Relation of Serum Homocysteine Levels and Chronic Kidney Disease in Patients with Systemic Lupus Erythematosus

Abstract

Abstract Background SLE is an autoimmune disease characterized by the production of autoantibodies to components of the cell nucleus in association with diverse clinical manifestations affecting almost all organ systems. It is a complex disease with variable presentations, course, and prognosis characterized by remissions and flares. The etiology of SLE remains unknown and is clearly multifactorial. Many observations suggest a role for genetic, hormonal, immunologic, and environmental factors. Objective To evaluate the relation between serum homocysteine levels and occurrence of chronic renal disease, renal functions, severity of proteinuria and progression to end stage renal disease in patients with systemic lupus erythematosus. Patients and Methods This study include 70 SLE patients with biopsy proven lupus nephritis who fulfill four or more of 2012 American College of Rheumatology (ACR) criteria for SLE. They were recruited from Rheumatology Outpatient Clinic and Rheumatology Inpatient Department of Ain Shams University Hospitals. Twenty healthy individuals were included as controls. Written consents were obtained from all patients participating in the study. Results In this study there was highly statistically significant difference between patients and controls as regards serum homocysteine levels, 17 patients had mild, 8 moderate and 5 severe hyperhomocysteinaemia, with (p- <0.001). Hypertension was recorded in 32 SLE patients (45.7%) and no one of controls was hypertensive. Carotid examination showed an overall increased intimal thickness (CIMT) in the 8 (11.4 %) SLE patients (3 of them have hypertension). There was highly statistically significant relation between levels of homocysteine with carotid intimal thickness imaging in patients group p-value <0.001. The current study proved that there statistically a significant correlation between serum homocysteine levels and class of CKD, 40 had normal and 30 had subnormal HC levels, mild HHC was observed in 17, moderate HHC in 8 cases, while sever HHC was 5 of cases with p- <0.001. Conclusion This study demonstrates that homocysteine is modifiable marker in SLE patients; hyperhomocysteinemia was significantly correlated with renal function and progression to end stage renal disease. The current study shows statistically significant relation between serum homocysteine levels and patients age, disease duration, diabetes mellitus, and hypertension. There were significant positive correlation between homocysteine levels and both blood urea nitrogen (BUN) and 24 hr urinary protein. Also, there statistically significant relation between homocysteine and CKD classes in SLE patients, 40% of patients with class IV LN had hyperhomocysteinamia.