DefinePK

Research Objective

To determine the frequency and clinico-haematological features of PDGFRA, PDGFRB and FGFR1 gene rearrangements in patients with persistent Eosinophilia using Fluorescence in situ hybridization.

Methodology

Cross-sectional study conducted at the Armed Forces Institute of Pathology, Rawalpindi Pakistan, from December 2018 to December 2019. Patients with absolute eosinophil count >1.5x10^9/L persistent for over six months or with Myeloid or Lymphoid neoplasms with persistent Eosinophilia were included. Patients with reactive Eosinophilia and those on treatment were excluded. Interphase FISH studies were performed using specific probes for PDGFRA, PDGFRB, and FGFR1 gene rearrangements. Data was analyzed using SPSS version 23.

Methodology Flowchart

                        graph TD;
    A["Patient Recruitment"] --> B["Eosinophilia >1.5x10^9/L or Neoplasm"];
    B -- Yes --> C["Exclude Reactive/Treated Patients"];
    C -- No --> D["Exclude"];
    C -- Yes --> E["Sample Collection Blood"];
    E --> F["Interphase FISH Analysis"];
    F --> G["Data Analysis SPSS"];
    G --> H["Results & Conclusion"];                    

Discussion

The study highlights the importance of FISH screening for detecting FIP1L1-PDGFRA gene rearrangement, which is often karyotypically occult. The frequency of FIP1L1-PDGFRA fusion in this study (20%) is comparable to other reported incidences. The rarity of PDGFRB and FGFR1 mutations was also noted. The findings suggest that idiopathic Eosinophilia is prevalent and requires further investigation.

Key Findings

A total of 60 patients were included. The only rearrangement detected was FIP1L1-PDGFRA gene fusion, found in 20% of patients. No PDGFRB or FGFR1 rearrangements were detected. Patients with PDGFRA rearrangement were all males, with a median age of 48 years. About 80% of eosinophilic patients had idiopathic Eosinophilia.

Conclusion

PDGFRA gene rearrangement was found in approximately 20% of patients with clonal Eosinophilia, while PDGFRB and FGFR1 rearrangements were not detected in this cohort. The majority of patients (80%) presented with idiopathic Eosinophilia, emphasizing the need for further research into its prevalence, diagnosis, and treatment.

Fact Check

1. Study Duration: The study was conducted from December 2018 to December 2019. (Confirmed in Methodology section).
2. FGFR1 Gene Rearrangements: No FGFR1 gene rearrangements were detected in the study. (Confirmed in Results and Conclusion sections).
3. PDGFRA Gene Rearrangement Frequency: FIP1L1-PDGFRA gene fusion was detected in 20% of the patients. (Confirmed in Results and Conclusion sections).

Mind Map