Infrequent Presentations of Chronic NPM1-Mutated Myeloid Neoplasms: Clinicopathological Features of Eight Cases from a Single Institution and Review of the Literature.

Non-acute myeloid neoplasms (MNs) with NPM1 mutations (NPM1mut-MNs) pose a diagnostic and therapeutic dilemma, primarily manifesting as chronic myelomonocytic leukemia (CMML) and myelodysplastic syndromes (MDS). The classification and treatment approach for these conditions as acute myeloid leukemia (AML) are debated. We describe eight cases of atypical NPM1mut-MNs from our institution and review the literature. We include a rare case of concurrent prostate carcinoma and MN consistent with chronic eosinophilic leukemia, progressing to myeloid sarcoma of the skin. Of the remaining seven cases, five were CMML and two were MDS. NPM1 mutations occur in 3-5% of CMML and 1-6% of MDS, with an increased likelihood of rapid evolution to AML. Their influence on disease progression varies, and their prognostic significance in non-acute MNs is less established than in AML. Non-acute MNs with NPM1 mutations may display an aggressive clinical course, emphasizing the need for a comprehensive diagnosis integrating clinical and biological data. Tailoring patient management on an individualized basis, favoring intensive treatment aligned with AML protocols, is crucial, regardless of blast percentage. Research on the impact of NPM1 mutations in non-acute myeloid neoplasms is ongoing, requiring challenging prospective studies with substantial patient cohorts and extended follow-up periods for validation.

Severe osteomalacia with multiple insufficiency fractures secondary to intravenous iron therapy in a patient with Rendu-Osler-Weber syndrome.

SUMMARY: This case report describes a 65-year-old man with a Rendu-Osler-Weber syndrome with secondary chronic anaemia, who received multiple intravenous (IV) iron infusions and sustained diffuse bone pain secondary to multiple insufficiency fractures. Laboratory study confirmed fibroblast growth factor 23 (FGF-23)-mediated hypophosphatemia as the main cause of a severe osteomalacia induced by ferric carboxymaltose (FCM).After 3 months or oral phosphate replacement and switching to iron sucrose, serum phosphate levels were normalized and patient improved clinically. INTRODUCTION: Some drugs can induce asymptomatic hypophosphatemia, which if sustained, can lead to a severe osteomalacia with multiple skeletal fractures. This complication has also been described with IV iron therapy. METHODS: This case report describes a patient with Rendu-Osler-Weber syndrome with chronic iron deficiency anaemia, recurrently treated with FCM, who developed a severe osteomalacia with multiple skeletal fractures. RESULTS: Laboratory study showed hypophosphatemia, with high ALP and high FGF-23. Images studies confirmed bone mass loss and multiple insufficiency fractures. A Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) did not show hidden tumor, so a diagnosis of FCM-induced hypophosphatemic osteomalacia was performed. Phosphate replacement improved clinical symptoms of the patient. CONCLUSION: Intravenous iron therapy, mainly FCM form, can cause hypophosphatemia, and in some cases induce a severe osteomalacia with multiple fractures, so it seems advisable to monitor serum phosphate levels in high risk patients, as those who receive repeated dose.

Use of eltrombopag for patients 65 years old or older with immune thrombocytopenia.

BACKGROUND: Eltrombopag is useful for immune thrombocytopenia (ITP). However, results of clinical trials may not accurately mirror clinical practice reality. Here we evaluated eltrombopag for primary and secondary ITP in our ≥65-year-old population. METHODS: A total of 106 primary ITP patients (16 with newly diagnosed ITP, 16 with persistent ITP, and 74 with chronic ITP) and 39 secondary ITP patients (20 with ITP secondary to immune disorders, 7 with ITP secondary to infectious diseases, and 12 with ITP secondary to lymphoproliferative disorders [LPD]) were retrospectively evaluated. RESULTS: Median age of our cohort was 76 (interquartile range, IQR, 70-81) years. 75.9% of patients yielded a platelet response including 66.2% complete responders. Median time to platelet response was 14 (IQR, 8-21) days. Median time on response was 320 (IQR, 147-526) days. Sixty-three adverse events (AEs), mainly grade 1-2, occurred. The most common were hepatobiliary laboratory abnormalities (HBLAs) and headaches. One transient ischemic attack in a newly diagnosed ITP and two self-limited pulmonary embolisms in secondary ITP were the only thrombotic events observed. CONCLUSION: Eltrombopag showed efficacy and safety in ITP patients aged ≥65 years with primary and secondary ITP. However, efficacy results in LPD-ITP were poor. A relatively high number of deaths were observed.

