Genetic Polymorphisms and the Clinical Response to Systemic Lupus Erythematosus Treatment Towards Personalized Medicine

The STING inhibitor (ISD-017) reduces glomerulonephritis in 129.B6.Fcgr2b-deficient mice

The absence of stimulator of interferon genes (STING) in 129.B6.Fcgr2b-deficient mice rescue lupus phenotypes. The administration of a STING inhibitor (ISD017) into the young 129.B6.Fcgr2b-deficient mice prevents lupus nephritis development. This study mainly aimed to evaluate the effects of STING inhibition (ISD107) on established SLE in mice to prove that ISD017 could be a good therapeutic drug to reverse the already set-up autoimmunity and kidney impairment. Twenty-four-week-old Fcgr2b-deficient mice were treated with cyclophosphamide (25 mg/kg, intraperitoneal, once per week), ISD017 (10 mg/kg, intraperitoneal, three times per week), or control vehicle for 8 weeks, and were analyzed for phenotypes. Both ISD017 and cyclophosphamide treatment increased long-term survival and reduced the severity of glomerulonephritis in Fcgr2b-deficient mice. While cyclophosphamide reduced activated B cells (B220+GL-7+), ISD017 decreased activated T cells (CD4+CD69+) and neutrophils (Ly6c+Ly6g+) in Fcgr2b-deficient mice. In addition, ISD017 reduced IL-1β and interferon-inducible genes. In summary, ISD017 treatment in symptomatic 129.B6.Fcgr2b-deficient mice reduced the severity of glomerulonephritis and increased long-term survival. ISD017 worked comparably to cyclophosphamide for treating lupus nephritis in 129.B6.Fcgr2b-deficient mice. ISD017 reduced activated T cells and neutrophils, while cyclophosphamide targeted activated B cells. These results suggested that STING inhibitors can potentially be a new therapeutic drug for treating lupus.

CYP2D6 genetic polymorphisms in Saudi systemic lupus erythematosus patients: A cross-sectional study

OBJECTIVES

To determine the prevalence of selected single nucleotide polymorphisms (rs1080985, rs28624811, rs1065852, rs28371725, and rs1135840) in cytochrome P450 2D6 (CYP2D6) gene among Saudi systemic lupus erythematosus (SLE) patients and to investigate the association between the genetic variants and clinical features of SLE.

METHODS

This cross-sectional study was carried out on adult Saudi patients at King Khalid University Hospital, Riyadh, Saudi Arabia. Patients with confirmed SLE based on the 2012 Systemic Lupus International Collaborating Clinics classification criteria were included in the study. Peripheral blood was collected for genomic deoxyribonucleic acid extraction and TaqMan® technologies were used for target genotyping. For statistical analysis, differences in genotype frequencies were determined using the Chi-square test, and the association between the variant genotypes and SLE features was evaluated using logistical regression models.

RESULTS

There were 107 participants included in this study. Overall, the most predominant (23.4%) recessive genotype was AA in rs28624811, and the least prevalent (1.9%) recessive genotype was TT in rs28371725. Moreover, the variant rs1080985 genotypes (GC or CC) were significantly associated with the presence of serositis manifestation (OR=3.15, p=0.03), even after adjusting for age and gender. However, the dominant rs28624811 genotype (GG) was associated with renal involvement (OR=2.56, p=0.03).

CONCLUSION

Systemic lupus erythematosus patients carrying CYP2D6 variants might be considered at risk for certain manifestations of SLE. Further studies are needed to investigate the implication of these genetic variations in clinical outcomes and drug response.

Cost Consequence Analysis of Belimumab versus Standard of Care for the Management of Systemic Lupus Erythematosus in Saudi Arabia: A Retrospective Cohort Study

BACKGROUND

Belimumab use for the management of systemic lupus erythematosus (SLE) has been limited, in part due to its high acquisition cost relative to the standard of care (SoC) and the uncertainties about its cost-effectiveness. Therefore, the aim of this study was to compare the cost and effectiveness of belimumab versus the SoC alone for the management of SLE using real-world data from the perspective of public healthcare payers in Saudi Arabia.

METHODS

Data were retrieved from a national prospective cohort of SLE, Saudi Arabia. Adult SLE patients (≥18 yrs.) treated with belimumab plus the SoC or the SoC alone for at least six months were recruited. The effectiveness was measured using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). Unit costs for health services and prescription drugs were retrieved from the Saudi ministry of health. Nonparametric bootstrapping with inverse probability weighting was conducted to generate the 95% confidence limits for the cost and effectiveness.

RESULTS

A total of 15 patients on belimumab plus the SoC and 41 patients on the SoC alone met the inclusion criteria and were included in the analysis. The majority of patients were females (91.07%) with a mean age of 38 years. The mean difference in cost and SLEDAI-2K score reduction between belimumab versus the SoC were USD 5303.16 [95% CI: USD 2735.61-USD 7802.52] and 3.378 [95% CI: 1.769-6.831], respectively. Belimumab demonstrated better effectiveness but higher cost in 96% of the bootstrap cost-effectiveness distributions.

CONCLUSION

Future studies should use more robust research designs and a larger sample size to confirm the findings of this study.