Role of Chemokine Signalling in the Pathogenesis of Good's Syndrome-CaseReports, Clinical Characterization from Single-Centre Perspective

Abstract

Good’s syndrome (GS), is a rare condition defined as a coexistence of thymoma and hipogammaglobulinaemia. Involvement of central lymphoid organ prompts concept about perturbation in lymphocyte migration and differentiation. Cell homing to bone marrow compartment depends on the CXCR4↔CXCL12 interaction. In this paper we describe two patients with GS-mild and severe form, presenting differences in the expression of CXCR4 on cells in peripheral blood and bone marrow. Patient 1 (mild form): (i) Mild hipogammaglobulinaemia (IgG=150 mg/dL), (ii) Low count of peripheral B cells (14%, 60 cells/μL) and NK (18%, 77cells/μL); high level of T cells (93.3%, 4006 cells/ μL), (iii) Moderate thymic enlargement (9 × 15 cm), (iv) CXCR4 expression in BM 82.6% (20139/μL), 34% CXCR4+CD19+ (8289/μL). Patient 2 (severe form): (i) Severe hipogammaglobulinaemia (IgG=20 mg/dL), (ii) Absence of B and NK cells deficiency (in peripheral blood 0.4% i.e., 10/μL, and 6.17%-47.3/μL respectively), (iii) Severe thymic enlargement (20 × 25 cm) (iv) CXCR4 expression in BM 46.3% (552/μL); 6.1%, CXCR4+CD19+ (174/ μL). Interestingly, the bone marrow of patient with severe form of GS contained more CD10-positive B cells than BM of the patient with mild form (80% vs. 5.88% of B cells), but in former as well as letter a significant proportion of the total CXCR4-positive lymphocytes are negative for B cells marker (comparable: 48.1% and 53.1% respectively). In our patients a tenfold decrease in the CD4-positive γδ T cells (CD4+TCRγδ) counts was observed. Both cases went up fatal due to progression of nasopharyngeal cancer (mild form) and breast cancer (severe form). This data confirm that earliest B cell precursors, pre-pro-B cells and end-stage B cells, plasma cells require CXCR4 ↔ CXCL12 interaction. In contrast in GS weak expression of CXCR4 in marrow precursors is source of B cell differentiation arrest on pro-B cell stage. The low level Nk and CD4+γδ T cells in Good syndrome is the new observation.