Geographical Differences Of Antinuclear Antibodies And The Predisposition Of Autoimmune Disease Among Adults From Four Regions Of Ghana

ABSTRACT Introduction: Despite being thought to be a group of rare disorders, the incidence of autoimmune conditions like Type 1 Diabetes Mellitus, Systemic Lupus Erythematosus, Rheumatoid arthritis and autoimmune thyroiditis are on the rise in Ghana. Autoimmune disorders result from a breakdown of immunologic tolerance leading to an immune reaction against self-autoantigens. Antinuclear antibodies are a group of autoantibodies that mediate the pathogenesis of several autoimmune conditions especially SLE and has been relevant biomarkers in the diagnosis of several connective tissue disorders. Recent studies have demonstrated the presence of antinuclear antibodies in the sera of the healthy population and in the sera of patients with autoimmune disorders, many years before the onset of the disease. Research on the susceptibility and potential of autoimmunity in the Ghanaian population is lacking. This study determined the prevalence, types, demographic and ethno-geographic correlates of antinuclear antibodies among healthy Ghanaian adults. Methods: Sera from 370 (133 males and 237 females, 1:1.8 male/female ratio) healthy Ghanaians from four regions and aged 18 years and above were tested for the presence of different antinuclear antibodies. The presence of anti-DFS70 was detected by chemiluminescent immunoassay and antidsDNA, chromatin, Ribosomal-P, Ro /SSA, SSA 52, SSA60, La / SSB, centromere B, anti-Sm, SmRNP, RNP 68, RNP A, Scl-70, and Jo1 were detected by multiplex immunoassay using BioRad Bioplex 2200 system. The health status and demographics of each participant was determined through the administration of a structured questionnaire. Results: The total prevalence of antinuclear antibodies (ANA positive) in the study participants is 14.21% which falls within the prevalence range estimated for other healthy populations. There was no significant difference in the positivity of antinuclear antibodies between both sexes, 14.84% and 12.61% (p-value=0.555) for male and female respectively. Most of the autoantibodies tested negative among majority of the study participants. There was no significant difference between age and the positivity for specific antinuclear antibodies tested (p-value 0.073-1) but there was a significant difference in ANA positivity with age (p-value=0.015). This conforms to the well-known hypothesis that autoantibody production increases with increasing age due to reduced self-regulatory mechanisms. There were significant ethnical and geographical differences in the prevalence of anti-dsDNA (p-values=0.048 and 0.013 respectively) with detection in only Ewes and Northerners (1.87% and 5.62% respectively) and the Upper West and Volta Regions (6.25% and 2.83% respectively). ANA positivity did not correlate with ethno-geographic distribution. Conclusion: It can be concluded that there is a high prevalence of antinuclear antibodies among healthy Ghanaian adults and that seems to be influenced mainly by age and sex. ANA positive frequency does not have a strong ethnic variability. Anti-dsDNA exhibit ethno -geographic variability