Yi-Hao Chiang

Upfront maintenance therapy with arsenic trioxide in acute promyelocytic leukemia provides no benefit for non-t(15;17) subtype.

Aims:  The optimal maintenance therapy for patients with acute promyelocytic leukemia (APL) who achieved complete remission (CR) and complete consolidation chemotherapy is still controversial. Whether the use of arsenic trioxide (ATO) alone or along with all‐trans retinoic acid (ATRA) improves overall survival (OS) or disease‐free survival (DFS) is still debated.

Germline variations at JAK2 , TERT , HBS1L - MYB and MECOM and the risk of myeloproliferative neoplasms in Taiwanese population

Germline variations at JAK2, TERT, HBS1L-MYB and MECOM have been found to associate with myeloproliferative neoplasms (MPNs) in European populations. Whether these germline variations are associated with MPNs in Taiwanese population is obscure. Here we aimed to evaluate the association of five germline variations (JAK2 46/1 haplotype tagged by rs12343867, JAK2 intron 8 rs12339666, TERT rs2736100, HBS1L-MYB rs9376092 and MECOM rs2201862) and the risk of MPNs in Taiwanese population. A total of 178 MPN patients (109 essential thrombocythemia, 54 polycythemia vera and 15 primary myelofibrosis) were enrolled into this study. The information of 17033 control subjects was obtained from Taiwan Biobank database. The JAK2 46/1 haplotype, JAK2 rs12339666 and TERT rs2736100 were significantly associated with Taiwanese MPNs (P = 3.6×10-19, 1.9×10-19 and 3.1×10-6, respectively), and JAK2V617F-positive MPNs (n=121) (P = 5.6×10-21, 4.4×10-21 and 8.6×10-7, respectively). In JAK2V617F-negative cases (n=55), only the JAK2 46/1 haplotype and JAK2 rs12339666 remained statistically significant (P= 0.009 and 0.007, respectively). When stratified by disease subtypes, the JAK2 46/1 haplotype and JAK2 rs12339666 were significantly associated with all three MPN subtypes, but TERT rs2736100 was only associated with essential thrombocythemia and polycythemia vera. We did not find any association of these five SNPs with CALR mutations in our cohort. Furthermore, the risk alleles of MECOM rs2201862 and HBS1L-MYB rs9376092 were demonstrated to be negatively associated with the risk of developing polycythemia vera. In conclusion, germline variations at JAK2 (both the 46/1 haplotype and rs12339666) and TERT rs2736100 were associated with MPNs in Taiwanese population.Germline variations at JAK2, TERT, HBS1L-MYB and MECOM have been found to associate with myeloproliferative neoplasms (MPNs) in European populations. Whether these germline variations are associated with MPNs in Taiwanese population is obscure. Here we aimed to evaluate the association of five germline variations (JAK2 46/1 haplotype tagged by rs12343867, JAK2 intron 8 rs12339666, TERT rs2736100, HBS1L-MYB rs9376092 and MECOM rs2201862) and the risk of MPNs in Taiwanese population. A total of 178 MPN patients (109 essential thrombocythemia, 54 polycythemia vera and 15 primary myelofibrosis) were enrolled into this study. The information of 17033 control subjects was obtained from Taiwan Biobank database. The JAK2 46/1 haplotype, JAK2 rs12339666 and TERT rs2736100 were significantly associated with Taiwanese MPNs (P = 3.6x10-19, 1.9x10-19 and 3.1x10-6, respectively), and JAK2V617F-positive MPNs (n=121) (P = 5.6x10-21, 4.4x10-21 and 8.6x10-7, respectively). In JAK2V617F-negative cases (n=55), only the JAK2 46/1 haplotype and JAK2 rs12339666 remained statistically significant (P= 0.009 and 0.007, respectively). When stratified by disease subtypes, the JAK2 46/1 haplotype and JAK2 rs12339666 were significantly associated with all three MPN subtypes, but TERT rs2736100 was only associated with essential thrombocythemia and polycythemia vera. We did not find any association of these five SNPs with CALR mutations in our cohort. Furthermore, the risk alleles of MECOM rs2201862 and HBS1L-MYB rs9376092 were demonstrated to be negatively associated with the risk of developing polycythemia vera. In conclusion, germline variations at JAK2 (both the 46/1 haplotype and rs12339666) and TERT rs2736100 were associated with MPNs in Taiwanese population.

Targeted next-generation sequencing identified novel mutations in triple-negative myeloproliferative neoplasms

Mutations in JAK2, MPL and CALR genes have been identified in the majority of myeloproliferative neoplasm (MPN) patients, and patients negative for these three mutations are the so-called triple-negative (TN) MPN. In this study, we examined the mutational profiles of 16 triple-negative MPN patients including 7 essential thrombocythemia (ET), 1 primary myelofibrosis and 8 polycythemia vera (PV). Targeted next-generation sequencing was performed using the ACTOnco Comprehensive Cancer Panel (Ion AmpliSeq Comprehensive Cancer Panel, Life Technologies) to target all coding exons of 409 cancer-related genes. Overall, 30 nonsynonymous somatic mutations were detected in 12 (75%) patients with a range of 1–5 mutations per sample. Notably, one ET patient was found to have JAK2V617F and KITP551L mutations at very low allele frequency. One MPLP70L and 1 MPLM602T mutations were identified each in 1 ET and 1 PV, respectively. Other recurrent mutations were also identified including KMT2C, KMT2D, IRS2, SYNE1, PDE4DIP, SETD2, ATM, TNFAIP3 and CCND2. In addition, germline mutations were also found in some cancer-related genes. Copy number changes were rare in this cohort of TN MPNs. In conclusion, both somatic and germline mutations can be detected in TN MPN patients.

Increased B cell activation is present in JAK2 V617F-mutated, CALR -mutated and triple-negative essential thrombocythemia

Essential thrombocythemia (ET) is a BCL-ABL1-negative myeloproliferative neoplasm. We have reported that increased activated B cells can facilitate platelet production mediated by cytokines regardless JAK2 mutational status in ET. Recently, calreticulin (CALR) mutations were discovered in ~30% JAK2/MPL-unmutated ET and primary myelofibrosis. Here we sought to screen for CALR mutations and to evaluate B cell immune profiles in a cohort of adult Taiwanese ET patients. B cell populations, granulocytes/monocytes membrane-bound B cell-activating factor (mBAFF) levels, B cells toll-like receptor 4 (TLR4) expression and intracellular levels of interleukin (IL)-1β/IL-6 and the expression of CD69, CD80, and CD86 were quantified by flow cytometry. Serum BAFF concentration was measured by ELISA. 48 healthy adults were used for comparison. 19 (35.2%) of 54 ET patients harbored 8 types of CALR exon 9 mutations including 4 (7.4%) patients with concomitant JAK2V617F mutations. Compared to JAK2V617F mutation, CALR mutations correlated with younger age at diagnosis (p=0.04), higher platelet count (p=0.004), lower hemoglobin level (p=0.013) and lower leukocyte count (p=0.013). Multivariate analysis adjusted for age, sex, follow-up period and hematological parameters confirmed that increased activated B cells were universally present in JAK2-mutated, CALR-mutated and triple-negative ET patients when compared to healthy adults. JAK2- and CALR-mutated ET have significantly higher fraction of B cells with TLR4 expression when compared to triple-negative ET (p=0.019 and 0.02, respectively). CALR-mutated ET had significantly higher number of CD69-positive activated B cells when compared to triple-negative ET (p=0.035). In conclusion, increased B cell activation is present in ET patients across different mutational subgroups.