Implications of blood indices in systemic lupus erythematosus patients: Two feasible determinants of disease activity and lupus nephritis

Aim of the work

To investigate whether or not neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) may by indicators of disease activity in systemic lupus erythematosus (SLE) with and without lupus nephritis (LN).

Patients and methods

This research was carried out on 40 adult SLE patients (20 with LN and 20 without) and 20 controls. The NLR and PLR were calculated. The SLE disease activity index (SLEDAI) was assessed.

Results

The mean age of the patients was 36.2 ± 7.6 years, 38 females and 2 males (F:M 19:1), with a disease duration of4.3 ± 1.2 years. The mean SLEDAI was 15.1 ± 4.7 being significantly higher in those with LN (17.5 ± 3.5) compared to those without (12.6 ± 4.6) (p = 0.001). The mean NLR (6.1 ± 2.1) and PLR (236.6 ± 86.9) were significantly increased in patients compared to the control (2.7 ± 1.2 and 125.2 ± 38.8 respectively) (p < 0.001). The NLR and PLR were both significantly related to the serum creatinine (r = 0.35, p = 0.03 and r = 0.5, p = 0.001) and SLEDAI (r = 0.36, p = 0.03 and r = 0.34, p = 0.03 respectively). NLR can significantly predict activity of SLE at cut off 5.6 with a sensitivity 80%, specificity 65% (p = 0.007) and PLR at cut off 217 with sensitivity 75%, specificity 65% (p = 0.035). The NLR can significantly predict LN at cut off 3.6 (sensitivity 80%, specificity 40%; p = 0.007) and PLR at cut off 186 (sensitivity 70%, specificity 60%; p = 0.035).

Conclusion

There is a remarkable link between PLR and NLR with SLEDAI. Thus, both may serve as promising affordable indicators of inflammation in SLE. The notable relation to LN may signal renal involvement in patients with SLE.