eighty - five percent of the patients with ms first presented with a clinically isolated syndrome ( cis ) , which is an acute or subacute episode of neurologic failure . as studies show about 21% of patients with cis present with optic neuritis ( on ) , 10% have brainsteminvolvement , 46% show long tract involvement manifestations , and 23% have multifocal deficits . the diagnosis of ms is made when the dissemination of neurologic disturbances in both time and space have been demonstrated by either clinical , paraclinical , or laboratory findings . the diagnosis can be made when alternate explanations of clinical and paraclinical findings are excluded . first monofocal neurologic sign or symptom ( no dissemination in time or space ) can be explained by cis or other differential diagnosis such as systemic rheumatic disease . for example , antiphospholipid syndrome ( aps ) and systemic lupus erythematosus ( sle ) can explain this finding . sle is an auto - immune disease which involves multi - organs , 50% of patients with lupus have cns involvement , which makes their prognosis poor . antiphospholipid antibodies ( apa ) can involve cns , presenting with transient ischemic attack , stroke and other more complex neurologic disturbances , and presence of multifocal white matter lesions on brain magnetic resonance imaging ( mri ) . thus , the objective of this study was to determine whether prevalence of positivity of collagen vascular tests such as anca ( p , c ) , ana , dsdna , and apa differ between patients with on and healthy subjects . this was a cross - sectional study of patients consecutively referred to the ms clinic in alzahra hospital and neuro - ophthalmology clinic in feiz hospital in isfahan for the evaluation of acute on between july 2010 and july 2011 . a total of 79 patients presenting a single , unilateral on episode , with no history of connective tissue disease were included in the study . the attack was diagnosed as a cis affecting optic nerve if they showed these clinical findings : pain on eye movement , decreased visual acuity , and defect in visual field with a compatible fundus examination ( mild or no optic disc edema ) which was not attributable to other diseases . the control group consisted of 79 healthy subjects , with no history of neurologic or connective tissue disease . the study received approval from the ethics committee of isfahan university of medical science and informed written consent was obtained from all study subjects . the following clinical data were obtained on the basis of the patients medical records : age , gender , and duration of attack . the initial clinical evaluation was performed in all cases by an expert neurologist ; symptoms and signs of neurological deficit were recognized and recorded . all subjects were questioned about individual or familial histories of connective tissue diseases , rheumatic manifestations , and aps such as stroke or transient ischemic attack , myocardial infarction , arterial or venous thrombosis , and recurrent abortion . sera of patients and controls were tested for esr , crp , anti-2-glycoprotein i antibody ( igg , igm ) , anticardiolipin antibody ( igm , igg ) , lupus anticoagulant , anti - dsdna , antinuclear antibody ( ana ) , anti - mpo ( p - anca ) , and anti - pr3 ( c - anca ) . patients with positive tests were objects of rheumatologic examination to confirm or rule out the connective tissue diseases . anticardiolipin antibodies ( igm , igg ) , anti-2-glycoprotein i antibody ( igm , igg ) , ana , anti dsdna , p - anca , and c - anca were detected by enzyme - linked immunoabsorbent assay , chorus kit . the cutoff values for anticardiolipin antibody igm were < 12 mplu / ml negative , 12 - 18 mplu / ml equivocal , and > 18 positive . the cutoff values for anticardiolipin antibody igg were < 12 gplu / ml negative , 12 - 18 gplu / ml equivocal , and > 18 positive . the cutoff values for 2-glycoprotein i ( igm , igg ) were < 12 au / ml negative , 12 - 18 au / ml equivocal , and > 18 positive . the cutoff values for ana were < 0.8 u / ml negative , 0.8 - 1.2 u / ml equivocal , and > 1.2 positive . the cutoff values for dsdna were < 12 iu / ml negative , 12 - 18 iu / ml equivocal and > 18 positive . the cutoff values for p - anca and c - anca were < 12 au / ml negative , 12 - 18 au / ml equivocal , and > 18 positive . lupus anticoagulant was detected according to international guidelines and by a manual agglutination assay ( trinity biotech ) . chi - squared test , t - test , and fisher exact test were used to test the hypothesis . the collected data were analyzed by spss software version 19 ( spss inc . , chicago , il ) . chi - squared test , t - test , and fisher exact test were used to test the hypothesis . the collected data were analyzed by spss software version 19 ( spss inc . , chicago , il ) . the mean  sd of age of cis cases was 27.5  7.5 and in control group it was 29.4  7.6 ( p = 0.12 ) . 