Relation between Vitamin D Level and Cyclin-Dependent Kinase-1 Gene Expression in Egyptian Patients with Lupus Nephritis and their Impact on Disease Activity.

INTRODUCTION

Lupus nephritis (LN) is a common complication of systemic lupus erythematosus. Vitamin D and cycline-dependent kinase-1 (CDK1) have been implicated in its pathogenesis. The aim of this study was to determine the relation between vitamin D level and CDK-1 in lupus nephritis patients and their impact on disease activity.

PATIENTS AND

METHODS

The current study was conducted on 50 LN patients and 20 control subjects from Egyptian population using ELISA to assess vitamin D level in serum and TaqMan assay for CDK1 gene expression.

RESULTS

Serum vitamin D level was significantly lower in LN patients and CDK-1 gene was down expressed in the majority of LN patients. A significant inverse correlation was found between vitamin D level and 24 h protein in urine, ANA, anti-dsDNA, CRP, with a significant positive correlation with renal biopsy indices, eGFR. There was a non-significant inverse correlation between vitamin D and CDK-1 (before RO-3306 addition) and a positive correlation after RO-3306. A significant positive correlation was found between CDK-1 gene expressions with urinary albumin/creatinine ratio. However, a significant positive correlation was found between CDK-1 (after RO-3306 addition) and proteinuria. While a significant positive correlation was found between CDK-1 expression (after RO-3306 addition) and ANA, a significant positive correlation was found between CDK-1 expression (before RO-3306 addition) and anti-dsDNA but CDK-1 is not associated with renal biopsy indices nor with activity indices of SLE. There was a positive correlation between CDK-1 gene expression and CRP before and after RO-3306 addition.

CONCLUSIONS

Vitamin D deficiency acts as a risk factor for developing LN. CDK-1 may have an association with the diagnosis of LN but its association with the progression of staging of LN is still confusing.