title: 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.forename: Claudia
authors.initials: C
authors.lastname: Mannu
authors.forename: Anna
authors.initials: A
authors.lastname: Gazzola
authors.forename: Francesco
authors.initials: F
authors.lastname: Bacci
authors.forename: Elena
authors.initials: E
authors.lastname: Sabattini
authors.forename: Carlo
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authors.lastname: Sagramoso
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authors.initials: F
authors.lastname: Roncolato
authors.forename: Maura
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authors.lastname: Rossi
authors.forename: Maria Antonella
authors.initials: MA
authors.lastname: Laginestra
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Sapienza
authors.forename: Claudio
authors.initials: C
authors.lastname: Agostinelli
authors.forename: Antonio
authors.initials: A
authors.lastname: De Leo
authors.forename: Milena
authors.initials: M
authors.lastname: Piccioli
authors.forename: Simona
authors.initials: S
authors.lastname: Righi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Artioli
authors.forename: Luigi
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authors.lastname: Chilli
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Da Pozzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Biase
authors.forename: Federica
authors.initials: F
authors.lastname: Sandri
authors.forename: Stefano A
authors.initials: SA
authors.lastname: Pileri
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Piccaluga