YKL-40 in serum: a promising biomarker of juvenile SLE and strongly correlated with disease duration

BACKGROUND

The biological function of YKL-40 is not well determined in different inflammatory and autoimmune diseases; however, some data highlighted its possible connection with disease activity.

AIM

We investigated the diagnostic utility of serum YKL-40 in patients with SLE and examined its correlation with disease activity. Additionally, we examined any differences in serum YKL-40 levels between juvenile and adult SLE patients.

METHODS

We included 78 female patients with SLE and 42 controls. The level of YKL-40 in serum was measured by ELISA.

RESULTS

The serum YKL-40 level in SLE patients was significantly higher compared to the control group (9 (3) ng/mL vs. 5.5 (0.1) ng/mL; p < 0.001). YKL-40 showed excellent diagnostic utility with an AUC of 1 (p < 0.001) and a cutoff point of 5.6, providing sensitivity and specificity of 100%. YKL-40 was higher in adolescents and those with a positive family history of SLE (p = 0.01 for both) and positively correlated with disease duration (r = 0.45, p < 0.001). YKL-40 level was significantly higher in patients with photosensitivity, fever, vasculitis, blood disorders, positive anti-dsDNA, and APL ab (p < 0.05 for all). Conversely, patients with skin manifestations had a significantly lower YKL-40 (p = 0.004). In juvenile SLE, the AUC was 0.65 and a p-value of 0.01, and at a cutoff value of (8.7) ng/mL, the sensitivity and specificity were 72% and 60%, respectively.

CONCLUSION

YKL-40 in serum could be a promising biomarker in patients with SLE, especially in adolescent-onset cases. It is independently influenced by disease duration, anemia, thrombocytopenia, positive anti-dsDNA, and APL ab features.

Pro-apoptotic Bax mRNA expression: A novel predictor for systemic lupus erythematosus disease flare-up

Objectives: In this study, we aimed to better understand the expression of pro-apoptotic Bad and Bax in the pathogenesis of systemic lupus erythematosus (SLE) and their relationship with the disease activity.

Patients and methods: Between June 2019 and January 2021, a total of 60 female patients with SLE (median age 29 years; IQR, 25.0-32.0) and 60 age- and sex-matched healthy female controls (median age: 30 years; IQR, 24.0-32.0) were included. The Bax and Bad messenger ribonucleic acid (mRNA) expression was measured by real-time polymerase chain reaction.

Results: The expression of Bax and Bad was significantly lower in SLE group than the control group. The median value of mRNA expression of Bax and Bad was 0.72 and 0.84, respectively versus 0.76 and 0.89 in the control group. The median value of (Bax*Bad)/β-actin index was 17.8 in the SLE group and 19.64 in the control group. The expression of both Bax, Bad and (Bax*Bad)/β-actin index had a good significant diagnostic utility (area under the curve [AUC]= 0.64, 0.70, and 0.65, respectively). The Bax mRNA expression showed a significant upregulation with disease flare-up. The efficacy of Bax mRNA expression in predicting SLE flare-up was good (AUC= 73%). In the regression model, the probability of flare-up reached 100%, with increasing Bax/β-actin as well, and the likelihood of flare-up increased 10,314 times with every unit increase of Bax/β-actin mRNA expression.

Conclusion: Deregulation of the mRNA expression of Bax may have a role in the susceptibility to SLE and may be associated with disease flare. A better understanding of the expression of these pro-apoptotic molecules may carry a great potential for the development of specific effective therapies.

Evaluation of the interaction between anti-apoptotic Bcl-2 protein family mRNA expression and autophagy gene Bcl-1 expression in Egyptian SLE patients

OBJECTIVES

Autophagy is a complex cellular process that maintains homeostasis in systemic lupus erythematosus. Abnormally high expression of Bcl-2 was observed in B and T lymphocytes in the peripheral blood in SLE patients. These may be responsible for the survival of self-reactive lymphocytes and the development of lupus, and the study aims at evaluating interaction between apoptosis and autophagy in Egyptian lupus patients.

METHODS

Sixty patients with SLE were diagnosed by fulfilling the Systemic Lupus International Collaborating Clinics (SLICC) classification criteria for SLE and sixty healthy age and sex matched control. All patients were subjected to full medical history and clinical examination. Activity was assessed using SLEDAI-2K score. Gene expression of Beclin-1, Bcl-2-L2, and Bcl-2 was measured.

RESULTS

The study revealed that the expression of anti-apoptotic Bcl-2 and Bcl-2-L2 was significantly higher in SLE patients than control subjects, as well as the major apoptotic agent (Beclin-1) mRNA, p = 0.03, < 0.001 and 0.02, respectively. The apoptotic Beclin-1 mRNA was positively correlated with SLE disease severity index, r = 0.25; p = 0.0.4; therefore, our results showed that expression of the Beclin-1 was significantly higher in SLE patients than control (p < 0.02).

CONCLUSION

The study showed that the mean levels of Beclin-1, LC-3, and interleukin (IL)-10 transcripts were significantly higher in SLE patients than in control.

Characteristics, evolution, and outcome of patients with non-infectious uveitis referred for rheumatologic assessment and management: an Egyptian multicenter retrospective study

OBJECTIVE

To investigate the characteristics, evolution, and visual outcome of non-infectious uveitis.

METHODOLOGY

Records of 201 patients with non-infectious uveitis (136 (67.7%) males and 84 (41.8%) juvenile-onset (≤ 16 years)) were retrospectively reviewed. Data were analyzed through Kruskal-Wallis and Mann-Whitney, chi-square (χ²) tests, and logistic regression.

RESULTS

The median disease and follow-up durations were 36 (interquartile range (IQR) 24-70) and 24 (IQR 10-36) months, respectively. Fifty-eight (28.9%) patients had persistently idiopathic uveitis, and 143 (71.1%) were associated with rheumatic diseases, of whom uveitis heralded, coincided with, and succeeded the rheumatic manifestation(s) in 62/143 (43.4%), 37/143 (25.9%), and 44/143 (30.7%) patients, respectively. Established rheumatic diseases were Behçet's disease (103/201 (51.2%)), juvenile idiopathic arthritis (13/201 (6.5%)), sarcoidosis (8/201 (4%)), seronegative spondyloarthropathy (7/201 (3.5%)), and Vogt-Koyanagi-Harada (7/201 (3.5%)), and other diagnoses were present in 5/201 (2.5%) patients. Patients with idiopathic uveitis were characterized by a juvenile-onset (p < 0.001), lower male predominance (p = 0.01), prevalent granulomatous (p < 0.001), and anterior (p = 0.001) uveitis. The median visual acuity at last visit was 0.3 (IQR 0.05-0.6). Visual loss was present in 45/201 (22.3%) patients (36/201 (17.9%) unilateral and 9/201 (4.4%) bilateral). Apart from a longer disease duration (p = 0.002), lower educational level (p = 0.03), and prevalent panuveitis (p < 0.001), visual loss was not associated with any other studied ocular or extra-ocular characteristics.

CONCLUSION

Behçet's disease (51.2%) and idiopathic uveitis (28.9%) were the most prevalent causes of non-infectious uveitis in our study. Visual loss (22.3%) was associated with a longer disease duration, lower education level, and prevalent panuveitis. Key Points • Most common causes of uveitis referred to rheumatologists were Behçet's disease and idiopathic uveitis. • Several rheumatic diseases initially presented only with uveitis, more commonly in adult and male patients. • Panuveitis was more frequent among patients with an established rheumatic disease, whereas granulomatous uveitis was uncommon. • Longer disease duration and presence of panuveitis were independently associated with visual loss.