Systemic lupus erythematosus is a multi-systemic, autoimmune disorder whichis episodic in nature with a broad spectrum of clinical and immunologicalmanifestations. As the course of lupus nephritis is often unpredictable, it isimportant to identify reliable, noninvasive methods to repeatedly assess thecondition of the kidneys in these patients during follow up.To assess the potential use of MCP1 as a marker for disease activity in lupusnephritis 56 SLE patients were recruited. They were divided into three groups onewith active lupus nephritis (n=19), another with inactive lupus nephritis (n=25) anda third formed of SLE patients who had no renal affection. Two other groups wereadded for comparison one formed of 12 cases who had non-lupus nephritis andanother of age and sex matched healthy controls (n=19).Urinary MCP1/creatinine ratio was found to be significantly higher in the twogroups of active nephritis –both lupus and non-lupus- (p<0.0001). Among thelupus groups, it correlated positively with rSLEDAI (r=0.486214, p=0.0001) aswell as with other known markers of lupus activity including the ESR(r=0.58189,p=0.0001), leucopenia and hypertension. Also, across all the study groups, theMCP1/creatinine ratio correlated positively with the protein/creatinine ratio(r=0.551, p<0.0001).Urinary MCP1/creatinine ratio increases in active nephritis regardless of itscause and thus it can be used as a non-invasive indicator of active renal affection inknown cases of systemic lupus.