Use of eltrombopag for secondary immune thrombocytopenia in clinical practice.

Eltrombopag is a second-line treatment in primary immune thrombocytopenia (ITP). However, its role in secondary ITP is unknown. We evaluated the efficacy and safety of eltrombopag in secondary ITP in daily clinical practice. Eighty-seven secondary ITP patients (46 with ITP secondary to autoimmune syndromes, 23 with ITP secondary to a neoplastic disease subtype: lymphoproliferative disorders [LPDs] and 18 with ITP secondary to viral infections) who had been treated with eltrombopag were retrospectively evaluated. Forty-four patients (38%) had a platelet response, including 40 (35%) with complete responses. Median time to platelet response was 15 days (95% confidence interval, 7-28 days), and was longer in the LPD-ITP group. Platelet response rate was significantly lower in the LPD-ITP than in other groups. However, having achieved response, there were no significant differences between the durable response of the groups. Forty-three patients (49·4%) experienced adverse events (mainly grade 1-2), the commonest being hepatobiliary laboratory abnormalities. There were 10 deaths in this case series, all of which were related to pre-existing medical conditions. In routine clinical practice, eltrombopag is effective and well-tolerated in unselected patients with ITP secondary to both immune and infectious disorders. However, the response rate in LPD-ITP is low.

Eltrombopag safety and efficacy for primary chronic immune thrombocytopenia in clinical practice.

BACKGROUND: Eltrombopag is effective and safe in chronic immune thrombocytopenia (ITP). However, clinical trials may not accurately reflect what happens in clinical practice. We evaluated the efficacy and safety of eltrombopag in primary chronic ITP in a real-world setting. METHODS: A total of 164 primary patients with chronic ITP from 40 Spanish centers, who had been treated with eltrombopag, were retrospectively evaluated. RESULTS: The median age of our cohort (72% women) was 63 yr (interquartile range, IQR, 45-75 yr). The median time with ITP diagnosis was 81 months (IQR, 30-192 months). The median number of therapies prior to eltrombopag was 3 (IQR, 2-4). At the time of eltrombopag start, 45 patients (30%) were receiving concomitant treatment for ITP. Forty-six patients (30%) had bleeding signs/symptoms the month before the treatment started. The median platelet count at eltrombopag initiation was 22 × 10(9) /L (IQR, 8-39 × 10(9) /L). A total of 135 patients (88.8%) achieved a platelet response. The median time to platelet response was 12 d (95% CI, 9-13 d). Maintained platelet response rate during the 15-month period under examination was 75.2%. Twenty-eight patients (18.4%) experienced adverse events, mainly grades 1-2. CONCLUSION: Eltrombopag is highly effective and well tolerated in unselected patients with primary chronic ITP.

Successful discontinuation of eltrombopag after complete remission in patients with primary immune thrombocytopenia.

Eltrombopag is effective and safe in immune thrombocytopenia (ITP). Some patients may sustain their platelet response when treatment is withdrawn but the frequency of this phenomenon is unknown. We retrospectively evaluated 260 adult primary ITP patients (165 women and 95 men; median age, 62 years) treated with eltrombopag after a median time from diagnosis of 24 months. Among the 201 patients who achieved a complete remission (platelet count >100 × 10(9) /l), eltrombopag was discontinued in 80 patients. Reasons for eltrombopag discontinuation were: persistent response despite a reduction in dose over time (n = 33), platelet count >400 × 10(9) /l (n = 29), patient's request (n = 5), elevated aspartate aminotransferase (n = 3), diarrhea (n = 3), thrombosis (n = 3), and other reasons (n = 4). Of the 49 evaluable patients, 26 patients showed sustained response after discontinuing eltrombopag without additional ITP therapy, with a median follow-up of 9 (range, 6-25) months. These patients were characterized by a median time since ITP diagnosis of 46.5 months, with 4/26 having ITP < 1 year. Eleven patients were male and their median age was 59 years. They received a median of 4 previous treatment lines and 42% were splenectomized. No predictive factors of sustained response after eltrombopag withdrawal were identified. Platelet response following eltrombopag cessation may be sustained in an important percentage of adult primary ITP patients who achieved CR with eltrombopag. However, reliable markers for predicting which patients will have this response are needed.

