Summary:Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder characterized by multiorgan pathology and autoantibodies against a variety of autoantigens.Lupus nephritis remains a major cause of morbidity and mortality in patients with systemic lupus erythematosus.Glycosaminoglycans (GAGs) are major components of the extracellular matrix and they have key roles in fibrotic diseases.This work was done in Rheumatology and Rehabilitation, and Biochemistry departments of Zagazig University Hospitals to evaluate the relation of the total urinary level of glycosaminoglycans, heparan sulfate and chondriotin sulfate levels to the disease activity and their relation to renal affection in SLE patients.This study comprised a total of 40 subjects, they were divided into 2 groups:1- Group I: included 30 patients suffering from SLE.2- Group II: included 10 normal volunteers.Our patients were collected according to the American Rheumatism Association (ARA) revised criteria for classification of SLE (Tan, et al., 1982) and their age ranged from (16-45) ys.All patients were subjected to full history taking with stress on arthritis or arthralgia, fever, vasculitic changes, Loin pain, dysuria, seizures, headache or psychosis.We divided our SLE patients according to disease activity index into 2 groups: table (2)Group I: inactive 56.7%.Group II: Active 43.3% : a- Mild active 23.3%b- Moderate active 10%.c-Severe active 10%.We redivided them according to renal involvement into 4 subgroups as follow:(I) Inactive: a- With renal involvement (23.3%).b- Without renal involvement (33.3%).(II) Active;a -With renal involvement (20/%)b-With out renal involvement (23.3%)Table (3)All patients were clinically examined with stress on: General examination, joint examination, skin rash, cardiovascular and chest examination, oedema of L.L., lymphadenopathy.All cases were subjected to laboratory investigations including:1- Complete blood picture.2- Erythrocytic sedementation rate.3- Complete urine analysis.4- Kidney function tests.5- 24 hour proteinuria.6- ANA.7- Anti DNA antibody.8- Liver function tests.9- Fasting blood sugar.10- Plain x ray pelvis & chest.11- Urinary glycosaminoglycans levels (ion exchange chromatography on DEAE- Sephacel) including HS & CS levels. by (Enzyme-linked immunosorbent assay)The following results were obtained:- Among clinical cnaracteristicas of disease activity in our SLE patients Raynaud’s phenomenon was the most common feature (33.3%) while pyrexia and serositis both affected only 3.3% of patients.- ESR level was higher in sever active patients anti DNA titres were higher in active SLE patients than inactive ones .- CS and Hs levels were higher in severe active patients- Ahighly significant difference between positive and negative cases of arthralgia, vasculitic skin rash and lymphadenopathy as regard total urinary GAG level. There was significant difference between positive and negative cases of Raynaud’s phenomenon and neuropsychiatric manifestations as regard total urinary GAG level while there was no statistical difference between positive and negative cases for pyrexia, seroitis and bleeding tendency as regard total urinary GAG level.- Non significant correlation between urinary GAG level and other laboratory parameter: including ESR, Anti DNA, 24 hour proteinuria and creatinine level.- A significant elevation of total urinary GAG in SLE patients compared to control group.- A significant elevation of urinary HS in SLE patients compared to control group while there is no statistical difference between the two groups as regard CS level.- A highly significant difference between SLE patients and control group as regard CS/HS ratio.- A significant elevation of total urinary GAG in active SLE patients with extrarenal disease compared to inactive patients.- A significant elevation of HS and CS levels in active SLE patients compared to inactive patients.- A significant difference between active SLE and inactive patients as regard CS/HS ratio.ConclusionIn conclusion, we believe that analysis of urinary GAG may represent an additional, non invasive diagnostic approach in SLE patients because it might indicate the presence of an early abnormal permeability of the renal filter in patients without other appreciable signs of kidney alteration.