Revisiting lymphocyte clonality testing in feline B-cell lymphoma

Area of Science:

• Veterinary Pathology
• Molecular Diagnostics
• Oncology

Background:

• Cytological and histopathological reviews alone are insufficient for differentiating feline small-cell lymphoma from mature lymphocyte populations.
• Polymerase chain reaction (PCR)-based immunoglobulin (IG) and T-cell receptor (TCR) clonality testing are crucial complementary tools for definitive diagnosis.
• Existing PCR assays for feline B-cell neoplasms face challenges with false negative and false positive results, impacting diagnostic reliability.

Purpose of the Study:

• To evaluate the diagnostic sensitivity and specificity of a newly developed multiplex PCR assay for routine feline B-cell clonality testing.
• To compare the performance of different primer sets within the multiplex assay for improved diagnostic accuracy.

Main Methods:

• A retrospective study involving 24 feline patients with suspected lymphoma.
• Comparative clonality testing using a novel multiplex PCR assay with various primer sets.
• Utilized feline lymphoma cell lines and confirmed patient material as positive controls.

Main Results:

• The novel multiplex PCR assay demonstrated enhanced diagnostic sensitivity, specificity, accuracy, and positive predictive value compared to previous methods.
• A slight decrease in negative predictive value was observed with the new assay.
• No single primer set outperformed others; combined application is suggested for optimal results.

Conclusions:

• The developed multiplex PCR assay offers improved diagnostic performance for feline B-cell clonality.
• Combined use of multiple primer sets within the assay is recommended for routine veterinary diagnostics.
• Further prospective studies on larger feline patient cohorts are needed to fully understand assay dynamics and optimize primer set selection.