl fusion transcript types would help in developing better strategies for immunization with the bcr-abl peptides against t(9;22) (q34;q11)-positive leukemia.

Although imatinib mesylate has shown encouraging activity in chronic myelogenous leukemia (CML), disease progression during therapy has been observed, manifested by clonal expansion of imatinib mesylate-resistant leukemia cells. On the other hand, myelosuppression related to treatment of imatinib mesylate is often managed with temporary interruption of treatment or dose reduction. We here report two CML patients who had imatinib mesylate-sensitive blast crisis (BC) immediately after discontinuation of imatinib mesylate therapy. The patients discontinued therapy because of neutropenia. Although there was no evidence of blastic phase during therapy, BC occurred 2 weeks after the withdrawal of treatment in both cases. Interestingly, additional chromosomal abnormalities were detected following the withdrawal of imatinib mesylate and disappeared by re-introduction of this agent. The same doses of imatinib mesylate was still effective and remission was sustained with imatinib mesylate alone again. Our report suggests the possibility that withdrawal of imatinib mesylate may lead to proliferation of blast clones even in patients showing good responses to imatinib mesylate without signs of disease progression. Am. J. Hematol. 76:275-278, 2004.

Sweet’s syndrome is an acute febrile neutrophilic dermatosis that is a known complication of the administration of filgrastim, a drug that causes increased neutrophil proliferation and differentiation. This complication has not previously been reported during treatment with sargramostim, a hematopoietic cytokine with activity that overlaps filgrastim. We report a case of Sweet’s syndrome in association with sargramostim treatment following chemotherapy for acute myelogenous leukemia. A suspected second episode occurred after subsequent chemotherapy and sargramostim treatment. Physicians should be aware of this possible association because the signs and symptoms of Sweet’s syndrome are easily mistaken as being due to infection. Am. J. Hematol. 76:283-285, 2004.

We describe a patient with eosinophilic folliculitis (EF) that developed 3 months after allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia. Skin biopsy specimen revealed numerous eosinophil infiltrations from the hair follicles to the sebaceous glands. No sign of skin graft-versus-host disease (GVHD) was found. The skin lesions and peripheral eosinophilia subsided within 5 weeks. In the following 8 months, the rash did not recur and GVHD has not developed. Taken together with previous reports, the present case demonstrates that it is important to recognize this distinct skin condition to avoid an inference that it may manifest itself as one of the signs of skin GVHD. Am. J. Hematol. 76:295-296, 2004.

Tyrosine kinase inhibitors (TKIs) are promising new agents for specific inhibition of malignant cell growth and metastasis formation. Because most of the TKIs have to reach an intracellular target, specific membrane transporters may significantly modulate their effectiveness. In addition, the hydrophobic TKIs may interact with so-called multidrug transporters and thus alter the cellular distribution of unrelated pharmacological agents. In the present work, we show that certain TKIs, already in the clinical phase of drug development, directly interact with the ABCG2 multidrug transporter protein with a high affinity. We found that in several in vitro assay systems, STI-571 (Gleevec; imatinib mesylate), ZD1839 (Iressa; gefitinib), and N-[4-[(3-bromophenyl)amino]-6-quinazolinyl]-2-butynamide (EKI-785) interacted with ABCG2 at submicromolar concentrations, whereas other multidrug transporters, human multidrug resistance protein (P-glycoprotein, ABCB1) and human multidrug resistance protein 1 (ABCC1), showed much lower reactivity toward these agents. Low concentrations of the TKIs examined selectively modulated ABCG2-ATPase activity, inhibited ABCG2-dependent active drug extrusion, and significantly affected drug resistance patterns in cells expressing ABCG2. Our results indicate that multidrug resistance protein modulation by TKIs may be an important factor in the clinical treatment of cancer patients. These data also raise the possibility that an extrusion of TKIs by multidrug transporters, e.g., ABCG2, may be involved in tumor cell TKI resistance.

We describe a patient with chronic myelogenous leukemia who developing severe intestinal bleeding after allogeneic peripheral blood stem cells transplantation (allo-PBSCT). PBSC were obtained from an HLA one-locus mismatch sibling donor. On day 26 after PBSCT, although there was no sign of graft-versus-host disease (GVHD) in either the skin or the liver, diarrhea and severe intestinal bleeding occurred. The histopathological examination of the colon revealed complete denudation of the epithelial cells of the mucosa and no obvious apoptosis. Neither red cell fragments nor hemorrhagic diathesis was seen during this episode and the patient was diagnosed as having GVHD. Methylpredonisolone followed by FK506 may be effective in controlling intestinal bleeding and was used in our patient. Acute GVHD involving only the intestine has rarely been described but when using HLA-mismatched PBSCs, acute GVHD may occur severely and atypically.

