Biomarkers for early complications post hematopoietic cell transplantation: Insights and challenges.

Hematopoietic cell transplantation is an established curative treatment option for various hematological malignant, and non-malignant diseases. However, the success of HCT is still limited by life-threatening early complications post-HCT, such as Graft Versus Host Disease (GVHD), Sinusoidal Obstruction Syndrome (SOS), and transplant-associated microangiopathy, to name a few. A decade of research in the discovery and validation of novel blood-based biomarkers aims to manage these early complications by using them for diagnosis or prognosis. Advances in this field have also led to predictive biomarkers to identify patients' likelihood of response to therapy. Although biomarkers have been extensively evaluated for different complications, these are yet to be used in routine clinical practice. This review provides a detailed summary of various biomarkers for individual early complications post-HCT, their discovery, validation, ongoing clinical trials, and their limitations. Furthermore, this review also provides insights into the biology of biomarkers and the challenge of obtaining a universal cut-off value for biomarkers.

Molecular characterization of triple-negative myeloproliferative neoplasms by next-generation sequencing.

The role of next-generation sequencing (NGS) in identifying mutations in the driver, epigenetic regulator, RNA splicing, and signaling pathway genes in myeloproliferative neoplasms (MPNs) has contributed substantially to our understanding of the disease pathogenesis as well as disease evolution. NGS aids in determining the clonal nature of the disease in a subset of these disorders where mutations in the driver genes are not detected. There is a paucity of real-world data on the utility of this test in the characterization of triple-negative myeloproliferative neoplasms (TN-MPN). In this study, 46 samples of TN-MPN (essential thrombocythemia (ET) = 17; primary myelofibrosis (PMF) = 23; & myeloproliferative neoplasm unclassified (MPN-u) = 6) were screened for markers of clonality using targeted NGS. Among these, 25 (54.3%) patients had mutations that would help determine the clonal nature of the disease. Eight of the 17 TN-ET (47%) and 13 of the 23 TN-PMF (56.5%) patients had noncanonical mutations in the driver genes and mutations in the genes involved in epigenetic regulation. Identification of mutations categorized as high molecular markers (HMR) in 2 patients helped classify them as PMF with high risk according to the MIPSS 70 scoring system. A novel mutation in the MPIG6B (C6orf25) gene associated with childhood myelofibrosis was detected in a 14-year-old girl. The presence of clonal hematopoiesis could be confirmed in four of the six MPN-u patients in this cohort. This study demonstrates the utility of NGS in improving the characterization of TN-MPN by establishing clonality and detecting noncanonical mutations in driver genes, thereby aiding in clinical decision-making.

Mutation Profile in BCR-ABL1-Negative Myeloproliferative Neoplasms: A Single-Center Experience From India.

OBJECTIVE/BACKGROUND: Recurrent somatic mutations in the JAK2, calreticulin (CALR), and the MPL genes are described as drivers of BCR-ABL1-negative myeloproliferative neoplasms (MPN) that includes polycythemia vera (PV), essential thrombocytosis (ET), primary myelofibrosis (PMF), and MPN unclassified (MPN-U). METHODS: We describe the mutation profile and clinical features of MPN cases diagnosed at a tertiary care center. JAK2V617F and MPL (S505/W515) mutations were screened by allele-specific polymerase chain reaction, while CALR exon 9 and JAK2 exon 12 mutations were screened by fragment analysis/Sanger sequencing. Among the 1,570 patients tested for these mutations during the study period, 407 were classified as MPN with a diagnosis of PV, ET, PMF, and MPN-U seen in 30%, 17%, 36%, and 17%, respectively, screened. RESULTS: Similar to previous reports from Asian countries, the incidence of PMF was the highest among the classic MPN. JAK2V617F mutation was detected in 90% of PV, 38% of ET, 48% of PMF, and 65% of MPN-U. JAK2 exon 12 mutations were seen in 5.7% of PV and 1.4% of PMF. CALR exon 9 mutations were seen in 33% of ET, 33% of PMF, and 12% of MPN-U. MPL mutations were detected in 2.8%, 2.7%, and 2.9% of ET, PMF, and MPN-U, respectively. Fifteen % of PMF, 26% of ET, and 22% of MPN-U were triple negative. CONCLUSION: There was a significantly higher incidence of CALR mutation in PMF and ET cases. Our study highlights the challenges in the diagnosis of JAK2-negative PV and the need for harmonization of criteria for the same.

JAK2 exon 12 mutations in cases with JAK2V617F-negative polycythemia vera and primary myelofibrosis.

Molecular detection of JAK2 mutation (V617F or exon 12) is included as a major diagnostic criterion for polycythemia vera (PV) by the WHO 2016 guidelines. JAK2 exon 12 mutations are seen in about 2-5% of JAK2V617F-negative cases of PV. Mutations in JAK2 cause constitutive activation of JAK-STAT pathway which results in variable phenotypes. PV patients with exon 12 mutations in JAK2 present characteristically with erythrocytosis. There are limited reports describing the spectrum of JAK2 exon12 mutations in myeloproliferative neoplasms (MPNs). Here, we describe the characteristics of a series of MPN patients with mutations in exon 12 of JAK2 of which two were novel variants associated with polycythemia. Interestingly, we noted two patients presenting as myelofibrosis having JAK2 exon 12 mutations.