Mandy L. Bohn


Two-color flow cytometric analysis was performed on paired samples of peripheral blood (PB) and pleural effusions (PE) of patients with metastatic malignancies. The purpose of these analyses was to test the hypothesis that there are significant differences in the distribution of immunocyte populations in the PE compared to that of the PB.

The majority of the pleural fluid immunocytes were CD3+ cells. The ratio of CD4+ to CD8+ cells was higher in the PE compared to PB. Levels of CD8+, CD19+ and CD14+ cells were not significantly different in the PE compared to the levels in the PB. CD16+CD56+ cells were lower in the PE versus PB. CD4+CD8+ cells, which represent a subset of activated T cells, were increased in the PE. Activation markers revealed that only a few pleural T cells were positive for CD25, while there was a significant increase in pleural HLA-DR+ T cells especially the CD4+ cells. Of the pleural fluid CD4+ cells a majority were of the CD4+Leu8+ subset.

These results suggest that a cell mediated immune response develops within the effusion of the pleural cavity as demonstrated by an accumulation of activated CD4+DR+ cells and CD4+Leu8+ cells. CD19+ and CD16+CD56+ populations are lower in the PE suggesting that humoral immunity and Natural Killer activity probably do not play a relevant role in the development of pleural immune reactivity.

These observations support the hypothesis that there are significant differences in the distribution of immunocyte populations between the PE and PB. These findings suggest that a suppressive mechanism is in effect in the pleural cavity. It might be reasonable to extrapolate therefore, that when immunocompetent cells are in close proximity to tumor cells a suppressor mechanism is established. This mechanism could contribute to the immunosuppressive state found in patients with advanced cancer.

LLU Discipline





Graduate School

First Advisor

James D. Kettering

Second Advisor

Elber Camacho

Third Advisor

John E. Lewis

Fourth Advisor

Robert W. Teel

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Immunologic Tests; Neoplasms -- immunology; Flow Cytometry



Page Count

vi; 61

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website


Loma Linda University. Del E. Webb Memorial Library. University Archives