TITLE:
Prevalence and Factors Associated with Positivity of Antinuclear Antibodies (ANA) Patterns, Native Anti-DNA and Extractable Nuclear Antigens (ENA) Antibodies: Experience from a Laboratory in Dakar
AUTHORS:
Diop Abdou, Diallo Thierno Abdoulaye, Ndiaye Babacar, Mahou Chantal, Diop Marième Gaye, Dubrous Phillippe, Seck Abdoulaye
KEYWORDS:
Antinuclear Antibodies, Extractable Nuclear antigen, Autoimmune Disease, Indirect Immunofluorescence
JOURNAL NAME:
Open Journal of Rheumatology and Autoimmune Diseases,
Vol.14 No.1,
February
29,
2024
ABSTRACT: Background: Diagnosis of autoimmune diseases (AID) is challenging, due to
overlapping features with other non-immune disorders. Anti-nuclear antibodies
(ANA) are sensitive screening tests but anti-deoxyribonucleic acid-antibody
(anti-DNA), and anti-extractable nuclear antigens (anti-ENA) are specific for
AIDs. We aimed to look at ANA patterns in our patients and correlated them with
anti-ENA for proper interpretation and better patient management
cost-effectively. Methods: A retrospective study was conducted over 1 year
from January to December 2022 who were tested for ANA at biology medical
laboratory of Pasteur Institute of Dakar. Anti-ENA and anti-DNA results were
also analyzed for ANA-positive patients. Statistical analysis was performed
using STATA 14.0, p Results: 216 patients were analyzed. Women predominated at 79.2% and mean age was 48
years [CI 95%, 46 - 50], with extremes of 10 and 89. Most represented age
group was [41 - 60] with 38%. ANA was positive in 27 (12.5%) of
patients, 59.2% of whom were strongly positive (titer of 1/1000, 1/3200 or
1/6400). The most common pattern was nuclear speckled, which was found in 77.8%
of samples. Anti-ENA and anti-DNA positivity in ANA-positive patients was found
respectively in 63% (17/27) and 1.4% (3/27) of the samples analyzed. Most
commonly identified anti-ENA was anti-Sm 29.6%, anti-SSA 29.6%, anti-Ro-52
25.9%, anti-RNP 18.5% and anti-SSB 14.8% which was associated with speckled
pattern. Association results indicated a significant relationship between both
tests and between ANA titer in the anti-ENA- and ANA-positive patients (p 0.001). Conclusions: ANA, Anti-ENA and
anti-DNA antibodies are essential for AIDS diagnosis. However, the testing
repertoire should follow an algorithm comprising of clinical features, followed
by ANA results with nuclear, mitotic, and cytoplasmic patterns, anti-ENA, and
anti-DNA for a more meaningful, and cost-effective diagnostic approach.