Mestrallet F, Sujobert P, Clémentine Sarkozy, Traverse-Glehen A, Callet-Bauchu E, Jp, Magaud, Salles G, Baseggio L, Service d’Hématologie [Centre Hospitalier Lyon Sud - HCL], Centre Hospitalier Lyon Sud [CHU - HCL] (CHLS), Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Laboratoire d'anatomie et de cytopathologie - Centre hospitalier Lyon Sud, Hospices Civils de Lyon (HCL), Centre de Recherche en Cancérologie de Lyon (UNICANCER/CRCL), Centre Léon Bérard [Lyon]-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Lyon Sud [CHU - HCL] ( CHLS ), Hospices Civils de Lyon ( HCL ) -Hospices Civils de Lyon ( HCL ), Hospices Civils de Lyon ( HCL ), Centre de Recherche en Cancérologie de Lyon ( CRCL ), Université Claude Bernard Lyon 1 ( UCBL ), and Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon]-Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS )
International audience; BACKGROUND: Altered Toll-like receptor (TLR) expression levels and/or mutations in its signaling pathway (such as MyD88 mutation) contribute to the pathogenesis of lymphoproliferative disorders (LPD). CD180 is an orphan member of the TLR family that modulates the signaling of several TLRs, but only limited studies have evaluated its expression by flow cytometry (FCM) in LPD. METHODS: Using a multiparameter FCM approach, we have assessed CD180 mean fluorescence intensity (MFI) in lymph nodes (LNs) and peripheral blood (PB) samples obtained from patients with follicular lymphoma (FL; LN/PB, n = 44/n = 15), chronic lymphocytic leukemia (CLL, n = 26/n = 21), mantle cell lymphoma (MCL, n = 13/n = 17), and marginal zone lymphoma (MZL, n = 16/n = 12). Specimens from non-tumoral PB and LN (n = 8/n = 12) were used as controls. RESULTS: In the LN specimens, FL and control B-cells showed similar CD180 expression (MFI = 1,049 vs. 1,381, P \textgreater 0.05; Mann-Whitney U-test). This level was markedly lower in the other LPDs, MCL (MFI = 396, P \textless 0.05), or CLL (MFI = 502 P \textless 0.05), and similar to MZL (MFI = 858, P \textgreater 0.05). However, the CD180 expression of FL B-cells assessed in PB was dim and/or negative, in the same range as MCL and CLL (FL MFI = 453, MCL MFI = 305, CLL MFI = 420, P \textgreater 0.05) but lower than in MZL (MFI = 895, P \textless 0.05). Therefore, these results suggest a modulation of CD180 expression by neoplastic FL B-cells based on the anatomical compartment. CONCLUSION: These FCM data confirm the usefulness of CD180 in the accurate diagnosis of LPDs and emphasize the need to interpret this marker according to the origin of the sample. (c) 2015 Clinical Cytometry Society