- Poster presentation
- Open Access
Dynamics of lymphocyte subpopulations during Legionnaires' disease
© Jager et al.; licensee BioMed Central Ltd. 2012
- Published: 14 November 2012
- Lymphocyte Subset
- Lymphocyte Subpopulation
- Absolute Lymphocyte Count
- Subacute Phase
- Multiparametric Flow Cytometry
Absolute lymphocytopenia (lymphocyte count <1.0 × 109/l) is recognized as an important hallmark of the immune response to severe infection and observed in patients with Legionnaires' disease (LD). Furthermore, LD is characterized by accumulation of activated T cells in the lungs. To explore the immune response in patients with LD, we studied the dynamics of peripheral blood lymphocyte subpopulations in the acute and subacute phase of the disease.
EDTA-anticoagulated blood was obtained from eight LD patients on the day the diagnosis was made (acute phase) through detection of Legionella pneumophila serogroup 1 antigen in urine. A second blood sample was obtained in the subacute phase. Multiparametric flow cytometry was used to calculate absolute lymphocyte counts and B-cell, T-cell, NK-cell, CD4+ and CD8+ T-cell counts. Expression of activation markers was analyzed on CD4+ and CD8+ T cells. C-reactive protein (CRP) levels were used to monitor treatment response.
The acute phase of LD is characterized by absolute lymphocytopenia which recovers in the subacute phase with an increase in absolute T-cell count and emergence of activated and memory-type CD4+ and CD8+ T cells. This confirms a role for T-cell activation in the immune response to LD.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.