Background: In SLE patients, cytokines are linked to endothelial cell damage. Nailfold capillaroscopy (NFC) is a simple method for evaluating micro-vascular abnormalities in different connective tissue diseases (CTDs). The study aimed to detect the levels of interleukin 17A (IL 17A), type I interferons (IFNs I) in the serum, and NFC changes in Egyptian SLE patients compared to a control group and to correlate NFC findings with patients' demographic features and serum levels of IL 17A and IFNs I. Results: Serum levels of IL 17A, IFN α, and IFN β were significantly higher in SLE patients than in control group (P < 0.0001). About thirty nine patients (73.6%) of the 53 SLE patients showed abnormal NFC changes. Egyptian SLE patients had a high prevalence of the NFC non-specific pattern, with 32 (60.4%) patients showing non-specific changes and 7 (13.2%) patients showing scleroderma pattern, including 3 (5.6%) patients with active scleroderma pattern and 4 (7.55%) patients with late scleroderma pattern. Furthermore, Raynaud's phenomenon (RP) was observed in 8 (15.1%) SLE patients, with 3 (5.6%) having normal NFC pattern and 5 (9.4%) having scleroderma pattern. All controls (n = 20) showed normal hairpin shape capillaries. Except for SLEDAI (P = 0.03) and the presence of RP (P < 0.0001), there were no significant differences in demographic and laboratory parameters between the three NFC patterns (normal, non-specific, and scleroderma); additionally, NFC score correlated significantly with SLEDAI (P = 0.021). Conclusion: As a result of the high disease activity, Egyptian SLE patients had elevated serum levels of IL 17A and IFNs I. The most common NFC pattern in Egyptian SLE patients was a non-specific pattern. NFC abnormalities in Egyptian SLE patients were correlated with disease activity but not with patients' ages, disease duration, or serum levels of IL 17A and IFNs I. SLE patients with scleroderma NFC pattern and RP should be closely followed for the possibility of appearance of anti-U1 RNP antibodies and MCTDS. [ABSTRACT FROM AUTHOR]