Myeloid neoplasm with a novel cryptic PDGFRB rearrangement detected by next-generation sequencing

Meta-analysis of the adoption of omalizumab in the treatment of pediatric allergic diseases

Introduction

Allergic diseases are common chronic conditions in children, omalizumab has a wide range of adoptions in various diseases. A meta-analysis was implemented to demonstrate the efficacy of omalizumab in the therapy of pediatric allergic diseases.

Materials and methods

English databases were searched. The search terms included "Omalizumab", "Children", "Allergic asthma", and "Atopic dermatitis". The literature was screened regarding inclusion and exclusion criteria, and data were extracted and analyzed using RevMan5.3.

Results

a total of six suitable studies, comprising 2761 patients, were selected for inclusion. The meta-analysis results implied that at 24 weeks, OR for worsening of symptoms in children was 0.10 (95 % confidence interval [CI] 0.03-0.41), Z = 3.24, P = 0.001 (P < 0.05); at 52 weeks, OR was 0.27 (95 % CI 0.09-0.83), Z = 2.28, P = 0.02 (P < 0.05); and during treatment, OR for adverse events in children was 0.87 (95 % CI 0.60-1.29), Z = 0.68, P = 0.49 (P > 0.05).

Conclusion

the study comprised six investigations that examined the effectiveness of omalizumab in treating pediatric allergic diseases. The findings demonstrated that, in comparison to standard treatment, omalizumab can greatly alleviate allergy-related clinical symptoms in children, slow down disease progression, and has a higher safety profile with fewer adverse reactions. These results have practical implications and highlight the potential value of omalizumab in pediatric allergy treatment.

Case of cryptic TNIP1::PDGFRB rearrangement presenting with myelodysplastic syndrome achieved hematologic and cytogenetic remission with low-dose imatinib plus decitabine therapy

For a long time, FIP1L1::PDGFRA fusion seems to be the only cryptic rearrangement of myeloid/lymphoid neoplasm with tyrosine kinase gene fusions. Recently, with the wide application of RNA sequencing, more cryptic rearrangements of other TK genes have been identified, especially the PDGFRB. Here we report a case of myelodysplastic syndrome with severe thrombocytopenia. Conventional karyotype analysis revealed a t (5;19) (q33; p13.2) but no PDGFRB rearrangement was detected by the PDGFRB break-apart probe. The TNIP1::PDGFRB fusion was eventually found by RNA sequencing, leading us to treat with low-dose imatinib plus decitabine, and the patient achieved hematologic improvement and cytogenetic remission.

Genomic and clinical findings in myeloid neoplasms with PDGFRB rearrangement

Platelet-derived growth factor receptor B (PDGFRB) gene rearrangements define a unique subgroup of myeloid and lymphoid neoplasms frequently associated with eosinophilia and characterized by high sensitivity to tyrosine kinase inhibition. To date, various PDGFRB/5q32 rearrangements, involving at least 40 fusion partners, have been reported. However, information on genomic and clinical features accompanying rearrangements of PDGFRB is still scarce. Here, we characterized a series of 14 cases with a myeloid neoplasm using cytogenetic, single nucleotide polymorphism array, and next-generation sequencing. We identified nine PDGFRB translocation partners, including the KAZN gene at 1p36.21 as a novel partner in a previously undescribed t(1;5)(p36;q33) chromosome change. In all cases, the PDGFRB recombination was the sole cytogenetic abnormality underlying the phenotype. Acquired somatic variants were mainly found in clinically aggressive diseases and involved epigenetic genes (TET2, DNMT3A, ASXL1), transcription factors (RUNX1 and CEBPA), and signaling modulators (HRAS). By using both cytogenetic and nested PCR monitoring to evaluate response to imatinib, we found that, in non-AML cases, a low dosage (100–200 mg) is sufficient to induce and maintain longstanding hematological, cytogenetic, and molecular remissions.

Developing a standardized approach for assessing mast cells and eosinophils on tissue biopsies: A Work Group Report of the AAAAI Allergic Skin Diseases Committee

Mast cells and eosinophils are commonly found, expectedly or unexpectedly, in human tissue biopsies. Although the clinical significance of their presence, absence, quantity, and quality continues to be investigated in homeostasis and disease, there are currently gaps in knowledge related to what constitutes quantitatively relevant increases in mast cell and eosinophil number in tissue specimens for several clinical conditions. Diagnostically relevant thresholds of mast cell and eosinophil numbers have been proposed and generally accepted by the medical community for a few conditions, such as systemic mastocytosis and eosinophilic esophagitis. However, for other mast cell- and eosinophil-associated disorders, broad discrepancies remain regarding diagnostic thresholds and how samples are processed, routinely and/or specially stained, and interpreted and/or reported by pathologists. These discrepancies can obfuscate or delay a patient's correct diagnosis. Therefore, a work group was assembled to review the literature and develop a standardized consensus for assessing the presence of mast cells and eosinophils for a spectrum of clinical conditions, including systemic mastocytosis and cutaneous mastocytosis, mast cell activation syndrome, eosinophilic esophagitis, eosinophilic gastritis/enteritis, and hypereosinophilia/hypereosinophilic syndrome. The intent of this work group is to build a consensus among pathology, allergy, dermatology, hematology/oncology, and gastroenterology stakeholders for qualitatively and quantitatively assessing mast cells and eosinophils in skin, gastrointestinal, and bone marrow pathologic specimens for the benefit of clinical practice and patients.

Interstitial Deletions Generating Fusion Genes

A fusion gene is the physical juxtaposition of two different genes resulting in a structure consisting of the head of one gene and the tail of the other. Gene fusion is often a primary neoplasia-inducing event in leukemias, lymphomas, solid malignancies as well as benign tumors. Knowledge about fusion genes is crucial not only for our understanding of tumorigenesis, but also for the diagnosis, prognostication, and treatment of cancer. Balanced chromosomal rearrangements, in particular translocations and inversions, are the most frequent genetic events leading to the generation of fusion genes. In the present review, we summarize the existing knowledge on chromosome deletions as a mechanism for fusion gene formation. Such deletions are mostly submicroscopic and, hence, not detected by cytogenetic analyses but by array comparative genome hybridization (aCGH) and/or high throughput sequencing (HTS). They are found across the genome in a variety of neoplasias. As tumors are increasingly analyzed using aCGH and HTS, it is likely that more interstitial deletions giving rise to fusion genes will be found, significantly impacting our understanding and treatment of cancer.

Myeloid/Lymphoid Neoplasms with Eosinophilia and TK Fusion Genes, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Eosinophilic disorders and related syndromes represent a heterogeneous group of neoplastic and nonneoplastic conditions, characterized by more eosinophils in the peripheral blood, and may involve eosinophil-induced organ damage. In the WHO classification of myeloid and lymphoid neoplasms, eosinophilic disorders characterized by dysregulated tyrosine kinase (TK) fusion genes are recognized as a new category termed, myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB or FGFR1 or with PCM1-JAK2. In addition to these aforementioned TK fusion genes, rearrangements involving FLT3 and ABL1 genes have also been described. These new NCCN Guidelines include recommendations for the diagnosis, staging, and treatment of any one of the myeloid/lymphoid neoplasms with eosinophilia (MLN-Eo) and a TK fusion gene included in the 2017 WHO Classification, as well as MLN-Eo and a FLT3 or ABL1 rearrangement.