Use of IGK gene rearrangement analysis for clonality assessment of lymphoid malignancies: a single center experience.

Abstract

Diagnosis of B-non Hodgkin lymphomas (NHLs) is based on clinical, morphological and immunohistochemi-cal features. However, in up to 10-15% of cases, analysis of immunoglobulin heavy (IGH) or light (IGK/IGL) chains genes is required to discriminate between malignant and reactive lymphoid proliferations. In this study, we evaluated the feasibility and efficiency of IGK analysis in the routine diagnostic of B-cell lymphoproliferative disorders (B-LD) when applied to formalin-fixed paraffin-embedded (FFPE) tissues. Clonality patterns were studied in 59 B-LD using the BIOMED-2 protocol for IGK assays, after failure of the IGH assay. PCR products were evaluated by both heterodu-plex and GeneScan analysis. IGK analysis was technically successful in all cases. Overall, it supported the histopa-thological suspicion in 52/59 cases (88%), the sensitivity and specificity being 83% and 80%, respectively. Further, positive and negative predictive values were 95% and 50%, respectively. Interestingly, among various lymphoma subtypes, marginal zone lymphoma and follicular lymphoma most frequently required IGK analysis. In conclusion, IGK study according to the BIOMED-2 protocol resulted feasible and extremely useful in supporting challenging diagnosis of B-LD even if applied on FFPE samples. Accordingly, when NHL is suspected, negative results at IGH analysis should not be considered as conclusive and further investigation of IGK is appropriate.

• Authors: Claudia Mannu, Anna Gazzola, Francesco Bacci, Elena Sabattini, Carlo Sagramoso, Fernando Roncolato, Maura Rossi, Maria Antonella Laginestra, Maria Rosaria Sapienza, Claudio Agostinelli, Antonio De Leo, Milena Piccioli, Simona Righi, Patrizia Artioli, Luigi Chilli, Gianpaolo Da Pozzo, Giuseppe De Biase, Federica Sandri, Stefano A Pileri, Pier Paolo Piccaluga
• Journal: American journal of blood research (Am J Blood Res) Vol. 1 Issue 2 Pg. 167-74 ( 2011) ISSN: 2160-1992 [Electronic] United States
• PMID: 22432078 (Publication Type: Journal Article)