Non-natural and photo-reactive amino acids as biochemical probes of immune function.

Wilms tumor protein (WT1) is a transcription factor selectively overexpressed in leukemias and cancers; clinical trials are underway that use altered WT1 peptide sequences as vaccines. Here we report a strategy to study peptide-MHC interactions by incorporating non-natural and photo-reactive amino acids into the sequence of WT1 peptides. Thirteen WT1 peptides sequences were synthesized with chemically modified amino acids (via fluorination and photo-reactive group additions) at MHC and T cell receptor binding positions. Certain new non-natural peptide analogs could stabilize MHC class I molecules better than the native sequences and were also able to elicit specific T-cell responses and sometimes cytotoxicity to leukemia cells. Two photo-reactive peptides, also modified with a biotin handle for pull-down studies, formed covalent interactions with MHC molecules on live cells and provided kinetic data showing the rapid clearance of the peptide-MHC complex. Despite "infinite affinity" provided by the covalent peptide bonding to the MHC, immunogenicity was not enhanced by these peptides because the peptide presentation on the surface was dominated by catabolism of the complex and only a small percentage of peptide molecules covalently bound to the MHC molecules. This study shows that non-natural amino acids can be successfully incorporated into T cell epitopes to provide novel immunological, biochemical and kinetic information.

Peptide binding motif predictive algorithms correspond with experimental binding of leukemia vaccine candidate peptides to HLA-A*0201 molecules.

The ability to reliably identify the peptides that can bind to MHC molecules is of practical importance for rapid vaccine development. Several computer-based prediction methods have been applied to study the interaction of MHC class I/peptide binding. Here we have compared the binding of peptides predicted by three algorithms (BIMAS, SYFPEITHI and Rankpep) to the binding of the peptides to HLA-A*0201 molecules in vitro, assessed using a MHC stabilization assay on live T2 cells. Fifty HLA-A*0201 peptides were selected from several target oncoproteins: Wilms' tumor protein (WT1), native and imatinib-mutated bcr-abl p210, JAK2 protein and Ewing's sarcoma fusion protein type 1. The sensitivity and specificity of BIMAS, SYFPEITHI and Rankpep respectively, were: 86%, and 82%; 75% and 73%; 64% and 82%. Combining two or more computer methods did not appear to significantly improve the predictive value.

Natural killer cells license dendritic cell cross-presentation of B lymphoma cell--associated antigens.

PURPOSE: Presentation of exogenous antigen by MHC class I molecules, or cross-presentation, is a property of dendritic cells, which is considered crucial for the priming of cytotoxic T-cell response to tumor antigens. However, the precise mechanisms of this process are not fully understood. EXPERIMENTAL DESIGN AND RESULTS: We show here in a human in vitro system, using B lymphoma cells as a tumor model, that the cross-presentation of cell-associated antigens to T cells by dendritic cells requires "help" from natural killer cells. When autologous dendritic cells that had taken up apoptotic B lymphoma cells and induced to a fully mature state were used to stimulate nonadherent cells of peripheral blood mononuclear cells from healthy donors, they induced strong cytotoxicity against B lymphoma cells in a HLA-A0201-restricted manner. The cells failed to induce cytotoxicity, however, when purified T cells were used as effector cells. Depletion of CD56+ cells, but not CD14+ or CD19+ cells, abrogated the cytotoxicity of nonadherent cells, showing that the help was provided by natural killer cells. Further, when natural killer cells were present in the cultures, a strong and persistent production of interleukin-18, but not interleukin-12 and interleukin-15, was observed. Blocking interleukin-18 significantly reduced the cytotoxicity of nonadherent cells against B lymphoma cells. CONCLUSIONS: These results suggest that capture of tumor cells and a full maturation status of dendritic cells are not sufficient to cross-prime CD8 T cells. Effective cross-priming requires further activation of dendritic cells by natural killer cells and an abundant production of interleukin-18, which, along with other yet undefined mechanisms, contribute to the generation of CTL response against B-cell lymphoma.