Gamma/delta T cells in patients with acute brucellosis

Early Diagnosis of Tularemia by Flow Cytometry, Czech Republic, 2003-20151

We retrospectively assessed the utility of a flow cytometry–based test quantifying the percentage of CD3+ T cells with the CD4–/CD8– phenotype for predicting tularemia diagnoses in 64 probable and confirmed tularemia patients treated during 2003–2015 and 342 controls with tularemia-like illnesses treated during 2012–2015 in the Czech Republic. The median percentage of CD3+/CD4–/CD8– T cells in peripheral blood was higher in tularemia patients (19%, 95% CI 17%–22%) than in controls (3%, 95% CI 2%–3%). When we used 8% as the cutoff, this test’s sensitivity was 0.953 and specificity 0.895 for distinguishing cases from controls. The CD3+/CD4–/CD8– T cells increased a median of 7 days before tularemia serologic test results became positive. This test supports early presumptive diagnosis of tularemia for clinically suspected cases 7–14 days before diagnosis can be confirmed by serologic testing in regions with low prevalences of tularemia-like illnesses.

Quantitative peripheral blood perturbations of γδ T cells in human disease and their clinical implications

Human γδ T cells, which play innate and adaptive, protective as well as destructive, roles in the immune response, were discovered in 1986, but the clinical significance of alterations of the levels of these cells in the peripheral blood in human diseases has not been comprehensively reviewed. Here, we review patterns of easily measurable changes of this subset of T cells in peripheral blood from relevant publications in PubMed and their correlations with specific disease categories, specific diagnoses within disease categories, and prognostic outcomes. These collective data suggest that enumeration of γδ T cells and their subsets in the peripheral blood of patients could be a useful tool to evaluate diagnosis and prognosis in the clinical setting.

Cell-mediated immunity in human brucellosis

Brucella can parasitize within human antigen-presenting cells modifying phagocytosis, phagolysosome fusion, antigen presentation, cytokine secretion, and apoptosis. Subversion of innate immune mechanisms by Brucella leads to defective Th1 immune responses and T-cell anergy in chronic brucellosis patients. This review summarizes the cellular immune responses in brucellosis, based on data derived exclusively from human cells or cell lines.