A multicenter investigation with D-FISH BCR/ABL1 probes.

Area of Science:

• Hematology
• Molecular Diagnostics
• Cytogenetics

Background:

• Chronic myeloid leukemia (CML) diagnosis relies on detecting the Philadelphia chromosome.
• Fluorescence in situ hybridization (FISH) is a key molecular diagnostic tool for CML.
• Standardization and validation of FISH methods are crucial for reliable clinical practice.

Purpose of the Study:

• To evaluate a novel dual-color fluorescence in situ hybridization (D-FISH) strategy for CML detection.
• To assess the clinical sensitivity, precision, and workload of the D-FISH method.
• To provide recommendations for training and quality assurance in D-FISH implementation.

Main Methods:

• Twenty-eight laboratories participated in a three-part study using bcr/abl1 D-FISH probes on bone marrow specimens.
• Laboratories trained on known samples, then blindly analyzed normal and abnormal specimens.
• Serial dilutions with varying percentages of abnormal nuclei were tested by laboratories and experts.

Main Results:

• The D-FISH strategy identified no false-negative cases.
• Fifteen false-positive cases were reported, with abnormal nuclei ranging from 1-6.6%.
• Participant results for serial dilutions approximated expected values; expert results showed higher precision.

Conclusions:

• The evaluated D-FISH strategy demonstrates potential for CML diagnosis with high sensitivity.
• False-positive results warrant attention for optimizing the normal cutoff and quality control.
• Further training and quality assurance are recommended for robust clinical application of D-FISH.