Analysis of anti-melanoma differentiation-associated gene 5 antibody in Hong Kong Chinese patients with idiopathic inflammatory myopathies: diagnostic utility and clinical correlations.

AIM: To compare the prevalence of the anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) in Hong Kong Chinese patients with dermatomyositis (DM) and polymyositis (PM); in addition, to examine the association of anti-MDA5 Ab and the clinical characteristics of these patients. METHODS: Twenty consecutive existing patients with DM being followed up at the Rheumatology Clinic of Kwong Wah Hospital, Hong Kong were recruited. Twenty patients with PM were recruited from the same clinic as the controls. A commercial line blot immunoassay was used to detect the anti-MDA5 Ab in all the participants. The frequencies of anti-MDA-5 Ab in the two groups were compared. The clinical characteristics of the patients with and without the antibody were analyzed. RESULTS: Anti-MDA5 Ab was found in 30% of patients with DM but not in patients with PM. All patients with the antibody exhibited the clinically amyopathic DM (CADM) phenotype. These patients were predominantly male, younger and with shorter disease duration. Anti-MDA5 Ab was significantly associated with rapidly progressive interstitial lung disease (RP-ILD) and digital ulcers. No statistically significant association was found between other disease or treatment variables and the antibody. CONCLUSION: Anti-MDA5 Ab is found exclusively in DM patients of the CADM subtype and is associated with RP-ILD and digital ulcers, suggesting that examination of this antibody is clinically useful in Hong Kong Chinese patients with idiopathic inflammatory myopathies. However, further studies are required to assess its prognostic significance, and to explore the difference of its presentations in various populations.

Local steroid injection versus wrist splinting for carpal tunnel syndrome: A randomized clinical trial.

AIM: We conducted a prospective randomized parallel clinical trial comparing the efficacy of local steroid injection and nocturnal wrist splinting in patients with carpal tunnel syndrome (CTS). METHODS: The well-validated and disease-specific Boston Carpal Tunnel Questionnaire (BCTQ) was employed and its score at 4 weeks after treatment was used as the primary outcome measure. Important secondary outcomes included patient satisfaction, the change of an objective finger dexterity test and the side effects. RESULTS: Twenty-five patients in the local steroid group and 25 patients in the wrist splinting group completed the study procedures. At 4 weeks after treatment, there was significant improvement of the BTCQ scores in both the steroid group and splinting group. There was improvement of the finger dexterity test only in the steroid group but not in the splinting group. However, there was no statistically significant difference in the changes of BTCQ scores between the two groups after treatment. Patient satisfaction score was higher in the steroid group. Patients in the steroid group took fewer painkillers after treatment. Four patients developed side effects after splinting and three after local steroid injection, which was not statistically significant. CONCLUSION: Although local steroid injection and nocturnal wrist splinting were equally effective in the treatment of patients with CTS, only the former improved objective hand function. Local steroid injection also resulted in better patient satisfaction and less painkiller use without causing more side effects.