Assessment of Serum Level of Chitinase-3-Like Protein-1 (Ykl-40) in Systemic Lupus Erythematosus Patients and Its Relation to Disease Activity

Background: Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disorder where such progress and prognosis cannot be anticipated. Chitinase-3-like protein 1 (YKL-40) is a multifunctional pro-inflammatory protein that plays a crucial role in immunity and inflammation, as well as in the control of cell differentiation, proliferation, and apoptosis.

Aim of the Work: To investigate the serum level of YKL-40 in SLE patients contrasted to healthy controls and to link it with symptom severity and organ involvement.

Patients and Methods: A total of 50 subjects; 25 SLE patients and 25 healthy controls matched for age and sex were enrolled in this cross-sectional study. The circulating level of YKL-40 was determined using the ELISA technique in patients and controls and was shown to correlate with clinical and laboratory results in SLE patients.

Results: Serum YKL-40 levels were considerably greater in SLE patients compared to controls (P≤ 0.001) and positively correlated with disease activity., ESR, CRP and serum creatinine level. Serum YKL-40 was greater in SLE patients with malar rash, fever and arthralgia and has no relation to lupus nephritis.

Conclusion: During active disease phases, serum YKL-40 may have a role in the inflammatory aetiology of SLE. It may serve as a valuable laboratory test in the future for detecting SLE activity and joint inflammation.