82.3% ( 65 ) of cis cases and 83.5% ( 66 ) of control group were female ) p = 0.83 ) . brain mri was completely normal in 45 patients and the others had plaques that were not compatible with mcdonald criteria 2005 . ana , p - anca , c - anca , anticardiolipin antibody ( igg ) , anticardiolipin antibody ( igm ) , and anti-2-glycoprotein i antibody ( igg ) were not positive neither in case group nor in control group . the results of anti - dsdna , anti-2-glycorotein i antibody ( igm ) , lupus anti - coagulant , and crp are reported in table 1 . a rheumatologist examined patients with positive tests ; none of the patients had a rheumatic disorder . the mean esr level was 9.1  9.5 in case group and 5.7  4.6 in control group ( p = 0.004 ) which was statically significant , although both were in normal range but it might show that in a long - term follow - up the mean esr level in cis patients was significantly higher than normal population . on is an inflammation of optic nerve , which is the first manifestation of ms in 30% of ms patients and will show up in 30 - 70% of them in the disease course . on as a cis is a differential diagnosis for cns involvement of some systemic autoimmune disease like sle , aps and autoantibody serology may help to clarify the issue . there is controversy in studies about prevalence of auto - antibodies in ms patients and their clinical associations . anas and apas in ms patients has been reported and a higher prevalence of certain type of apas in on and spinal cord involvement of ms has been mentioned . reported that 26.7% of relapsing - remitting and 30.4% of chronic progressive ms patients had positive ana in their study whereas ana is positive in 2 - 8% of normal population . studied 13 patients with optic - spinal form of ms and 46.2% found to be positive for ana and 46.2% positive for p - anca which was significantly higher than control group consisting of patients with conventional ms . all subjects in two groups were negative for c - anca and anti - dsdna . in a retrospective study in us , the prevalence of auto - antibodies and apa in ms were 69% and 55% respectively . collard et al . reported a frequency of 22.5% for anas in a prospective cohort of ms patients . reported that anticardiolipin antibodies were positive in 15% of patients with ms . on the other hand , rombos et al . did not report any higher prevalence of anticardiolipin anti - bodies ( igg or igm ) in ms patients comparing with control group . another study showed a higher prevalence of anas and anti 2-glycoproteion i antibody ( igm ) in ms patients and specific anas in cis patients than in controls whereas anticardiolipin antibodies prevalence was similar in both groups . the study did not show any contribution between the site of neurologic involvement and the presence of autoantibodies . in the current study , we observed no higher prevalence of positivity of connective tissue disease tests in patients with on when compared with normal population . our results suggest that those patients who are experiencing their first demyelinating attack should not be screened for connective tissue disease if they do not have a history of rheumatic disease or symptoms suggesting them .
background : it may be difficult to differentiate between the first demyelinating attack and the neurological manifestations of connective tissue diseases.materials and methods : a total of 79 patients with optic neuritis were compared with 79 healthy controls . 
 their blood samples were tested for erythrocyte sedimentation rate ( esr ) , c - reactive protein ( crp ) , anti2-glycoprotein i antibody ( igg , igm ) , anticardiolipin antibody ( igm , igg ) , lupus anticoagulant , anti - double strand dna ( anri - ds dna ) , antinuclear antibody ( ana ) , anti - myeloperoxidae ( p - anca ) , and anti - proteinase 3 ( c - anca).results : in clinically isolated syndrome group 2-glycoprotein ( igm ) and lupus anti - coagulant were positive in 1.3% of patients whereas ana was positive in 1.3% and anti-2-glycoprotein i ( igm ) was positive in 2.5% of control group . 
 no rheumatologic disease was found in objects with positive tests.conclusion:this study shows no specific difference between two groups .