Susan Nyanzi


Context: There is now consistent evidence from population and epidemiological studies that cigarette smoking is an independent risk factor for Rheumatoid Arthritis (RA), via Rheumatoid Factor (RF) production (Deighton, 1997; Saag, 1997; Silman, 1996; Uhlig, 1999; Wolfe, 2000). Antinuclear Antibodies (ANA) are another collection of autoantibodies that are being associated with smoking and RA initiation. To our knowledge, no studies have examined the effects of smoking on both ANA and RF simultaneously in healthy subjects.

Objectives: To determine whether cigarette smoking has an effect on ANA and RF positivity in healthy blood donors.

Design, Setting, Participants: This was a cross-sectional, observational, retrospective study. 576 consenting volunteer blood donors recruited from the local blood banks gave additional blood samples, answered the general blood bank questionnaire and our study questionnaire. Data on demographics, smoking history and selected RA risk factors were collected.

Main Outcome Measures: ANA and RF positivity.

Results:Moderate and light lifetime smoking was protective for ANA positivity relative to non-smoking and heavy smoking (O/?=2.670, 95% C7= 1.322-5.391, /?=0.006). Simple contrasts suggested this was due to moderate lifetime smoking being protective for ANA positivity compared to non-smoking (<9/?=0.337, 95% C7=0.115-0.989, p=0.048) and heavy smoking (<9/?=0.173, 95% C/=0.055-0.545,/?=0.003). No associations were found between current smoking status and ANA or RF positivity. Nor was one found with past and current second hand smoke. For never smokers there was an interaction of second hand smoke exposure with age. Those not exposed to second hand smoke showed increasing probability of ANA positivity with age. Those exposed to second hand smoke showed no such increase (0/?=0.908, 95% C7=0.828-0.996, /?=0.042). Total years smoked for exsmokers increased the likelihood of testing positive for ANA (0/?=l.O45, 95% C/+1.007- 1.084, /?=0.021). No associations were found between smoking status and ANA or RF positivity.

Conclusion: Immunological changes induced by smoking or nicotine may help explain the observed biphasic effect found with ANA positivity. For ex-smokers, smoke exposure may produce a permanent physiological change on the formation of ANA complexes that is irreversible.


School of Public Health

First Advisor

Jerry W. Lee

Second Advisor

Kristian Lindsted

Third Advisor

Edwin Krick

Degree Name

Doctor of Public Health (DrPH)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Arthritis, Rheumatoid -- etiology; Smoking -- adverse effects; Antibodies, Antinuclear.



Page Count

xiii; 117

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