A Sensitive Assay of Tumor Necrosis Factor α in Sera from Duchenne Muscular Dystrophy Patients

Abstract

Duchennne muscular dystrophy (DMD) is a genetically determined disorder resulting from absence of the protein encoded by the dystrophin gene, which is located on chromosome Xq21 (1)(2). Almost all patients develop progressive muscular weakness and atrophy that begin at a young age in association with myofiber degeneration and necrosis (3)(4)(5). The pathophysiologic significance of serum cytokines in DMD is unclear. Lundberg et al. (6) have reported recently that tumor necrosis factor α (TNFα) mRNA is expressed in muscle from DMD patients. Other investigators have demonstrated TNFα protein expression in muscle from DMD patients, using immunohistochemical staining (7). However, correlation between TNFα in serum and mechanisms of progression of DMD has been difficult to study because serum concentrations of TNFα often are too low to measure by conventional methods (8)(9). We recently established a highly sensitive method for measurement of TNFα in serum by an immuno-PCR assay (10), which has a sensitivity 5 × 104 times greater than that of a conventional ELISA. The new method can determine serum TNFα concentrations in both DMD patients and healthy subjects. In the present study, we measured serum TNFα …