Previous Article | Next Article ![]()
Clinical and Diagnostic Laboratory Immunology, 01 1997, 89-92, Vol 4, No. 1
F Sabatier, F Dignat-George, JL Mege, C Brunet, D Raoult and J Sampol
Valvular endocarditis is the most serious complication of chronic Q fever,
an infectious disease due to Coxiella burnetii. Although its pathogenesis
is poorly understood, the role of the immune system has been evoked. The
aim of this study was to investigate lymphocyte subsets in the peripheral
blood of infected patients by analyzing the distribution of T- and
B-lymphocyte subsets. Since various infectious diseases have been found to
be associated with modified antigen expression, we also measured the
antigen density of the main lymphocyte markers by quantitative flow
cytometry. The absolute values of CD3+ T cells and CD19+ B cells were lower
in infected subjects than in controls. The decrease in the CD4+ T-cell
count was more pronounced than that in the CD8+ T-cell count, leading to a
significantly lower CD4/CD8 ratio in patients. The decreases in CD4+ T
cells and CD19+ B cells were correlated with levels of C. burnetii-specific
immunoglobulin G, showing that CD4+ lymphopenia is related to the activity
of chronic Q fever. Quantitation of antigen expression on lymphocytes
showed that CD3, CD4, CD8, and CD19 were expressed similarly in patients
and controls. In contrast, CD2 and CD11a expression levels, which are both
related to naive and memory phenotypes, were modified in patients. The
study of CD45RO and CD45RA expression by CD4+ T cells provided evidence
that lymphopenia preferentially affected unprimed lymphocytes.
Copyright © 1997 by the American Society for Microbiology. All rights reserved.
CD4+ T-cell lymphopenia in Q fever endocarditis
Laboratoire d'Hematologie, Hopital de la Conception, Marseille, France.
This article has been cited by other articles:
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. | Infect. Immun. |
|---|---|---|
| J. Clin. Microbiol. | J. Virol. | ALL ASM JOURNALS |