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Updated: Aug 8, 2026
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
Molecular immunoglobulin/T-cell receptor clonality diagnosis by gene scan in lymphoproliferative disorders
Doaa Shaheen1, Amal Abd Elkader, Samy Marouf
1Mansoura University, Clinical Pathology Department, Hematology Unit, Mansoura Faculty of Medicine, Mansoura, Egypt.
Insights
Gene scanning offers a sensitive and specific method for detecting malignant clones in lymphoproliferative disorders. This technique accurately identifies clonality in conditions like leukemia and lymphoma, improving diagnostic capabilities.
Area of Science:
- Hematology
- Molecular Biology
- Oncology
Background:
- Clonal diagnosis of lymphoproliferative disorders faces challenges in sensitivity, specificity, and throughput.
- Existing techniques for determining clonality in lymphoid malignancies require improvement.
Purpose of the Study:
- To evaluate the utility of gene scanning (GS) for detecting clonality in Immunoglobulin (Ig)/T-cell receptor (TCR) gamma gene rearrangements.
- To assess the sensitivity and specificity of GS in various lymphoproliferative disorders.
Main Methods:
- Polymerase chain reaction (PCR) amplification of IgH and TCR gamma genes.
- Gene scanning (GS) analysis to identify clonal gene rearrangements.
- Analysis of precursor B/T-acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), and reactive lymphocytosis.
Main Results:
- Gene scanning detected monoclonality in ALL (up to 88% with combined primers) and CLL (up to 90% with combined primers).
- In B-cell NHL, clonal rearrangement was detected in 50% (FR2b) and 25% (FR3a).
- All reactive lymphocytosis cases showed polyclonal rearrangement with TCR gamma primers; GS demonstrated 100% sensitivity and positive predictive value.
Conclusions:
- Gene scanning is a sensitive and specific method for detecting malignant clones in PCR products from lymphoproliferative disorders.
- GS analysis improves the diagnostic accuracy for clonality in lymphoid malignancies.
- This technique addresses limitations of current diagnostic methods for lymphoproliferative disorders.
Abstract:
There remains significant controversy over the techniques used for clonal diagnosis of lymphoproliferative disorders because of questions regarding the sensitivity, specificity and throughput. This has stimulated us to explore the use of gene scan to determine clonality of Immunoglobulin (Ig)/T-cell receptor (TCR) (gamma gene rearrangement in a variety of morphologically, cytochemically, pathologically and immunophenotypically defined precursor B/T-ALL (12 patients), 5 patients with NHL, 10 patients with CLL and a group of reactive lymphocytosis as a reference group (10 subjects). Polymerase chain reaction (PCR) was done for IgH gene (FR3a, FR2b, LJH and JH primers) and for TCR gamma gene and the malignant clone was identified using gene scan (GS) analysis. In the ALL group, monoclonality was detected using GS and using IgH (FR2b) 75% had a clonal band, 63% with IgH (FR3a) and 88% with a combination of FR3a/FR2b. The results of TCR gamma monoclonality were 50% using primer mix I, 25% using primer mix II and 75% using a combination. In the CLL group, clonal IgH gene rearrangement was detected by FR2b in 80% of cases, while by FR3a clonal rearrangement was detected in 60%, the combination of FR2b and FR3a increased the detection rate to 90%. In B-cell NHL, the FR2b was clonally rearranged in 50% while FR3 was positive in 25%. In reactive lymphocytosis, all cases revealed polyclonal rearrangement with TCR gamma primers. The sensitivity and positive predictive value of GS was 100% and the specificity and negative predictive value was 86.6%. In conclusion, gene scanning provides a sensitive and specific method for detection of the malignant clone in PCR product in patients with lymphoproliferative disorders.
