Th2 shift in juvenile muscular atrophy of distal upper extremity: A combined allergological and flow cytometric analysis

Juvenile muscular atrophy of the distal upper extremity (JMADUE) is considered to be a type of flexion myelopathy; however, we recently reported cases of JMADUE associated with airway allergy successfully treated by plasma exchange. To further characterize the allergo-immunological features of JMADUE, 11 consecutive JMADUE patients in the neurology clinic at Kyushu University Hospital were studied. Past and present together with family histories of common allergic disorders were investigated. Total serum IgE was measured by an enzyme linked immunosorbent assay (ELISA) and allergen-specific IgE by a liquid phase enzyme immunoassay. Intracellular interferon (IFN) γ-, interleukin (IL)-4-, IL-5- and IL-13-producing T cells in peripheral blood were analyzed by flow cytometry. Data from 42 healthy subjects were used as controls for allergological studies. Flow cytometric data from 21 healthy subjects were also used for comparison. The patients exhibited significantly higher frequencies of coexisting airway allergies such as allergic rhinitis (p=0.0057) and pollinosis (p=0.0064), family histories of allergic disorders (p=0.0075), and mite antigen specific IgE (p=0.0361) compared with the healthy subjects. Patients with JMADUE had a significantly higher percentage of IFNγ ^-IL-4 ⁺CD4 ⁺T cells (p=0.0017), but not IL-5- or IL-13-producing CD4 ⁺T cells, and a reduced intracellular IFNγ/IL-4 ratio in CD4 ⁺T cells (p=0.002) compared to the controls. These findings suggest that JMADUE has a significant T helper 2 (Th2) shift, which may in part contribute to the development of spinal cord damage.