The assessment of urinary Galectin-3 Binding Protein (G3BP)/creatinine ratio as a biomarker for lupus nephritis in Egyptian patients

Abstract Aim of the Study This research aims to review the clinical usefulness of the urinary Galectin-3 Binding Protein (uG3BP)/creatinine ratio in lupus nephritis (LN) patients and its relationship to disease activity to assess its utility as a biomarker for lupus nephritis in Egyptian patients. Results This cross-sectional study involved 60 patients with systemic lupus erythematosus (SLE), who were divided into two categories according to their scores on the SLE Disease Activity Index 2000(SLEDAI-2 K). Group 1 consisted of 20 individuals diagnosed with inactive SLE, as indicated by a SLEDAI-2 K score(0–2). Group 2 comprised 40 patients with active SLE which were subdivided into two subgroups according to kidney involvement; group 2a included 20 patients without kidney affection(SLEDAI-2 K = 8.65 ± 4.76), and Group 2b consisted of 20 patients diagnosed as active disease with LN(SLEDAI-2 K = 18.80 ± 8.28). A mean age of 25 ± 9.9 years was observed among the participants, of whom 82% were females. Group 2b exhibited a significantly higher uG3BP/creatinine ratio in comparison to Groups 1 and 2a( P < 0.001). Additionally, the nephritis group demonstrated a greater ratio than the active non-nephritis group( P < 0.001), while the active group without kidney involvement had a higher ratio in comparison to the inactive patients( P = 0.005). Active SLE was identified with a sensitivity of 77.5% and a specificity of 71.4% using a uG3BP/creatinine ratio cut-off value of 42.5 ng/mg. Moreover, a sensitivity of 90% and a specificity of 60% were achieved in detecting active patients with lupus nephritis at a cut-off value of 52 ng/mg. Conclusion The uG3BP/creatinine ratio shows promise as a non-invasive biomarker for lupus nephritis, warranting further validation in larger and diverse patient cohorts.