B lymphocyte subsets in patients with rhinoscleroma.

OBJECTIVE To identify the presence of B lymphocytes in the rhinoscleroma granulomas as a possible precursor of plasma cells, whose presence has always been described but whose role is still unclear. STUDY DESIGN Case series with chart review. SETTING Sapienza University of Rome. METHODS The study was carried out on 6 patients (3 women, 3 men). The following parameters were examined for each patient: clinical manifestations, number of leukocytes, lymphocytes and lymphocyte subsets (CD3+, CD4+, CD8+, and CD19+) in blood samples, time from the onset of symptoms, biopsies, and expression of CD3, CD4, CD8, and CD20 antigens in tissue samples with immunohistochemical techniques. RESULTS In this study, the values of CD3+, CD4+, and CD8+ T lymphocyte subsets in venous peripheral blood are in line with previously reported data, whereas CD19+ lymphocyte cells tended to show an ambiguous behavioral pattern. In tissue samples, approximately one-third of the T lymphocyte population showed a CD3+/CD8+ immunophenotype (cytotoxic/suppressor), and two-thirds of the T lymphocytes expressed a CD3+/CD4+ immunophenotype (helper/inducer). The authors also identified an unexpected large amount of CD20+ non-plasmacellular B cells in addition to the plasma cells usually detected in rhinoscleroma biopsies. CONCLUSIONS This study demonstrates the presence of B lymphocytes in rhinoscleroma tissue. It is presumable that the mature B cells activated by antigenic stimulation of Klebsiella rhinoscleromatis are the precursors of the plasma cells typically found in the granuloma of rhinoscleroma.