A Study on Semaphorin 3A Level in Juvenile-onset Systemic Lupus Erythematosus Patients.

Background: Juvenile-onset systemic lupus erythematosus (jSLE) is an uncommon yet severe autoimmune/inflammatory condition affecting multiple bodily systems, typically manifest-ing before the age of 18. This disease exhibits significant complexity, displaying considerable variation among patients. Its effects can range in severity from minor to fatal, characterized by a pattern of recurring flare-ups and periods of remission, making its natural progression difficult to predict.

Aim of the work: The aim of this work is to investigate the correlation between semaphorin 3A and systemic lupus erythematosus patients who follow up at Pediatric Rheumatology Unit Chil-dren's Hospital at Cairo University.

Patients & methods: This cross-sectional research was performed at the Pediatric Rheumatology Unit Cairo University Children's Hospital and included cases with jSLE under treatment and fol-low-up from the period of August 2021 to August 2022.

Results: Regarding demographic data of the studied subjects, highly significant variances were noted among the patient group & control group regarding age (years) & sex. However, there were non-significant variances among the patient group and control group concerning weight. In the current research, median (IQR) onset of disease was 2 (1 3) years, mean ± SD age at dis-ease diagnosis was 8.98 ± 2.13 years, median (IQR) disease duration 2 (1 3) years, family history was negative in 36 (90.0%) patients and consanguinity was negative in 28 (70.0%). The distribution of the manifestations within the patients group was as follow 7 (17.5%) with mu-cocutaneous, 7 (17.5%) with vasculitis, 4 (10.0%) with serositis, 11 (27.5%) with cardiac, 17 (42.5%) with renal, 11 (27.5%) with GIT, 5 (12.5%) with hematological, and 4 (10.0%) with neu-rological manifestations. In addition, there were 2 (5.0%) with arthritis, 31 (77.5%) with arthral-gia, and 2 (5.0%) with fever mean ± SD systolic BP was 115.95 ± 8.38 & mean ± SD diastolic BP was 75.60 ± 6.11. Regarding treatments in the patients' group, the median steroid dose was 15mg (5-25) with medi-an duration of 2 (1 3), 38 (95.0%) patients received hydroxychloroquine with mean ± SD hy-droxychloroquine dose of 205.26 mg ± 51.71. 23 (57.5%) patients received cyclophosphamide with mean ± SD number of cyclophosphamide doses 7.17 mg ± 2.42. Mycophenolate was re-ceived in 27 (67.5%) with mean ± SD dose of 614.07 mg ± 225.85. There were highly statistically significant differences between control group and patients' group concerning TLC, creatinine, & ESR. Highly statistically significant variance was noted among the control group and patients group concerning CRP. Regarding the patients' group, the mean ± SD serum C3 was 99.89 mg/dl ± 28.45, median (IQR) serum C4 was 14.5 mg/dl (8.8 25.5), and median (IQR) albumin creatinine ratio was 27 IU/ML (16 186). There was positive ANA with titre and pattern in 34 patients (85.0%), positive antids-DNA in 25 patients (62.5%), and positive anticardiolipin IgM and IgG in 5 patients (12.5%). Renal biopsy was found to be normal in 23 (57.5 percent), lupus nephritis class II, III in 3 (7.5 percent), lupus nephritis class III in 10 (25.0%), and lupus nephritis class IV in 4 (10.0%). Urine analysis results showed the following: normal in 28 (70.0%), albumin in 2 (5.0%), casts in 2 (5.0%), pus cell in 4 (10.0%), albumin + casts in 2 (5.0%) and albumin + pus cell in 2 (5.0%). Regarding semaphorin 3A level, a highly statistically significant variance was noted among the control & patients group concerning semaphorin 3A level found to be lower in cases than control with a p-value below 0.001. In patients' group, a negative correlation for semaphorin 3A with SBP, DBP, AST and ESR and also a positive correlation with steroid duration in the studied pa-tients. In addition, highly significant association between semaphorin 3A & positive CRP. How-ever, no significant relationship between semaphorin 3A & SLE manifestations except arthritis was found related to semaphorin 3A level. ROC curve shows that the semaphorin 3A cut-off point to predict SLE ≤ 3 with sensitivity = 47.50, specificity=92.50, PPV=86.4, and NPV=63.8.

Conclusion: Reduced plasma Semaphorin 3A levels were found in this study; furthermore, their clinical relationship in SLE proposes their significant job in this illness. Furthermore, the ROC results demonstrated that Semaphorin 3A could be a new symptomatic biomarker in SLE with very high sensitivity for the determination of SLE, demonstrating that they might be helpful bi-omarkers for the evaluation of SLE. However, extra studies that focus on the potential role of Semaphorin 3A in SLE are needed.