Antinuclear antibodies staining patterns and their clinical association in systemic lupus erythematosus: a cohort of 126 Libyan patients
Background: Nuclear constituent such as histone protein, double stranded (ds) DNA, DNA/histone complexes (nucleosomes), various nuclear enzymes and other protein/ribonucleoproteins are common target antigens for antinuclear antibodies (ANA). On this base, different intranuclear immunofl uorescent ANA staining patterns can be detected in SLE.
Objective: To study a different ANA patterns in our patients with SLE and to detect the associations between ANA patterns and clinical manifestations of SLE in our patients.
Methods: The study included 126 SLE patients who were registered in rheumatology out patient’s clinic in Tripoli Medical Center in Libya in the period from January 2015 to January 2018. All patients met ≥ 4/11 of the 1982 American College of Rheumatology (ACR-82) criteria. Age, sex and clinical manifestations of their illness at diagnosis were recorded. ANA analysis by immunofluorescence (IF) microscopy (HEP-2cells) was sent to Bioscientia laboratory Ingelheim, Germany for all patients. Anti double stranded DNA (crithidia luciliae) analysis was also sent to the same laboratory for all patients.
Results: One hundred and twenty six patients (124 females and 2 males) were included in the study. Their mean age was 32.46 years. The most common ANA pattern in our patients was combined homogenous and fine speckled (HSANA) which present in 50/126 (39.7%) of patients followed by speckled pattern (S-ANA) in 37/126 (29.4%) of patients. The classical homogeneous pattern (H-ANA) was present in only 13/126 (10.3%) of our patients. Nucleolar pattern (N-ANA) ± other patterns were recorded in 14/126 (11.1%). Clinical manifestations as renal disorder was associated with HS-ANA, H-ANA, and S-ANA patterns more than N-ANA± other patterns (p<0.00001). Arthritis was less associated with S-ANA pattern than other patterns (p - value=0.0049). Haematological disorders occurred more in H-ANA pattern than other patterns (p<0.00001). Positive anti dsDNA analysis was associated more with HS-ANA and H-ANA than N-ANA± other patterns and S-ANA (p<0.0001).
Conclusion: Combined homogenous and fine speckled (HS-ANA) is the dominant immuno fluorescent antinuclear antibody pattern among Libyan patients with SLE which was more associated with renal disorders and positive anti dsDNA antibodies than other patterns. Nucleolar pattern ± other patterns were recorded in 11.1% of our patients and associated with least renal disorders and positive anti dsDNA antibodies.
Keywords: Antinuclear antibodies, Systemic Lupus Erythematosus, Antids DNA antibodies