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, biologists 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.

Inclusion Criteria:

• Samples from patients with:

  • LF: Follicular lymphoma
  • MCL: Mantle cell lymphoma
  • CLL/SLL: chronic lymphocytic leukemia/small lymphocytic leukemia
  • MZL : splenic marginal zone
  • Clt :control B-cells

Exclusion Criteria:

• Patient <18 years old

99 LN (lymph nodes) and 65 PB (peripheral blood) samples obtained from patients diagnosed with LPDs in our institution between 2012 and 2014 were evaluated for CD180 expression by FCM. The diagnosis were made according to the WHO 2008 classification, including clinical and morphological analysis, immunophenotyping, and conventional and molecular cytogenetics (and/or fluorescent in situ hybridization). The diagnoses were follicular lymphoma (FL) (LN, n=44; PB, n=15), small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL)/CLL (LN, n=26; PB, n=21), MCL (LN, n=13; PB,n=17), and MZL (LN, n=16; PB, n=12). All PB samples presented circulating neoplastic B-cells, and in several cases, the diagnosis was made at the same time in LN and PB FL, n=4; SLL/CLL, n=18; MCL, n=5. MZL, n=6.