Expression of ANA patterns by Indirect Fluorescent Assay in a local Hong Kong population from private sector

Abstract

Abstract Objective Our aim was to investigate the association among age, sex and Antinuclear Antibody (ANA) patterns expressed in Hong Kong population for improving the autoimmune diagnosis by using ANA HEp-2 slides under fluorescent microscope. Methods A total of 65 blood samples from both male and female were collected and examined under fluorescent microscope. Haemolysed samples were excluded. In this research, a HEp-2 complete Kits with the methodology of indirect fluorescent antibody (IFA) was utilized for the detection and semi - quantification of antinuclear antibodies to distinguish positive ANA patterns classified in International Consensus on ANA Patterns (ICAP) for human body. Results In this experiment, we obtained that the number of positive samples was 6 (9%), the number of suspected (weak) positive samples was 4 (6%) and the number of negative samples was 55 (85%). In 6 positive samples, they were all females aged between 59 – 89. 5 in 6 positive samples in the result were over age 69 (83%). The positive ANA patterns included AC2 – Speckled, AC3 – Centromere, AC6 – Discrete Nuclear Dots, AC7 – Discrete Nuclear Dots, and AC8 – Nucleolar patterns separately. No AC-29 - DNA topoisomerase I was examined and resulted. We found that Hong Kong have a higher distribution of ANA positive frequency for female (9.23%) than male. Conclusion Our data indicated that ANA patterns were found in female aged above 69 is more likely to suffer from autoimmune disease related to ANA, providing an important foundation for considering and studying the trend in the elderly who are easier to have an ANA related autoimmune disease in Hong Kong.