Epidemiology, clinical picture and long‐term outcomes ofFIP1L1‐PDGFRA‐positive myeloid neoplasm with eosinophilia: Data from 151 patients

Abstract

FIP1L1-PDGFRA-positive myeloid neoplasm with eosinophilia (F/P+ MN-eo) is a rare disease: robust epidemiological data are lacking and reported issues are scarce, of low sample-size and limited follow-up. Imatinib mesylate (IM) is highly efficient but no predictive factor of relapse after discontinuation has yet been identified. One hundred and fifty-one patients with F/P+ MN-eo (143 males; mean age at diagnosis 49 years; mean annual incidence: 0.18 case per million population) were included in this retrospective nationwide study involving all French laboratories who perform the search of F/P fusion gene (study period: 2003-2019). The main organs involved included the spleen (44%), skin (32%), lungs (30%), heart (19%) and central nervous system (9%). Serum vitamin

World Health Organization‐defined eosinophilic disorders: 2022 update on diagnosis, risk stratification, and management

“…46 In instances where FIP1L1-PDGFRA screening is not available, evaluation of the serum tryptase can be a useful surrogate marker for FIP1L1-PDGFRA-positive disease, since increased levels segregate with this molecular abnormality (observed in 79% of patients in one series) and myeloproliferative variants of HE. 8,47 The FIP1L1-PDGFRA gene fusion has also been also identified in cases where bone marrows show increased mast cell numbers with associated peripheral eosinophilia. 6 The bone marrows of such patients typically exhibit loose mast cell clusters, compared to classic SM, where dense mast cell aggregates are associated with the KIT D816V mutation.…”

“…107 In the largest cohort to date of 148 imatinib-treated patients, 1, 5-, and 10-year overall survival rates were 99%, 98%, and 89%, respectively. 8 Although in-depth and durable molecular responses occur with imatinib, discontinuation of the drug can lead to relapse. 5,14 In a dose de-escalation trial of imatinib in five patients who had achieved a stable hematologic and molecular remission at 300-400 mg daily for at least 1 year, molecular relapse was observed in all patients after 2-5 months of either imatinib dose reduction or discontinuation.…”

“…108 Recent cohorts reported relapse rate (molecular or hematologic) of 33%-57% in patients who discontinued imatinib, within a median of 10 months. 8,109 Time to imatinib initiation and duration of imatinib treatment were independent factors of relapse after discontinuation of imatinib. 8 Molecular remissions could be reestablished with re-induction of imatinib in most cases at a dose range of 100-400 mg daily.…”

“…8,109 Time to imatinib initiation and duration of imatinib treatment were independent factors of relapse after discontinuation of imatinib. 8 Molecular remissions could be reestablished with re-induction of imatinib in most cases at a dose range of 100-400 mg daily. Hematologic relapse was noted only several weeks after discontinuation of imatinib in four patients in a Mayo series.…”

Immunomodulating Therapies in Acute Myocarditis and Recurrent/Acute Pericarditis

“…Furthermore, brain CT or brain MRI should be performed when embolic stroke is suspected in patients with eosinophilic myocarditis or Loeffler cardiomyopathy ( 144 ). Additionally, testing for FIP1L1-PDGFRA fusion gene should be performed in selected cases when clinical (e.g., male sex, splenomegaly), biologic (e.g., high B12 vitamin and/or tryptase levels) features and/or primary resistance to steroids are observed ( 145 ). Polymerase chain reaction testing for specific viruses (e.g., Herpesviridae, especially HHV 6) and the RegiSCAR scoring system can be useful in patients with suspected Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) ( 146 ).…”