5). as the cut off point, individuals with titres of anti-MBL antibodies above this level were significantly more frequent in SLE individuals (9 individuals) than in settings (2 individuals). One SLE individual experienced an extremely high titre of this antibody. No associations of titres of anti-MBL antibodies and (i) genotypes of MBL gene, (ii) concentrations of serum MBL, or (iii) disease characteristics of SLE, were apparent. Thus, we have confirmed that anti-MBL antibodies are indeed present in sera of some individuals with SLE, but the significance of these autoantibodies in the pathogenesis of SLE remains unclear. < 00001, median MBL concentration standard deviation (s.d.); 474 493 and 306 292, in SLE individuals and healthy settings, respectively (Fig. 1). The assay was performed in the presence of EDTA in order to inhibit the binding between the carbohydrate recognition website of MBL and carbohydrates within the Fc portion of IgG. Furthermore, selected samples were digested with pepsin and F(ab)2 fragments were purified. F(abdominal)2 fragments did bind to MBL coated plates, indicating that IgGCMBL connection detected with this assay is indeed antigen-antibody binding (results not demonstrated). We found a patient with an extremely higher level of serum anti-MBL, and the titre of anti-MBL antibodies in the serum of this patient was designated 1000 U/ml. The number of subjects possessing a titre of more than 2 sd. above the average of healthy settings (895, indicated by dotted collection in Fig. 1) was 9 of the individuals with SLE, and 2 of the healthy settings. This difference was statistically significant (00341 by Fisher's precise test). Open in a separate windows Fig. 1 Autoantibodies to mannose-binding lectin (MBL) in serum samples. Anti-MBL antibodies were measured in 111 samples from individuals with systemic lupus erythematosus (SLE) and in 113 samples from healthy controls, in the presence of EDTA (1 mm). Dotted collection indicates 2 standard deviation (s.d.) above average in healthy settings. 05296). Among individuals with the same genotype, SLE individuals tended to have higher MBL concentrations than settings, but without statistical significance (AA; = 03385, Abdominal; = 05556, BB; = 01573 by MannCWhitney's = 9)= 102) P-value

Malar rash34407309Discoid lupus01305951Photosensitivity12206821Oral ulcers22009999Arthritis55909999Serositis42202099Renal disorder12904399Neurological disorder0?909999Haematologic disorder?Haemolytic anemia0?809999?leukopenia45207422?lymphopenia44809999?thrombocytopenia12704447Anti-ds DNA Ab47401225Anti-Sm Ab0?809999Antiphospholipid Ab31803673ANA89505033Infections requiring hospitalization32907155 Open in a separate window Anti-MBL antibody positive was defined as possessing a titre higher than mean +2 s.d. of 113 healthy individuals. Serositis, pleuritis or pericarditis; renal disorder, proteinuria or cellular casts; neurological disorder, seizures or psychosis; Anti-ds DNA Ab, anti-double strand DNA antibody; L-cysteine Anti-Sm Ab, anti-Sm antibody; Antiphospholipid Ab, antiphospholipid antibody. P= AA + Abdominal versus BB by chi-square analysis. We next analysed whether or not titres of anti-MBL antibodies are associated with numerous disease guidelines of SLE in 111 SLE individuals. Anti-DNA antibodies and total IgG tended to become positively related with anti-MBL antibodies, but statistical significance was not achieved. No additional correlation was Rabbit Polyclonal to P2RY11 observed (Table 2). Table 2 Associations of titres of anti-mannose-binding lectin (MBL) antibody and various disease guidelines of systemic lupus erythematosus (SLE) in 106 SLE individuals

Disease guidelines of SLE P-valuea

Anti-DNA antibody02173C308844C402131CH5007919IgG00665IgA09026IgM01637 Open in a separate windows aSpearman’s rank correlation test. DISCUSSION In this study, we found out the presence of autoantibodies against MBL in some individuals with SLE. This is definitely in accordance with the study by Seelen et al. [34], which was published very recently. We confirmed that we were indeed detecting anti-MBL antibodies by; addition of EDTA in the enzyme immunoassay, therefore inhibiting the Ca2+ dependent binding of carbohydrate acknowledgement website on MBL to carbohydrates on IgG; digesting IgG with pepsin, and confirming the binding region of IgG was on F(abdominal)2; and detecting an inhibition of aqueous MBL to the binding L-cysteine of IgG to solid phase MBL. These methods and results are much like those reported by Seelen et al. [34], except that we did detect dose dependent inhibition by our inhibition assay. The reason behind this discrepancy is definitely unclear, but may possibly be due to the nature of anti-MBL antibodies in individual individuals, or concentrations or conformations of MBL used in the assays. Similarities in structure and function exist between MBL and C1q, L-cysteine and it is known that C1q-deficient or anti-C1q antibody positive individuals have a high probability of developing SLE [5,30,35,36]. It has been reported that MBL deficiency may be associated with the event of SLE [18C22], although deficiency of MBL is not an extremely high risk element, in contrast to deficiencies of additional.