The concentration of autoantibodies was measured on ELISA reader at 450 nm

The concentration of autoantibodies was measured on ELISA reader at 450 nm. of tested patients and in two controls. The enhanced IgA immunoreactivity to tTG-2 was found in 10/49 patients’ sera, while 4/45 patients had higher serum MSC2530818 IgG immunoreactivity. The enhanced serum IgG immunoreactivity to RoSS antigen was found in 9/47 analyzed MM patients’ sera. Statistical analysis of data obtained revealed that only the levels of anti-tTG-2 IgA immunoreactivity in patients with MM were significantly higher than these obtained in healthy controls (P < 0.02) == Conclusion == Data obtained showed the existence of the enhanced serum immunoreactivity to gliadin, tTG-2 and Ro/SSA antigens in some patients with MM. These at least partially could contribute to the immunological imbalance frequently found in this disease. == Background == Multiple myeloma (MM) is a clonal B-cell disorder which diagnosis comprise the examination of bone marrow for plasma cell infiltration, detection and quantification of monoclonal protein "M" component in the serum or urine, and evidence of end-organ damage (hypercalcemia, renal insufficiency, anemia or bone lesions). Many of the laboratory parameters contribute to myeloma diagnosis due to plenty of immunological disturbances [1]. It was shown that MSC2530818 the antibodies contained in M component have various specificity to: some proteins, double-stranded DNA, several antibiotics [2], and sometimes to gliadin (and/or calreticulin?) [3]. As the enhanced levels of the serum antibodies to gliadin are found in patients with celiac disease, as well as S5mt of antibodies to transglutaminase-2 (TTG-2) [4,5], to calreticulin [6,7] and Ro/SSA antigen [8], the aim of this work was the screening of MM patients’ sera for their immunoreactivity to food constituent gliadin, and to autoantigens: tissue transglutaminase-2 (tTG-2) and Ro/SSA antigen, in order to assess whether immunoreactivity to mentioned antigens at least partially contributes to the immunological imbalance in multiple myeloma. == Methods == == Patients == Sera from 61 patients with MM in various stages of disease, before or after some cycles of conventional therapy, were analyzed for immunity to gliadin, tissue TTG-2, and Ro/SSA antigen. Determination of serum IgA and IgG immunoreactivity to gliadin (IU/ml), to tTG-2 (IU/ml), or to Ro/SSA (IU/ml), was done by diagnostic, commercial ELISA (Binding Site) tests. Briefly, 100 l of diluted (1:100) human sera, commercial controls and calibrators were dispensed in appropriate wells of the plates provided in the kit. During the first incubation, autoantibodies recognizing the antigen bind to it and all unbound proteins were removed by washings. After that, purified peroxidase labeled rabbit anti human IgA or IgG conjugate (100 l) which binds to the captured human autoantibodies was added, and the excess unbound conjugate is removed by washings. The conjugate was treated with TMB (3,3,5,5-tetramethylbenzidine). The reaction was stopped by the addition of phosphoric acid. The concentration of autoantibodies was measured on ELISA reader at 450 nm. Cut offs for each test was evaluated as the mean X+2 SD. The control group consisted of 50 healthy volunteers (age range was 2758 years, 26 were female). Statistical analysis of data obtained was performed by Mann Whitney Test. Experimental research that is reported in the manuscript has been performed with the approval of the ethics committee of Institute of Oncology and Radiology of Serbia. == Results MSC2530818 == Cut off values of anti-gliadin reactivity obtained analyzing 50 healthy sera were 3.46 IU/ml for IgA and 5.83 IU/ml for IgG. The elevated serum IgA immunoreactivity to gliadin was found in 14/56 patients and in one of controls. From these patients, 4 were with IgA myeloma and 4 were with IgG myeloma, while 6 were without M component in their sera. Statistical analysis of data obtained revealed that the level of anti-gliadin IgA.