We compared interferon alpha (IFN-alpha) therapy with stem cell transplantation (SCT) for patients with chronic-phase chronic myelogenous leukemia in a multicenter prospective study to investigate the optimal indication and timing of SCT, especially from HLA-matched unrelated donors. Of 257 eligible patients, 145 patients who were younger than 50 years were assigned to the IFN-alpha cohort (n = 87) or the SCT cohort (n = 58), according to family donor availability. In the IFN-alpha cohort, 52 patients received IFN-alpha and chemotherapy (the IFN1 group), and 35 patients received an SCT from an unrelated donor (the U-SCT group). In the SCT cohort, 47 patients received an SCT from a related donor (the R-SCT group). In the IFN1 group, 88% of the patients achieved a complete hematologic response, and 33% achieved a complete cytogenetic response. At a median follow-up period of 53 months, the predicted 6-year survival rate was 72% in the IFN1 group, 81% in the R-SCT group, and 81% in the U-SCT group. When overall survival was evaluated for the IFN-alpha and R-SCT cohorts by intention to treat according to family donor availability, the 6-year survival rates were 76% and 84%, respectively. When the outcomes of the U-SCT and IFN1 groups were compared, the survival rate of U-SCT group patients was significantly better than for IFN1 group patients without a major cytogenetic response and seemed better for IFN1 group patients younger than 35 years. Therefore, U-SCT may be recommendable to patients who fail to achieve a major cytogenetic response in IFN-alpha therapy and to younger patients.

Progression of CML from chronic phase to blast crisis is accompanied by accumulating genetic alterations. To analyze whether this abnormality can be prevented by inhibition of Bcr-Abl, we measured the frequency of spontaneous and irradiation-induced HPRT mutations in cells treated with or without imatinib mesylate (Gleevec, STI571). Imatinib treatment of cells expressing Bcr-Abl reversed the mutation frequency to a value comparable to that of Bcr-Abl negative cells. Experiments with a Bcr-Abl deletion mutant indicate that in addition to the kinase activity, protein-protein interactions are required for induction of the mutator phenotype by Bcr-Abl.

Imatinib mesylate (Gleevec, Glivec) is an orally administered competitive inhibitor of the BCR-ABL tyrosine kinase created by the Philadelphia chromosome (Ph+) in chronic myeloid leukemia (CML). In patients with newly diagnosed and previously untreated (apart from hydroxyurea and/or anagrelide) CML in the chronic phase, imatinib mesylate 400 mg/day, compared with interferon-alpha (IFNalpha) plus cytarabine, resulted in higher hematologic response (HR) and cytogenetic response (CR) rates and fewer patients progressing to the accelerated phase or blast crisis in a large comparative trial. Preliminary results indicate that, compared with IFNalpha plus cytarabine, imatinib mesylate treatment was associated with similar total costs, but resulted in a higher health-related quality of life (HR-QOL). Imatinib mesylate was also effective in patients with chronic-phase CML refractory to or intolerant of treatment with IFNalpha (as 400 mg/day) and in those with blast-crisis or accelerated-phase CML (600 mg/day). In the latter groups, HR and CR rates were lower than those in patients with chronic-phase CML. Imatinib mesylate-associated adverse events were common in clinical trials, but were mostly mild to moderate in severity. The most frequently reported adverse events were superficial edema, nausea, muscle cramps, diarrhea, vomiting, and skin rash. Myelosuppression (thrombocytopenia and neutropenia) was also reported, especially in patients with advanced disease. In patients with previously untreated chronic-phase CML, serious adverse events (both hematologic and nonhematologic) were less common with imatinib mesylate than with IFNalpha plus cytarabine treatment. CONCLUSION: Imatinib mesylate is a valuable therapy for patients with newly diagnosed Ph+ chronic-phase CML. It is better tolerated and produces higher HR, CR and freedom from progressive disease rates than conventional therapy with IFNalpha plus cytarabine. Preliminary results indicate that, compared with IFNalpha plus cytarabine, imatinib mesylate treatment was associated with similar total costs, but resulted in a higher HR-QOL. Imatinib mesylate is also effective in patients with accelerated-phase and blast-crisis CML, and patients with chronic-phase CML who have failed IFNalpha therapy. Given its efficacy and generally manageable adverse event profile, imatinib mesylate offers an important early treatment option for patients with CML.