Enzyme Linked Immunosorbent Assay For Thymosin Alpha 1 And Its Clinical Application

Background Thymosin α1 (Tα1) was the first thymic hormone perified homogeneity and sequenced from partially purified thymosin fraction 5 (TF5). Tal is an acidic polypeptide (PI 4.2) consisting of 28 amino acids and its biological activities were complex. In addition to inducing the expression of T-cell markers, Tal influences primarily helper T-cells and stimulates the production of lymphokins such as Y -interferon and interleukin 2 receptors. In the past few years, numerous reports have demonstrated that Tal level decreased in patients with acquired immunodeficiency syndrome (AIDS), Hepatitis B and Hepatitis C, but Tal overexpressed on some pathological cells in the condition of tumor. Therefore, Tal might play a certain role in the pathogenesis of some diseases.Objective To establish a specific enzyme- linked immunosorbent assay (ELISA) for thymosin al (Tal) and to investigate Tal levels in normal adults and in some pathological conditions.Methods Multiclonal antiserum from rabbit directed toal was prepared to set up the ELISA for al. Plasma or serumal levels were measured in normal adults, and in patients with chronic idiopathic thrombocytopenic purura ( ITP ) non-immune thrombocytopenia benign and malignant tumors DM and patients suffering from kidney diseases. The association of Tal level with PAIgG in ITP patients, the association of Tal level with tumor invasion, metastasis and its difference after different treatment in patients with malignant tumors were also studied. Tal levels in DM1 DM2 patients and kidney disease patients were also measured using this assay.Results The detectable limit of this Tal ELISA was 0.16 ug/L. The mean rate of recovery was 108.8 %, and the mean coefficient of variation for intra- and inter-batchEnzyme linked immunosorbent assay for thymosin alpha 1 and its clinical application Abstractassay were ( 7.05 ± 2.89 ) % and ( 11.44 ±2.84 ) %, respectively. The mean level of Tα1 was (0.78 ± 0.34) ug/L in plasma of 63 normal adults . The mean plasma Tal level of chronic ITP patients was lower than the normal level (P<0.001), while there was no significant difference between the normal level and the level of the non-immune thrombocytopenia patients. The plasma levels of benign and malignant tumors patients were both higher than the normal level (p<0.001), its increasing extend in malignant tumors was much greater than in benign tumors, and the difference between the plasma level of benign tumors patients and the malignant tumors patients was significant (P<0.05). The serum Tal level of patients with malignant tumors was correlated with tumor invasion, metastasis and surgical intervention. The Tal level of DM1 and DM2 patients were both lower than that of the normal level, but only the difference between the plasma level of DM1 patients and the normal level was significant(P<0.01), the difference between the plasma level of DM1 and DM2 was also significant (P<0.05). In kidney disease patients, the Tal level is lower than the normal level (p<0.01) regardless of the kidney function, but the difference between the immune kidney disease and the non-immune kidney disease was significant (P<0.01).Conclusion The ELISA for Tal is a sensitive, accurate and reproducible method. Plasma Tal assay is useful in understanding the clinical status of immune disease and tumor, and might be used as a new useful marker for the immunologic status and for aggressive behavior of tumor.